AVA Research map
What the published corpus says about each named thing: viruses, drugs, receptors, clinical pictures. Each entry counts verified statements you can open, and nothing else.
A statement is linked to an entity when it names it, in any of its spellings, in its wording or in the verbatim excerpt that backs it. A list of names decides, not a model: the same text always gives the same link. Two entities appear together when one verified statement names them both.
Relations with a verb (inhibits, treats, is the receptor of…) are read by an agent from each statement's sentence, only between the entities that sentence names and only when it says so. Each links to the statement that backs it.
Viruses
FeLValso: feline leukemia virus
Gammaretrovirus of cats; the subject of this project.
According to the statements:
- FeLV is associated with lymphoma (7)
- FeLV is associated with leukemia (5)
- PCR detects FeLV (4)
- lymphoma is associated with FeLV (2)
- The FeLV challenge studies did not use immunosuppressants before or during challenge.
- FeLV serology was not performed in the laboratory efficacy studies described in the serological-results section.
- Soluble truncated Env proteins derived from enFeLV inhibited enFeLV and FeLV-B infection in the reported laboratory experiments.
- FeLVCHECK Ag ELISA was validated against ViraCHEK/FeLV ELISA using 112 feline sera classified as 42 positive and 70 negative.
and 129 more
- NR-LAMP did not show cross-reactivity with the tested FIV, FCoV, FCV, FPLV, and FHV materials.
- The review reports that molecular analyses identified common integration sites near c-myc, flvi-1, flvi-2, fit-1, pim-1, and flit-1 in FeLV-associated lymphomas.
- The review reports that lymphoma occurs in 10–20% of progressive FeLV infections.
- The review describes FeLV-associated lymphomas as predominantly high-grade T-cell lymphomas.
FIValso: feline immunodeficiency virus
Named together with: antibody (7), FIP (5), proviral load (2), FCoV (2), PCR (1), GS-441524 (1)
- NR-LAMP did not show cross-reactivity with the tested FIV, FCoV, FCV, FPLV, and FHV materials.
- FeLV antigen was detected in two cats in the group undergoing detailed investigation after abnormal electropherograms.
- The estimated association between FIV infection and Leishmania positivity was not statistically significant, with OR 2.359, 95% CI 0.901–6.179, and P = 0.081.
- Among 38 cats infected with FIV and/or FeLV, 12 were also serologically or molecularly positive for Leishmania spp.
and 19 more
- The FeLV triage model had an AUC of 0.69, with a 95% confidence interval of 0.64–0.74.
- In FIV-infected cats, antigenemia or reverse transcriptase activity was below detection limits, and the reported effect on proviral load was less marked than in FeLV-infected cats.
- The study enrolled 27 naturally FeLV-infected cats and 31 naturally FIV-infected cats.
- Neoplasms were reported in 34 of 128 cats reactive only for FeLV, corresponding to 26.6%.
enFeLValso: endogenous FeLV
According to the statements:
Named together with: env (3), FeLV-B (2), mouse (1), LTR (1), PiT1 (1), PiT2 (1)
- Soluble truncated Env proteins derived from enFeLV inhibited enFeLV and FeLV-B infection in the reported laboratory experiments.
- The authors identify the influences of endogenous FeLV and host genetics as opportunities for future FeLV research.
- Most sequenced amplicons from PCRs 5 and 6, which were expected to amplify only FeLV-B, clustered with endogenous FeLV.
- The tested infectious enFeLV Env pseudotypes infected mouse-derived MDTF cells expressing feline Pit1 but did not infect MDTF cells expressing feline Pit2.
and 5 more
- The integration-time analysis substituted a domestic cat noncoding-region divergence rate for an unknown enFeLV LTR mutation rate.
- The exact in vivo roles of the soluble enFeLV-derived Env proteins remain unresolved.
- The potential protective role of enFeLV in oncogenesis remains incompletely understood.
- Which enFeLV loci are active and associated with the generation of recombinant viruses remains unknown in the account presented by this paper.
HIV-1also: HIV, human immunodeficiency virus
Named together with: integration (4), proviral load (4), integrase (3), human (2), KoRV (2), MLV (2)
- The review reports that RAD51 can support HIV-1 LTR transcription.
- The review reports that HTLV-1 p30 suppresses homologous recombination and shifts double-strand break repair toward non-homologous end joining.
- The review reports that stimulation of RAD51 nucleofilament formation can restrict HIV-1 integration.
- The review states that HIV-1 Gag, Pol, and Env have indispensable roles in the viral replication cycle.
and 11 more
- The review identifies drug resistance and therapeutic precision as persistent challenges in HIV-1 research.
- Substitutions in residues involved in HIV-1 integrase-capsid contacts produced eccentric virions with RNA nucleoids outside the cores.
- HIV-1 integrase promotes encapsulation of viral genomic RNA into mature viral cores.
- HIV-1 integrase filament repeat spacing matches the mature HIV-1 capsid hexamer lattice spacing of 91 Å.
FeLV-Aalso: subgroup A
According to the statements:
- PCR detects FeLV-A (1)
Named together with: FeLV-B (6), PCR (2), env (2), FeLV-C (1), lymphoma (1), dog (1)
- Nested PCR detected FeLV-A alone in five positive samples and FeLV-A plus FeLV-B in six, with no FeLV-C amplification.
- Table 2 records cat 324 as having leucemic lymphoma and env sequences assigned to both FeLV-A and FeLV-B.
- Sequencing identified FeLV-A in 15 cats, with FeLV-B also detected in five of these cats.
- The Discussion describes FeLV-B as arising through recombination between FeLV-A and endogenous retroviral sequences.
and 5 more
- Guigna FeLV sequences formed a phylogenetic cluster with greater than 90% bootstrap support adjacent to the Chilean domestic-cat cluster.
- Sequenced amplicons produced with FeLV-B-specific primers contained FeLV-A sequences rather than confirming FeLV-B infection.
- F8701 retained the FeLV-A interference subgroup phenotype despite its broadened cellular host range.
- F8701 underwent productive replication in cultured canine D17 cells more efficiently than the reference FeLV-A strains tested.
FeLV-Balso: subgroup B
According to the statements:
Named together with: FeLV-A (6), env (3), enFeLV (2), PCR (2), lymphoma (1), FeLV-C (1)
- Soluble truncated Env proteins derived from enFeLV inhibited enFeLV and FeLV-B infection in the reported laboratory experiments.
- Nested PCR detected FeLV-A alone in five positive samples and FeLV-A plus FeLV-B in six, with no FeLV-C amplification.
- Table 2 records cat 324 as having leucemic lymphoma and env sequences assigned to both FeLV-A and FeLV-B.
- Sequencing identified FeLV-A in 15 cats, with FeLV-B also detected in five of these cats.
and 5 more
- Most sequenced amplicons from PCRs 5 and 6, which were expected to amplify only FeLV-B, clustered with endogenous FeLV.
- The Discussion describes FeLV-B as arising through recombination between FeLV-A and endogenous retroviral sequences.
- Sequenced amplicons produced with FeLV-B-specific primers contained FeLV-A sequences rather than confirming FeLV-B infection.
- Guigna FeLV sequences formed a phylogenetic cluster with greater than 90% bootstrap support adjacent to the Chilean domestic-cat cluster.
KoRValso: koala retrovirus
Named together with: koala (7), proviral load (2), HIV-1 (2), T cell (1), mouse (1), latency (1)
- The review identifies FeLV as a representative gammaretrovirus.
- The review states that comparative studies focus on three incompletely understood layers of retroviral regulation: pre-integration latency, post-integration latency and T cell-mediated control of proviral expression.
- The review states that FeLV is among gammaretrovirus-related examples considered in the comparative discussion.
- Among the koala tumor subtypes reported, osteosarcomas had the highest mean percentage of KoRV-positive tumor-cell labeling.
and 4 more
- In this koala study, relative KoRV-A proviral load was significantly lower in bone tumor samples than in healthy bone samples.
- The koala bone tumor group had a higher median KoRV capsid immunohistochemistry H-score than the control group.
- The study detected KoRV capsid protein expression in all examined koala bone tumor samples by immunohistochemistry.
- Whether the comparative epigenetic mechanisms discussed for MLV, KoRV, FIV, SIV or HIV-1 apply directly to FeLV remains unresolved in this source.
MLValso: murine leukemia virus, MuLV
Named together with: integration (2), HIV-1 (2), FPV (2), vaccination (2), antibody (2), LTR (1)
- At T1, 80 of 88 evaluable kittens met the study's HI-based threshold for presumptive FPV protection, with no statistically significant difference by vaccine formulation or inactivated-vaccine injection site.
- The modified-live FPV vaccine group had higher reported FPV antibody titres than the pooled inactivated-vaccine groups at T1 and T12, but not at T2.
- The authors observed a uniform silent-population proportion across wild-type and BET-independent vectors bearing FeLV LTRs, unlike the increased silent population reported for retargeted MLV LTR vectors.
- This article is a comparative review based on PubMed literature searches, not a primary FeLV experiment.
and 1 more
- Whether the comparative epigenetic mechanisms discussed for MLV, KoRV, FIV, SIV or HIV-1 apply directly to FeLV remains unresolved in this source.
HTLV-1also: HTLV
Named together with: HIV-1 (2), LTR (2), PCR (1), T cell (1), CRISPR (1)
- The study did not assess downstream viral transcript expression, inflammatory cytokines or T-cell activation markers.
- The review reports that HTLV-1 p30 suppresses homologous recombination and shifts double-strand break repair toward non-homologous end joining.
- The review reports that RAD51 can support HIV-1 LTR transcription.
- The review pooled the index patient's data with systematically collected published cases of rapidly progressive or relapsing HTLV-1-associated myelitis that included spinal imaging.
FCoValso: feline coronavirus, FIPV
Named together with: FIV (2)
- NR-LAMP did not show cross-reactivity with the tested FIV, FCoV, FCV, FPLV, and FHV materials.
- The study reported no significant association between DCHBV infection and coinfection with FIV, FeLV or FCoV.
BLValso: bovine leukemia virus
According to the statements:
- env inhibits BLV (1)
Named together with: env (3), proviral load (1)
- BLV proviral copy numbers were lower with Env-SU and mutants M1–M4 than with mock supernatant, with reported p < 0.01.
- The study examined only cell-free BLV infection because quantification of cell-to-cell spread through syncytium formation was unsuccessful.
- In the BLV colony-formation assay, Env-SU mutants M1–M4 each produced zero G418-resistant colonies, compared with 48.3 ± 4.9 for mock controls, with p < 0.001.
- Whether BLV inhibition results from Env-SU competition for CAT1 binding or from another mechanism remains unresolved.
FPValso: feline panleukopenia virus
Named together with: antibody (4), vaccination (4), MLV (2)
- The modified-live FPV vaccine group had higher reported FPV antibody titres than the pooled inactivated-vaccine groups at T1 and T12, but not at T2.
- The study found no statistically significant difference in anti-FPV antibody titres between kittens receiving the inactivated vaccine at the three anatomical sites.
- At T1, 80 of 88 evaluable kittens met the study's HI-based threshold for presumptive FPV protection, with no statistically significant difference by vaccine formulation or inactivated-vaccine injection site.
- The authors could not identify and exclude animals exposed to natural FPV challenge during follow-up because HI detects antibodies from both natural exposure and vaccination.
FeLV-Calso: subgroup C
Named together with: FeLV-A (1), PCR (1), FeLV-B (1)
- Nested PCR detected FeLV-A alone in five positive samples and FeLV-A plus FeLV-B in six, with no FeLV-C amplification.
Drugs and biologicals
raltegravir
Named together with: progressive infection (2), PCR (1), viral load (1), proviral load (1)
- Case two had undetectable viral RNA before raltegravir administration despite detectable proviral DNA.
- The authors state that the absence of a control group and concurrent supportive therapies prevent causal attribution of clinical evolution to raltegravir.
- The study was a prospective, longitudinal, single-arm intervention involving 14 naturally infected cats with progressive FeLV infection and FeLV-related disease.
- Reported median survival from raltegravir initiation was 10.8 months, with a reported 95% confidence interval of 8.9–N/A.
and 2 more
- The observed virological and clinical changes cannot be confidently attributed to raltegravir rather than the natural course of infection and concurrent care.
- Whether raltegravir improves survival in cats with progressive FeLV infection remains unresolved.
GS-441524also: GS441524
According to the statements:
- GS-441524 treats FIP (1)
Named together with: FIV (1), FIP (1)
- In the reported cohort, the average starting GS-441524 dosage was 7 mg/kg/day, with dosage increases in 65% of cats and treatment extension in 35%.
- This study collected survey data from caretakers of FeLV- and/or FIV-positive cats treated with GS-441524 for presumptive effusive FIP.
- Whether GS-441524 influences the course of concurrent infections remains a question for future investigation.
Interventions
vaccination
According to the statements:
Named together with: antibody (6), FPV (4), neutralization (2), MLV (2), neutralizing antibodies (2)
- The study's subgroup analyses were limited by only 18 seropositive cats and 23 cats with a recorded vaccination history; multivariable regression and multiple-comparison adjustment were not performed.
- Some vaccinated cats without detectable FHV-1 neutralising antibodies were FeLV antigen-positive, an observation explicitly described as exploratory.
- The authors could not identify and exclude animals exposed to natural FPV challenge during follow-up because HI detects antibodies from both natural exposure and vaccination.
- The study found no statistically significant difference in anti-FPV antibody titres between kittens receiving the inactivated vaccine at the three anatomical sites.
and 4 more
- The modified-live FPV vaccine group had higher reported FPV antibody titres than the pooled inactivated-vaccine groups at T1 and T12, but not at T2.
- At T1, 80 of 88 evaluable kittens met the study's HI-based threshold for presumptive FPV protection, with no statistically significant difference by vaccine formulation or inactivated-vaccine injection site.
- The immune mechanisms and correlates underlying protection for vaccine components other than FPL, including FeLV, remain unresolved.
- Whether FeLV-related impairment of humoral immunity explains absent detectable FHV-1 neutralising antibodies in vaccinated FeLV-positive cats remains an open question.
CRISPRalso: Cas9, genome editing
Named together with: T cell (1), PCR (1), HTLV-1 (1)
- The study did not assess downstream viral transcript expression, inflammatory cytokines or T-cell activation markers.
Receptors
PiT1also: SLC20A1
Receptor of FeLV-B.
Named together with: env (1), enFeLV (1), PiT2 (1), mouse (1)
- The tested infectious enFeLV Env pseudotypes infected mouse-derived MDTF cells expressing feline Pit1 but did not infect MDTF cells expressing feline Pit2.
PiT2also: SLC20A2
Named together with: env (1), PiT1 (1), enFeLV (1), mouse (1)
- The tested infectious enFeLV Env pseudotypes infected mouse-derived MDTF cells expressing feline Pit1 but did not infect MDTF cells expressing feline Pit2.
Proteins
p27also: capsid antigen, CA
According to the statements:
- ELISA detects p27 (1)
- p27 is associated with viral load (1)
Named together with: antigenemia (6), proviral load (3), PCR (3), viral load (2), antibody (2), viremia (1)
- The cat classified as likely regressive had no detectable blood viral RNA by RT-qPCR despite a positive p27 antigen test.
- All p27-antigen-positive cats were positive for FeLV proviral DNA by blood qPCR.
- Molecular characterization was restricted to cats with positive p27 antigen screening results.
- Among cats classified as progressively infected, blood p27 antigen concentration was positively correlated with viral RNA load in saliva.
and 3 more
- The study operationally defined regressive FeLV infection as p27 antigen-negative but provirus-positive.
- In low positive cats, SNAP detected FeLV p27 antigen more frequently in whole blood than in plasma or serum at enrollment.
- During 2008–2021, FeLV proviral DNA was detected more frequently than p27 antigen in the surveyed Iberian lynx population.
integrase
Named together with: HIV-1 (3)
- HIV-1 integrase promotes encapsulation of viral genomic RNA into mature viral cores.
- HIV-1 integrase filament repeat spacing matches the mature HIV-1 capsid hexamer lattice spacing of 91 Å.
- The authors determined a cryo-EM structure of primate lentiviral integrase in complex with RNA that formed a linear filament of integrase octamer repeat units.
- In the SIVtal integrase-RNA TAR cryo-EM structure, integrase tetramers engage RNA chains solely through their C-terminal domains.
and 1 more
- Substitutions in residues involved in HIV-1 integrase-capsid contacts produced eccentric virions with RNA nucleoids outside the cores.
reverse transcriptase
Named together with: FIV (1), proviral load (1), antigenemia (1)
- In FIV-infected cats, antigenemia or reverse transcriptase activity was below detection limits, and the reported effect on proviral load was less marked than in FeLV-infected cats.
Genes
envalso: envelope gene
According to the statements:
- env inhibits BLV (1)
- env inhibits FeLV-B (1)
- env reduces proviral load (1)
- env inhibits enFeLV (1)
Named together with: FeLV-B (3), BLV (3), enFeLV (3), pol (2), gag (2), FeLV-A (2)
- Soluble truncated Env proteins derived from enFeLV inhibited enFeLV and FeLV-B infection in the reported laboratory experiments.
- Sequencing identified FeLV-A in 15 cats, with FeLV-B also detected in five of these cats.
- Table 2 records cat 324 as having leucemic lymphoma and env sequences assigned to both FeLV-A and FeLV-B.
- The tested infectious enFeLV Env pseudotypes infected mouse-derived MDTF cells expressing feline Pit1 but did not infect MDTF cells expressing feline Pit2.
and 8 more
- BLV proviral copy numbers were lower with Env-SU and mutants M1–M4 than with mock supernatant, with reported p < 0.01.
- In the BLV colony-formation assay, Env-SU mutants M1–M4 each produced zero G418-resistant colonies, compared with 48.3 ± 4.9 for mock controls, with p < 0.001.
- The review states that HIV-1 Gag, Pol, and Env have indispensable roles in the viral replication cycle.
- F8701 Env mediated greater pseudotype infectivity than Glasgow-1 Env in several non-feline mammalian cell lines.
LTRalso: long terminal repeat
Named together with: integration (2), HTLV-1 (2), HIV-1 (2), enFeLV (1), FIV (1), gag (1)
- The ocelot-derived 569-nucleotide FeLV U3 (LTR)-gag sequence OQ148669 showed 98.95% identity with domestic-cat sequence MT229941.1 from Colombia.
- The authors observed a uniform silent-population proportion across wild-type and BET-independent vectors bearing FeLV LTRs, unlike the increased silent population reported for retargeted MLV LTR vectors.
- The review reports that RAD51 can support HIV-1 LTR transcription.
- The review reports that HTLV-1 p30 suppresses homologous recombination and shifts double-strand break repair toward non-homologous end joining.
and 3 more
- In most detected NCCIT transcripts containing parts of HK2 solo LTRs, the authors identified the solo LTR as providing a polyadenylation signal and site.
- The review states that FIV, not FeLV, has published evidence of histone modification differences at the proviral promoter during latency and reactivation.
- The integration-time analysis substituted a domestic cat noncoding-region divergence rate for an unknown enFeLV LTR mutation rate.
gag
Named together with: pol (2), env (2), LTR (1), HIV-1 (1)
- The ocelot-derived 569-nucleotide FeLV U3 (LTR)-gag sequence OQ148669 showed 98.95% identity with domestic-cat sequence MT229941.1 from Colombia.
- The review states that HIV-1 Gag, Pol, and Env have indispensable roles in the viral replication cycle.
- The authors reported fewer pol regions than gag or env regions, with a statistically significant trend of pol deletion.
pol
Named together with: gag (2), env (2), HIV-1 (1)
- The review states that HIV-1 Gag, Pol, and Env have indispensable roles in the viral replication cycle.
- The authors reported fewer pol regions than gag or env regions, with a statistically significant trend of pol deletion.
Diseases and conditions
lymphomaalso: lymphosarcoma
According to the statements:
- FeLV is associated with lymphoma (7)
- lymphoma is associated with FeLV (2)
- lymphoma is associated with progressive infection (1)
Named together with: leukemia (6), proviral load (2), T cell (2), integration (2), progressive infection (1), env (1)
- The review reports that lymphoma occurs in 10–20% of progressive FeLV infections.
- The review reports that molecular analyses identified common integration sites near c-myc, flvi-1, flvi-2, fit-1, pim-1, and flit-1 in FeLV-associated lymphomas.
- The review describes FeLV-associated lymphomas as predominantly high-grade T-cell lymphomas.
- FeLV is associated with multiple fatal disease syndromes in cats, including lymphoma.
and 16 more
- Table 2 records cat 324 as having leucemic lymphoma and env sequences assigned to both FeLV-A and FeLV-B.
- The review reports discordant findings on provirus detection in lymphomas from antigen-negative cats.
- The review identifies c-myc, flvi-1, flvi-2, fit-1, pim-1, and flit-1 as common integration loci associated with FeLV-associated lymphoma.
- Histopathological examination of duodenal, jejunal, and mesenteric lymph node biopsies confirmed feline lymphocytic alimentary lymphoma.
leukemia
According to the statements:
- FeLV is associated with leukemia (5)
Named together with: lymphoma (6), bone marrow (1)
- The bone marrow profile was consistent with reactive eosinophilic hyperplasia, but cytomorphology alone could not exclude chronic eosinophilic leukemia.
- The reported DCH–FeLV co-detection does not establish a role for DCH in FeLV-associated lymphoma or leukemia.
- The reported diagnostic agreement does not establish sensitivity for FeLV-associated lymphoma or leukemia, or demonstrate a mechanism of oncogenesis.
- The reported infection prevalence cannot establish the incidence of FeLV-associated lymphoma or leukemia in this population.
and 4 more
- This case does not establish that FeLV caused the reported leukemia.
- The reported FeLV detection frequencies cannot establish the incidence or mechanisms of FeLV-associated lymphoma or leukemia in this cohort.
- Extending this sarcoma imaging workflow to FeLV-associated lymphoma or leukemia would require separate validation.
- The reported assay validation does not establish whether FeLV DNA positivity identifies FeLV-driven lymphoma or leukemia.
FIPalso: feline infectious peritonitis
According to the statements:
- GS-441524 treats FIP (1)
Named together with: FIV (5), antibody (2), progressive infection (2), GS-441524 (1), proviral load (1)
- FeLV antigen was detected in two cats in the group undergoing detailed investigation after abnormal electropherograms.
- The IgY preparations used in the reviewed feline studies did not target feline viral particles.
- The authors considered the FeLV-positive subgroup too small to draw conclusions about the influence of FeLV on FCGS occurrence in cats with FIP.
- The study defined successful FIP treatment as clinical remission without relapse until day 183.
and 8 more
- Progressive FeLV infection was identified in two of the 100 cats with FIP.
- This study collected survey data from caretakers of FeLV- and/or FIV-positive cats treated with GS-441524 for presumptive effusive FIP.
- The study prospectively assessed cardiac changes in twenty cats with naturally occurring FIP and no previous history of heart disease.
- Median cTnI at initial evaluation was above the reported upper reference interval in cats with FIP.
immunosuppression
Named together with: FIV (1), antibody (1)
- The FeLV challenge studies did not use immunosuppressants before or during challenge.
- The authors identify insufficient early antibody responses and severe late-stage immunosuppression as possible causes of false-negative FIV antibody results.
- The identity of the receptor for the retroviral immunosuppressive domain remains unresolved.
- Whether immunosuppressive-domain signaling involves the Ras-Raf-MEK-MAPK and PI3K-AKT-mTOR pathways remains unconfirmed.
anemiaalso: anaemia
Named together with: platelet (1), bone marrow (1), viral load (1), neutrophil (1)
- All anaemic CMhm-infected cats had at least one concurrent disease, as did most non-anaemic cats, and the difference was not significant.
- At the population level, the anaemia in these cats was mild, normocytic-normochromic and non-regenerative.
- It is unknown whether FeLV RNA load in bone marrow, spleen or blood relates to the specific type or severity of cytopenia (anemia, thrombocytopenia, neutropenia, pancytopenia).
- The single FeLV-positive cat falling in the anaemic group may suggest a contributory role of FeLV, according to the authors. The FeLV association itself was not statistically significant (1/13 vs 0/25).
fibrosarcoma
- The imaging data showed a trend toward greater acidification with higher fibrosarcoma grade.
myelosuppressionalso: myelodysplasia
Named together with: bone marrow (1)
- Leukocyte classification was not significantly associated with FeLV seropositivity in this dataset.
stomatitis
- The study enrolled 34 cats with histopathologically confirmed FCGS and 18 healthy controls in a prospective case-control design.
Course of infection
integration
Named together with: proviral load (4), HIV-1 (4), LTR (2), MLV (2), PCR (2), lymphoma (2)
- The review reports that molecular analyses identified common integration sites near c-myc, flvi-1, flvi-2, fit-1, pim-1, and flit-1 in FeLV-associated lymphomas.
- Four initially FeLV-positive samples were excluded after testing negative for proviral DNA by PCR.
- The review identifies c-myc, flvi-1, flvi-2, fit-1, pim-1, and flit-1 as common integration loci associated with FeLV-associated lymphoma.
- In regressive FeLV infection, a partially effective immune response can clear primary viraemia without preventing lifelong infection through integrated proviral DNA.
and 9 more
- The authors observed a uniform silent-population proportion across wild-type and BET-independent vectors bearing FeLV LTRs, unlike the increased silent population reported for retargeted MLV LTR vectors.
- The review reports that stimulation of RAD51 nucleofilament formation can restrict HIV-1 integration.
- Vector copy number, measured by quantitative PCR, is the current standard clinical measure of LVV-modified cell engraftment but does not determine integration site location or clonality.
- This article is a comparative review based on PubMed literature searches, not a primary FeLV experiment.
progressive infection
According to the statements:
- lymphoma is associated with progressive infection (1)
- progressive infection is associated with proviral load (1)
Named together with: regressive infection (3), bone marrow (2), antigenemia (2), viremia (2), viral load (2), raltegravir (2)
- The review reports that lymphoma occurs in 10–20% of progressive FeLV infections.
- Among cats classified as progressively infected, blood p27 antigen concentration was positively correlated with viral RNA load in saliva.
- Cats classified as progressively infected had significantly higher proviral copy numbers than cats classified as regressively infected, although their reported ranges overlapped.
- The diagnostic approach does not uniquely identify progressive infection because some early regressive infections can also be antigenemic or salivary RNA positive.
and 9 more
- The review describes poor immune responsiveness to FeLV in progressively infected cats as resulting in lifelong persistent viraemia.
- The authors considered the FeLV-positive subgroup too small to draw conclusions about the influence of FeLV on FCGS occurrence in cats with FIP.
- Progressive FeLV infection was identified in two of the 100 cats with FIP.
- The review states that progressive FeLV disease in domestic cats can cause hematopoietic neoplasia.
regressive infection
According to the statements:
- regressive infection is associated with antigenemia (1)
Named together with: proviral load (7), progressive infection (3), antigenemia (2), PCR (2), lymphoma (1), p27 (1)
- The authors acknowledge that antigen-gated molecular testing may have missed regressive infections with very low viral loads.
- Cats classified as progressively infected had significantly higher proviral copy numbers than cats classified as regressively infected, although their reported ranges overlapped.
- The study operationally defined regressive FeLV infection as p27 antigen-negative but provirus-positive.
- The authors identify possible misclassification of regressive FeLV infections as negative controls because antigen-based assays do not detect antigen-negative, provirus-positive infections.
and 7 more
- The diagnostic approach does not uniquely identify progressive infection because some early regressive infections can also be antigenemic or salivary RNA positive.
- The study could not detect provirus-positive, antigen-negative regressive FeLV infections because blood samples were unavailable for provirus qPCR.
- The review reports discordant findings on provirus detection in lymphomas from antigen-negative cats.
- In regressive FeLV infection, a partially effective immune response can clear primary viraemia without preventing lifelong infection through integrated proviral DNA.
viremia
Named together with: progressive infection (2), proviral load (2), integration (2), PCR (2), point-of-care test (1), p27 (1)
- The cat classified as likely regressive had no detectable blood viral RNA by RT-qPCR despite a positive p27 antigen test.
- Four initially FeLV-positive samples were excluded after testing negative for proviral DNA by PCR.
- The review describes poor immune responsiveness to FeLV in progressively infected cats as resulting in lifelong persistent viraemia.
- In regressive FeLV infection, a partially effective immune response can clear primary viraemia without preventing lifelong infection through integrated proviral DNA.
and 3 more
- Mortality attributable to the investigated viruses has not been detected in free-ranging wildcats, and serological surveys cannot detect active viremia or unsampled groups such as kittens.
- The authors suggest that lynxes may control FeLV infection within bone marrow and other lymphoid tissues, while acknowledging that viral strain and infectious dose were not investigated.
- Whether FeLV-specific IgY can neutralize the virus and alleviate viremia remains a research question in this review.
latency
Named together with: PCR (2), T cell (2), proviral load (2), HIV-1 (2), integration (2), FIV (1)
- The authors acknowledge that hypothetical latent bone-marrow infections might have gone undiagnosed by serology and whole-blood PCR.
- The review states that comparative studies focus on three incompletely understood layers of retroviral regulation: pre-integration latency, post-integration latency and T cell-mediated control of proviral expression.
- The review states that FIV, not FeLV, has published evidence of histone modification differences at the proviral promoter during latency and reactivation.
- The review states that epigenetic control of non-human retroviruses is less explored than HIV-1 and may provide insight into HIV-1 mechanisms.
and 1 more
- Whether the detected FeLV-homologous sequences represent latent FeLV infection remains unresolved.
transmission
Named together with: dog (1), PCR (1)
- The review discusses how viral interference assays, Sanger sequencing, PCR, and next-generation sequencing have sequentially defined FeLV classification, transmission, and disease-inducing potential.
- The source and direction of FeLV transmission involving the sampled wildcats remain unresolved.
- Whether F8701 can establish productive infection or transmission in dogs in vivo remains unknown.
neutralization
Named together with: vaccination (2), antibody (2), neutralizing antibodies (2), viremia (1)
- Some vaccinated cats without detectable FHV-1 neutralising antibodies were FeLV antigen-positive, an observation explicitly described as exploratory.
- Whether FeLV-specific IgY can neutralize the virus and alleviate viremia remains a research question in this review.
- Whether FeLV-related impairment of humoral immunity explains absent detectable FHV-1 neutralising antibodies in vaccinated FeLV-positive cats remains an open question.
abortive infection
Named together with: progressive infection (1), regressive infection (1)
- The review describes abortive FeLV infection as an effective immune response producing complete viral elimination after localised replication in oropharyngeal lymph nodes.
- The review recognizes four FeLV infection statuses in cats: progressive, regressive, focal, and abortive, depending on the effectiveness of the immune response.
focal infection
Named together with: proviral load (2), point-of-care test (1), integration (1), PCR (1), viremia (1), bone marrow (1)
- Four initially FeLV-positive samples were excluded after testing negative for proviral DNA by PCR.
- Restricted peripheral-blood sampling left potential focal infection in bone marrow or lymphoid tissue uncharacterized.
Markers
proviral loadalso: provirus
According to the statements:
- env reduces proviral load (1)
- progressive infection is associated with proviral load (1)
Named together with: PCR (9), regressive infection (7), integration (4), HIV-1 (4), antigenemia (3), p27 (3)
- All p27-antigen-positive cats were positive for FeLV proviral DNA by blood qPCR.
- The study operationally defined regressive FeLV infection as p27 antigen-negative but provirus-positive.
- Cats classified as progressively infected had significantly higher proviral copy numbers than cats classified as regressively infected, although their reported ranges overlapped.
- The authors identify possible misclassification of regressive FeLV infections as negative controls because antigen-based assays do not detect antigen-negative, provirus-positive infections.
and 31 more
- Median log10 FFV proviral load in buccal swabs was lower in FFV mono-infected cats than in FFV/FeLV co-infected cats (p = 0.003).
- In FIV-infected cats, antigenemia or reverse transcriptase activity was below detection limits, and the reported effect on proviral load was less marked than in FeLV-infected cats.
- Four initially FeLV-positive samples were excluded after testing negative for proviral DNA by PCR.
- The study could not detect provirus-positive, antigen-negative regressive FeLV infections because blood samples were unavailable for provirus qPCR.
viral load
According to the statements:
- p27 is associated with viral load (1)
Named together with: antigenemia (3), PCR (3), bone marrow (3), progressive infection (2), p27 (2), raltegravir (1)
- The cat classified as likely regressive had no detectable blood viral RNA by RT-qPCR despite a positive p27 antigen test.
- The study did not find a statistically significant difference in blood viral RNA loads between the A and AB groups.
- Among cats classified as progressively infected, blood p27 antigen concentration was positively correlated with viral RNA load in saliva.
- The diagnostic approach does not uniquely identify progressive infection because some early regressive infections can also be antigenemic or salivary RNA positive.
and 6 more
- The study could not determine end-of-life viral load or cause of death because additional FeLV testing and necropsies were unavailable.
- In 31 cats with FeLV-associated clinical signs and at least one hematologic cytopenia, FeLV RNA was detected by RT-qPCR in all cats, whereas 24 of 31 were positive for serum FeLV antigen.
- Viral RNA was significantly more abundant in the spleen than in whole blood and bone marrow in these cats.
- Case two had undetectable viral RNA before raltegravir administration despite detectable proviral DNA.
antigenemia
According to the statements:
- regressive infection is associated with antigenemia (1)
Named together with: p27 (6), proviral load (3), viral load (3), regressive infection (2), progressive infection (2), PCR (2)
- The cat classified as likely regressive had no detectable blood viral RNA by RT-qPCR despite a positive p27 antigen test.
- Molecular characterization was restricted to cats with positive p27 antigen screening results.
- Among cats classified as progressively infected, blood p27 antigen concentration was positively correlated with viral RNA load in saliva.
- The study operationally defined regressive FeLV infection as p27 antigen-negative but provirus-positive.
and 5 more
- In FIV-infected cats, antigenemia or reverse transcriptase activity was below detection limits, and the reported effect on proviral load was less marked than in FeLV-infected cats.
- The diagnostic approach does not uniquely identify progressive infection because some early regressive infections can also be antigenemic or salivary RNA positive.
- In low positive cats, SNAP detected FeLV p27 antigen more frequently in whole blood than in plasma or serum at enrollment.
- During 2008–2021, FeLV proviral DNA was detected more frequently than p27 antigen in the surveyed Iberian lynx population.
Tests
PCRalso: qPCR, RT-PCR
According to the statements:
Named together with: proviral load (9), viral load (3), antibody (3), p27 (3), ELISA (2), FeLV-B (2)
- Molecular characterization was restricted to cats with positive p27 antigen screening results.
- The cat classified as likely regressive had no detectable blood viral RNA by RT-qPCR despite a positive p27 antigen test.
- Nested PCR detected FeLV-A alone in five positive samples and FeLV-A plus FeLV-B in six, with no FeLV-C amplification.
- All p27-antigen-positive cats were positive for FeLV proviral DNA by blood qPCR.
and 19 more
- The review discusses how viral interference assays, Sanger sequencing, PCR, and next-generation sequencing have sequentially defined FeLV classification, transmission, and disease-inducing potential.
- The authors identify possible misclassification of regressive FeLV infections as negative controls because antigen-based assays do not detect antigen-negative, provirus-positive infections.
- The survey detected 22 DCH-positive cases, reported as 4%, by conventional PCR, with sequencing confirmation of the amplicons.
- Four initially FeLV-positive samples were excluded after testing negative for proviral DNA by PCR.
antibodyalso: serology
According to the statements:
- vaccination causes antibody (1)
- vaccination increases antibody (1)
Named together with: FIV (7), vaccination (6), FPV (4), PCR (3), FIP (2), p27 (2)
- FeLV serology was not performed in the laboratory efficacy studies described in the serological-results section.
- Molecular characterization was restricted to cats with positive p27 antigen screening results.
- All p27-antigen-positive cats were positive for FeLV proviral DNA by blood qPCR.
- The authors acknowledge that antigen-gated molecular testing may have missed regressive infections with very low viral loads.
and 15 more
- FeLV antigen was detected in two cats in the group undergoing detailed investigation after abnormal electropherograms.
- Among 38 cats infected with FIV and/or FeLV, 12 were also serologically or molecularly positive for Leishmania spp.
- Some vaccinated cats without detectable FHV-1 neutralising antibodies were FeLV antigen-positive, an observation explicitly described as exploratory.
- FHV-1 seropositivity was not significantly associated with FeLV antigen status in this cohort (OR = 0.40; 95% CI: 0.13–1.25).
ELISA
According to the statements:
- ELISA detects p27 (1)
Named together with: PCR (2), viremia (1), regressive infection (1), viral load (1), proviral load (1), p27 (1)
- FeLVCHECK Ag ELISA was validated against ViraCHEK/FeLV ELISA using 112 feline sera classified as 42 positive and 70 negative.
- The cat classified as likely regressive had no detectable blood viral RNA by RT-qPCR despite a positive p27 antigen test.
- The authors identify possible misclassification of regressive FeLV infections as negative controls because antigen-based assays do not detect antigen-negative, provirus-positive infections.
- The study did not extensively assess cross-reactivity, and the authors identify potential assay interference in cats with profound inflammation or immune activation as unresolved.
and 1 more
- FIVCHECK Ab ELISA uses a recombinant antigen derived from FIV gp40, which the authors describe as immunodominant in FIV infection.
point-of-care testalso: in-clinic test
Named together with: PCR (1), antibody (1), viremia (1), focal infection (1), FIV (1), proviral load (1)
- Four initially FeLV-positive samples were excluded after testing negative for proviral DNA by PCR.
- The cat's initial point-of-care FeLV antigen and FIV antibody tests were negative, but scheduled-interval follow-up testing was not performed.
neutralizing antibodies
Named together with: antibody (2), vaccination (2), neutralization (2)
- Some vaccinated cats without detectable FHV-1 neutralising antibodies were FeLV antigen-positive, an observation explicitly described as exploratory.
- Whether FeLV-related impairment of humoral immunity explains absent detectable FHV-1 neutralising antibodies in vaccinated FeLV-positive cats remains an open question.
Cells and tissues
bone marrow
Named together with: viral load (3), proviral load (2), progressive infection (2), hematopoietic stem cells (2), mouse (2), focal infection (1)
- Leukocyte classification was not significantly associated with FeLV seropositivity in this dataset.
- Restricted peripheral-blood sampling left potential focal infection in bone marrow or lymphoid tissue uncharacterized.
- Viral RNA was significantly more abundant in the spleen than in whole blood and bone marrow in these cats.
- The authors diagnosed atypical CMML of eosinophilic lineage from bone marrow examination and peripheral blood studies.
and 11 more
- The bone marrow profile was consistent with reactive eosinophilic hyperplasia, but cytomorphology alone could not exclude chronic eosinophilic leukemia.
- The authors acknowledge that hypothetical latent bone-marrow infections might have gone undiagnosed by serology and whole-blood PCR.
- Idiopathic HES could not be excluded because bone marrow biopsy was declined and only one myeloblast was observed.
- The review states that progressive FeLV disease in domestic cats can cause hematopoietic neoplasia.
T cell
Named together with: lymphoma (2), latency (2), HIV-1 (2), integration (2), KoRV (1), CRISPR (1)
- The review describes FeLV-associated lymphomas as predominantly high-grade T-cell lymphomas.
- The study did not determine lymphoma immunophenotype, preventing analysis of T-cell versus B-cell response differences.
- The study did not assess downstream viral transcript expression, inflammatory cytokines or T-cell activation markers.
- The review states that comparative studies focus on three incompletely understood layers of retroviral regulation: pre-integration latency, post-integration latency and T cell-mediated control of proviral expression.
and 1 more
- The review states that epigenetic control of non-human retroviruses is less explored than HIV-1 and may provide insight into HIV-1 mechanisms.
neutrophilalso: neutropenia
Named together with: platelet (2), lymphocyte (1), macrophage (1), bone marrow (1), viral load (1), anemia (1)
- The authors reported diffuse alpha-naphthyl acetate esterase positivity in 21.3% of cells that appeared morphologically compatible with myeloid/neutrophilic lineage.
- A review cited by the guidelines did not identify useful prognostic value for neutrophil–lymphocyte, monocyte–lymphocyte or platelet–lymphocyte ratios in retrovirus-positive cats.
- It is unknown whether FeLV RNA load in bone marrow, spleen or blood relates to the specific type or severity of cytopenia (anemia, thrombocytopenia, neutropenia, pancytopenia).
B cell
Named together with: bone marrow (1), CD4 (1), CD8 (1), T cell (1), lymphoma (1), mouse (1)
- The study did not determine lymphoma immunophenotype, preventing analysis of T-cell versus B-cell response differences.
- Mouse bone marrow immunophenotyping showed lower percentages of B cells and CD8+ cells and increased CD4+ cells after PI exposure.
hematopoietic stem cells
Named together with: bone marrow (2), progressive infection (1), mouse (1)
- The review states that progressive FeLV disease in domestic cats can cause hematopoietic neoplasia.
- PI exposure did not significantly alter bone marrow or splenic hematopoietic stem and progenitor cell populations in the mouse experiments.
lymphocyte
Named together with: neutrophil (1), platelet (1), lymphoma (1), macrophage (1)
- Histopathological examination of duodenal, jejunal, and mesenteric lymph node biopsies confirmed feline lymphocytic alimentary lymphoma.
- A review cited by the guidelines did not identify useful prognostic value for neutrophil–lymphocyte, monocyte–lymphocyte or platelet–lymphocyte ratios in retrovirus-positive cats.
macrophage
Named together with: lymphocyte (1), neutrophil (1), platelet (1), PBMC (1)
- L. tarentolae infection persisted in feline-derived cells for at least 72 h, when 41.6% of macrophages were infected with an average of 2.1 parasites per infected cell.
- A review cited by the guidelines did not identify useful prognostic value for neutrophil–lymphocyte, monocyte–lymphocyte or platelet–lymphocyte ratios in retrovirus-positive cats.
plateletalso: thrombocytopenia
Named together with: neutrophil (2), anemia (1), lymphocyte (1), macrophage (1), bone marrow (1), viral load (1)
- A review cited by the guidelines did not identify useful prognostic value for neutrophil–lymphocyte, monocyte–lymphocyte or platelet–lymphocyte ratios in retrovirus-positive cats.
- It is unknown whether FeLV RNA load in bone marrow, spleen or blood relates to the specific type or severity of cytopenia (anemia, thrombocytopenia, neutropenia, pancytopenia).
PBMC
Named together with: macrophage (1)
- The feline PBMC infection experiment used blood from a single healthy cat.
- L. tarentolae infection persisted in feline-derived cells for at least 72 h, when 41.6% of macrophages were infected with an average of 2.1 parasites per infected cell.
CD4
Named together with: bone marrow (1), CD8 (1), mouse (1), B cell (1)
- Mouse bone marrow immunophenotyping showed lower percentages of B cells and CD8+ cells and increased CD4+ cells after PI exposure.
CD8
Named together with: CD4 (1), bone marrow (1), mouse (1), B cell (1)
- Mouse bone marrow immunophenotyping showed lower percentages of B cells and CD8+ cells and increased CD4+ cells after PI exposure.
Species
catalso: feline, Felis catus
- FeLVCHECK Ag ELISA was validated against ViraCHEK/FeLV ELISA using 112 feline sera classified as 42 positive and 70 negative.
- Molecular characterization was restricted to cats with positive p27 antigen screening results.
- All p27-antigen-positive cats were positive for FeLV proviral DNA by blood qPCR.
- The cat classified as likely regressive had no detectable blood viral RNA by RT-qPCR despite a positive p27 antigen test.
and 123 more
- The comet-assay comparison included 25 cats with abnormal serum protein electropherograms and 25 cats without electropherogram abnormalities that were clinically assessed as healthy.
- FeLV antigen was detected in two cats in the group undergoing detailed investigation after abnormal electropherograms.
- FeLV-test-positive cat No. 1 had reduced serum albumin and elevated alpha- and beta-globulin concentrations, while its gamma-globulin concentration was within the listed reference range.
- Protein fraction disturbances and unexplained blood-count changes were also observed in clinically well cats that tested negative for the infectious diseases examined.
koala
Named together with: KoRV (7), proviral load (2), HIV-1 (1), mouse (1), T cell (1), latency (1)
- The review identifies FeLV as a representative gammaretrovirus.
- The review states that comparative studies focus on three incompletely understood layers of retroviral regulation: pre-integration latency, post-integration latency and T cell-mediated control of proviral expression.
- The review states that FeLV is among gammaretrovirus-related examples considered in the comparative discussion.
- The study detected KoRV capsid protein expression in all examined koala bone tumor samples by immunohistochemistry.
and 3 more
- The koala bone tumor group had a higher median KoRV capsid immunohistochemistry H-score than the control group.
- In this koala study, relative KoRV-A proviral load was significantly lower in bone tumor samples than in healthy bone samples.
- Among the koala tumor subtypes reported, osteosarcomas had the highest mean percentage of KoRV-positive tumor-cell labeling.
mousealso: murine
According to the statements:
- enFeLV tested in mouse (1)
Named together with: bone marrow (2), koala (1), enFeLV (1), KoRV (1), env (1), hematopoietic stem cells (1)
- PI exposure did not significantly alter bone marrow or splenic hematopoietic stem and progenitor cell populations in the mouse experiments.
- The metabolomic analyses identified sphinganine and ceramide as common metabolites upregulated in association with PI exposure in THP-1 cells and mice.
- Mouse bone marrow immunophenotyping showed lower percentages of B cells and CD8+ cells and increased CD4+ cells after PI exposure.
- The tested infectious enFeLV Env pseudotypes infected mouse-derived MDTF cells expressing feline Pit1 but did not infect MDTF cells expressing feline Pit2.
and 1 more
- The review identifies FeLV as a representative gammaretrovirus.
human
Named together with: HIV-1 (2), T cell (1), latency (1), proviral load (1), integration (1)
- In the reviewed human cases, the RESULTS section reports radiographic myelitis in 98%, longitudinally extensive myelitis in 91%, and focal myelitis in 7%.
- The review states that epigenetic control of non-human retroviruses is less explored than HIV-1 and may provide insight into HIV-1 mechanisms.
- HIV-1 integrates into host-cell DNA as a provirus.
dogalso: canine
Named together with: FeLV-A (1), PCR (1), transmission (1)
- Sequencing of the lesion PCR product showed 99.62% identity with the L infantum reference sequence MG778653.
- F8701 underwent productive replication in cultured canine D17 cells more efficiently than the reference FeLV-A strains tested.
- Whether F8701 can establish productive infection or transmission in dogs in vivo remains unknown.