Serum proteins and DNA integrity in cats: observations in two FeLV antigen-positive cases
Journal of veterinary research · 2025
In plain language
The study screened 125 cats and examined 25 in detail after abnormal results on a test that separates blood proteins. Two of these cats tested positive for FeLV antigen; changes in proteins and in the integrity of DNA in immune cells were documented, including in cats assessed as clinically healthy. Protein changes and altered blood cell counts were also found in clinically healthy cats that tested negative for the infections examined. These findings do not show that FeLV caused the changes or that immune cells functioned less well.
Scientific detail
This observational clinical study, published in Journal of veterinary research in 2025, screened 125 cats. Twenty-five cats with abnormal electropherograms were selected for detailed analyses; FeLV antigen was detected in two of them. The comet-assay comparison included these 25 cats and a further 25 cats without electropherogram abnormalities that were assessed as clinically healthy. This was not a controlled infection experiment. The extracted claims are classified as evidence level C.
Cat No. 1, identified in the Results as FeLV-test-positive, had a reduced serum albumin concentration and elevated alpha- and beta-globulin concentrations, while its gamma-globulin concentration remained within the listed reference range. This pattern is a single-case observation relevant to inflammation; it neither demonstrates increased antibody production nor measures immunosuppression. The study documents serum protein and lymphocyte DNA-integrity abnormalities in FeLV antigen-positive cats, including animals assessed as clinically healthy. These are preliminary observations of inflammatory protein patterns and cellular DNA damage, not a demonstration of FeLV-specific immunosuppression, impaired immune-cell function or causation.
The Discussion acknowledges protein fraction disturbances and unexplained blood-count changes in clinically healthy cats that tested negative for the infectious diseases examined. These negative results do not exclude every possible infection or other cause. The authors stated that, to their knowledge, the comet assay was not used in veterinary laboratory diagnostics. Interpretation is limited by the observational, preliminary and unreplicated design, selection based on abnormal electropherograms, unknown age and sex, and the inclusion of only two FeLV antigen-positive cats. The supplied text does not report confirmatory FeLV testing, infection stage, longitudinal outcomes or direct immune-function measurements. It also does not establish FeLV prevalence among all 125 cats or FeLV-specific assay performance.
What we know
Level C evidence documents two FeLV antigen-positive cats within the group selected for abnormal electropherograms. Cat No. 1 had reduced albumin, elevated alpha- and beta-globulins, and gamma-globulins within the listed reference range. Serum protein and lymphocyte DNA-integrity abnormalities were observed in FeLV antigen-positive cats, including clinically healthy animals. The comet-assay comparison included 25 cats with abnormal electropherograms and 25 without abnormalities that were assessed as clinically healthy. Protein disturbances and blood-count changes were also observed in clinically healthy cats with negative tests for the infections examined.
What we don't know
It has not been established that FeLV caused the abnormalities, that FeLV-specific immunosuppression or impaired immune-cell function was present, or that the protein pattern in cat No. 1 reflected increased antibody production. The supplied text does not report confirmatory FeLV testing, infection stage, longitudinal outcomes or direct immune-function measurements; age and sex are also unknown. Neither FeLV prevalence among all 125 cats nor FeLV-specific comet-assay performance has been established. Negative tests do not rule out every infection or other cause of the abnormalities.
Evidence
EvidenceLevel C — Preliminary evidenceConfidence 100/100
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.
Excerpt verified in the source — verbatim, in the source's own language“Table 2. Concentrations of individual protein fractions in serum protein electrophoresis – cat No. 1 Fraction Relative area (%) Concentration (g/L) Range (g/L) Albumin-to-globulin ratio Albumins 29.93 20.06↓ 27–39 α-globulins 30.96 20.74↑ 6.5–12.1 β-globulins 19.72 13.21↑ 4.5–8.7 γ-globulins 19.39 12.99 10.0–18.6 Total protein 67 60–80 A/G ratio 0.43”
The Results identifies this cat as FeLV-test-positive. Its protein pattern provides a single-case observation relevant to inflammation, but neither demonstrates increased antibody production nor measures immunosuppression.
EvidenceLevel C — Preliminary evidenceConfidence 100/100
FeLV antigen was detected in two cats in the group undergoing detailed investigation after abnormal electropherograms.
Excerpt verified in the source — verbatim, in the source's own language“The results of the plate tests for viral infections were as follows: FIV antibodies were detected in two cats, FeLV antigen was detected in two cats and FIP antibodies were also detected in two cats.”
This supports the presence of two FeLV-antigen-positive observations within the selected group. It does not establish infection stage or FeLV prevalence in all 125 cats. The source's terminology concerning FIP antibodies is preserved in the excerpt without treating that result as confirmation of FIP.
EvidenceLevel C — Preliminary evidenceConfidence 100/100
The comet-assay comparison included 25 cats with abnormal serum protein electropherograms and 25 cats without electropherogram abnormalities that were clinically assessed as healthy.
Excerpt verified in the source — verbatim, in the source's own language“Twenty-five cats for which native serum protein electrophoresis revealed clear abnormalities were selected for the comet assay. In addition, a comparative analysis was performed using the assay on 25 cats without abnormalities in their electropherograms. These cats were clinically assessed as healthy.”
This establishes an observational comparison group, not a controlled infection experiment. The preliminary, unreplicated design does not establish causation or FeLV-specific assay performance.
EvidenceLevel C — Preliminary evidenceConfidence 100/100
Protein fraction disturbances and unexplained blood-count changes were also observed in clinically well cats that tested negative for the infectious diseases examined.
Excerpt verified in the source — verbatim, in the source's own language“It should be noted that individuals with overall condition assessed as good and which tested negative for infectious diseases also had protein fraction disturbances and unexplained changes in their blood counts.”
This author-stated caveat limits attribution of the abnormalities to the tested infections. Negative plate tests do not establish that every possible infection or other cause was absent.
Provenance
Source: The use of selected electrophoretic techniques to assess the health of domestic cats (Felis catus).
AVA