Influence of caprine arthritis-encephalitis virus infection on the activity of peripheral blood lymphocytes

Non-specific lymphocyte transformation assay using phytohemagglutinin (PHA) as a mitogen was applied to evaluate influence of caprine arthritis-encephalitis virus (CAEV) infection on activity of peripheral blood lymphocytes. Animals were selected for the CAEV-infected and CAEV-non-infected groups according to the results of two serological surveys carried out at one year interval, with the use of an ELISA test. In goats which were not infected with CAEV, lymphocytes stimulation index (SI) revealed a high diversity of the results with an mean value equal to 5.86 (minimum = 0.45, maximum = 40.00, SD = 8.40). SI values for infected goats reached the average of 1.10 (minimum = 0.46, maximum = 1.85, SD = 0.26). The difference between the average lymphocyte stimulation indices was statistically highly significant in both groups (p = 0.002) which could be an evidence of CAEV infection influence on lymphocyte reactivity. Regarding ELISA test as a "golden standard" the application of lymphocyte transformation assay in diagnosis of CAEV infection was assessed. The ROC curve was drawn. The area under the curve was only 0.324, which indicates very low accuracy of this method and limits its use for the diagnosis of the disease.