Immunological and PCR analyses for borna disease virus in psychiatric patients and blood donors in Japan

The involvement of Borna disease virus (BDV) in psychiatric diseases in hum ans remains controversial. T-cell memory response and seroprevalence of BDV in patients with psychiatric disorders and blood donors in Japan were eval uated collectively by Western blot (WB) analysis with inhibition test, elec trochemiluminescence immunoassay, immunofluorescence assay, and T-cell prol iferative response as well as detection of BDV p24 RNA in peripheral blood mononuclear cells (PBMCs). Positive proliferative responses to both BDV p40 and p24 proteins were detected in 9% of patients with mood disorders (4 of 45), 4% of schizophrenic patients (2 of 45), and 2% of blood donors (1 of 45). By WE analysis, the antibody to BDV p40,vas detected only in 2% of pat ients with mood disorders (1 of 45). The BDV p24 antibody was detected in 2 % of patients with mood disorders (I of 45) and 9% of schizophrenic patient s. (4 of 45) No plasma reacted with both BDV proteins. The finding of a lo, ver seroprevalence than previously reported suggests the presence of false- positive cases in the previous report. BDV RNA was detected only in 2% of p atients with mood disorders (1 of 45). In these three serological assays, T -cell responses, and PCR analysis, there was no significant difference in t he prevalence among the three groups. However, we found three psychiatric p atients who were positive for both BDV antibodies and T-cell proliferative responses and one patient who was positive for BDV RNA in PBMCs. These find ings suggest the usefulness of the proliferative T-cell response and that c ertain individuals are infected with BDV or a BDV-related virus.