Serum antibodies reactive with non-human primate retroviruses identified in acute onset schizophrenia

Schizophrenia is a pervasive neuropsychiatric disease of uncertain etiology , Previous studies have postulated that retroviruses may contribute to the etiology of some cases of schizophrenia. We examined the possible relations hip between retroviral infection and schizophrenia by measuring antibodies to a number of different primate retroviruses in the sera of individuals un dergoing their first hospitalization for this disease. Sera from patients w ith first onset schizophrenia and matched healthy controls were analyzed by immunoblot and enzyme linked immunosorbent assays using purified retroviru s antigens to identify and quantify antibodies reactive with retrovirus pro teins. A significantly increased incidence of antibodies reactive to gag en coded proteins of Mason-Pfizer monkey virus (MPMV), baboon endogenous virus (BaEV) and simian retrovirus type 5 (SRV-5) was observed in the sera of sc hizophrenia patients compared to controls. The reactivity of the cases and controls displayed the greatest differences in terms of antibodies to the p roteins of Mason-Pfizer monkey virus. Employing an algorithm of enzyme link ed immunosorbent assay reactivity followed by immunoblot confirmation, we f ound that MPMV antibodies in 28.9% of the individuals with first episode sc hizophrenia patients as compared to 3.7% of the unaffected controls (P < 0. 009, Fisher's Exact Test), These studies are consistent with the occurrence of retrovirus replication in some individuals who are undergoing their fir st episode of schizophrenia.