Individuals with schizophrenia had elevated levels of one Epstein-Barr virus (EBV) antibody but atypically low levels of another, which investigators deemed an “aberrant immune response.”

Faith Dickerson, PhD, MPH, Lorraine Jones-Brando, PhD,and colleagues investigated the IgG antibodies and genetics of 432 individuals with schizophrenia and 311 without. The investigators used solid-phase immunoassays to measure antibodies, and they measured titers of antibodies not just for EBV but also for related viruses. The group with schizophrenia was slightly older, with a mean age of 38.2 years, compared with a mean age of 32.03 years in the group without schizophrenia. Also, 65.7% of the study participants in the schizophrenia group were male, compared with 39.2% of those in the group without schizophrenia. More than 60% of participants in the schizophrenia group were cigarette smokers, compared with 14.8% of the controls. The study was published in Schizophrenia Bulletin.

Compared with the controls, individuals with schizophrenia had elevated levels of EBV viral capsid antibody (EBV-VCA) with a mean effect size of 0.356 (P less than .002); however, the levels of EBV nuclear antigen-1 (EBNA-1) were not significantly different from those seen in individuals without schizophrenia, reported Dr. Dickerson of the Stanley Research Program at Sheppard Pratt, and Dr. Jones-Brando of Johns Hopkins University, both in Baltimore.

The investigators also examined adjusted odds ratios for individuals with schizophrenia having levels of antibodies higher than percentile cutoffs of the controls; for example, the aOR for those individuals having EBV VCA levels at the 90th percentile of controls was 2.03 (95% confidence interval, 1.23-3.37; P = .007). The aORs for EBNA-1 were not significant.

Those results suggest an aberrant immune response to EBV because, in most cases, EBV VCA and EBNA-1 are expressed at roughly equal levels, the investigators said.

“There are a number of therapeutic interventions available for the modulation of EBV infection including antiviral medications and pharmacological compounds which can modulate the immune response,” they wrote.

“An increased understanding of the role of EBV infection might thus lead to novel methods for the prevention and treatment of schizophrenia.”

The study was funded by the Silvio O. Conte Center at Johns Hopkins University in Baltimore, and the Stanley Medical Research Institute, Chevy Chase, Md. Dr. Dickerson, Dr. Jones-Brando, and colleagues reported having no conflicts of interest.

SOURCE: Dickerson F et al. Schizophr Bull. 2019 Sep 11;45(5):1112-9.