Meta-Analysis of Anti-Toxoplasma gondii IgM Antibodies in Acute Psychosis.
BACKGROUND
A number of different infections are associated with acute psychosis. However, relationships between infections and acute psychosis in patients with schizophrenia have not been extensively explored. Exposure to Toxoplasma gondii is a replicated risk factor for schizophrenia. Previous studies have focused on T. gondii IgG antibodies, which are a marker of lifetime exposure, whereas IgM antibodies are a marker of acute/recent exposure, persistent infection, or reinfection. We performed a meta-analysis of T. gondii IgM antibodies and acute psychosis, to further investigate whether infections may be associated with relapse in schizophrenia.


METHODS
We identified articles by systematic searches of PubMed, PsycINFO, and ISI databases. We included studies, in English, of serum T. gondii IgM antibodies in patients with acute psychosis and controls.


RESULTS
Sixteen independent samples (2353 patients and 1707 controls) met inclusion criteria. Data were pooled using a random effects model. There was a significant increase in risk of positive T. gondii IgM antibodies in acute psychosis compared with controls (7.6% vs 5.7%, OR = 1.68, 95% CI = 1.23-2.27, P = .001). The association was stronger for patients with chronic schizophrenia (8.7% vs 4.6%, OR = 2.54, 95% CI = 1.63-3.96, P < .001) than first-episode psychosis. In meta-regression analyses, age, sex, and publication year were unrelated to the association; however, there was a significant association with geographic region.


CONCLUSIONS
An increased seroprevalence of T. gondii IgM in patients with acute psychosis complements and extends previous findings, suggesting that infections may be relevant to the etiopathophysiology of relapse in some patients with schizophrenia.
Department of Psychiatry and Health Behavior, Georgia Regents University, Augusta, GA;
Joel M
JM
Monroe
Medical College of Georgia, Georgia Regents University, Augusta, GA.
Peter F
PF
Buckley
Department of Psychiatry and Health Behavior, Georgia Regents University, Augusta, GA; brmiller@gru.edu.
Brian J
BJ
Miller
D000913:Antibodies, Protozoan / Q000097:blood*; D006801:Humans; D007075:Immunoglobulin M / Q000276:immunology*; D011618:Psychotic Disorders / Q000276:immunology*; D012559:Schizophrenia / Q000276:immunology*; D014122:Toxoplasma / Q000276:immunology*; D014123:Toxoplasmosis / Q000276:immunology*
D000913:Antibodies, Protozoan; D007075:Immunoglobulin M
infection; meta-analysis; psychosis; relapse; toxoplasmosis