Prenatal maternal immune disruption and sex-dependent risk for psychoses

Background. Previous studies suggest that abnormalities in maternal immune activity during pregnancy alter the offspring's brain development and are associated with increased risk for schizophrenia (SCZ) dependent on sex. Method. Using a nested case-control design and prospectively collected prenatal maternal sera from which interleukin (IL)-1 beta, IL-8, IL-6, tumor necrosis factor (TNF)-alpha and IL-10 were assayed, we investigated sex-dependent associations between these cytokines and 88 psychotic cases [SCZ=44; affective psychoses (AP)=44] and 100 healthy controls from a pregnancy cohort followed for >40 years. Analyses included sex-stratified non-parametric tests adjusted for multiple comparisons to screen cytokines associated with SCZ risk, followed by deviant subgroup analyses using generalized estimating equation (GEE) models. Results. There were higher prenatal IL-6 levels among male SCZ than male controls, and lower TNF-alpha levels among female SCZ than female controls. The results were supported by deviant subgroup analyses with significantly more SCZ males with high IL-6 levels (>highest quartile) compared with controls [odd ratio (OR)(75)=3.33, 95% confidence interval (CI) 1.13-9.82], and greater prevalence of low TNF-alpha levels (