Immune Variations Appear to Be Unrelated to Psychosis, Schizophrenia
Examination of raw data does not show a multi-modal distribution of immune parameter data in patients.
The findings of a meta-analysis in Schizophrenia Bulletin did not support a proposed framework that linked immune variations and antipsychotic response in patients with schizophrenia.
Previous genetic, preclinical, and postmortem data have suggested that immune dysregulation may influence the pathogenesis of psychosis. If so, the researchers explained, patterns of immune variation might further predict patient response to treatment.
To assess immune variations, this study focused on cytokines, a category of proteins associated with the immune system that includes substances such as interleukin.
The investigators identified English-language studies through PubMed, Embase, and PsycINFO databases. The 35 studies included were composed of 1263 antipsychotic-naïve patients who experienced a first episode of psychosis and 1470 control participants. Genetic and in vitro studies were excluded.
Antipsychotic-naïve patients with first-episode psychosis exhibited increased levels of interleukin (IL)-6, IL-17, tumor necrosis factor-α, interferon (IFN)-γ, and transforming growth factor-β compared with control participants; IL-6, IL-17, and IFN-γ, were robust to sensitivity analyses.
Patients did not exhibit variations in C-reactive proteins, total lymphocyte counts, IL-1β, interleukin-2, soluble IL-2 receptor, IL-4, IL-8, and IL-10 levels compared with healthy control participants.
Overall, the researchers found reduced immune variability in patients; however, they pointed out that this study only accounted for peripheral immune parameter distribution and this methodology alone may be insufficient.
Pillinger T, Osimo E, Brugger S, et al. A meta-analysis of immune parameters, variability, and assessment of modal distribution in psychosis and test of the immune subgroup hypothesis [published online November 8, 2018]. Schizophr Bull. doi:10.1093/schbul/sby160