Serum levels of interleukin-33 and its soluble form receptor (sST2) are associated with cognitive performance in patients with schizophrenia.

OBJECTIVE: Changes in immune system have been reported in schizophrenia. This study aimed to evaluate the involvement of IL-33, a member of the IL-1 cytokine family, in schizophrenia and its association with cognitive performance in these patients. METHODS: Forty patients with chronic schizophrenia and 40 healthy subjects participated in the study. Serum levels of IL-33 and sST2 (soluble form of the IL-33 receptor) were measured using enzyme-linked immunosorbent assay (ELISA). Patients were evaluated with the Brief Assessment of Cognition in Schizophrenia (BACS) and the Schizophrenia Cognition Rating Scale (SCoRS). RESULTS: Patients with schizophrenia and controls presented similar serum levels of IL-33 and sST2. Levels of both markers were positively correlated with cognitive performance in patients with schizophrenia. CONCLUSION: We found a significant correlation between IL-33 and sST2 levels and cognition in schizophrenia. Our results might help in the understanding of how immune markers are associated with cognitive impairment in schizophrenia. It remains to be determined whether the association between IL-33/sST2 and cognition is restricted to patients with schizophrenia.

Adiponectin and Stnfr2 peripheral levels are associated with cardiovascular risk in patients with schizophrenia.

OBJECTIVES: To investigate the association between cytokine peripheral levels and the risk of cardiovascular disease in patients with schizophrenia and controls. METHODS: A sample of 40 patients and 40 control subjects participated in the study. Psychiatric diagnosis was established following structured clinical assessment. The Framingham Score was used to assess cardiovascular risk (CVR). Serum levels of the cytokines IL-1ß, IL-6, IL-8, IL-10, IL-12p70 and TNF-α were determined by cytometric bead array (CBA) technique, and the serum levels of IL-33, sST2, sTNFR1, sTNFR2, Leptin and Adiponectin by Enzyme-Linked Immunosorbent assay (ELISA). RESULTS: Patients with schizophrenia showed greater frequency of moderate CVR when compared with controls (p = 0.14). In addition, patients showed higher levels of sTNFR2 and Adiponectin compared to controls (p = 0.007 and p < 0.001, respectively). Adiponectin and sTNFR2 were associated with CVR only in patients (p = 0.0002 and p = 0.033, respectively). In multivariate analysis controlling for socio-demographic and clinical confounders, illness duration (r = 0.492; p < 0.002) and sTNFR2 (r = 0.665; p < 0.004) were independent predictors of CVR. CONCLUSION: Our results reinforce the concept that patients with schizophrenia are at greater risk to develop cardiovascular diseases, and suggest that the associated chronic low-grade inflammation might play a role in this process.