Abnormal serum IL-10 and IL-19 levels in childhood- and adolescent-onset schizophrenia: associations with negative symptoms and language function.

BACKGROUND: The pathophysiological mechanisms of childhood- and adolescent-onset schizophrenia (CAOS) remain incompletely understood, with cytokine abnormalities potentially playing an important role. This study aimed to investigate the relationships of altered serum interleukin (IL)-10 and IL-19 levels with the clinical symptoms and cognitive function of CAOS patients. METHODS: The cross-sectional study included 97 CAOS patients and 40 healthy controls. Serum IL-10 and IL-19 levels were measured. Clinical symptoms were assessed using the Positive and Negative Syndrome Scale (PANSS), and cognitive function was evaluated using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). RESULTS: Compared to healthy controls, the CAOS patients had significantly lower serum IL-10 levels (p = 0.005) and higher IL-19 levels (p = 0.046). IL-10 was significantly negatively correlated with PANSS negative symptoms (r=-0.338, p = 0.001). The CAOS patients performed significantly worse than healthy controls across all RBANS cognitive domains (all p < 0.001), with significant correlations observed between the severity of clinical symptoms and cognitive impairment. In the healthy controls, IL-10 was significantly negatively correlated with language (r=-0.394, p = 0.012), whereas no such correlation was observed in the CAOS patients (p > 0.05). Low IL-10 levels were significantly associated with CAOS (B = 0.387, p = 0.002, RR = 1.472, 95% CI: 1.159–1.870), with a population attributable fraction of 19.1%. The association between IL-19 and CAOS did not reach statistical significance (B = 0.217, p = 0.081, RR = 1.243, 95% CI: 0.973–1.586). CONCLUSIONS: The CAOS patients had decreased IL-10 and increased IL-19 serum levels, with IL-10 levels associated with negative symptoms and language. These results suggest that IL-10 may serve as a potential biological marker associated with CAOS susceptibility, while the role of IL-19 requires further investigation. CLINICAL TRIAL: Not applicable.