Immune dysregulation is associated with symptom dimensions and cognitive deficits in schizophrenia: accessible evidence from complete blood count

Background Schizophrenia (SCZ) is a psychotic disorder with an unknown pathogenesis accompanied by varying degrees of cognitive deficits. Recent studies have shown that immune dysregulation plays an important role in developing symptoms and cognitive deficits in SCZ. This study aimed to determine the complete blood count (CBC), including white blood cells, neutrophils, monocytes, lymphocytes, platelets, neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and monocyte-lymphocyte ratio (MLR), in patients with SCZ and explore their correlations with SCZ symptom dimensions and cognitive function. Methods Seventy-four patients with SCZ and 57 age- and sex-matched healthy controls with available demographic and clinical information were recruited for this study. Blood samples were collected, and symptom dimensions and cognitive function were evaluated using the Positive and Negative Syndrome Scale (PANSS) and MATRICS Consensus Cognitive Battery (MCCB) separately. Results Our results demonstrate that SCZ patients showed higher monocyte counts, PLR, MLR, and worse performance in the total MCCB than healthy controls. Neutrophil and lymphocyte counts and NLR were positively related to symptom severity and negatively related to depressive symptoms. White blood cell (WBC) count, monocyte count, and MLR were positively correlated with cognitive performance in patients with SCZ. Conclusion In summary, this study suggests that cognitive deficits and symptom severity in patients were associated with dysregulation of immunity. Moreover, we found that WBC could be used as a marker for symptom severity and cognitive deficits in SCZ and that neutrophils are more closely related to the former and monocytes to the latter. We hope that clinicians will pay more attention to dysregulated immunity in patients with SCZ in the future.