Neutrophil/lymphocyte ratio is increased in the acute phase of schizophrenia and regardless the use and types of antipsychotic drugs

BACKGROUND: It has been found that patients with schizophrenia are often accompanied by concomitant changes in inflammation levels during acute exacerbations, and some studies have suggested that the inflammatory indices neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), and monocyte/lymphocyte ratio (MLR) may be biomarkers of acute exacerbations in schizophrenia; however, few studies have simultaneously explored the differences in these inflammatory indices in the drug-free patients with schizophrenia in acute phase (DSA), medicated patients with schizophrenia in acute phase (MSA), medicated patients with schizophrenia in remission period (MSR), as well as the effects of different antipsychotic medications on inflammatory indices. METHOD: A total of 651 subjects including 184 healthy controls (HC), 167 DSA, 119 MSA, and 181 MSR were included in this study. Demographic and disease information was collected from each individual and venous blood was collected to detect immune cells and calculate the inflammatory indices NLR, PLR, and MLR, and statistical methods such as analysis of variance (ANOVA) and multiple comparisons were utilized to explore the alteration of these inflammatory indices under the influence of different antipsychotics and in HC, DSA, MSA, and MSR. RESULTS: NLR was significantly higher in DSA and MSA than in HC after adjusting the confounders of sex, age, smoking, years of education, marital status, BMI, diabetes, and hypertension. PLR and MLR were not significantly different in patients with schizophrenia and in HC, and were not significantly different in patients with schizophrenia in any group. In MSA and MSR, NLR was positively correlated with disease duration and negatively correlated with the use of mood stabilizers. CONCLUSIONS: NLR was significantly increased in acute phase of schizophrenia, regardless of use of antipsychotic drugs, but not significantly increased in stable phase, which might be a promising biomarker for acute phase of schizophrenia.