Cytokine profile among a sample of bipolar and schizophrenic patients: a comparative study

Abstract

Background Bipolar disorder (BD) and schizophrenia are serious forms of mental illness which are considered to be complex and multisystemic conditions. Several lines of evidence point to the key role of immune dysfunction in both disorders, with recent reports citing abnormal blood levels of cytokines where the most obvious mechanism is a dysregulation of the balance of proinflammatory and anti-inflammatory cytokines. Objective The aim was to explore the presence of immune dysfunction in BD in comparison with schizophrenia and to compare them to apparently healthy control persons. Participants and methods This study was a cross-sectional study on 90 individuals (30 diagnosed as BD, 30 as schizophrenic, and 30 apparently healthy controls). Age matched and sex matched. They were assessed by general medical and neurological examination. Semistructured clinical interview for DSM-IV (SCIDI), positive and negative schizophrenia scale (PANSS) for the schizophrenia group, Yearsania rating scale (YMRS) for the bipolar group, and laboratory investigations include: serum interleukin (IL)1B level and serum IL6 level for the three groups. Result The mean serum IL1B level was found to be higher in the bipolar group than that of the control group and schizophrenia group .The mean serum IL1B level in the schizophrenia group was higher than that of the control group. The mean serum IL6 level was higher in the bipolar and schizophrenia groups than that of the control group. It was also found that serum IL1B showed a highly significant correlation with the duration of illness in the bipolar group, while serum IL6 showed a significance with the duration of illness in the bipolar and schizophrenia groups. In the bipolar group, significant correlation was found between IL6 and number of episodes, while in the schizophrenia group, a significant correlation was found between IL6 and age at onset of illness and number of episodes. Conclusion There is mounting evidence of increased immune markers, particularly proinflammatory cytokines in BD and schizophrenia patients. So, identifying the biomarkers could represent new tools which could help to improve diagnosis and find prognostic markers which offers great promises toward a better understanding of the etio-pathological mechanisms involved in BD and schizophrenia, and for the development of prevention and personalized treatments.