Association of Inflammatory Markers and Negative Symptoms in Patients with Schizophrenia in a Tertiary Care Hospital, West Bengal

The influence of the immune system deregulation on the risk of schizophrenia is increasingly recognized. Several proinflammatory and anti-inflammatory cytokines have been studied in drug-naive, first-episode, and/or chronic schizophrenia patients. Peripheral and CNS-localized inflammatory processes are hypothesized to contribute to the complex pathophysiology of schizophrenia. We thus hypothesized that inflammatory markers would predict development of psychotic symptoms in patients with schizophrenia. The aim of the study was to assess the association of serum interleukin-6 (IL-6) level, high sensitivity C-reactive protein (hsCRP) levels with positive and negative symptoms of schizophrenia. We recruited 90 clinically stable patients with schizophrenia and 80 healthy control subjects from Nil Ratan Sircar Medical College, Kolkata, West Bengal. Psychopathology was evaluated using Positive and Negative Syndrome Scale (PANSS) and Wisconsin Card Sorting Test to screen the neurocognitive Function. Serum IL-6 and hsCRP levels were assessed. A positive correlation was observed between CRP and PANSS negative symptoms (r=0.6, p=0.03), between IL-6 and PANSS negative symptoms (r=0.56, p=0.001) and There was no correlation between CRP, IL-6 with positive symptoms of schizophrenia (p=0.3 and p=0.21). Serum IL-6 was significantly higher in Patients in comparison with healthy controls. The correlation between CRP, IL-6 and negative PANSS of patients supports a role for inflammation in the pathophysiology of schizophrenia. Till now no specific treatment can be recommend for patients with more negative symptoms. This is particularly problematic for individuals burdened with negative symptoms in the face of mild or absent positive symptoms. These patients are at clinical high-risk and associated with worse functional outcomes. Though limited by a relatively small sample size, our findings demonstrate that inflammatory cytokines may underlie the development of negative symptoms in individuals with schizophrenia. Identification of biomarkers may help to improve treatment efficacy as well as outcomes.