Differential serum acute-phase biomarker profile in schizophrenia and bipolar disorder

Abstract

There is a growing interest in inflammation and immune dysfunction in severe psychiatric disorders such as schizophrenia and bipolar disorder. This dysfunction seems to consist in abnormal blood levels of cytokines and acute-phase proteins, with increased levels of C-reactive protein (CRP), fibrinogen, homocysteine and erythrocyte sedimentation rate (ESR). Higher levels can be found in acute episodes and in patients with a higher cardiovascular risk.

Acute-phase protein serum parameters were determined in a sample of 100 outpatients with schizophrenia (n = 50) or bipolar disorder (n = 50) so as to assess differences in pro-inflammatory state. Metabolic state was assessed through BMI, waist circumference, glucose, cholesterol and triglyceride levels.

The whole sample showed higher levels of fibrinogen (mean 4 ± 0.9 g/L), triglycerids (mean 2.9 ± 8.5 mmol/L), cholesterol-LDL (mean 3 ± 0.9 mmol/L), and homocysteine (mean 16.2 ± 7.3 umol/L) than our laboratory reference values from healthy individuals.

After correcting for gender and pharmacological treatment, patients with schizophrenia showed higher levels of ESR, fibrinogen, glucose and CRP, while homocysteine was not statistically different between patients with schizophrenia or bipolar disorder (see Table 1).

These results may suggest a different biomarker profile in bipolar and schizophrenic outpatients, with a more severe pro-inflammatory state in schizophrenia. Serum homocysteine levels could be a state marker in both disorders.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Table 1

NS: not significant. ^*P < 0.05.