Increased serum levels of CCL11/eotaxin in schizophrenia.

Background: Inflammatory and immune alterations occur and may be relevant in patients with schizophrenia. Chemokines are a subgroup of cytokines that play a major role in the recruitment of determined subsets of leukocytes into tissues. To date no study has evaluated whether levels of chemokines are altered in patients with schizophrenia.

Objective: To evaluate serum levels of CC and CXC chemokines of schizophrenic patients and age- and gender-matched controls.

Methods: Forty male institutionalized schizophrenic patients (mean+/-SD age, 52.3+/-9.9) and 20 asymptomatic matched controls were recruited for this study. Severity of symptoms was assessed using BPRS, PANSS and AIMS. All patients were under typical antipsychotic treatment. Serum concentrations of chemokines were measured by ELISA.

Results: There was no statistical difference in serum levels of CCL2, CCL3, CCL24, CXCL9 and CXCL10 between controls and patients. Serum levels of CCL11 were increased in schizophrenic patients when compared to controls. Serum levels of chemokines were not correlated with the length of disease or hospitalization and the severity of involuntary movements, positive and/or negative symptoms.

Conclusion: CCL11 is a ligand for CCR3, a receptor expressed preferentially on Th2 lymphocytes, mast cells and eosinophils. Higher serum levels of CCL11 in schizophrenia reinforce the view that this disease may be associated with a Th1/Th2 imbalance with a shift toward a Th2 immune response.