BACKGROUND:

The soluble intercellular adhesion molecule-1 (sICAM-1) is a marker for the activation of the cellular immune system. Since an activation of the immune system has been observed in a part of the schizophrenic patients, we measured the serum levels of soluble ICAM-1 (sICAM-1) in schizophrenic patients and correlated them to the patient's psychopathology.

METHODS:

To monitor a possible effect of antipsychotic therapy, 36 schizophrenic patients were examined twice: first without antipsychotic medication immediately after admission to the hospital and then, after clinical improvement before discharge. The results were compared with those of 36 age- and gender-related healthy individuals.

RESULTS:

The schizophrenic patients showed significantly decreased serum levels of sICAM-1 at the first examination (248 +/- 95 ng/mL) and at re-examination (266 +/- 95 ng/mL) compared with the comparison group (323 +/- 74 ng/mL). Patients with more pronounced negative symptoms showed higher levels of sICAM-1 at the first examination.

CONCLUSIONS:

We conclude that reduced sICAM-1 levels in schizophrenia indicate a reduced activity of the cellular immune system in at least a subgroup of schizophrenic patients.