Low levels of antibodies to cardiolipin in first episode and chronic schizophrenia

To measure anticardiolipin antibodies (aCL) in major psychiatric diseases. Samples: Experiment 1: 96 subjects were evaluated: 20 first episode schizophrenia patients, 20 chronic schizophrenia patients in acute exacerbation, 19 bipolar patients, 20 schizoaffective patients and 17 healthy age-matched controls. Experiment 2: 97 subjects were studied: 20 first episode schizophrenia patients, 60 chronic schizophrenia patients in acute exacerbation and 17 healthy matched controls. Methods: Diagnosis was according to DSM-IV. Serum samples were tested for aCL in parallel by enzyme linked immunosorbant assay in the presence of bovine serum. Five positive control samples with high levels of aCL were run in parallel. Background binding to wells uncoated with cardiolipin (CL) was also measured. Results: Experiment 1: aCL levels were similar in the control, bipolar and schizoaffective groups. In contrast, aCL levels in the schizophrenic groups were significantly lower than controls (p=0.000002 and 0.00002 respectively). Experiment 2: Significantly lower levels of aCL antibodies were found in all schizophrenic patients (p=0.0002 for all schizophrenic patients versus controls). Interestingly, background levels in both experiments were higher in the schizophrenic groups than controls. Conclusions: Serum aCL levels are lower in schizophrenic patients, and especially in first episode cases, compared to controls. One possible explanation for the lower levels of aCL in schizophrenic patients is the consumption of these antibodies in an acute phase and exacerbation of the disease. The higher background levels in schizophrenic patients may indicate a high level of antibodies to some serum component in schizophrenic patients, which is still unclear and needs further elucidation.