Erythrocyte Aggregability Enables the Distinction between Negative and Depressive Symptoms among Schizophrenia and Schizoaffective Disorder Patients

Objective: Based on the membrane-phospholipid hypothesis of schizophrenia, the authors tested the assumption that erythrocyte aggregation is differentially associated with negative and depressive symptoms of schizophrenia and schizoaffective disorder. Methods: A cell flow properties analyzer was used to measure erythrocyte aggregation levels in 68 in patients with schizophrenia and schizoaffective disorder between ages 18 and 60 years and 30 normal comparison subjects without known neuropsychiatric disorders, proportionally matched for age and gender. Positive, negative and general psychopathological symptoms were quantified with the Positive and Negative Syndrome Scale (PANSS). Multiple regression analysis was used to examine the association of erythrocyte aggregation with clinical symptoms. Results: There were no significant differences in erythrocyte aggregation levels between schizophrenic and schizoaffective disorder patients and normal control subjects. The erythrocyte aggregability directly and strongly correlated with the severity of negative syndrome, but inversely with affective components of the disorders. These findings were unrelated to gender, age at testing, age at onset and duration of the illnesses, body mass index, serum cholesterol and fibrinogen levels, smoking, and current medication. Conclusion: The findings provide evidence that erythrocyte aggregation may serve as a potential endophenotype marker to distinguish negative and depressive features in schizophrenia and schizoaffective disorder patients.