Indices of congenital leukocyte elastase (LE) activity and adaptive immunity (a level of autoantiboies to nerve growth factor--AabNGF) in blood serum of patients with schizophrenia (attack-like, continuous and slow progressive types) and schizoaffective psychosis have been compared with clinical presentations of the disorders. A patient's state was assessed by clinico-psychopathological methods and with the Positive and Negative Syndromes Scale (PANSS). All schizophrenia types and schizoaffective psychosis were accompanied by LE activity elevation. An increase of AabNGF level was observed only in attack like and continuous schizophrenia. Correlations between AabNGF level and negative symptoms evaluated, using the PANSS, suggest a relation of autoimmune reactions against NGF to the progression of schizophrenic process. Differences in AabNGF level between schizoaffective psychosis and attack-like schizophrenia confirm nosologic independence of schizoaffective psychosis and demand for additional differential laboratory diagnosis of these disorders.