Cerebrospinal fluid angiotensin-converting enzyme (ACE) correlates with length of illness in schizophrenia

The aim of the study was to evaluate a possible progression with time of ce rebrospinal fluid (CSF) angiotensin-converting enzyme (ACE) levels in treat ed schizophrenia patients. CSF ACE was determined in duplicate by a sensiti ve inhibitor-binding assay (IBA) from morning CSF samples of 56 acute and c hronic in-patients with schizophrenic psychoses diagnosed according to DSM- IV. CSF ACE correlated significantly with length of schizophrenic psychosis (r = 0.39, p = 0.003). There was also a positive significant correlation b etween CSF ACE and duration of current psychotic episode (r = 0.39, p = 0.0 03) as well as duration of current hospitalization (r = 0.66, p < 0.001). T hese significances were maintained even when patients who were not treated with antipsychotics at the time of sampling were excluded. The correlations also remained significant when controlling for current neuroleptic dose in chlorpromazine equivalents. Serum ACE did not correlate with any clinical variable. No significant correlations between serum or CSF ACE and age, dia gnostic subgroup, gender, serum ACE, CSI; to serum albumin ratios, or neuro leptic dose in chlorpromazine equivalents were detected. The elevation of C SF ACE seemed to be confined to a subgroup of chronic patients with few pos itive symptoms. Elevated CSF ACE may reflect an increased solubilization of ACE from cell membranes in the central nervous system or constitute an inc reased expression of the ACE gene in response to some stimuli. This may be a function of treatment or a result of the deteriorating schizophrenic proc ess. (C) 2000 Elsevier Science B.V. All rights reserved.