A study in first-episode psychosis patients: does angiotensin I-converting enzyme (ACE) activity associated with genotype predict symptoms severity reductions after treatment with the atypical antipsychotic risperidone?

ABSTRACT

BACKGROUND: Our previous studies showed increased angiotensin I-converting enzyme (ACE) activity in chronic schizophrenia (SCZ) patients compared to healthy control (HC) volunteers, and the relevance of combining ACE genotype and activity for predicting SCZ was suggested. METHODS: ACE activity was measured in plasma of ACE insertion/deletion (I/D) genotyped HC volunteers (N = 53) and antipsychotic-naïve first-episode psychosis (FEP) patients (N = 45), assessed at baseline (FEB-B) and also after 2-months (FEP-2M) of treatment with the atypical antipsychotic risperidone. RESULTS: ACE activity measurements showed significant differences among HC, FEP-B and FEP-2M groups (F = 5.356, df = 2, p = 0.005), as well as between HC and FEP-2M (post-hoc Tukey's multiple comparisons test, p = 0.004). No correlation was observed for ACE activity increases and symptom severity reductions in FEP as assessed by total PANSS (r = -0.131, p = 0.434). FEP subgrouped by ACE I/D genotype showed significant ACE activity increases, mainly in the DD genotype subgroup. No correlation between ACE activity and age was observed in FEP or HC groups separately (r = 0.210, p = 0.392), but ACE activity levels differences observed between these groups were influenced by age. CONCLUSIONS: The importance of measuring the ACE activity in blood plasma, associated to ACE I/D genotyping to support the follow-up of FEP patients did not show correlation with general symptoms amelioration in the present study. However, new insights into the influence of age and I/D genotype for ACE activity changes in FEP individuals upon treatment was demonstrated.