Blood ACE Activity Is Significantly Lowered in Psoriasis Compared to Atopic Dermatitis: A Small Pilot Study in Young Males

PURPOSE: Emerging evidence suggests the involvement of the renin-angiotensin system (RAS) in the pathogenesis and progression of autoimmune dermatological diseases. In a small exploratory study, we investigated angiotensin-converting enzyme (ACE) activity in blood obtained from male probands with psoriasis vulgaris (n = 4) and atopic dermatitis (AD, n = 5). METHODS: The degradation capacity of dabsylated synthetic bradykinin (DBK) with and without inhibition was determined using a thin-layer chromatography (TLC)-based neuropeptide reporter assay. RESULTS: We observed a significantly reduced capacity for cleavage of DBK in psoriasis patients compared with that in AD patients and controls. In patient samples, the variation in the measured values was generally greater than that in healthy controls. We could not confirm the increased ACE activity in the circulation in psoriasis patients reported by others, likely because of different study designs and detection methods. We did not include samples of female patients and focused on younger men to avoid hormonal effects and minimize age-related factors. CONCLUSION: This preliminary study of the hypothesis-generating nature lacks power, but it certainly adds a question to the current view of the role of ACE in psoriasis. Treatments targeting specific components of the RAS could ameliorate inflammatory responses; thus, research in this area is becoming increasingly important.