Serum Heme Oxygenase-1 and Antioxidant Enzyme Levels in Vitiligo: Relationship with Disease Activity and Response to Narrowband UVB Phototherapy. A Prospective Study

Abstract Oxidative stress contributes to melanocyte loss in vitiligo. Heme oxygenase-1 (HO-1), a major Nrf2-regulated cytoprotective enzyme, protects melanocytes against oxidative injury, but data on circulating HO-1 in relation to clinical features and phototherapy remain limited. We compared serum HO-1, catalase (CAT), glutathione peroxidase (GPx), malondialdehyde (MDA) and nitric oxide (NO) between patients with vitiligo and healthy controls, and evaluated their clinical associations and changes after narrowband ultraviolet B (NB-UVB) phototherapy. This prospective study enrolled 45 adults with non-segmental vitiligo and 35 age- and sex-matched healthy controls. Disease activity and extent were assessed with the VIDA and VASI scores. HO-1 was measured by ELISA and the other markers spectrophotometrically. Eight patients had paired measurements after three months of NB-UVB. Compared with controls, patients had higher CAT (p = 0.021) and lower MDA (p = 0.004) and NO (p = 0.015) levels; GPx differed significantly (p = 0.012), whereas serum HO-1 did not (p = 0.309). No marker differed between active (n = 31) and stable (n = 14) disease. MDA correlated positively with VASI (r = 0.337), whereas CAT and GPx were not correlated with MDA or NO. After NB-UVB, serum HO-1 increased significantly (median 0.49 to 0.80 ng/mL; p = 0.036) and VIDA decreased (p = 0.014); changes in the other markers were not significant. Higher CAT with lower MDA and NO levels may reflect an adaptive systemic antioxidant response, while the association of MDA with disease extent indicates ongoing lipid peroxidation. The rise in serum HO-1 after NB-UVB suggests that HO-1 induction may contribute to the effect of phototherapy and warrants confirmation in larger studies.