BACKGROUND: Alopecia areata (AA) is a common form of localized, non-scarring hair loss. The cause of AA is unknown but reports suggest an autoimmune etiology, where oxygen free radicals play an important role. OBJECTIVE: The aim of this study was to investigate the role of a hydroxyl radicals (.OH)-modified antioxidant enzyme, superoxide dismutase (SOD), in AA autoimmunity. METHODS: SOD was modified by .OH radicals. Binding characteristics of autoantibodies in AA patients (n=26) against .OH-modified SOD (.OH-SOD) were evaluated by immunoassays and the results were compared with those of healthy, age-matched controls (n=30). The effects of .OH radicals on immunoglobulin G (IgG) isolated from AA patients were studied. RESULTS: Highly specific binding to .OH-SOD was observed in 32% of the samples of patient sera, whereas normal human sera showed negligible binding with either antigen. Competitive inhibition immunoassays reiterated the results from direct binding. Protein-A-purified IgG from AA patients (AA-IgG) also showed strong binding to .OH-SOD as compared to IgG from normal human controls (p<0.001). In addition, AA-IgG from patients with alopecia universalis recognized .OH-SOD to a greater extent than did AA-IgG from patients with the patchy, persistent type of alopecia. Furthermore, sera from AA patients had lower levels of SOD activity as compared to control sera. CONCLUSION: This is the first report showing an association between .OH-modified SOD and AA. These novel results demonstrate that .OH radical-mediated changes in SOD present unique neo-epitopes that might contribute to antigen-driven antibody induction in AA.
Alopecia ; Alopecia Areata* ; Autoantibodies* ; Autoimmunity ; Free Radicals ; Hair ; Humans ; Immunoassay ; Immunoglobulin G ; Oxygen ; Reactive Oxygen Species ; Superoxide Dismutase*

BACKGROUND: Vitiligo is a depigmenting skin disorder in which genetic factors play an important role. OBJECTIVE: To examine the association of CYP2C9 *1/*2/*3 gene polymorphism with vitiligo. METHODS: In this case controlled study, 95 Saudi patients with vitiligo (50 men and 45 women), with a mean age of 27.3 years, were analyzed. Patients were compared to 86 healthy controls from the same locality (76 men and 10 women), with a mean age of 20.1 years. In all participants, DNA was extracted and processed for characterization of 2C9 *1/*2/*3 gene variants using real time-polymerase chain reaction. RESULTS: Vitiligo patients have a significantly higher CYP2C9 *3 allele carriage rate compared to controls (32.7% versus 4.7%, p=0.00, odds ratio=9.9, 95% confidence interval=3.3~29.6). On the other hand, frequencies of CYP2C9 *2 genotypes and alleles did not show any significant difference between vitiligo cases and controls. When the frequencies of CYP2C9 genotypes were compared among subgroups of age, gender, family history, and disease patterns, the cases with positive consanguinity had significantly higher frequencies of homozygous genotypes than others (p=0.029). CONCLUSION: CYP2C9 *3 allele carriage is probably associated with vitiligo susceptibility.
Alleles ; Case-Control Studies ; Consanguinity ; DNA ; Genotype ; Hand ; Humans ; Male ; Polymorphism, Genetic ; Skin ; Vitiligo*