Vitiligo is a dermatological disorder with an autoimmune mechanism characterized by production of a variety of autoantibodies. Different levels of immunoglobulins can indicate the presence and the stage of some autoimmune diseases. We aimed to investigate serum IgA, IgM and IgG subclass levels and melanocyte-reactive antibodies in 65 vitiligo patients by the immunonephelometric assay (35 healthy people as controls). Compared with normal controls, a significant increase in total IgG, IgG1 and IgG2 (p = .005, p = .003 and p = .043, respectively) was observed in progressive nonsegmental vitiligo patients. Also, we found a significant decrease in IgG3 (p = .000 and p = .023) in progressive nonsegmental vitiligo patients and segmental patients. Moreover, we found the serum levels of IgG4 subclass in stable nonsegmental patients were significantly higher than those in normal controls (p = .018). Compared with controls, the positive rates of melanocyte-reactive antibodies were higher in progressive nonsegmental patients and stable nonsegmental patients (p = .032 and p = .046, respectively). Furthermore, we found higher level of IgG4 and lower level of IgM in male than those in female. Higher IgG1 level was also observed in patients with a family history than in those without a family history. In addition, there was a significant inverse correlation between the concentrations of IgG4 and disease duration. Our evaluation about the level of immunoglobulins might provide a useful insight into the pathological process of vitiligo.
Keywords: IgG subclasses; Immunoglobulin; Immunonephelometric assay; Melanocyte-reactive antibodies; Vitiligo.