Immunological study in vitiligo and contact depigmentation

Tuberculin response, peripheral T-lymphocytes counts and serum immunoglobulin levels were studied in 28 cases of vitiligo and 27 cases of contact depigmentation (CD). There were 50% reactors in vitiligo versus 92.6% in CD. Peripheral T-lymphocyte counts were low in vitiligo (38.1%) versus normal (55.8%) and in CD (53.4%) and the difference was statistically highly significant (p<0.001). Immunoglobulin were abnormal except in 3 cases in vitiligo and 2 cases of CD and difference in immunoglobulin levels in both conditions was statistically non-significant. IgA alone was decreased in 3 cases of vitiligo. It is concluded that there is suppression of cell mediated immune response in vitiligo versus normal in CD.