Evaluation of Histologically and Histochemically Proven Cases of Vitiligo and its Correlation with CD4+ and CD8+ Lymphocyte Counts using Flow Cytometry.

Abstract

Vitiligo is an acquired cutaneous disorder characterized by progressive and selective destruction of melanocytes from the epidermis. Autoimmunity is strongly implicated in its pathogenesis. The destruction of melanocytes has a correlation with the peripheral blood lymphocyte imbalance mainly including Cytotoxic T cells (CD8+cells) and Helper T cells (CD4+cells). The progression of vitiligo is associated with higher CD8+ counts and lower CD4+ counts thus, altering CD4+: CD8+ ratio. To evaluate the clinically suspected cases of vitiligo histopathologically and histochemically and to establish the co-relation of autoimmunity with the flow cytometric analysis of CD8+ and CD4+ lymphocyte counts. In this study, 40 patients with proven vitiligo were taken. The destruction of melanocytes was confirmed by Haematoxylin & Eosin (H & E) and by histochemical stains using Dihydroxyphenylacetic Acid (DOPA) reaction. Blood sample from these vitiligo patients and 10 control subjects was taken. Flow Cytometry was used for the determination of CD8+ and CD4+ counts in the vitiligo patients and control subjects. Then CD4+: CD8+ ratio was calculated and comparison between vitiligo patients and control subjects was done. T-test was used for the statistical analysis. There was statistically significant decrease in CD4+: CD8+ ratio. CD4+: CD8+ ratio was decreased in 57.5% cases of vitiligo with increase in CD8+ counts and decreased CD4+ counts. It was concluded from this study that cellular immunity might have a role to play in the pathogenesis of vitiligo causing the destruction of melanocytes.