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

Abstract

Introduction: 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. Aim: 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. Materials and Methods: 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. Results: 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. Conclusion: 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.

Keywords

• cellular
• depigmentation
• immunity
• melanin