Involvement of T cells in early evolving segmental vitiligo

Area of Science:

• Dermatology
• Immunology
• Autoimmune Diseases

Background:

• Recent research suggests shared autoimmune mechanisms between segmental vitiligo (SV) and nonsegmental vitiligo (NSV).
• While T-cell infiltration is documented in active nonsegmental vitiligo lesions, the histopathology of active segmental vitiligo margins remains less understood.

Purpose of the Study:

• To investigate the presence of T-cell inflammatory responses in the active margins of segmental vitiligo lesions.
• To compare the histopathological characteristics of active SV lesions with normal skin controls.

Main Methods:

• Biopsies were obtained from the active margins of lesions in 12 patients with early or actively spreading SV.
• Samples were compared to normal skin controls from the symmetrical contralateral site within the same dermatome.
• Immunohistochemical staining was performed for CD4, CD8, CD25, and interferon-gamma.

Main Results:

• Lymphocytic infiltration was observed in 70% of the studied SV patients.
• CD4+ T cells infiltrated the dermis, while CD8+ T cells were found in the epidermis and at the dermal-epidermal junction.
• A statistically significant increase in CD8+ T cells (P < 0.04) was noted in active SV lesions compared to controls.

Conclusions:

• The findings indicate that segmental vitiligo exhibits an autoimmune mechanism, particularly in its early, evolving stages.
• The presence of T-cell infiltration supports the hypothesis of overlapping autoimmune processes in both SV and NSV.