Differential expression of serum CXCL9 and CXCL10 levels in vitiligo patients and their correlation with disease severity and stability: A cross-sectional study.

Background Vitiligo is an acquired disorder of pigmentation with an elusive pathogenesis, though various theories have been proposed. The presence of peri-lesional autoreactive CD8+ T cell infiltrate suggests the involvement of abnormal immune responses and autoimmunity in vitiligo. Recent studies have identified the IFN-γ-CXCL9/CXCL-10 axis as a key component of the autoimmune response that perpetuates disease activity in vitiligo. Objectives The primary objective was to estimate serum CXCL9 and CXCL10 levels in vitiligo patients compared to age- and sex-matched controls. Additionally, the study aimed to find correlations between CXCL9 and CXCL10 levels and disease severity and stability. Secondary objectives included comparing levels in segmental/nonsegmental vitiligo and stable/progressive vitiligo and assessing the impact of age and gender. Methods A hospital-based cross-sectional study included 60 vitiligo patients and 30 age- and sex-matched controls. Serum levels of CXCL9 and CXCL10 were assessed using Enzyme-linked immunosorbent assay (ELISA). Cases were clinically evaluated for the type of vitiligo (segmental or non-segmental), disease severity (VASI score), and disease stability (VIDA score). Statistical analysis included t-tests, chi-square tests, and correlation coefficients. P value less than 0.5 was taken as significant. Results Serum CXCL9 and CXCL10, both, were significantly raised in vitiligo patients as compared to controls (p-value = 0.001* & 0.001* respectively) and correlated positively with both VASI score (p-value = 0.001* & 0.001* respectively) and with VIDA score (p-value = 0.032* & 0.001* respectively). Serum CXCL10 showed significant elevation in progressive vitiligo, and CXCL9 exhibited a non-significant trend. No significant difference was observed between segmental and non-segmental vitiligo. Both chemokines positively correlated with disease severity and stability, while age and gender did not significantly impact chemokine levels. Limitations Small sample size of control population. The voluntary sampling technique led to an unequal number of patients in progressive and stable vitiligo groups, as well as in segmental and non-segmental groups. The current study did not include blister fluid analysis and the effect of therapy on the chemokine levels. Conclusion The expression of chemokines CXCL9 and CXCL10 is markedly increased and correlates positively with disease severity and instability, underscoring their mechanistic role in vitiligo pathogenesis. The values were also higher in the progressive group than in the stable group, inferring their conceivable potential as serum biomarkers. *represents statistically significant results.