Interleukin-6: a possible inflammatory link between vitiligo and type 1 diabetes

Vitiligo is a pigmentation disorder of unknown aetiology, but it has been reported in association with other autoimmune diseases including type 1 diabetes mellitus (T1D). Vitiligo and T1D share a common theory of autoimmunity, but still an inflammatory link between them remains to be investigated. This study investigates the status and contribution of the inflammatory markers tumour necrosis factor-alpha (TNF alpha), interleukin (IL)-6 and IL-1 in patients with vitiligo, T1D and vitiligo-associated T1D (Vt-T1D). The data showed that sera from Vt-T1D patients (n=21) had higher levels of, TNF alpha, IL-6 and IL-1 beta compared with vitiligo patients (n=39), T1D patients (n=37) or controls (n=42). Interestingly, serum levels of IL-6 were found to be significantly higher in Vt-T1D patients compared with the levels of TNF alpha and IL-1 beta. These data also showed that IL-6 was high in Vt patients as compared to the levels of TNF alpha and IL-1 beta, whereas in T1D patients, IL-6 and TNF alpha were almost the same but were higher than IL-1 beta. In conclusion, this is the first study to show an inflammatory link between vitiligo and T1D. The data conclude that IL-6 plays an important role in the pathogenesis of Vt-T1D patients and is likely to gain favour as a therapeutic target in these patients.