A Cross-Sectional Study of the Levels of Cytokines IL-6, TNF-α, and IFN-γ in Blood and Skin (Lesional and Uninvolved) of Vitiligo Patients and their Possible Role as Biomarkers.

Introduction: Vitiligo is a multifactorial disorder, most often explained by the autoimmune hypothesis. The objective of this study is to measure the levels of cytokines IL-6, TNF-α, and IFN-γ in the blood and skin (lesional and uninvolved) of vitiligo patients and to compare it with that of age-matched controls. Methods: IL-6, TNF-alpha, and IFN-gamma cytokines were measured with a BioRad 6110 ELISA reader. We compared the levels of these cytokines in generalized versus localized vitiligo and stable versus unstable vitiligo. We also correlated cytokine levels in blood/lesion/uninvolved skin with body surface area (BSA) involvement and Vitiligo Disease Activity (VIDA) scoring. Result: Forty-three participants, each with vitiligo and control, were analyzed. The values of TNF-α and IL 6 in sera were significantly higher in the vitiligo group compared with the controls (p < 0.001), whereas INF-γ was significantly lower in the vitiligo group than the control group. TNF-α, INF-γ levels when compared between blood, lesional skin, and normal skin in all vitiligo patients were found to be significant (p < 0.001). Conclusion: We conclude vitiligo is strongly associated with increased levels of TNF-α and IL 6.

Diagnosing leprosy: revisiting the role of the slit-skin smear with critical analysis of the applicability of polymerase chain reaction in diagnosis.

BACKGROUND: Diagnosing leprosy is challenging, especially in early-stage cases, and the need for a sensitive diagnostic tool is urgent. Polymerase chain reaction (PCR) holds promise as a simple and sensitive diagnostic tool, but its usefulness in the Indian context requires further evaluation. Slit-skin smear (SSS) remains the conventional method of leprosy detection. Hence, this study was undertaken to evaluate and compare the diagnostic efficacy of PCR versus that of SSS. METHODS: Punch biopsy of skin and SSS were obtained from the active margins of lesions. Cases were clinically grouped according to whether they were multibacillary (MB) or paucibacillary (PB) and classified into tuberculoid (TT), borderline tuberculoid (BT), borderline lepromatous (BL), lepromatous (LL), histoid, and indeterminate groups after clinicopathological correlation. DNA was extracted from biopsy specimens, and multiplex PCR was carried out incorporating primers intended for the amplification of a specific 372-bp fragment of a repetitive sequence of Mycobacterium leprae DNA. RESULTS: Among 164 patients, PCR was positive in 82.3%. The sensitivity of PCR was significantly greater (P < 0.0001) than that of SSS in both the MB (85.9% vs. 59.8%) and PB (75.4% vs. 1.8%) subgroups; the difference in sensitivity in the PB subgroup is remarkable. Positivity by PCR and SSS was found in 100% of LL and histoid leprosy, but PCR had significantly greater (P < 0.0001) positivity in BT leprosy and was of definite increased value in indeterminate and TT leprosy. CONCLUSIONS: Polymerase chain reaction had higher sensitivity compared with SSS, especially in diagnostically challenging and PB cases. Thus, the use of this costly but sensitive tool should be restricted to this subgroup, because SSS is sufficiently sensitive in the diagnosis of LL and histoid leprosy.