Impaired activation of lesional CD8+ T-cells is associated with enhanced expression of Programmed Death-1 in Indian Post Kala-azar Dermal Leishmaniasis.

Post Kala-azar dermal leishmaniasis (PKDL), caused by Leishmania donovani is the dermal sequel of Visceral Leishmaniasis and importantly, is the proposed disease reservoir. The survival of Leishmania parasites within monocytes/macrophages hinges on its ability to effectively nullify immune activation mechanisms. Thus, delineating the disease-promoting immune mechanisms can facilitate development of immunotherapeutic strategies. Accordingly, in the absence of an animal model, this study aimed to delineate the status of CD8+ T-cells in patients with PKDL. At disease presentation, the absence of CD4+ T-cells at lesional sites was concomitant with an overwhelming infiltration of CD8+ T-cells that demonstrated an absence of Perforin, Granzyme and Zap-70, along with an enhanced expression of Programmed Death-1 (PD-1) and the skin-homing CCL17. Additionally, the lesional CCR4+CD8+ population was associated with an enhanced expression of IL-10 and IL-5. In circulation, the enhanced CD8+CCR4+ T-cell population and raised levels of CCL17/22 was associated with an increased frequency of PD-1, while CD127 was decreased. Taken together, in PKDL, the enhanced plasma and lesional CCL17 accounted for the dermal homing of CD8+CCR4+ T-cells, that along with a concomitant upregulation of PD-1 and IL-10 mediated immune inactivation, emphasizing the need for designing immunotherapies capable of reinvigorating T-cell potency.

Cyclosporine in toxic epidermal necrolysis: a brief review of the emerging therapeutic modality.

Toxic epidermal necrolysis (TEN) is a severe life-threatening adverse drug reaction that predominantly involve the skin and mucous membranes, and is associated with high mortality (25-35% or even higher) and with various long term sequelae. There is no universally accepted treatment for TEN, but key elements of management include rapid diagnosis, identification and interruption of the culprit drug, evaluation of the prognosis using SCORTEN, specialized supportive care ideally in an intensive care unit, and consideration of immunomodulating agents. Cyclosporine has recently emerged as a promising immunomodulating agent in the management of TEN and we have performed a brief review of evidence highlighting its role in TEN management.

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.