No abstract

Background Tissue resident memory T cells (TRMs) persist long-term in peripheral tissues without recirculation, triggering an immediate protective inflammatory state upon the re-recognition of the antigen. Despite evidence incriminating the dysregulation of TRMs in autoimmune diseases, few studies have examined their expression in cutaneous lupus erythematosus (CLE). Objectives We aimed to examine whether there are differences among TRM populations in CLE depending on different clinical conditions, such as the CLE subtype or association with systemic lupus erythematosus, and to determine the effect of type I interferon (IFN) on the development of TRMs in CLE. Methods CLE disease activity was evaluated using the Cutaneous Lupus Erythematosus Disease Area and Severity Index. The expression of the TRM markers CD69 and CD103 in CLE lesions was evaluated by immunofluorescence. Flow cytometry was performed on peripheral blood mononuclear cells after IFNα treatment. Results The number of TRMs expressing either CD69 or CD103 was significantly higher in CLE lesions than in control skin; however, it was not significantly different between discoid lupus erythematosus and subacute CLE, or dependent on the presence of concomitant systemic lupus. Lesional severity was not correlated with an increase in TRMs in CLE. IFNα treatment induced a conspicuous increase in CD69 expression in skin-homing T cells, more profoundly in CD4+ T cells than in CD8+ T cells. Conclusions Skin TRMs, either CD69 or CD103-positive cells, showed increased levels in the lesional skin of CLE, and IFNα increased the expression of CD69 in T cells.

Desmoplastic melanoma (DM) is a rare variant of malignant melanoma and constitutes less than 1% of all cutaneous melanomas 1 . Like all melanomas, especially melanomas of the skin, DM is easily diagnosed in the majority of cases, but some cases can mimic other tumors and cause misdiagnoses. Furthermore, because of the aggressive local behavior and high local recurrence rate of DM, proper diagnosis is essential 2,3 . Recently, there has been