Thymus and Leishmania at the Crossroads: Autoimmunity and Cancer.

Leishmania infections profoundly reshape host immunity, yet their impact on central T-cell development remains underappreciated. The thymus, a key site for establishing a functional and self-tolerant T-cell repertoire, is highly sensitive to systemic inflammatory cues. Growing evidence indicates that parasitic diseases, including leishmaniasis, can perturb thymic structure and function through direct parasite presence or sustained inflammatory stress. Such disturbances may alter thymocyte maturation, leading to reduced T-cell output and the release of cells with aberrant specificity. Beyond compromising protective immunity, these changes may create conditions favourable to immune dysregulation, including the emergence of autoimmune manifestations and a microenvironment permissive to malignant transformation. This narrative review synthesises current findings on how Leishmania interacts with immunological tissues and highlights the thymus as a potential and overlooked target whose dysfunction may bridge infection, autoimmunity and cancer.