Dados do Trabalho

Título

THE LEISHMANIA SKIN TEST DETERMINES CLINIC-IMMUNOLOGIC AND THERAPEUTIC OUTCOMES IN CUTANEOUS LEISHMANIASIS

Introdução

Cutaneous Leishmaniasis is a disease caused by an intracellular parasite of the Leishmania braziliensis species. The Leishmania skin test assesses and reflects the presence of immune T cells specific to Leishmania antigens.

Objetivo (s)

The study is a case-control that aims to compare the clinical, immunological, and pathological differences between Leishmania skin test-positive and negative in cutaneous leishmaniasis caused by Leishmania braziliensis.

Material e Métodos

Sixty-seven CL patients were included, and we evaluated randomized samples of these patients by collecting ulcer biopsies to obtain tissue for in situ histopathological and in vitro analysis, totaling 26 LST- and 16 LST+. The double or simple immunostaining technique was applied using specific antibodies to identify and quantify the markers: CD8+ and granzyme B+. The cell culture and determination of cytokines were quantified by ELISA. Statistical analyses were performed using GraphPad Prism 8 and RStudio software. 

Resultados e Conclusão

We found that Leishmania skin test-negative patients had significantly larger and a greater number of lesions with a longer duration of illness compared to Leishmania skin test-positive patients. Additionally, therapeutic failure of meglumine antimonate was significantly higher in Leishmania skin test-negative patients. The study also found that granulomas were seen much less frequently in Leishmania skin test-negative patients. CD8+ T cells were more frequent and significantly different in Leishmania skin test-negative biopsies. Granzyme B+ cells did not significantly differ between the two groups, although Leishmania skin test-negative individuals had considerably higher levels of free Granzyme B. The higher quantity of Granzyme B in the supernatant of Leishmania skin test-negative cells is not associated with CD8+/Granzyme B+ cells. The free granzyme B is contributing to tissue necrosis without controlling the number of parasites, affecting therapeutic failure and worst outcome in Leishmania skin test-negative in CL patients. Overall, the study sheds light on the differences between Leishmania skin test-positive and Leishmania skin test-negative cutaneous leishmaniasis in terms of in situ immune responses and association with the worst clinical and therapeutic outcomes.

Palavras Chave

Leishmaniasis; Clinic; Immune response