Screening for anti-Leishmania antibodies and Leishmania infections in kidney transplant recipients and donors from Brazil

This study examines the prevalence of anti-Leishmania IgG antibodies and Leishmania spp. infections among Brazilian kidney transplant recipients and their living donors before and after transplantation. A total of 48 donor-recipient pairs were recruited from July 14, 2022, to December 18, 2023. ELISA was used to test donors and recipients with a crude antigen of Leishmania major-like (Lm-ELISA), along with recombinant Lb6H (rLb6H-ELISA) and K39 (rK39-ELISA). Additionally, PCR was used to test recipients. Of the 48 donors, 25 (52.1%, 95%CI: 38.3-65.5) tested positive with Lm-ELISA, 4 (8.3%, 95%CI: 2.8-20.1) with rLb6H-ELISA, and 2 (4.2%, 95%CI: 0.4-14.8) with rK39-ELISA. Before transplantation, 31 recipients (64.6%, 95%CI: 50.4-76.6) were positive with Lm-ELISA, 5 (10.4%, 95%CI: 4.1-22.6) with rLb6H-ELISA, 1 (2.1%, 95%CI: <0.01-11.9) with rK39-ELISA, and 2 (4.2%, 95%CI: 0.4-14.8) with PCR. At 365 days post-transplant, 35 recipients underwent serological and molecular testing. Of these, 14 (40.0%, 95%CI: 25.5-56.5) tested positive with Lm-ELISA, 4 (11.4%, 95%CI: 3.9-26.5) with rLb6H-ELISA, 0 (0.0%, 95%CI: 0.0-11.8) with rK39-ELISA, and 2 (5.7%, 95%CI: 0.6-19.6) with PCR. Combining serological and molecular methods showed promising potential for early detection and ongoing monitoring of leishmaniasis in kidney transplant recipients and their donors. These findings highlight the urgent need for regulatory measures to implement Leishmania-specific donor screening and recipient monitoring using PCR and targeted serological tests, as well as close observation of signs and symptoms of leishmaniasis.