Unusual Clinical Manifestations of Leishmania (L.) infantum chagasi in an HIV-coinfected Patient and the Relevance of ITS1-PCR-RFLP: A Case Report

Patients coinfected with Leishmania/HIV can develop atypical forms of visceral leishmaniasis (VL), making it indispensable to identify the etiological agent. We are presenting a post-mortem specie definition by ITS1-PCR-RFLP in a larynx tissue of a patient presented coinfection Leishmania/HIV. This patient was from a leishmaniasis endemic region in São Paulo (SP), Brazil, and was diagnosed clinically with mucocutaneous leishmaniasis. Before a rK39 immunochromatographic test positive, a tiny stored paraffin-embedded larynx tissue was obtained post-mortem and submitted to 3 conventional PCR assays: kDNA (K20/K22 and RV1/RV2), and ITS1 (LITSR/L5.8S). The last one was followed by RFLP (HaeIII) and analyzed by 4% Metaphor agarose gel electrophoresis. Leishmania genus and Leishmania (Leishmania) subgenus were defined by kDNA-PCR, with K20/K22 (120 bp) and RV1/RV2 (145 bp), respectively. ITS1-PCR-RFLP identified L. (L.) infantum chagasi species visualized by the restriction patterns of 180, 70 and 50 bp. This case draws attention to the necessity for a clear identification of the etiological agent causing infection, especially in endemic regions of cutaneous and visceral leishmaniasis, and particularly in patients with comorbidities who often present atypical forms of the disease. L. (L.) infantum chagasi, which is usually responsible for VL, had changed its clinical spectrum for mucocutaneous. Unequivocal identification was carried out by ITS-PCR-RFLP, therefore confirming rK39 result. These techniques, which complemented each other, have a convenient cost-benefit ratio that makes them suitable to be applied in developing countries.