Molecular tools for understanding Trypanosoma cruzi reactivation and follow up during tripanocidal treatment in HIV coinfected patients

DIEGO NICITA; ALEJANDRO BENATAR; JUAN M. BURGOS; MARISA FERNANDEZ; ANALIA BOSCHI; ALEJANDRO G. SCHIJMAN; SUSANA BESUSCHIO; MARCELO CORTI

Maceio

Congreso; 52 congresso da sociedade brasileira de medicina tropical; 2016

Chagas disease reactivation is an AIDS defined illness. Standard T.cruzireactivation diagnosis is based on direct observation methods. Thisdiagnosis is usually belated and it is supposed to be a reason for bad prognosison this opportunistic infection.We included 3 patients with diagnosis ofHIV/AIDS disease (without antiretroviral treatment, CD4+ Tcell count were 7-25cel/mm3), chronic T.cruzi infection, and neurologicaldisorders. Real-Time PCRs against T.cruzi satellite DNA were carried outfrom cerebrospinal fluid (CSF) and peripheral blood samples (Bs) before thebeginning of parasitological treatment (pTtm) and during follow up. Molecularcharacterization of parasites was based on amplification of nuclear sequences.Two patients started pTtm after microscopical detection of trypomastigoteforms in the CSF samples. The thirdone started empiric pTtm. CSF-based parasitic loads were higher (3.5, 4.3 log parasite-equivalents/ml) than thosefound in Bs of the respective patients (0.3, 2.09, 2.15 log p-e/ml) withdrawn at the same day.Parasite DNA in Bs (DNAemia) became undetectable in all patients from the 4thto 6th day of pTtm, remaining undetectable until patients death20-40 days later. Interestingly, a CSF sample showed the highest parasitic loadafter 7 days of pTtm in the patient with bloodstream clearance at the 4thday onwards. The patient with the lowest DNAemia was the one with CSF negativefindings. Results suggest that DNAemia could beassociated to CSF parasite colonization. CSF-basedparasitic loads are higher than bloodstream ones. Moreover, during pTtm DNAemiaturned negative but CSF-based parasitic load increased; this could be due tothe drug difficulty to reach CNS, unknown drugs interactions withbenznidazole, parasite tropism for CNS, or aggregatinginfections (Criptococcus neoformans in last patient). All characterized parasites belonged to V and/or VI T.cruzi Discrete Typing Units, frequentlyfound in patients of this geographic region.