Molecular evaluation of Chagas disease reactivation and treatment follow-up in HIV coinfected patients

Abstract

Background: Chagas disease reactivation is an AIDS defined illness that usually affects Central Nervous System. Gold-Standard diagnosis for T.cruzi reactivation is based on microscopical observation methods.Methods & Materials: Seven patients with HIV/AIDS diagnosis, T.cruzi serological findings, neurological disorders, and suspected of Chagas disease reactivation were included between 2015?2017 from two health centers of Buenos Aires, Argentina. Real-time PCRs (qPCR) against T.cruzi satellite DNA were carried out from cerebrospinal fluid (CSF) and peripheral blood samples (BS) for parasite load quantification. Molecular parasite characterization was based on amplification of spliced leader intergenic region, 24 srDNA, and A10 polymorphic sequences.Results: Patients were aged from 41 to 69 years old, 43% were women, CD4+ T cell counts were between 7 and 53 cell/mm3. All of them received tripanocidal treatment (TrypT).Five CSFs were withdrawn before TrypT starting. Two had microscopical detection of trypomastigote forms (MDTryp) and quantification over 500 p.e/mL by qPCR. The other 3 CSF samples were non-detectable by both methods. The remaining two patients CSF were obtained after starting TrypT with MDTryp negative findings but qPCR positive results with parasite burden below 13 p.e/mL.Among the 3 patients with negative CSF findings, 2 had positive MDTryp on BS with 119 and 3512 p.e/mL. The third was negative by MDTryp and had 2 p.e/mL before TrypT.All patients had qPCR positive findings on BS (2 -1426 p.e/mL) and decreased their parasitic loads during TrypT.All characterized parasites from BS and CSF samples belonged to DTU (Discrete Typing Unit) II, V or VI, frequently found in Southern Cone region.Out of this small series, 4 patients died: 2 because of brain ?Chagoma?, 1 due to status epilepticus and 1 due to acute abdomen. Two of the 3 survivors were those with negative CSF findings for both methods.Conclusion: Chagas disease reactivation occurred on deep inmunosupressed HIV people. Its diagnosis by MDTryp and qPCR is complementary. qPCR detected T.cruzi DNA on negative MDTryp findings even during treatment. TrypT always reduces T.cruzi DNA loads. qPCR might be an useful therapeutical marker.