Real-time PCR in HIV/Trypanosoma cruzi coinfection with and without Chagas disease reactivation: Association with HIV viral load and CD4+ level

Background: reactivation of chronic chagas disease,which occurs in approximately 20% of patients coinfected with hiv/trypanosoma cruzi (t. cruzi),is commonly characterized by severe meningoencephalitis and myocarditis. the use of quantitative molecular tests to monitor chagas disease reactivation was analyzed. methodology: polymerase chain reaction (pcr) of kdna sequences,competitive (c-) pcr and real-time quantitative (q) pcr were compared with blood cultures and xenodiagnosis in samples from 91 patients (57 patients with chronic chagas disease and 34 with hiv/t. cruzi coinfection),of whom 5 had reactivation of chagas disease and 29 did not. principal findings: qrt-pcr showed significant differences between groups; the highest parasitemia was observed in patients infected with hiv/t. cruzi with chagas disease reactivation (median 1428.90 t. cruzi/ml),followed by patients with hiv/t. cruzi infection without reactivation (median 1.57 t. cruzi/ml) and patients with chagas disease without hiv (median 0.00 t. cruzi/ml). spearman's correlation coefficient showed that xenodiagnosis was correlated with blood culture,c-pcr and qrt-pcr. a stronger spearman correlation index was found between c-pcr and qrt-pcr,the number of parasites and the hiv viral load,expressed as the number of cd4+ cells or the cd4+/cd8+ ratio. conclusions: qrt-pcr distinguished the groups of hiv/t. cruzi coinfected patients with and without reactivation. therefore,this new method of qrt-pcr is proposed as a tool for prospective studies to analyze the importance of parasitemia (persistent and/or increased) as a criterion for recommending pre-emptive therapy in patients with chronic chagas disease with hiv infection or immunosuppression. as seen in this study,an increase in hiv viral load and decreases in the number of cd4+ cells/mm3 and the cd4+/cd8+ ratio were identified as cofactors for increased parasitemia that can be used to target the introduction of early,pre-emptive therapy. © 2011 de freitas et al.