Parasite persistence in treated chagasic patients revealed by xenodiagnosis and polymerase chain reaction

Britto, Constança; Silveira, Celeste Aída Nogueira; Cardoso, Maria Angélica; Marques, Patrícia; Luquetti, Alejandro O.; Macêdo, Vanize; Fernandes, Octávio

doi:10.1590/s0074-02762001000600014

Cited by 57 publications

(48 citation statements)

References 14 publications

(14 reference statements)

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“…Studies carried out on adult persons with chronic T. cruzi infection have shown great differences in the trypanocidal effectiveness and in the progression towards chronic chagasic cardiopathy (CCC) 3,4,6,8,11,24 .…”

Section: Introductionmentioning

confidence: 99%

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Evaluation of the ELISA-F29 test as an early marker of therapeutic efficacy in adults with chronic Chagas disease

Fabbro

Velázquez

Bizai

et al. 2013

Rev. Inst. Med. trop. S. Paulo

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SUMMARYThis work compared the time at which negative seroconversion was detected by conventional serology (CS) and by the ELISA-F29 test on a cohort of chronic chagasic patients treated with nifurtimox or benznidazole. A retrospective study was performed using preserved serum from 66 asymptomatic chagasic adults under clinical supervision, and bi-annual serological examinations over a mean follow-up of 23 years. Twenty nine patients received trypanocide treatment and 37 remained untreated. The ELISA-F29 test used a recombinant antigen which was obtained by expressing the Trypanosoma cruzi flagellar calcium-binding protein gene in Escherichia coli. Among the untreated patients, 36 maintained CS titers. One patient showed a doubtful serology in some check-ups. ELISA-F29 showed constant reactivity in 35 out of 37 patients and was negative for the patient with fluctuating CS. The treated patients were divided into three groups according to the CS titers: in 13 they became negative; in 12 they decreased and in four they remained unchanged. ELISA-F29 was negative for the first two groups. The time at which negativization was detected was significantly lower for the ELISA-F29 test than for CS, 14.5 ± 5.7 and 22 ± 4.9 years respectively. Negative seroconversion was observed in treated patients only. The results obtained confirm that the ELISA-F29 test is useful as an early indicator of negative seroconversion in treated chronic patients.

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Section: Introductionmentioning

confidence: 99%

“…Furthermore, there has been an increase in the use of molecular methods for detecting T. cruzi in blood samples of treated patients 4,7,19,20 .…”

mentioning

confidence: 99%

Evaluation of the ELISA-F29 test as an early marker of therapeutic efficacy in adults with chronic Chagas disease

Fabbro

Velázquez

Bizai

et al. 2013

Rev. Inst. Med. trop. S. Paulo

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“…The persistence of Trypanosoma cruzi tissue form in chronic chagasic patients (CCP) seems to be a common event in the behavior of this organism judging for the detection of the parasite itself, or parts of its genome, in treated and/or untreated long-term infected people (Añez et al, 1999;Britto et al, 2001). This statement is supported by previous reports from experimental hosts or natural infected individuals (Tarleton et al, 1997;Olivares-Villagomez et al, 1998).…”

Section: Introductionmentioning

confidence: 99%

Trypanosoma cruzi persistence at oral inflammatory foci in chronic chagasic patients

et al. 2011

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a b s t r a c tThe persistence of Trypanosoma cruzi in seropositive individuals, previously diagnosed as chronic chagasic patients (CCP), was detected for the first time in biopsies taken from gingival inflammatory foci processed by polymerase chain reaction (PCR). Seven out of 31 (22.5%) gum samples from selected unquestionably CCP showing different degrees of gingival inflammation revealed T. cruzi-DNA using 3 specific PCR assays. All the included CCP had been diagnosed in previous studies carried out over the last 19 years. Samples of inflamed gums were recently taken from the indicated patients at: an outpatient hospital cardiac unit; a village where Chagas disease is endemic; and a specialized diagnostic research center, showing molecular evidence of parasite persistence in 17.6%, 42.8% and 14.3% of them, respectively. The relatively frequent parasite persistence, demonstrated here in oral inflammatory processes of treated and/or untreated patients bearing long term T. cruzi-infection, suggests the establishment of secondary small foci for the maintenance of hidden or inapparent chagasic infection. The easy and low-risk, non-invasive method to get the sample may add the use of gingival biopsy as a potential alternative diagnostic tool to confirm T. cruzi-infection in CCP. The significance of T. cruzi persistence as a primary cause of chronic Chagas disease and the proposal of this mechanism to explain the pathogenesis in CCP are considered.

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“…Also, the polymerase chain reaction (PCR), has been T he disparity in trypanocidal action of available drugs as well as their negative side effects have prompted a search for new compounds with low toxicity and increased efficacy during the chronic phase of Chagas disease (Rodríguez et al, 2002). One of the major challenges regarding the evaluation of treatment effectiveness is the lack of reliable laboratorial approaches for use as tools for cure criteria (Chiari, 1999 used to detect T. cruzi in the blood of chronic chagasic patients (Britto et al, 1995(Britto et al, , 2001Solari et al, 2001). Recently, a strong correlation was reported between positive PCR and the presence of lytic antibodies among chagasic patients, suggesting that PCR could be effective in evaluating parasitological cure in patients who received a specific treatment (Zulantay et al, 2004).…”

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confidence: 99%

Monitoring the efficacy of specific treatment in chronic Chagas disease by polymerase chain reaction and flow cytometry analysis

Sánchez¹,

Coronado²,

Zulantay³

et al. 2005

Parasite

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Summary :PCR and FC-ALTA were used to monitor parasite clearance in 54 chronic chagasic patients who had completed therapy with allopurinol (ALLO, n = 31) or itraconazole (ITRA, n = 23) ten years earlier. All patients maintained positive conventional serology. 25 of them showed positive XD (ALLO, n = 11 and ITRA, n = 14) and 29 negative XD (ALLO, n = 20 and ITRA, n = 9). 43 patients were positive by both techniques (ALLO, n = 23 and ITRA, n = 20). Seven of 54 patients were negative by PCR and positive by FC-ALTA and three of 54 were positive by PCR and negative by FC-ALTA. Only one case with both tests negative should be considered cured. Of 29 patients with negative XD, 14 treated ALLO (70 %) and nine with ITRA (77.8 %) showed positive PCR and FC-ALTA. These results do not show differences of efficacy among the drugs, and reinforce the relevance of using sensitive tools such as PCR and FC-ALTA for the follow-up of patients with chronic Chagas disease. Résumé : ÉVALUATION DE L'EFFICACITÉ DE TRAITEMENTS SPÉCIFIQUES DE LA MALADIE DE CHAGAS PAR PCR ET CYTOMÉTRIE DE FLUX La PCR et la cytométrie de flux (FC-ALTA) ont été employées pour vérifier la guérison de 54 patients infectés par

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Parasite persistence in treated chagasic patients revealed by xenodiagnosis and polymerase chain reaction

Abstract: Polymerase chain reaction (PCR) was compared with xenodiagnosis performed 20 years after try-

Cited by 57 publications

References 14 publications

Evaluation of the ELISA-F29 test as an early marker of therapeutic efficacy in adults with chronic Chagas disease

Evaluation of the ELISA-F29 test as an early marker of therapeutic efficacy in adults with chronic Chagas disease

Trypanosoma cruzi persistence at oral inflammatory foci in chronic chagasic patients

Monitoring the efficacy of specific treatment in chronic Chagas disease by polymerase chain reaction and flow cytometry analysis

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