Real-Time PCR for the Evaluation of Treatment Response in Clinical Trials of Adult Chronic Chagas Disease: Usefulness of Serial Blood Sampling and qPCR Replicates

Hdl Handle:
http://hdl.handle.net/10144/619323
Title:
Real-Time PCR for the Evaluation of Treatment Response in Clinical Trials of Adult Chronic Chagas Disease: Usefulness of Serial Blood Sampling and qPCR Replicates
Authors:
Parrado, R; Ramirez, JC; de la Barra, A; Alonso-Vega, C; Juiz, N; Ortiz, L; Illanes, D; Torrico, F; Gascon, J; Alves, F; Flevaud, L; Garcia, L; Schijman, AG; Ribeiro, I
Journal:
Antimicrobial Agents and Chemotherapy
Abstract:
This work evaluated a serial blood sampling procedure to enhance the sensitivity of duplex real-time PCR (qPCR) for baseline detection and quantification of parasitic loads and post-treatment identification of failure in the context of clinical trials for treatment of chronic Chagas disease, namely DNDi-CH-E1224-001 (NCT01489228) and MSF-DNDi PCR sampling optimization study (NCT01678599). Patients from Cochabamba (N= 294), Tarija (N= 257), and Aiquile (N= 220) were enrolled. Three serial blood samples were collected at each time-point and qPCR triplicates were tested per sample. The first two samples were collected during the same day and the third one seven days later.A patient was considered PCR positive if at least one qPCR replicate was detectable. Cumulative results of multiple samples and qPCR replicates enhanced the proportion of pre-treatment sample positivity from 54.8 to 76.2%, 59.5 to 77.8%, and 73.5 to 90.2% in Cochabamba, Tarija, and Aiquile cohorts, respectively. This strategy increased the detection of treatment failure from 72.9 to 91.7%, 77.8 to 88.9%, and 42.9 to 69.1% for E1224 low, short, and high dosage regimens, respectively; and from 4.6 to 15.9% and 9.5 to 32.1% for the benznidazole arm in the DNDi-CH-E1224-001 and MSF-DNDi studies, respectively. The addition of the third blood sample and third qPCR replicate in patients with non-detectable PCR results in the first two samples, gave a small, non-statistically significant improvement in qPCR positivity. No change in clinical sensitivity was seen with a blood volume increase from 5 to 10 ml. The monitoring of patients treated with placebo in the DNDi-CH-E1224-001 trial revealed fluctuations in parasitic loads and occasional non-detectable results. In conclusion, serial sampling strategy enhanced PCR sensitivity to detecting treatment failure during follow-up and has the potential for improving recruitment capacity in Chagas disease trials, which require an initial positive qPCR result for patient admission.
Publisher:
American Society for Microbiology
Issue Date:
3-Dec-2018
URI:
http://hdl.handle.net/10144/619323
DOI:
10.1128/AAC.01191-18
PubMed ID:
30509941
Submitted date:
2018-12-10
Language:
en
ISSN:
1098-6596
Appears in Collections:
Other Diseases

Full metadata record

DC FieldValue Language
dc.contributor.authorParrado, Ren
dc.contributor.authorRamirez, JCen
dc.contributor.authorde la Barra, Aen
dc.contributor.authorAlonso-Vega, Cen
dc.contributor.authorJuiz, Nen
dc.contributor.authorOrtiz, Len
dc.contributor.authorIllanes, Den
dc.contributor.authorTorrico, Fen
dc.contributor.authorGascon, Jen
dc.contributor.authorAlves, Fen
dc.contributor.authorFlevaud, Len
dc.contributor.authorGarcia, Len
dc.contributor.authorSchijman, AGen
dc.contributor.authorRibeiro, Ien
dc.date.accessioned2018-12-17T18:15:50Z-
dc.date.available2018-12-17T18:15:50Z-
dc.date.issued2018-12-03-
dc.date.submitted2018-12-10-
dc.identifier.citationReal-Time PCR for the Evaluation of Treatment Response in Clinical Trials of Adult Chronic Chagas Disease: Usefulness of Serial Blood Sampling and qPCR Replicates. 2018 Antimicrob. Agents Chemother.en
dc.identifier.issn1098-6596-
dc.identifier.pmid30509941-
dc.identifier.doi10.1128/AAC.01191-18-
dc.identifier.urihttp://hdl.handle.net/10144/619323-
dc.description.abstractThis work evaluated a serial blood sampling procedure to enhance the sensitivity of duplex real-time PCR (qPCR) for baseline detection and quantification of parasitic loads and post-treatment identification of failure in the context of clinical trials for treatment of chronic Chagas disease, namely DNDi-CH-E1224-001 (NCT01489228) and MSF-DNDi PCR sampling optimization study (NCT01678599). Patients from Cochabamba (N= 294), Tarija (N= 257), and Aiquile (N= 220) were enrolled. Three serial blood samples were collected at each time-point and qPCR triplicates were tested per sample. The first two samples were collected during the same day and the third one seven days later.A patient was considered PCR positive if at least one qPCR replicate was detectable. Cumulative results of multiple samples and qPCR replicates enhanced the proportion of pre-treatment sample positivity from 54.8 to 76.2%, 59.5 to 77.8%, and 73.5 to 90.2% in Cochabamba, Tarija, and Aiquile cohorts, respectively. This strategy increased the detection of treatment failure from 72.9 to 91.7%, 77.8 to 88.9%, and 42.9 to 69.1% for E1224 low, short, and high dosage regimens, respectively; and from 4.6 to 15.9% and 9.5 to 32.1% for the benznidazole arm in the DNDi-CH-E1224-001 and MSF-DNDi studies, respectively. The addition of the third blood sample and third qPCR replicate in patients with non-detectable PCR results in the first two samples, gave a small, non-statistically significant improvement in qPCR positivity. No change in clinical sensitivity was seen with a blood volume increase from 5 to 10 ml. The monitoring of patients treated with placebo in the DNDi-CH-E1224-001 trial revealed fluctuations in parasitic loads and occasional non-detectable results. In conclusion, serial sampling strategy enhanced PCR sensitivity to detecting treatment failure during follow-up and has the potential for improving recruitment capacity in Chagas disease trials, which require an initial positive qPCR result for patient admission.en
dc.language.isoenen
dc.publisherAmerican Society for Microbiologyen
dc.rightsPublished by American Society for Microbiology Archived on this site with permission and copyright by the American Society for Microbiologyen
dc.titleReal-Time PCR for the Evaluation of Treatment Response in Clinical Trials of Adult Chronic Chagas Disease: Usefulness of Serial Blood Sampling and qPCR Replicatesen
dc.identifier.journalAntimicrobial Agents and Chemotherapyen

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