EVALUATION OF THE PERFORMANCE OF A LAMP PROTOTYPE KIT FOR DETECTION OF Trypanosoma cruzi DNA IN CLINICAL SAMPLES

BESUSCHIO, SUSANA A.; WEHRENDT D. P; PICADO DE PUIG, ALBERT; CRUZ MATA, ISRAEL; BENATAR, ALEJANDRO F.; NDUNGU J. M ; SCHIJMAN A. G

Congreso; Reunión Conjunta de Sociedades de Biociencias; 2017

EVALUATION OF THE PERFORMANCE OF ALAMP PROTOTYPE KIT FOR DETECTION OF Trypanosomacruzi DNA IN CLINICAL SAMPLESSusana Alicia Besuschio (1), Diana Patricia Wehrendt (1),Albert Picado (2), Israel Cruz Mata (2), Alejandro FranciscoBenatar (1), Joseph Mathu Ndung?u (2), Alejandro GabrielSchijman (1)(1) LaBMECh -INGEBI -CONICET-Argentina. (2) Foundationfor Innovative New Diagnostics ? Switzerland.The protozoan Trypanosoma cruzi (T. cruzi) causes ChagasDisease (ChD), with 7 million infected people worldwide. Withouttreatment, the disease evolves from an acute phase with nonspecificsymptoms, high parasitaemia and slow seroconversion to achronic phase (CCD), frequently asymptomatic, with low parasitaemiaand serodiagnosis as the gold standard. ImmunocompromisedCCD patients can reactivate (RCD), sometimes with severe clinicalsymptoms. For Congenital Chagas (CI) low cost microscopy, whichlacks sensitivity and is operator-dependent, is routinely employedbecause serodiagnosis is only useful around 10 months of age. RealTime quantitative PCR (qPCR) has been validated for molecular detectionand monitoring of T. cruzi infection, but it must be performedin specialized laboratories. Recent Target Product Profiles for ChDdiagnosis recommended the use of easier methods for point-of-careapplications. The aim of this study was to evaluate a kit prototypebased on Loop mediated isothermal amplification (LAMP) for T.cruziDNA detection in human blood samples. The LAMP prototype containsdried reagents in the caps of microtubes and targets satelliteDNA repeats (Analytical sensitivity=0.1 par. equivalents/mL fromEDTA-blood, extracted using a commercial kit). The reaction is completedin 40 minutes and visualized by naked-eye. LAMP sensitivity(Se) and specificity (Sp) were compared to qPCR in 221 EDTA-bloodsamples from 172 patients of three clinical groups: Congenital (CI),Chronic (CCD) and Reactivated Chagas Disease (RCD). The NonInfected Control group (NIC) included 87 samples, 21 from babies.For the CCD group (n=109), Se was low and Sp was 98.5% (IC0.93-0.99), resembling qPCR results. For RCD (n=26), the Newmartest (p