Evaluación de homogeneidad y estabilidad de anticuerpos IgG anti Trypanosoma Cruzi en muestras de suero sanguíneo empleadas como ítem de ensayo del programa de evaluación externa del desempeño del Tamizaje de la enfermedad de Chagas.

Abstract

Chagas disease is an American continent endemic illness, caused by the protozoan Trypanosoma cruzi. Diagnosis is mainly based upon serologic methodologies such as Chemiluminescent Microparticle Immunoassay (CMIA), which is employed in Costa Rica for donated blood screening. In order to perform a continuous monitoring of blood banks performance, the Chagas Disease Screening Evaluation Program proficiency test has been established. The objective of the present investigation was to assess the homogeneity and stability of proficiency test items according to INTE-ISO/IEC 17043:2010 standard. For that purpose fulfillment, experimental designs and testing methods were carried out following INTE/ISO 13528:2016 standard guidelines. In quantitative terms, it was determined that the analyzed sera had some heterogeneity degree, as well as insufficient stability regarding the analyte of interest which corresponds to IgG class anti-T. cruzi antibodies. Given the qualitative nature of ARCHITECT Chagas immunoassay and the fact that the samples demonstrated no significant reactivity changes, the proficiency test items were accepted as suitable for evaluation of participant performance.