A Capture ELISA for the Diagnosis of Visceral Leishmaniasis Using a Monoclonal Antibody against a Leishmanial Urinary Antigen

A capture ELISA system was developed for diagnosis of visceral leishmaniasis (VL) using a monoclonal antibody raised against an antigen previously detected in the urine of VL patients. Urine samples from confirmed VL cases from Yemen, Nepal, Spain, Sudan and Brazil were tested in the capture ELISA in comparison with urine samples from endemic and non-endemic areas along with urine samples from patients with malaria, brucellosis, schistosomiasis and patients with non-infectious diseases. All of VL patient samples from different geographical areas (apart from 2 samples from Brazil) gave a positive result, while no cross-reaction was found with the control samples. The results obtained with the capture-ELISA were compared to those obtained with KAtex, a previously described latex agglutination test, showed that the KAtex and the new ELISA are comparable in terms of specificity (100%) but a better sensitivity (94.1%) was found for the capture-ELISA. Moreover, the capture-ELISA adds a useful quantitative dimension to antigen detection. In addition, the boiling of urine samples, which is necessary for KAtex, was not required in the capture-ELISA. These results suggest that the antigen detection in urine by the new capture ELISA system provides a useful method for diagnosis of VL and fulfils the requirements of a non-invasive method for diagnosis of VL. Iran. Biomed. J. 9 (3): 117-122, 2005