Immunodiagnosis of Visceral Leishmaniasis: Current Status and Challenges: A Review Article

Background: Diagnosis of Visceral Leishmaniasis (VL) is still challenging. This review highlighted current status and challenges in the serological diagnosis of VL. Furthermore, the drawback of currently available serological tests and the most recent advancement in the designing and application of these assays for the diagnosis of VL are addressed. Methods: All the published literature cited within PubMed, ISI Web of Science, Google Scholar, Scopus, and IranMedex, regarding the immunodiagnosis of VL in human were sought from 2000 till Mar 2017. The search terms were “visceral leishmaniasis”, or “kala-azar" subsequently combined with the search terms "diagnosis", "serodiagnosis", "hum@n", "serological", "antigen detection" or "antibody detection". Data were extracted from literature which fulfilled our eligibility criteria. Results: Direct agglutination test (DAT) and rk39 dipstick have made a great improvement in the serological diagnosis of VL. Besides, other kinesin-related protein including K26, K28, and KE16 provided promisingly diagnostic accuracy in the diagnosis of VL. The Latex Agglutination Test for the diagnosis of VL (KAtex), with moderate sensitivity but high specificity, made a substantial contribution to the field. Moreover, a range of protein antigens has recently been detected in the urine of VL patients with encouraging diagnostic value. Conclusion: The suboptimal diagnostic accuracy of the currently available serological assays for the diagnosis of human VL necessitates further research and development in this field. Outcomes of immunodiagnostic tests based on recombinant antigens are favorable. These proteins might be the most appropriate antigens to be further evaluated and utilized for the diagnosis of human VL.