RAPID DIAGNOSIS OF INDIAN VISCERAL LEISHMANIASIS USING ACHATININ(H), A 9-O-ACETYLATED SIALIC-ACID BINDING LECTIN

We have developed a rapid, accurate, and inexpensive hemagglutination assay (HA) for diagnosis of Indian visceral leishmaniasis (VL) using a chatinin(H), a 9-O-acetylated sialic acid binding lectin. The assay is based on the selective binding of achatinin(H) to 9-O-acetylated deri vatives of sialic acid (9-O-AcSA), which appears exclusively on the er ythrocytes of patients with VL. Blood samples from 35 patients with de monstrable splenic or bone marrow amastigotes were assayed by HA and c ompared with an ELISA. All cases were correctly diagnosed by HA, and w ere in concordance with the ELISA. The increase in 9-O-AcSA ws corrobo rated by direct fluorimetric estimation of sialic acid and its 9-O-ace tylated derivative. Therefore, 9-O-acetylated derivatives of sialic ac id, absent in normal erythrocytes, serve as an important biomarker, an d indirectly reflect the presence of the parasite. Accordingly, this a ssay can be used for detection of active kala-azar cases and merits cl inical consideration.