Serodiagnosis of Leishmania donovani infections: assessment of enzyme-linked immunosorbent assays using recombinant L-donovani gene B protein (GBP) and a peptide sequence of L-donovani GBP

The repetitive sequence of Leishmania major gene B protein (GBP) has previo usly been shown to be a useful tool in the diagnosis of cutaneous leishmani asis (CL). Here, we have assessed enzyme-linked immunosorbent assays (ELISA s) using recombinant L. donovani GBP (rGBP) and a peptide sequence of L. do novani GBP (GBPP) in the diagnosis of L, donovani infections in Sudan. The sensitivity of the rGBP ELISA in diagnosing visceral leishmaniasis (VL) and post kala-azar dermal leishmaniasis (PKDL) was 92% and 93%, respectively. In contrast, the sensitivity of the GBPP ELISA was 55% for VL and 63% for P KDL. Plasma antibody reactivity of donors with VL and PKDL remained high fo r an extended period after the end of treatment. Antibody-reactivity to rGB P and GBPP was detected in 71% and 14% of plasma samples from CL patients, respectively. Plasma from healthy Sudanese donors living in an area endemic for malaria but free of leishmaniasis was negative in both assays.