Serodiagnosis of anthroponotic cutaneous leishmaniasis (ACL) caused by Leishmania tropica in Sanliurfa Province, Turkey, where ACL Is highly endemic

Abstract

In this study, we aimed to evaluate the validity of the conventional enzyme-linked immunosorbent assay (ELISA) and the Western blotting test for the diagnosis of anthroponotic cutaneous leishmaniasis (ACL) using serum samples obtained from 51 patients with parasitologically proven nontreated CL (NonT-CL patients) and 62 patients under treatment for CL (UT-CL patients). Additionally, 29 serum samples obtained from patients with parasitologically and serologically proven visceral leishmaniasis (VL) were also used as positive controls, and serum samples from 43 blood donors were used as negative controls. All sera were diluted to the same dilution (1/100). Leishmania infantum MON-1 was used as the antigen in the conventional ELISA. The sera of 27 (93.1%) of 29 VL patients were seropositive by ELISA, while the sera of 40 (78.4%) of 51 NonT-CL patients and 43 (69.3%) of 62 UT-CL patients were seropositive by the conventional ELISA. The absorbance values of the CL patients' sera were significantly lower than the absorbance values of the VL patients' sera. Bands between 15 and 118 kDa were detected in two groups of CL patients. Among all bands, the 63-kDa band was found to be more sensitive (88.5%). When we evaluated the Western blotting results for the presence of at least one of the diagnostic antigenic bands, the sensitivity was calculated to be 99.1%. By using serological tests, a measurable antibody response was detected in most of the CL patients in Sanliurfa, Turkey. It is also noted that this response can be changed according to the sizes, types, and numbers of lesions that the patient has. The Western blot test was found to be more sensitive and valid than the conventional ELISA for the serodiagnosis of ACL. In some instances, when it is very difficult to demonstrate the presence of parasites in the smears, immunodiagnosis can be a valuable alternative for the diagnosis of ACL.

FIG. 1.

Mean ELISA absorbance values with 95% confidence intervals observed for sera from different groups.

FIG. 2.

Frequency of recognition of the diagnostic bands in human sera obtained from ACL and VL patients and the control group.

FIG. 3.

WB analysis of SDS-polyacrylamide gels of promastigote forms of the Leishmania infantum strain recognized by serum samples from patients with CL and VL and from negative controls. MW, molecular weight markers.