Molecular and Immunological Characterization of Cutaneous Leishmaniasis in Giad area, Al Gezira state/Sudan

Abstract

The characteristics form of cutaneous leishmaniasis in the old world is the oriental sore. The causative organisms are leishmania tropica (L.tropica), leishmania major (L. major) and leishmania aethiopicain (L.aethiopicain) in different parts of Orient and Africa. The aim of this study is to investigat the situation of cutaneous leishmaniasis (CL) in Giad area, using immunological and molecular methods. The study was conducted in Giad industrial city located in Al-Gezira state on the western bank of the Blue Nile. Fifty six patients with suspected CL were enrolled in this study, Fourty eight from them, had healed scar and eight have active lesion. Tissue samples from suspected CL lesions were collected and smears were made on slides. Fingerprick blood samples were also collected on Whatmann filterpaper. In the present study, investigation of Sandflies species, the vector of leishmaniasis was carried out using indoor spraying. Investigation of CL from active lesions by direct microscopy showed no Leishmania parasite in slit smear. A species- specific polymerase chain reaction (PCR) assay was also conducted to amplify DNA sequence of leishmania parasite, from both human and sandfly. Negative results have also been obtained indicating the absence of the parasite in lesions and peripheral blood of participants. The frequencies of human IL-4RP2 alleles (183 bp, 253 bp and 123 bp) were also investigated in this study and the results showed 0.92, 0.58 and 0.02 respectively and the heterozygosity of (183) bp and (253) bp is 0.39 Leishmanin skin test was applied in theis study to school children in Giad area to investigate the antibody response. The results showed 54.7%, positive on and leishmanin rate increased with age and it was statistically significant, (p = 0.00 < 0.05). The present study is first study that show antibody response to CL infection. The direct agglutination test assay (DAT) was applied to blood samples using the L.major and L.donovani fixation antigen. The mean of antibody levels has been higher with L.major antigen than L.donovani antigen and the difference is significant, (p = 0.01 <0.05). The mean of levels of antibody has been higher in females compared to males. In addition, the range of age groups between 11 – 30 years has been shown a higher mean of DAT levels than other age groups. The enzyme linked immunosorbent assay (ELISA) using L.major crude parasite antigen. The mean of anti L.major IgG concentration was 9606.932 IU/ml. Anti-L.major IgG level showed almost a liner increase with age in patients lower than 20 years. However, it is stable in all age groups, and highest in 20-30 years. The level of the mean of anti-L.major IgG concentration is the same in males and females, and statistically is not significant (p= 0.9). The mean of the antibodies and anti L.major IgG levels has been higher in patients with scars more than those with skin lesions patients and this was statistically significant with DAT using L.major antigen (p = 0.033), DAT using L.donovani antigen (p = 0.00) and ELISA (p = 0.032).