Leishmania braziliensis-GPI Anchored Membrane Proteins as an Alternative Tool for Specific Sero-Diagnosis of Active American Cutaneous Leishmaniasis

Purified Leishmania braziliensis-GPI-anchored membrane proteins (L. braziliensis-GPI-AMP) were antigenically validated to be proposed as candidate antigens to serologically diagnose American cutaneous leishmaniasis (ACL). Validation was carried out in 140 sera-samples, 71 from patients suffering active ACL previously diagnosed using clinical, parasitological, serological and molecular (Polymerase chain reaction-PCR assay) methods, and 69 from individuals either healthy or suffering from other etiologies in order to estimate its sensitivity and specificity, respectively. The use of the L. braziliensis-GPI-AMP antigen in western blot assays revealed 99% (70/71) sensitivity to detect circulating anti-Leishmania antibodies in sera-samples of the tested patients. The positive reactivity was evidenced by a constant band of 50 kDa molecular mass detected in all the patients suffering ACL. A 100% specificity of the L. braziliensis-GPI-AMP antigen as diagnostic tool was recorded after confirming negative results in all control samples. The obtained values of sensitivity (99%), specificity (100%), positive predictive value (1.00) and negative predictive value (0.99) demonstrated the reliability of the L. braziliensis-GPI-AMP antigen to sero-diagnose ACL. In addition, the constant expression of the 50kDa band, led us to consider it as a biochemical marker capable of producing reliable, sensitive and specific signal to detect active ACL.