Evaluation of Antigens from Various Leishmania Species in a Western Blot for Diagnosis of American Tegumentary Leishmaniasis

A Western blot method that uses antigens from culture promastigote forms of Leishmania (Viannia) braziliensis, L. (Leishmania) amazonensis, L. (Leishmania) tropica, and a trypanosomatid (strain 268T) isolated from naturally infected tomatoes was evaluated for laboratory diagnosis of American tegumentary leishmaniasis (ATL). Serum samples were obtained from 108 patients with ATL (group I), 23 chagasic patients (group II), 32 patients with other diseases (group III), and 78 healthy individuals (group IV). The overall analysis showed a sensitivity of 76.90%, 90.40%, 78.50%, and 87.90%, a specificity of 100%, 93.80%, 87.80%, and 77.10%, a positive predictive value of 100%, 94.00%, 89.50%, and 72.50%, a negative predictive value of 75.70%, 90.00%, 75.40%, and 90.20%, and a concordance coefficient kappa of 0.7358, 0.8400, 0.6491, and 0.6287 for L. (V.) braziliensis, L. (L.) amazonensis, L. (L.) tropica, and strain 268T antigens, respectively. The antigenic profile recognized by serum samples from patients with ATL and with Chagas' disease permits serologic distinction between these infections.