Dynamics of the antibody response in patients with therapeutic or spontaneous cure of American cutaneous leishmaniasis

The antigen specificity and the level of the antibody response were analyse d in Perambuco Stare, Brazil, in sera collected in 1995-96 from 58 patients with clinical American cutaneous leishmaniasis (ACL), 25 ACL patients with apparent cure after chemotherapy with meglumine antimonate, and 10 ACL pat ients with spontaneous cure. Assessment was by immunoblot analysis, ELISA a nd indirect immunofluorescence, with Leishmania (Viannia) braziliensis anti gens, with a particular interest in evaluating whether the dynamics of the antibody response could be useful to monitor clinical cure. A clear decreas e of IgG antibody reactivity was noticed after clinical healing, for all of the antigens analysed, with the exception of the 19 kDa antigen, whose rec ognition frequency in fact increased in the spontaneously cured patients, s uggesting that this antigen may play a role in protective immunity against cutaneous leishmaniasis. The recognition frequencies of the most frequently recognized antigens (27 and 30 kDa antigens) diminished approximately 2-fo ld in patients clinically healed, suggesting that they could be useful as a marker of cure of ACL. In addition, some of the healthy individuals living in endemic areas presented the same immunoblotting pattern of reactivity o bserved in active ACL, possibly representing asymptomatically infected indi viduals.