Humoral immune responses among mucosal and cutaneous leishmaniasis patients caused by Leishmania braziliensis

Mucosal leishmaniasis is arguably the most morbid sequelae of cutaneous lei shmaniasis. The importance of early diagnosis for effective therapy, couple d with the difficulty of diagnosing the disease parasitologically, prompted this investigation of humoral immune markers of mucosal disease. Promastig ote soluble antigens of Leishmania braziliensis, isolated from cutaneous an d mucosal lesions, were separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis; antigens were identified by immunoblotting with parasi te-specific IgG antibody-positive sera of patients with mucosal disease (n = 18) and cutaneous disease (n = 23). For antigens of the cutaneous parasit e WR 2095, mucosal sera generally reacted intensely to antigens of 75, 66, and 45 kDa and weakly to 48-50-kDa antigens, whereas cutaneous sera general ly detected weakly the first 3 antigens and intensely the latter doubler. T he data suggest that the transition from the cutaneous antigenic profile to a mucosal antigenic profile could be used to predict mucosal disease in ap proximately half of mucosal patients. An additional finding was that antibo dies present in the sera of patients with mucosal disease labeled a 66-kDa peptide of normal human lip mucosa more intensely than did cutaneous sera. Autoimmune processes stimulated by the reaction of IgG, originally directed against the 66-kDa of L. braziliensis, to the 66-kDa antigen of mucosal ti ssue may contribute to the clinical presentation of mucosal leishmaniasis.