Background

PCR-based approaches targeting kinetoplast DNA were evaluated for the diagnosis of American cutaneous leishmaniasis (ACL) in regions of endemicity in northeastern Brazil. A total of 119 cutaneous biopsy specimens from patients with ACL and nonleishmaniasis cutaneous lesions were studied. Two PCR-based systems were used; one was specific for the subgenus Viannia, and the other was specific for the genus Leishmania. The PCR specific for the subgenus Viannia had a sensitivity of 95.4%, whereas the genus-specific PCR detected the target DNA in 88.2% of the samples tested. The specificities of the assays, determined with samples from a group with nonleishmaniasis cutaneous lesions, was 100%. The results of the conventional tests indicate that the sensitivities of the PCR-based methods were significantly higher than those of smear examination, histological staining, and isolation by culture (P < 0.05). Antibodies specific for Leishmania braziliensis were detected by indirect immunofluorescence in 82.9% of the patients tested. Parasites were isolated from 40 of 86 patients (46.5%). Sixty-seven percent of dermal scrapings and 66.2% of stained tissue sections were positive by microscopy. Amplified products from the subgenus-specific PCR hybridized with the Leishmania panamensis minicircle, confirming infection consistent with L. braziliensis. The evidence available at present incriminates L. braziliensis as the only causative agent of ACL in the state of Pernambuco in Brazil.

The antigen specificity and the level of the antibody response were analysed in Perambuco State, 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 patients with spontaneous cure. Assessment was by immunoblot analysis, ELISA and indirect immunofluorescence, with Leishmania (Viannia) braziliensis antigens, with a particular interest in evaluating whether the dynamics of the antibody response could be useful to monitor clinical cure. A clear decrease of IgG antibody reactivity was noticed after clinical healing, for all of the antigens analysed, with the exception of the 19 kDa antigen, whose recognition frequency in fact increased in the spontaneously cured patients, suggesting 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-fold 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 observed in active ACL, possibly representing asymptomatically infected individuals.

The antibody response in patients with American cutaneous leishmaniasis was analyzed by immunoblotting with soluble and insoluble antigens of Leishmania braziliensis. The recognition of the 27-and/or 30-kDa soluble antigens was considered relevant for the diagnosis of cutaneous leishmaniasis. Immunoblotting was found to be significantly more sensitive and specific than indirect immunofluorescence and enzyme-linked immunosorbent assay.

A case of phaeohyphomycosis with subcutaneous abscesses involving skin, muscle and bone was caused by Exophiala spinifera. This is the first report of E. spinifera causing bone degeneration in Recife-PE, Brazil.