Foxp3 expression in lesions of the different clinical forms of American tegumentary leishmaniasis.

As the diversity in clinical presentation of American tegumentary leishmaniasis (ATL) is determined mainly by the immune response of host, our aim was to evaluate the in situ expression of Foxp3 [marker of regulatory T (Treg) cell] in lesions of the different clinical forms of ATL. Foxp3(+) cells were observed in 39.5% (32/81) of the samples and the number of positive cells was low in all the clinical forms. Even presenting a significantly lower number of CD4(+) T cells, diffuse cutaneous leishmaniasis (DCL) showed a higher expression of Foxp3 when compared with localized cutaneous leishmaniasis (LCL) and mucocutaneous leishmaniasis (MCL). In LCL and MCL, the number of Foxp3(+) cells correlated positively with the number of apoptotic cells (active caspase-3(+) cells). A positive correlation was also observed between the expression of active caspase-3 and FasL in these clinical forms. Our data suggest that increased number of Treg cells may be associated to the hyporesponsiveness observed in DCL and also indicate that the apoptosis may be a possible mechanism of action of Foxp3(+) Treg cell in LCL and MCL. However, further studies are required to better understand the mechanism of action of Treg cell.

[Evaluation of secondary bacterial infection's influence on the course of cutaneous leishmaniasis in Corte de Pedra, Bahia]. / Avaliação da influência da infecção bacteriana secundária na evolução da leishmaniose cutânea em Corte de Pedra, Bahia.

In order to study the prevalence of secondary bacterial infection in ulcerated lesions and its relationship to the healing process, 84 leishmaniotic patients were evaluated. Diagnosis of the secondary infection was made by bacterial aerobic culture of peripheral tissue specimen of the ulcer. All patients received antimonial therapy during 20 days and washed their ulcers with common soap. Cases were composed mainly of adolescent and adult farmer patients with single lesions. The evaluated ulcers were encountered on legs and feet in 47.6%. Secondary bacterial infection was found in 45/83 (54.2%), and was more frequent in lesions located below the knee. Staphylococcus aureus predominated (89%). The ulcers' healing process, evaluated in 79 patients one month after finishing treatment, was not influenced by the secondary bacterial infection.

Histological analysis and the pathogenesis of mucocutaneous leishmaniasis.

A series of over 400 well-documented biopsies of mucocutaneous leishmaniasis was evaluated to elucidate the histological processes associated with the elimination of parasites, and their correlation with the course of the disease. Non-specific inflammation was the most frequent and least effective response; its onset might be delayed, and in this event particularly the incidence of metastasis from skin to mucosa was high. Lysis of parasite-laden macrophages appeared to be the basic mechanism of parasite reduction, even when it was not overt. When it was acute the onset was usually rapid, and though it resulted in much tissue destruction the prognosis was generally better and mucosal metastasis rare. Lysis and non-specific inflammation both led to the formation of a post-necrotic type of granuloma, but reversion of the process was almost as common as progression. Ultimately a tuberculoid granuloma evolved and proceeded to resolution. In about 5 per cent of cases, macrophage activation appeared to bring about early resolution; neither reversion nor mucosal metastasis was seen.

Mucosal leishmaniasis in Brazil.

The clinical diagnosis and laboratory identification of Leishmania braziliensis braziliensis, a parasitic disease affecting the upper aerodigestive tract, is difficult. A retrospective computer-assisted analysis of patient records was done after examination of 58 patients with mucosal leishmaniasis in an endemic area of L. braziliensis braziliensis in Bahia, Brazil during January 1987. Biopsies of clinically active and clinically inactive mucosal patients were examined for parasites using routine hematoxylin and eosin histopathology and a new technique for rapid detection of Leishmania amastigotes using a genus-specific indirect immunofluorescent assay. No amastigotes were found in specimens from seven patients with clinically inactive mucosal disease using immunofluorescent monoclonal assay techniques, whereas specimens from seven out of 14 patients with clinically active mucosal disease were positive. These results suggest that the immunofluorescent antibody technique is markedly superior in identifying the intracellular amastigote in tissue sections of mucosal biopsies when compared to histopathology techniques or with other standard tests done in rural areas of Brazil. Various clinical and laboratory test data of the entire group of patients were examined and the efficacy of treatment evaluated. The median interval of time noted between cutaneous and mucosal disease was 4.5 years. Relapse was noted in 31% of patients treated with a low dose of meglumine antimoniate (10 mg per kg of body weight). Patients treated with a high dose of meglumine antimoniate (20 mg per kg of body weight) had a relapse rate of 27.3%. A chi-square statistical analysis revealed no significant difference (chi 2 = 0.049) between the two groups. Patients were considered cured if mucosal granulations were clinically absent after 4.6 years.