Detection of cytokines and nitric oxide synthase in skin lesions of Jorge Lobo's disease patients

Studies investigating the immunopathological aspects of Jorge Lobo's disease have shown that the inflammatory infiltrate consists mainly of histiocytes and multinucleated giant cells involving numerous yeast-like cells of Lacazia loboi, with the T lymphocytes more common than B lymphocytes and plasma cells. The quantification of cytokines in peripheral blood mononuclear cells culture supernatant has revealed alterations in the cytokines profile, characterized by predominance of a Th2 profile. In view of these findings and of the role of cytokines in cell interactions, the objective of the present study was to investigate the presence of the cytokines IL-10, TGF-ß1 and TNF-α, as well as iNOS enzyme in granulomas induced by L. loboi. Histological sections obtained from skin lesions of 16 patients were analyzed by immunohistochemistry for the presence of these cytokines and iNOS. The results showed that TGF-ß1 was the cytokine most frequently expressed by cells present in the inflammatory infiltrate, followed by IL-10. There was a minimum to discrete positivity of cells expressing TNF-α and iNOS. The results suggest that the presence of immunosuppressive cytokines in skin lesions of patients with the mycosis might be responsible for the lack of containment of the pathogen as demonstrated by the presence of numerous fungi in the granuloma.

Experimental reproduction of the Jorge Lobos disease in BALB/c mice inoculated with Lacazia loboi obtained from a previously infected mouse

Long-term maintenance of Lacazia loboi in the laboratory has not been reported. We report here the use BALB/c mice to maintain the Lacazia loboi for extended period of time. Eight to ten week-old mice were inoculated intradermally in both hind footpads with a fungal suspension from a macerated footpad obtained from an original mouse previous infected with the fungi and sacrificed 8 months after inoculation. The inoculated animals were sacrificed at different time intervals, footpads were excised, the right one was submitted to histopathological examination and the left one was macerated in sterile saline for fungal count and viability index determination. The inoculated animals presented the histopathological picture identical to the mice previously inoculated with material from human lesion. Granulomatous infiltrates with predominance of macrophages and giant cells were observed. The granulomas evolved progressively as observed in the different times of sacrifice. After 7 months of inoculation, macroscopic lesions were observed, and the number of fungi obtained from macerated footpads was higher than the number of inoculated fungi. The pattern of lesion development was similar to what was observed in animals infected with a fungal suspension obtained from a human lesion. Considering the histopathological findings, the clinical manifestations, and the finding of a higher number of fungi obtained than the inoculated into footpads of each mice, we believe the BALB/c mice strain is as an excellent way to amintain L. loboi in laboratory. Moreover, even after serial passages of the funfi, the granulomatous lesions are reproduced consistently in laboratory conditions.

Blastomycosis: report of three cases from Alberta with a review of Canadian cases

Approximately 120 cases of blastomycosis have been reported from Canada to-date. The great majority of these occurred in the Eastern provinces. Since 1970, three cases of blastomycosis have been seen in Alberta. The first case, with meningeal and pulmonary involvements, was diagnosed at post-mortem. The second case was that of a 75-year-old male with a history of pancytopenia, aortic arteriosclerosis, exposure to mercury, and fever. KOH and periodic-acid schiff (PAS) stained smears of the lung tissue, received after autopsy, showed numerous budding yeast cells of Blastomyces dermatitidis along with some hyphal filaments. Similarly, budding cells of B. dermatitidis and hyphal segments were observed in large numbers in the PAS and Gomori's methenamine-silver (GMS) stained sections made from adrenals, lung, kidney, and spleen tissues. Attempts to culture the fungus on a variety of selective and non-selective media were unsuccessful, due to heavy bacterial contamination. The indirect fluoroscent antibody results were 2+ with the B. dermatitidis conjugate. The third case was that of a 31-year-old male, who was admitted to the hospital with the chief complaint of chest pain. Biopsy tissue sections, stained with the GMS procedure revealed a few foci with B. dermatitidis yeast cells. The immunodiffusion and complement fixation (CF) tests gave positive results against B. dermatitidis antigen (titre, 1:16). The CF titre declined following treatment with amphotericin B and the immunodiffusion test became negative after the institution of antifungal therapy. Except for the last patient, the other two patients had no history of travel in any known endemic areas. In addition to these cases, a survey of blastomycosis occurring in this country has been presented along with on the disease in dogs and a cat.