Immunochemical study of a Paracoccidioides brasiliensis polysaccharide-like antigen.

The polysaccharide antigen from P. brasiliensis has been largely employed in serologic tests ,as well as in skin tests, to evaluate cellular immunity. SDS-PAGE analysis of this antigen has revealed a variability in the number of bands exhibited by isolates SN, 265, 339, 113, and 18 (7 to 16 bands). The antigens obtained from isolates 2, PTL, 192 and Adel showed two or three bands. Glycoprotein analysis demonstrated a broad region between 50 and 90 kDa. Major bands of 48 and 30 kDa were present in almost all antigens. Optimal complement fixing dilution appears to be unaffected by the number of bands presented by different antigens. The immunoblot analysis revealed that the 90 and 30 kDa bands were mainly recognized by sera from paracoccidioidomycosis patients. Bands of high molecular weight were also recognized by most of the sera studied. Sera from histoplasmosis recognized the 94 kDa band. In conclusion, although the isolates exhibit quantitative variability in the number of fractions, it is possible to use only one or two samples given the greatest frequency of reactivity is seen in the 30 and 90 kDa fractions.

Severe acute paracoccidioidomycosis in children.

This report describes clinical and immunologic features of five illustrative cases of paracoccidioidomycosis in previously healthy children. All had disseminated disease and two of them died despite treatment. The major clinical presentation in four patients was fever and diffuse superficial and intraabdominal adenopathy, with or without hepatosplenomegaly. Other sites were also affected: three patients had multiple osteoarticular lesions, occasionally with intense tissue destruction; two had cutaneous eruptions; two had pericardial effusions; and two had pulmonary involvement, once considered an organ spared in the young. We detected variable lymphocyte responses to mitogens and to Candida albicans antigen and non-responsiveness to Paracoccidioides brasiliensis cell wall antigen. High concentrations of serum immunoglobulins and anti-P. brasiliensis antibodies were present. These immune alterations tended to resolve with treatment, suggesting a reversible nature of the immune defect. We conclude that this mycosis has a high morbidity and mortality in children, which is probably related to an antigen-specific immunodeficiency. Further studies are needed to increase knowledge of this mycosis in children.

Immunodeficiency secondary to juvenile paracoccidioidomycosis: associated infections.

Four patients with acute paracoccidioidomycosis, hypoalbuminemia, ascites and associated infections are reported. They have been admitted to hospital 35 times, 4 of them due to active paracoccidioidomycosis, 14 to associated infections, 14 to ascites, edema and diarrhoea and 3 to herniorrhaphy. Two of them recovered after sepsis and central nervous system, muscular and subcutaneous cryptococcosis. The remaining two died. One had infectious diarrhoea (S. flexneri), peritoneal tuberculosis and sepsis (S. epidermidis); the other had bacterial meningitis, erysipelas, beta-hemolytic Streptococcus sepsis and miliary tuberculosis. Their immunodeficiency was attributed to enteric protein loss and/or malabsorption and malnutrition and was recognized by reduced response to delayed hypersensitivity skin tests in four patients and hypogammaglobulinemia in three of them. The authors discuss the need for prospective studies to be carried out, aiming at the mechanisms involved in secondary infections. Alternatives for maintaining the patients' adequate nutritional state should be investigated, to guarantee proper immune response and thus the ability to control intervening infections in patients with juvenile paracoccidioidomycosis.