No abstract

We evaluated cross-reactivity in the antigen assay used for the diagnosis of histoplasmosis by testing urine samples from patients with disseminated fungal infections. The mycoses chosen for this study were selected on the basis of the observation that during clinical testing, cross-reactions may occur between Histoplasma capsulatum var. capsulatum, Paracoccidioides brasiliensis, Blastomyces dermatitidis, Coccidioides immitis, and Penicillium marneffei. We detected antigen in 12 of 19 patients with blastomycosis, 8 of 9 with paracoccidioidomycois, in 17 of 18 with P. marneffei infection, and in one with disseminated H. capsulatum var. duboisii infection. Cross-reactions were not observed in the assays for six patients with disseminated coccidioidomycosis. Cross-reactivity between the agents of other endemic mycoses should be considered in interpreting a positive H. capsulatum var. capsulatum antigen assay. Antigen detection may provide a rapid, provisional diagnosis for patients with serious infections caused by one of these organisms.

A Platelia EIA index cut-off > or =1.0 in the BAL fluid in a lung transplant recipient with a compatible clinical illness may be considered as suggestive of IA.

Supplemental Digital Content is available in the text

Histoplasmosis remains a common infection in endemic regions of North America and Latin America, causing a broad spectrum of clinical findings. Experience during recurrent outbreaks in Indianapolis has shown the importance of immunosuppressive conditions including the acquired immunodeficiency syndrome (AIDS) as a risk factor for disseminated disease and expanded our knowledge of the common clinical manifestations. Pericarditis, rheumatologic manifestations, esophageal compression, and sarcoidlike manifestations were found to be relatively common findings in histoplasmosis. These studies have established the useful role of serologic testing and have led to the discovery of antigen testing for diagnosis of histoplasmosis. This experience also has offered the opportunity to examine the outcome of treatment in persons with AIDS, contributing to studies that have found itraconazole to be an excellent alternative to amphotericin B in persons with mild or moderately severe infection.