This study compares the deposition of proteoglycans in the extracellular matrix of the lung lesions of the adult respiratory distress syndrome (ARDS) and bronchiolitis obliterans organizing pneumonia (BOOP) to those present in idiopathic pulmonary fibrosis (IPF). Tissue from individuals with ARDS (n = 7), BOOP (n = 5), IPF (n = 5), and control subjects (n = 5) was examined for glycosaminoglycans and collagen by histochemistry, and for hyaluronan, versican, decorin, biglycan, Types I and III collagen, type I procollagen and alpha-smooth muscle actin (alpha-SMA) using immunohistochemistry. The results showed that glycosaminoglycan deposition in the lesions of ARDS, BOOP, and IPF corresponded to the deposition of versican. Versican localized to the thickened interstitium in the fibroproliferative phase of ARDS, to the intraluminal buds in BOOP, and to early fibroblast foci in IPF. The versican-rich areas contained little mature collagen, but the myofibroblasts in these areas stained for type I procollagen, suggesting early collagen synthesis, and stained intracellularly for decorin. The localization of versican in ARDS, BOOP, and IPF suggests that this proteoglycan may influence early repair processes in the lung.

The second-generation MVista Blastomyces antigen enzyme immunoassay was not quantitative; therefore, specimens obtained previously were tested in the same assay as new specimens to assess the change in antigen levels. Furthermore, the sensitivity in serum had not been fully evaluated. The purpose of this study was to evaluate a quantitative Blastomyces antigen assay and detection of antigen in serum. Calibrators containing known concentrations of Blastomyces galactomannan were used to quantify antigen in urine and serum from patients with proven blastomycosis and from controls. Paired current and previously obtained urine specimens were tested to determine if quantification eliminated the need for concurrent testing to assess change in antigen. Pretreatment of serum with EDTA at 104°C was evaluated to determine if dissociation of immune complexes improved detection of antigenemia. Antigenuria was detected in 89.9% of patients with culture-or histopathology-proven blastomycosis. Specificity was 99.0% in patients with nonfungal infections and healthy subjects, but cross-reactions occurred in 95.6% of patients with histoplasmosis. Change in antigen level categorized as increase, no change, or decrease based on antigen units determined in the same assay agreed closely with the category of change in ng/ml determined from different assays. Pretreatment increased the sensitivity of detection of antigenemia from 35.7% to 57.1%. Quantification eliminated the need for concurrent testing of current and previously obtained specimens for assessment of changes in antigen concentration. Pretreatment increased the sensitivity for detection of antigenemia. Differentiation of histoplasmosis and blastomycosis is not possible by antigen detection.A ntigen detection is a useful method for diagnosis of blastomycosis. The sensitivity has been reported to be over 90% and specificity has been reported to be 100% in healthy subjects, but cross-reactions occur in most patients with histoplasmosis (6). In a recent report of 59 patients with proven blastomycosis (4), culture was positive in 86%, histopathology in 81%, antigen in 74%, cytopathology in 38%, and immunodiffusion for antibody in 32% (4). Antigen detection was considered to be a "reliable method to make an accurate and rapid diagnosis of blastomycosis, particularly when a large burden of disease is present, and when cytological analysis is performed at less-experienced centers" (4). Blastomyces antigen detection was also reported to be useful for diagnosis of blastomycosis in solid organ transplant patients (7).Because of interassay variability, specimens obtained earlier have been tested simultaneously with current specimens to assess the change in antigen levels. In a Histoplasma antigen assay, quantification of galactomannan antigen eliminated the need to test the previously obtained specimen with the current specimen to determine change in antigen level (5). In a recent study, quantification and improved detection of antigen in serum following EDTA treatment at 104°C in the t...

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