[Monitoring and prophylaxis]

Invasive deep mycoses following bone marrow and solid-organ transplantation remain a major cause of morbidity and mortality. Species of Candida and Aspergillus account for more than 80% of these mycoses. Because these infections are often difficult to diagnose and treat successfully, antifungal prophylaxis is recommended in high-risk patients. Fluconazole is useful in patients who are at risk of invasive candidiasis, including bone marrow transplants, liver and pancreatic transplants. Although invasive aspergillosis is frequent in patients with bone marrow, lung and heart transplantation, no established methods have been available for its prophylaxis. Recently, efforts to improve the efficiency of diagnostic tests have been directed toward the detection of fungal components or metabolites. The requirements for clinical use (monitoring) are as follows: capability of early diagnosis, quantitative measurement, and easy sampling and simple assay procedure. The detection of plasma (1-3)-beta-D-glucan (BDG), a characteristic cell wall component of almost all fungi, is widely used in Japan. Twenty-seven episodes of fungemia were observed in our hematology ward and all were positive with BDG. Positive results were observed before the documentation of fungemia in 14 patients (51.9%). Although the positive rate of BDG also was 100% in 17 patients with invasive aspergillosis, it rose slightly at an early stage of the disease in 13 patients (76.5%). The determination of plasma BDG appears useful in the monitoring of deep fungal infection, but its usefulness for early diagnosis remains to be determined. The utility of detection of Aspergillus galactomannan by ELISA and fungal DNA by polymerase chain reaction are also discussed.