[Plasma (1-->3)-beta-D-glucan determination for screening deep mycosis].
Plasma (1-->3)-beta-D-glucan determination has been developed for the diagnosis of fungemia and deep mycosis to make up for the low yield of blood culture. This method uses Factor G, a coagulation enzyme of the horseshoe crab that is highly sensitive to this glucan. Since (1 -->3)-beta-D-glucan is a characteristic fungal cell-wall constituent which is common to virtually all fungi, the method aims to screen fungal infections as a whole. This is advantageous today when new fungi are appearing one after another as a causative agent of opportunistic deep fungal infections. Plasma (1-->3)-beta-D-glucan concentrations in 60 normal individuals were less than 10pg/ml. With a cutoff value at 20pg/ml, the sensitivity of the test was 90%, and the specificity was 100%. No cases of fungal colonization showed values above the cutoff level. In addition to invasive candidiasis, aspergillosis, and cryptococcosis, trichosporonosis was also found positive with the test. Glucanemia was not associated with primary cryptococcosis, probably because the growth of the organism is checked by the competent immunity in these afebrile patients. Levels of plasma (1-->3)-beta-D-glucan were variable in aspergilloma, indicating that the disease is essentially a colonization, but that (1-->3)-beta-D-glucan may appear in the blood when cavitary walls are invaded, depending on the integrity of local or systemic immunity. In addition to being useful for diagnosis, the test is also helpful in initiating early treatment of deep mycosis with improved survival.
Obayashi
T
T
Department of Clinical Pathology, Jichi Medical School, Tochigi-pref.
D002986:Clinical Trials as Topic; D005936:Glucans / Q000032:analysis*; D006801:Humans; D015337:Multicenter Studies as Topic; D009181:Mycoses / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D047071:beta-Glucans
D005936:Glucans; D047071:beta-Glucans; C033363:beta-1,3-glucan