title: [Analysis of Cases with Elevated Blood (1->3)-β-D-glucan in Relation to an Infection Marker, Neutrophil CD64 Expression].
abstract: (1->3)-β-D-glucan (BDG) is a constituent of the fungal cell wall and its blood level is known as a marker of fungal infection including pneumocystis pneumonia (PCP). Meanwhile, peripheral blood neutrophil CD64 expression (CD64) is upregulated in various infections. We analyzed patients with positive BDG (cut off 11.0 pg/mL) and those whose CD64 was measured simultaneously. In patients who visited our hospital from 2005 to 2011, BDG was measured in 3,960 samples. The number of positive samples were 441 obtained from 185 patients. In patients with positive BDG, the initial BDG was 24.3 [16.4-70.5] pg/mL (median [interquartile range]). Positive BDG samples were derived mainly from the department of Rheumatology or that of Allergy and Respirology. Common primary diseases were rheumatoid arthritis (RA) or other connective tissue diseases, followed by malignancy, none (only abnormal chest X-ray) and bronchial asthma. The rates of afebrile patients, patients on immunosuppressive therapy and those with a normal range of white blood cell count were 63.7%, 50.9% and 40.8%, respectively. The main causes of positive BDG were PCP (n = 38, 20.5%) and non-PCP mycosis (n = 48, 25.9%, including 26 cases of aspergillosis). Others (99 patients, 53.6%) had positive BDG of unknown origin and 53 of them ameliorated spontaneously, most of whom could have been examples of pseudo-positive BDG. The number of deceased patients was 57 (30.8%) consisting of 9 PCP, 16 non-PCP mycosis and others. The median initial positive BDG levels in patients with PCP, non-PCP mycosis and others were 49.9, 28.9 and 19.7pg/mL, respectively. The positive rate of CD64 (cut off 2,000 molecules/cell) measured simultaneously with initial positive BDG was 77.8%. In RA patients with PCP, 94.7% of them had positive CD64 and the levels of CD64 were significantly higher than those in RA patients with bacterial pneumonia (median 9,386 vs 4,399 molecules/cell) in that same period. The positive rate of CD64 was lower in patients with positive BDG of unknown origin than those with PCP or non-PCP mycosis, which implies positive CD64 can exclude pseudo-positive BDG. Immunosuppressed patients often exhibit positive BDG. Simultaneous measurement of BDG and CD64, a quick pan-infection marker, assists the decision whether the positive BDG is true or false-positive.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Hashimoto
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Matsui
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009181:Mycoses / Q000175:diagnosis* / Q000453:epidemiology; D009504:Neutrophils / Q000166:cytology* / Q000276:immunology; D011020:Pneumonia, Pneumocystis; D017452:Receptors, IgG / Q000097:blood*; D047071:beta-Glucans / Q000097:blood*
chemical_list: D015415:Biomarkers; D017452:Receptors, IgG; D047071:beta-Glucans