galactomannan and arabitol

The biomarkers galactomannan and 1,3-β-d-glucan have been well studied over the past years and are gaining a role in the diagnosis of invasive fungal infections. Although not as well studied until recently, molecular methods for the diagnosis of invasive fungal infection are also being evaluated. Outcomes data for molecular testing are expanding, but have not yet provided enough evidence for inclusion of molecular diagnostics in formal clinical guidelines. Lack of standardization and validation of the various molecular assays and platforms has hindered their widespread acceptance in the evaluation of invasive fungal infections, although the future is promising.

Topics: Aspergillosis; beta-Glucans; Biomarkers; Bronchoalveolar Lavage Fluid; Candidiasis; False Positive Reactions; Galactose; Humans; Mannans; Pathology, Molecular; Polymerase Chain Reaction; Predictive Value of Tests; Sugar Alcohols

We prospectively evaluated a combination of fungal biomarkers in adult haematology patients with focus on their clinical utility at different time points during the course of infection. In total, 135 patients were monitored once to twice weekly for serum (1-3)-ß-d-glucan (BG), galactomannan (GM), bis-methyl-gliotoxin and urinary d-arabinitol/l-arabinitol ratio. In all, 13 cases with proven or probable invasive fungal disease (IFD) were identified. The sensitivity of BG and GM at the time of diagnosis (TOD) was low, but within 2 weeks from the TOD the sensitivity of BG was 92%. BG >800 pg/mL was highly specific for IFD. At a pre-test probability of 12%, both BG and GM had negative predictive values (NPV) >0.9 but low positive predictive values (PPV). In a subgroup analysis of patients with clinically suspected IFD (pre-test probability of 35%), the NPV was lower, but the PPV for BG was 0.86 at cut-off 160 pg/mL. Among IFD patients, 91% had patterns of consecutively positive and increasing BG levels. Bis-methyl-gliotoxin was undetectable in 15 patients with proven, probable and possible IA. To conclude, BG was the superior fungal marker for IFD diagnosis. Quantification above the limit of detection and graphical evaluation of the pattern of dynamics are warranted in the interpretation of BG results.

Topics: Adolescent; Adult; Aged; beta-Glucans; Biomarkers; Diagnostic Tests, Routine; Female; Galactose; Gliotoxin; Hematologic Diseases; Humans; Invasive Fungal Infections; Male; Mannans; Middle Aged; Prospective Studies; Proteoglycans; Sensitivity and Specificity; Serum; Sugar Alcohols; Urinalysis; Young Adult