Use of Circulating Galactomannan Screening for Early Diagnosis of Invasive Aspergillosis in Allogeneic Stem Cell Transplant Recipients

TLDR

Screening for galactomannan (GM) is widely used in European centers for allogeneic stem cell transplant recipients, but the timing of GM antigenemia onset remains unknown. A prospective cohort of allogeneic stem cell transplant recipients was monitored to analyze the relationship between GM antigenemia and other diagnostic triggers for initiating antifungal therapy. Prospective GM screening achieved 94.4 % sensitivity and 98.8 % specificity, outperformed other triggers, and detected antigenemia 8–9 days before radiologic or microbiologic diagnosis and 83.3 % before therapy, proving especially valuable in steroid‑treated patients or when other signs were masked.

Abstract

Screening for galactomannan (GM) has been adopted by many European centers as part of the management plan for allogeneic stem cell transplant recipients. However, the temporal onset of GM antigenemia remains unknown. A series of allogeneic stem cell transplant recipients were monitored prospectively, and the relationship between antigenemia and other diagnostic triggers for initiation of antifungal therapy was analyzed. GM detection had a sensitivity of 94.4% and a specificity of 98.8%. Positive and negative predictive values were 94.4% and 98.8%, respectively. This statistical profile was better than that of other triggers, including unexplained fever, new pulmonary infiltrates, isolation of Aspergillus species, and abnormalities seen on computed tomography. Antigenemia preceded diagnosis on the basis of radiologic examination or Aspergillus isolation by 8 and 9 days in 80% and 88.8% of patients, respectively. Antigenemia preceded therapy in 83.3% of patients. Detection of GM was especially useful when patients were receiving steroid treatment or when coexisting conditions masked the diagnosis of invasive aspergillosis. Prospective screening for GM allows earlier diagnosis of aspergillosis than do conventional diagnostic criteria.