Serum galactomannan strongly correlates with outcome of invasive aspergillosis in acute leukaemia patients

Invasive aspergillosis (IA) remains an important cause of mortality in acute leukaemia patients. Previous studies reported that serum galactomannan (GM) levels correlate strongly with IA outcomes in patients with haematological cancers. This study aimed to clarify the usefulness of serial GM testing for outcome evaluation of IA in acute leukaemia patients. We retrospectively analysed 58 acute leukaemia patients who had IA during neutropenic period after chemotherapy and whose serum GM was serially monitored until discharge or death. The kappa correlation coefficient was used to determine the strength of correlation between GM and clinical outcome (survival or death) of IA. The correlation between clinical outcome and GM kinetics was good at week 6 [κ = 0.663, 95% confidence interval (CI): 0.465-0.861] and excellent at week 12 (κ = 0.819, 95% CI: 0.667-0.91). Survival was significantly better in patients whose GM values normalised than in patients with persistently positive GM (P < 0.0001) regardless of whether neutropenia resolved or acute leukaemia responded to chemotherapy. In neutropenic patients with acute leukaemia, serum GM correlated strongly with survival outcome of IA. This finding further supports the usefulness of the GM index as a surrogate marker for assessing IA outcome and the need for serial GM testing in therapeutic monitoring.