Serum aspergillus galactomannan antigen values strongly correlate with outcome of invasive aspergillosis - A study of 56 patients with hematologic cancer

BACKGROUND. Determining the outcome of patients with aspergillosis can be particularly difficult because patients with aspergillosis are at risk for other conditions that mimic this infection. Galactomannan is an Aspergillus- specific antigen released during invasive aspergillosis and is detected by the quantitative serum galactomannan index (GMI) test. METHODS. Using a kappa correlation coefficient test (KCC), the strength of correlation was determined between GMI and survival outcome of aspergillosis among 56 adults with hematologic cancer (90% had myeloma) who underwent serial GMI monitoring until hospital discharge or death. RESULTS. All 56 patients received antineoplastic therapy (myeloablative followed by stem cell transplantation [autologous in 21 patients and allogeneic in 3 patients] or nonmyeloablative therapy [32 patients]). The overall correlation between survival outcome and GMI was excellent (KCC = 0.8609; 95% confidence interval [95% Cl], 0.7093-1.000 [P <.00011) and was comparable among neutropenic and nonneutropenic patients (KCC = 0.8271; 95% Cl, 0.6407-1.000 [P <.0001] and KCC = 1.0; 95% Cl, 1-1 [P =.0083], respectively). CONCLUSIONS. The survival outcome of patients with aspergillosis strongly correlated with serum GMI. These findings have important implications for patient care and clinical trials of mold-active antifungal agents.