Association of Mannose-Binding Lectin Deficiency with Acute Invasive Aspergillosis in Immunocompromised Patients

Background. Invasive aspergillosis is a devastating infection with attributable mortality of 40% despite antifungal therapy. In animal models of aspergillosis, deficiency of mannose-binding lectin (MBL), a pattern recognition receptor that activates complement, is a susceptibility factor. MBL deficiency occurs in 20%-30% of the population. We hypothesized that MBL deficiency may be a susceptibility factor for invasive aspergillosis in humans. Methods. Serum MBL concentrations were measured by enzyme-linked immunosorbent assay in 65 patients with proven or probable acute invasive aspergillosis and 78 febrile immunocompromised control subjects. MBL concentrations and the frequency of MBL deficiency were compared. Results. The median serum MBL level was significantly lower in patients with aspergillosis than in control subjects (281 ng/mL vs 835 ng/mL; P=.007). MBL deficiency (MBL concentration,