Serum IgG responses against Aspergillus proteins before hematopoietic stem cell transplantation or chemotherapy identify patients who develop invasive aspergillosis

The ability to identify patients at particularly low risk for invasive aspergillosis (IA) would facilitate more efficient targeting of antifungal prophylaxis. We measured baseline serum immunoglobulin responses against 6 purified recombinant Aspergillus fumigatus proteins before hematopoietic stem cell transplantation (HSCT) or chemotherapy in 73 subjects, including 19 patients who subsequently developed proven or probable IA and 54 uninfected controls. We also assessed responses at the time of IA diagnosis and 4 weeks later (acute and convalescent sera, respectively). Baseline IgG responses against enolase, Ahp1, Hsp90, Crf1, and Cdc37 were significantly higher in the patients with IA compared with controls (P < .05). Cutoff concentrations identified by reveiver-operating characteristic curve analysis were 67%-84% sensitive and 52%-67% specific. In a population with a 15% likelihood of developing IA, positive and negative predictive values would be 22%-26% and 92%-95%, respectively. Positive IgG responses against Hsp90, Pep2, Crf1, and Cdc37 were specifically associated with early-onset IA (