Background: Invasive aspergillosis (IA) remainsanimportant cause of mortalityin immunocompromised acute myeloid leukemia (AML) patients receiving induction chemotherapy and in patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) for hematological malignancies. In this study, we evaluated the performance of different factors in predicting the occurrence of IA, including the Aspergillusantigen galactomannan (GM) detection in sera.
Material/methods: We included all AML patients receiving induction chemotherapy and patientsundergoing allo-HSCT for any hematological malignancy at our center between April 2006 and April 2014. Serologic detection of circulating GM fungal biomarker was considered during the 100 days following the first day of induction chemotherapy in AML patients or from the day of allo-HSCT. Only patients with at least three serum GM results were considered. The GM tests have been performedroutinely using the ELISA kit (Platelia Aspergillusantigen ELISA, Biorad), giving the results in index. IA cases were classified as proven or probable according to the EORTC criteria. The value of the first antigen test, the delay to positivity, and the slope of the progression of the index value between the first two antigens concentrations were considered as predictors of IA.
Results: A total of 775 patients were included: 292 AML and 483 allo-HSCT patients. During the follow-up, we identified 121 episodes with at least one positive GM test with a cumulative incidence at day 100 of 13.8%. We also diagnosed 48 IA (2 proven, 46 probable), with a cumulative incidence at day 100 of 5.5% in total, 7.2% in AML and 4.3% in allo-HSCT, respectively. We then classified the GM positive episodes in 82 false-positive (68%) and 39 true-positive episodes (32%) for IA, respectively. A majority of IA events occurred during the first 30 days of follow up, GM positivity showing a positive predictive value of 41% versus a negative predictive value of 99%. The three IA predictor factors had similar independent effects and their combinations were performed, allowing establishing an area under ROC of 0.79 (95% CI: 0.70-0.89). Cut off values of the first positive GM serum and slope were equal or higher than 1.04 and 0.04, respectively, and delay to positivity equal or less than 15 days. A prognostic score defining the IA risk probability was defined as the number of predictors present (values from 0 to 3). This score was tested on positive follow-up and a score superior or equal to 2 was indicative of IA in 62% of the cases.
Conclusions: As IA has a significant impact on hematology patient’s survival, this GM predictive score combining three predictors (value of the first antigen index, delay of positivity and slope of the index values) may help clinicians to conclude about starting an early preemptive IA treatment.
Full conference title:
- ECCMID 26th (2016)