D-index: A New Scoring System in Febrile Neutropenic Patients for Predicting Invasive Fungal Infections

摘要

Objective: Neutropenia is a critical risk factor for invasive fungalinfections (IFIs). We retrospectively performed this study to assessthe performance of the D-index, a new test that combines both theduration and the severity of neutropenia, in predicting IFIs amongpatients with acute myelogenous leukemia.Materials and Methods: Fifteen patients with IFIs and 28 patientswho did not develop IFIs were enrolled in the study. The D-index wasdefined as the area over the neutrophil curve, whereas the cumulative-D-index (c-D-index) was the area over the neutrophil curve from thestart of neutropenia until the first clinical manifestation of IFI.Results: The D-index and the c-D-index tended to be significantlyhigher in patients with IFIs, with medians of 10,150 (range: 4000-22,000) and 5300 (range: 2300-22,200), respectively (p=0.037 andp=0.003, respectively). The receiver operating characteristic analysesshowed that there was a cutoff point of 3875 for the D-index inpredicting IFI; the sensitivity, specificity, and positive and negativepredictive values were 100%, 67.9%, 35.4%, and 100%, respectively.There was also a cutoff point of 4225 for the c-D-index in predictingIFI; the sensitivity, specificity, and positive and negative predictivevalues for the c-D-index were 93.3%, 71.4%, 36.6%, and 98.4%.Conclusion: The D-index and especially the c-D-index could be usefultools with high negative predictive value to exclude as well as topredict IFIs in the management of neutropenic patients.