D-index as a Risk Factor for Invasive Fungal Infections in Patients With Acute Lymphoblastic Leukemia From a Reference Hematology Center in Bogota

Introduction Patients with hematologic malignancies are susceptible hosts for the development of invasive fungal infection (IFI), one of the main life-threatening infectious complications faced by these patients. Currently, we have antifungal prophylaxis strategies and antifungal treatment schemes and we recognize that the main risk factor involved is profound and prolonged neutropenia. D-index and cumulative D-index are quantitative parameters, which determine the magnitude of neutropenia, as a function of duration and depth and their value correlates with the occurrence of IFI. Material and methods A case-control study in patients older than 18 years with acute lymphoblastic leukemia (ALL) was admitted between 2009 and 2019 at the National Cancer Institute for induction, consolidation and salvage chemotherapy. Results A total of 167 patients were included, who received 288 cycles of chemotherapy, the latter were considered the unit of analysis. A generalized estimating equations (GEE) model was designed to analyze correlated data; three quantitative and continuous variables of interest were included in this model: age (years), D-index and deep neutropenia (days). For the population D-index, an odds ratio (OR) = 1.000227 (95% CI 1.0002-1.0004); p < 0.001 was obtained. Conclusion D-index is associated with the development of IFI in patients with ALL, with an exponential increase in OR as the absolute value of the D-index increases.