Modeling Invasive Aspergillosis Risk for the Application of Prophylaxis Strategies

Abstract

The epidemiology of invasive aspergillosis (IA) is evolving. To define the patient groups who will most likely benefit from primary or secondary Aspergillus prophylaxis, particularly those whose medical conditions and IA risk change over time, it is helpful to depict patient populations and their risk periods in a temporal visual model. The Sankey approach provides a dynamic figure to understand the risk of IA for various patient populations. While the figure depicted within this article is static, an internet-based version could provide pop-up highlights of any given flow's origin and destination nodes. A future version could highlight links to publications that support the color-coded incidence rates or other actionable items, such as bundles of applicable pharmacologic or non-pharmacologic interventions. The figure, as part of the upcoming Infectious Diseases Society of America's aspergillosis clinical practice guidelines, can guide decision-making in clinical settings.

Keywords: Sankey; antifungal prophylaxis; hematopoietic cell transplantation; invasive aspergillosis; solid organ transplantation.

Figure 1.

A Sankey plot of patient population groups at risk for invasive aspergillosis (IA), stratified by dynamic changes in immunocompetence. This plot displays transitions in cohort risk. The left axis shows medical conditions that place a patient at risk for IA. Each risk group has a node representing the number of patients, not the relative risk of infection. The height of nodes is weighted to the number of patients within the risk group, except for a minimal risk in the smallest cohorts. The right axis shows the level of immunocompetence at the latest node. This multistate heatmap shows risk change between nodes. Red is major immunosuppression, and there are gradations in color. The deepest red represents high-risk situations where prophylaxis is strongly recommended. Yellow represents variable or brief episodes of immunosuppression signifying an intermediate level of risk where prophylaxis may be needed, particularly where multiple risk factors exist. Green represents circumstances with limited or no ongoing immunocompromise where prophylaxis is not needed. Gray represents limited, but poorly defined, IA risk. Abbreviations: aGVHD, acute graft-vs-host disease; ALL, acute lymphoid leukemia; Allo-HCT, allogeneic hematopoietic cell transplantation; AML, acute myeloid leukemia; Auto-HCT, autologous hematopoietic cell transplantation; CAR T-cell, chimeric antigen receptor T-cell therapy; cGVHD, chronic graft-vs-host disease; CLL, chronic lymphocytic leukemia; CML, chronic myelogenous leukemia; COVID-19, coronavirus disease 2019; ESLD, end-stage liver disease; HCT, hematopoietic cell transplantation; IgE, immunoglobulin E; Jak-2, Janus kinase 2; MDS, myelodysplastic syndrome; R-CHOP, chemotherapy with rituximab, cyclophosphamide, doxorubicin hydrochloride, vincristine sulfate, and prednisone; RVD, chemotherapy with lenalidomide, bortezomib, and dexamethasone; SOT, solid organ transplantation; WBC, white blood cells.