Sandra Castejon Ramirez, MD

My research aims to optimize the diagnosis and treatment of bloodstream infections in immunocompromised patients in the early phase after hematopoietic cell transplant and cellular therapy. I approach this goal from two angles. First, I conduct host-immune profiling to identify biomarkers and understand how a host responds to infection, using cytokine analysis and RNA sequencing in collaboration with the Mejías Lab. Second, I use microbial metagenomic next-generation sequencing, in collaboration with the clinical microbiology lab, to optimize the identification of pathogens. 

A recent focus of my research is improving the care and treatment of patients with fever and negative infection tests. Fever occurs in 80% of allogeneic hematopoietic cell transplant recipients, and it is frequently related to noninfectious immunological processes. Traditionally, these patients are treated with a long course of antibiotics to combat the unknown illness, but this approach can lead to infections by antibiotic resistant pathogens. As part of my research, my colleagues and I investigated the efficacy of shorter antibiotic courses; we found that patients who received short antibiotic courses did not have worse outcomes and we were able to limit antibiotic exposure, thus limiting opportunities to develop resistance.

A final aspect of my research involves developing machine learning models to help predict infections. In collaboration with the Department of Biostatistics, I am working to develop  algorithms that integrate clinical data to maximize our ability to predict bloodstream infections in patients who have received a hematopoietic cell transplant.