Dr. Karger has multiple research interests including studying immune responses to COVID-19 infection and vaccines, predicting and delaying the progression of chronic kidney disease, and studying cardiovascular and kidney disease complications in patients with type 1 diabetes. She serves as Director of the Central Laboratory for the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), which tests biomarkers such as creatinine, cystatin C, beta-2 microglobulin and beta-trace protein to improve GFR estimating equations. Improved GFR estimates give clinicians the ability to detect disease progression at earlier stages. In addition, she serves as co-investigator for the Epidemiology of Diabetes Interventions and Complications trial (EDIC) and co-director of the Biomedical Assay Laboratory for the Division of Intramural Population Health Research at the National Institute of Child Health and Human Development (NICHD).