Amy Karger, MD, PhD

Dr. Karger is a member of the Division of Molecular Pathology and Genomics and a faculty investigator at the Advanced Research and Diagnostic Laboratory (ARDL). She 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. Dr. Karger currently serves as Program Director and Principal Investigator for one of four federally funded Serological Sciences Network (SeroNet) Capacity Building Centers, which has been tasked with developing serological assays to test for COVID-19 antibodies, and is conducting research studies to better understand the immune response to COVID-19 infection and vaccination. Additionally, she has been appointed as co-chair of the SeroNet Serology Assays Ops Group. 

Dr. Karger also 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). Previously, Dr. Karger served as a principal investigator with the Preventing Early Renal Loss in Diabetes (PERL) consortium. The consortium undertook a multi-center, double-blind, placebo-controlled, randomized clinical trial aimed at evaluating the efficacy of allopurinol in preventing kidney function loss in individuals with type 1 diabetes; the trial found no evidence of benefit from serum urate reduction with allopurinol.

• Thomas SN, Karger AB, Altawallbeh G, Nelson KM, Jacobs DR Jr, Gorlin J, Barcelo H, Thyagarajan B. Ultrasensitive detection of salivary SARS-CoV-2 IgG antibodies in individuals with natural and COVID-19 vaccine-induced immunity. Sci Rep. 2022 May 25;12(1):8890. doi: 10.1038/s41598-022-12869-z
• Perkins BA, Bebu I, Gao X, Karger AB, Hirsch IB, Karanchi H, Molitch ME, Zinman B, Lachin JM, and de Boer IH. Early trajectory of estimated glomerular filtration rate and long-term advanced kidney and cardiovascular complications in type 1 diabetes. Diabetes Care. 2022 Mar 1;45(3):585-593. doi: 10.2337/dc21-1883. PMID: 35015817
• Honda Y, Mok Y, Ishigami J, Ashley KE, Hoogeveen RC, Ballantyne CM, Karger AB, Couper D, Selvin E, and Matsushita K. The fifth-generation cardiac troponin T and cardiovascular disease in the community. J Am Coll Cardiol. 2021 Nov 16;78(20):2019-2021. doi: 10.1016/j.jacc.2021.08.066. PMID: 34763781 No abstract available.
• Ishigami J, Karger AB, Lutsey PL, Coresh J, and Matsushita K. Stability of serum bone-mineral, kidney, and cardiac biomarkers after a freeze-thaw cycle: The ARIC Study. Am J Epidemiol. 2022 Feb 19;191(3):534-537. doi: 10.1093/aje/kwab251. PMID: 34643231 No abstract available.
• Martinez RJ, Pankratz N, Schomaker M, Daniel J, Beckman K, Karger AB, Thyagarajan B, Ferreri P, Yohe SL, Nelson AC. Prediction of false positive SARS-CoV-2 molecular results in a high-throughput open platform system. J Mol Diagn. 2021 Jun 8:S1525-1578(21)00166-5. doi: 10.1016/j.jmoldx.2021.05.015
  
• Murthy V, Altawallbeh G, Larson-Nath C, Karger AB, Thomas SN. Transient hyperphosphatasemia following pediatric liver transplantation in a patient with hepatic and skeletal abnormalities.  Clin Chim Acta. 2021 Apr 4:S0009-8981(21)00115-7. doi: 10.1016/j.cca.2021.03.030.
  
• Thomas SN, Altawallbeh G, Zaun CP, Pape KA, Peters JM, Titcombe PJ, Dileepan T, Rapp MJ, Bold TD, Schacker TW, Arbefeville S, Ferrieri P, Thyagarajan B, Jenkins MK, Karger AB. Initial determination of COVID-19 seroprevalence among outpatients and healthcare workers in Minnesota using a novel SARS-CoV-2 total antibody ELISA. Clin Biochem. 2021 Feb 1:S0009-9120(21)00027-8. doi: 10.1016/j.clinbiochem.2021.01.010.
• Karger AB, Eckfeldt JH, Rynders GP, Chaudhari J, Miao S, Van Lente F, Coresh J, Levey AS, Inker LA. Long-term longitudinal stability of kidney filtration marker measurements: implications for epidemiological studies and clinical care. Clin Chem 2020 Nov 30;hvaa237. Doi: 10.1093/clinchem/hvaa237. 
• Inker LA, Couture SJ, Tighiouart H, Abraham AG, Beck GJ, Feldman HI, Greene T, Gudnason V, Karger AB, Eckfeldt JH, Kasiske BL, Mauer M, Navis G, Poggio ED, Rossing P, Shlipak MG, Levey AS. A new panel estimated GFR, Including b2-microglobulin and b-trace protein and not Including race, developed in a diverse population. Am J Kidney Dis 2020 Dec 4:S0272-6386(20)31126-4. Doi: 10.1053/j.ajkd.2020.11.005. 
• Seegmiller JC, Kokaisel EL, Story SJ, Zaun CP, Peters JM, Thomas SN, and Karger AB. Method comparison of SARS-CoV-2 serology assays involving three commercially available platforms and a novel in-house developed enzyme-linked immunosorbent assay Clin Biochem. 2020;S0009-9120(20)30812-2. doi:10.1016/j.clinbiochem.2020.08.004.
• Nomura SO, Karger AB, Weir NL, Duprez DA, Tsai MY. Free fatty acids, cardiovascular disease, and mortality in the Multi-Ethnic Study of Atherosclerosis. J Clin Lipidol. 2020;14(4):531-541. doi:10.1016/j.jacl.2020.06.005.
• Garg PK, Guan W, Karger AB, Steffen BT, Budoff M, Tsai MY. Lipoprotein (a) and risk for calcification of the coronary arteries, mitral valve, and thoracic aorta: The Multi-Ethnic Study of Atherosclerosis. J Cardiovasc Comput Tomogr. 2020;S1934-5925(20)30175-1. doi:10.1016/j.jcct.2020.06.002.
• Chen N, Shi H, Zhang L, Zuo L, Xie J, Xie D, Karger AB, Miao S, Ren H, Zhang W, Wang W, Pan Y, Minji W, Sui Z, Okparavero A, Simon A, Chaudhari J, Eckfeldt JH, Inker LA, Levey AS. GFR Estimation Using a Panel of Filtration Markers in Shanghai and Beijing. Kidney Med. 2020;2(2):172-180. Published 2020 Jan 31. doi:10.1016/j.xkme.2019.11.004.
• Karger AB, Steffen BT, Nomura SO, Guan W, Garg PK, Szklo M, Budoff MJ, and Tsai MY. Association between homocysteine and vascular calcification incidence, prevalence, and progression in the MESA cohort. J Am Heart Assoc. 2020 Feb 4;9(3):e013934. doi: 10.1161/JAHA.119.013934. Epub 2020 Jan 30.
• Weir NL, Nomura SO, Steffen BT, Guan W, Karger AB, Klein R, Klein BEK, Cotch MF, and Tsai MY. Associations between omega-6 polyunsaturated fatty acids, hyperinsulinemia and incident diabetes by race/ethnicity: The Multi-Ethnic Study of Atherosclerosis. Clin Nutr. 2020 Jan 22. pii: S0261-5614(20)30008-X. doi: 10.1016/j.clnu.2020.01.003.
• Cao J, Nomura SO, Steffen BT, Guan W, Remaley AT, Karger AB, Ouyang P, Michos ED, and Tsai MY. Apolipoprotein B discordance with low-density lipoprotein cholesterol and non-high-density lipoprotein cholesterol in relation to coronary artery calcification in the Multi-Ethnic Study of Atherosclerosis (MESA).J Clin Lipidol. 2019 Nov 29. pii: S1933-2874(19)30354-X. doi: 10.1016/j.jacl.2019.11.005.
• Eriksen BO, Schaeffner E, Melsom T, Ebert N, van der Giet M, Gudnason V, Indridasson OS, Karger AB, Levey AS, Schuchardt M, Sørensen LK, Palsson R. Comparability of plasma iohexol clearance across population-based cohorts. Am J Kidney Dis. 2019 Dec 23. pii: S0272-6386(19)31122-9. doi: 10.1053/j.ajkd.2019.10.008. 
• Johnson LM, Lynch M, Johnson C, Karger AB. Evaluation of LeadCare Ultra® as an initial screen for elevated blood lead levels. Clin Biochem. 2019 Feb 19. pii: S0009-9120(18)31255-4. doi: 10.1016/j.clinbiochem.2019.02.010.
• Steffen BT, Thanassoulis G, Duprez D, Stein JH, Karger AB, Tattersall MC, Kaufman JD, Guan W, Tsai MY. Race-based differences in lipoprotein(a)-associated risk of carotid atherosclerosis. Arterioscler Thromb Vasc Biol. 2019; Feb 7: doi: 10.1161/ATVBAHA.118.312267.
• Cao J ,Karger AB, Critically elevated potassium in a 55-year-old female with chronic lymphocytic leukemia. Lab Med 2018 M 28.
  PMID:29608741https://www.ncbi.nlm.nih.gov/pubmed/29608741
• Johnson, LM, Gniadek TJ, Cohn CS, Bachowski G, Karger AB. A 43-year-old woman with unexplained elevation of hCG. Clin BIochem 2018 Mar 26 pii:S0009-9120(17)31253-5. Doi: 10.1016/j.clinbiochem.2018.03.016. https://www.ncbi.nlm.nih.gov/pubmed/29588177
• Bjornstad P, Karger AB, Maahs DM. Measured GFR in Routine Clinical Practice-The Promise of Dried Blood Spots. Adv Chronic Kidney Dis. 2018 Jan;25(1) 76-83.doi: 10:1053/ackd:2017.09.003 https://www.ncbi.nlm.nih.gov/pubmed/29499891
• Gruenberg JM, Stein TA, Karger AB. Determining the utility of creatinine delta checks: A large retrospective analysis. Clin Biochem 2018 Feb 1 pii: S0009-9120(17)31254-7. Doi: 10:1016/j.clinbiochem.2018.01.023. (Epub ahead of print). https://www.ncbi.nlm.nih.gov/pubmed/29402415
• Karger AB, Inker LA, Coresh J, Levey AS, Eckfeldt JH. Novel Filtration Markers for GFR Estimation. EJIFCC 2017 Dec 19:28(4):277-288.eCollection 2017 Dec. https://www.ncbi.nlm.nih.gov/pubmed/29333147
• Danni Li, Angela Radulescu, Rupendra T. Shrestha, Matthew Root, Amy B. Karger, Anthony A. Killeen, James S. Hodges, Shu-Ling Fan, Angela Ferguson, Uttam Garg, Lori J. Sokoll, Lynn A. Burmeister. Association of biotin ingestion with performance of hormone and nonhormone assays in healthy adults. JAMA 2017.;318(12):1150-1160.doi:10.1001/jama.2017.13705. https://goo.gl/yeqStZ
• Cao J, Senn C, Castaneda P, Humphries S, Karger AB. Establishing a stand-alone laboratory dedicated to the care of patients with Ebola virus disease. Lab Med, 2017 Mar 13, doi: 10.1093/labmed/lmw072.
• Karger AB, Saenger AK. A Setback to Universal Pediatric Lipid Screening and a Call for More Research. Clin Chem Feb 2017, 63 (2) 620-621; DOI: 10.1373/clinchem.2016.267989.
• Karger AB. To delta check or not to delta check? That is the question...J Appl Lab Med Jan 2017, 1 (4) 457-459; DOI: 10.1373/jalm.2016.022020.
• American Association for Clinical Chemistry (AACC) Government Relations Committee and AACC’s Pediatric and Maternal-Fetal Division. Advancing Children's Health through Pediatric Laboratory Medicine. Aug. 1, 2016. https://www.aacc.org/health-and-science-policy/aac...
• Selvaratnam R, Karger AB. A Newborn with Distended Abdomen. PMID: 27471243. Clin Chem 2016 Aug; 62(8) 1061-4.
• Karger AB, Seen C, Skogseth K, Floodman S. Rare erroneous results on the Siemens Dimension Vista® platform due to urine carryover: A warning to current users. J Clin Biochem DOI:10.1016/j.clinbiochem.2016.05.003 Published online 9 May 2016. http://www.sciencedirect.com/science/article/pii/S0009912016300492
• Eckfeldt JH, Karger AB, Miller WG, Rynders GP, Inker LA. Performance in measurement of serum cystatin C by laboratories participating in the college of american pathologists 2014 CYS survey. Arch Pathol Lab Med 2015;139:888-893.
• Holman CJ, Karger AB, Mullan BD, Brundage RC,Balfour HH. Quantitative Epstein-Barr Virus Shedding and Its Correlation with the Risk of Posttransplant Lymphoproliferative Disorder.Clin Transplant 26:741-747, 2012.
• Karger AB and Killeen AA. Applications of Sanctions by the Centers for Medicare and Medicaid Services and by Accrediting Organizations for Proficiency Testing Failure: A 9-Year Study.Clin Leadersh Manag Rev25:20-24, 2011.
• Karger AB, Park S, Reyes S, Bienengraeber M, Dyer RB, Terzic
  A, Alekseev AE. Role for SUR2A ED domain in allosteric coupling
  within the KATP channel complex. J Gen Physiol 131:185-196,
  2008.
• Karger AB, Wilson JD, Bower M, Schimmenti LA, Thyagarajan B. Detection of PAX2 Deletions and Duplications Using Multiplex Ligation-Dependent Probe Amplification. Genet Test Mol Biomarkers 17:786-788, 2013.