Klaus Bendtzen, born  in Copenhagen 1944, is professor emeritus of Immunology and Inflammation.

He is an MD from 1969. He specialized in internal medicine and rheumatology and served as chief physician at Rigshospitalet Natl. University. Hospital in Copenhagen from 1990 to 2015.

He also served as external professor of inflammation of the oral cavity at School of Dentistry, University of Copenhagen.

He was president of the Danish Society for Immunology between 1997 and 2002. He founded Institute for Inflammation Research at Rigshospitalet in 1995 and BioMonitor Ltd. in 2003, now a subsidiary of Eurodiagnostica Ltd., Malmö, Sweden. 

As of 2024 he has authored or co-authored more than 700 papers, monographs and textbook chapters in the field of basic and clinical immunology, autoimmunity, rheumatology, gastro-enterology, neurology, pharmacology and cytokinology; download: KBWrittenPublications2022. He has authored/co-authored 5 patents and is author and scientific advisor for the Danish National Encyclopedia (immunology and inflammation).

His most important scientific achievement is likely the discovery in 1985 that nonspecific mediators of the innate immune system, e.g. interleukin-1 and tumor necrosis factor alpha, are selectively toxic to insulin-producing beta-cells and thus may be involved in the development of insulin-dependent diabetes mellitus (IDDM)/type1 diabetes (T1D), see

- Bendtzen K, Mandrup-Poulsen T, Nerup J et al. Cytotoxicity of human pI 7 interleukin-1 for pancreatic islets of Langerhans. Science 1986; 232:1545.

- Bendtzen K. Immune hormones (cytokines); pathogenic role in autoimmune rheumatic and endocrine diseases. Autoimmunity 1989; 2:177.

- Clarke J. Nature Portfolio: Milestones: Cytokines directly implicated in TiD [editorial]. Nature 2021.

- Clarke J. Diabetes Milestone 8: Cytokines directly implicated in TiD [editorial]. Nature 2021; 2021S10.

Several domestic and foreign honorary awards has been received.