Valma Harjutsalo, FinnGen, Teemu Palviainen, Markku Lehto, Carol Forsblom, Anu Loukola, Laurent Lagrost, Pirkko J. Pussinen, Anmol Kumar, Mari-Anne Härma, Jaakko Kaprio, Per-Henrik Groop, Iiro Toppila, Markus Perola, Kajsa Emilia Roslund, Jaakko Leskelä, Jean-Paul Pais de Barros, Milla Pietiäinen, Niina Sandholm, Aino Salminen, Mariann I. Lassenius, Veikko Salomaa, Aki S. Havulinna, K. A. Elisa Kopra, Department of Oral and Maxillofacial Diseases, HUS Head and Neck Center, HUS Abdominal Center, Nefrologian yksikkö, Institute for Molecular Medicine Finland, Genetic Epidemiology, Clinicum, Medicum, HUS Internal Medicine and Rehabilitation, Department of Medicine, Research Programs Unit, CAMM - Research Program for Clinical and Molecular Metabolism, HUSLAB, University Management, Department of Public Health, Complex Disease Genetics, Per Henrik Groop / Principal Investigator, and Helsinki University Hospital Area
Background Translocation of lipopolysaccharide from gram‐negative bacteria into the systemic circulation results in endotoxemia. In addition to acute infections, endotoxemia is detected in cardiometabolic disorders, such as cardiovascular diseases and obesity. Methods and Results We performed a genome‐wide association study of serum lipopolysaccharide activity in 11 296 individuals from 6 different Finnish study cohorts. Endotoxemia was measured by limulus amebocyte lysate assay in the whole population and by 2 other techniques (Endolisa and high‐performance liquid chromatography/tandem mass spectrometry) in subpopulations. The associations of the composed genetic risk score of endotoxemia and thrombosis‐related clinical end points for 195 170 participants were analyzed in FinnGen. Lipopolysaccharide activity had a genome‐wide significant association with 741 single‐nucleotide polymorphisms in 5 independent loci, which were mainly located at genes affecting the contact activation of the coagulation cascade and lipoprotein metabolism and explained 1.5% to 9.2% of the variability in lipopolysaccharide activity levels. The closest genes included KNG1 , KLKB1 , F12 , SLC34A1 , YPEL4 , CLP1 , ZDHHC5 , SERPING1 , CBX5 , and LIPC . The genetic risk score of endotoxemia was associated with deep vein thrombosis, pulmonary embolism, pulmonary heart disease, and venous thromboembolism. Conclusions The biological activity of lipopolysaccharide in the circulation (ie, endotoxemia) has a small but highly significant genetic component. Endotoxemia is associated with genetic variation in the contact activation pathway, vasoactivity, and lipoprotein metabolism, which play important roles in host defense, lipopolysaccharide neutralization, and thrombosis, and thereby thromboembolism and stroke.