title: Haplotypes of IL1B, IL1RN, IL1R1, and IL1R2 and the risk of venous thrombosis.
abstract: OBJECTIVE
  It has been suggested that the overall effect of the major proinflammatory cytokine interleukin-1 (IL-1) on coagulation and fibrinolysis is prothrombotic. The aim of this study was to investigate whether common variations in IL1B, IL1RN, IL1R1, and IL1R2 influence the risk of venous thrombosis.
  
  
  RESULTS
  In a case-control study on the causes of deep venous thrombosis, the Leiden Thrombophilia Study (LETS), we genotyped 18 single nucleotide polymorphisms (SNPs) in IL1B, IL1RN, IL1R1, and IL1R2, enabling us to tag a total of 25 haplotype groups. Overall testing of the haplotype frequency distribution in patients and controls indicated that a recessive effect was present in IL1RN (P=0.031). Subsequently the risk of venous thrombosis was calculated for each haplotype of IL1RN. Increased thrombotic risk was found for homozygous carriers of haplotype 5 (H5, tagged by SNP 13888T/G, rs2232354) of IL1RN (Odds ratio=3.9; 95% confidence interval: 1.6 to 9.7; P=0.002). No risk was associated with haplotype 3 of IL1RN, which contains the frequently examined allele 2 variant of the intron 2 VNTR.
  
  
  CONCLUSIONS
  We found that IL1RN-H5H5 carriership increases the risk of venous thrombosis.
authors.affiliation: Hemostasis and Thrombosis Research Center, Department of Hematology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands.
authors.forename: Rick
authors.initials: R
authors.lastname: van Minkelen
authors.forename: Marieke C H
authors.initials: MC
authors.lastname: de Visser
authors.forename: Jeanine J
authors.initials: JJ
authors.lastname: Houwing-Duistermaat
authors.forename: Hans L
authors.initials: HL
authors.lastname: Vos
authors.forename: Rogier M
authors.initials: RM
authors.lastname: Bertina
authors.forename: Frits R
authors.initials: FR
authors.lastname: Rosendaal
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism; D016022:Case-Control Studies; D005260:Female; D005340:Fibrinogen / Q000378:metabolism; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006239:Haplotypes; D006720:Homozygote; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000235:genetics; D053590:Interleukin 1 Receptor Antagonist Protein / Q000235:genetics*; D053583:Interleukin-1beta / Q000235:genetics*; D007438:Introns; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D053573:Receptors, Interleukin-1 Type I / Q000235:genetics*; D053574:Receptors, Interleukin-1 Type II / Q000235:genetics*; D018570:Risk Assessment; D012307:Risk Factors; D020246:Venous Thrombosis / Q000097:blood / Q000235:genetics*
chemical_list: D015415:Biomarkers; C508585:IL1B protein, human; C508590:IL1R1 protein, human; C508592:IL1R2 protein, human; C507763:IL1RN protein, human; D053590:Interleukin 1 Receptor Antagonist Protein; D053583:Interleukin-1beta; D053573:Receptors, Interleukin-1 Type I; D053574:Receptors, Interleukin-1 Type II; D005340:Fibrinogen; D002097:C-Reactive Protein