title: Multidrug resistance gene-1 polymorphisms and resistance to cyclosporine A in patients with steroid resistant ulcerative colitis.
abstract: BACKGROUND
  Cyclosporine A (CsA) is inconstantly effective in inducing remission in acute attacks of ulcerative colitis (UC) not responding to steroids. This study aimed to establish whether multidrug resistance gene (MDR)1 polymorphisms would be associated with CsA failure.
  
  
  METHODS
  The distribution of the different genotypes of single nucleotide polymorphisms (SNP) G2677T/A and C3435T of MDR1 exons 21 and 26, respectively, was studied in 154 patients (mean age, 44 yr) who had received CsA to treat severe attacks of steroid resistant UC in 11 centers in France and Belgium. Patients were classified as CsA failure (n = 50) when they needed colectomy within 30 days after CsA initiation. The SNPs were detected by use of a 5' nuclease allelic discrimination assay.
  
  
  RESULTS
  There was a significant association between the G2677T/A polymorphism distribution (exon 21) and the risk for CsA failure (P = 0.0001). The TT genotype of exon 21 was significantly associated with the risk compared with the two other genotypes (odds ratio, 3.77; 95% confidence interval, 1.42-9.97, P = 0.007). There was no significant association between the genotype C3435T distribution (exon 26) and the risk of CsA failure (P = 0.23).
  
  
  CONCLUSIONS
  The TT genotype of exon 21 MDR1 polymorphisms is associated with a higher risk of CsA failure in patients with steroid resistant UC. Further studies should be performed to establish whether other treatments could be more efficient to avoid surgery in this subset of patients.
authors.affiliation: Department of Gastroenterology, Assistance Publique des Hôpitaux de Paris (AP-HP), Hôpital Européen Georges Pompidou, Paris, France.
authors.forename: Fady
authors.initials: F
authors.lastname: Daniel
authors.forename: Marie-Anne
authors.initials: MA
authors.lastname: Loriot
authors.forename: Philippe
authors.initials: P
authors.lastname: Seksik
authors.forename: Jacques
authors.initials: J
authors.lastname: Cosnes
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Gornet
authors.forename: Marc
authors.initials: M
authors.lastname: Lémann
authors.forename: Francine
authors.initials: F
authors.lastname: Fein
authors.forename: Gwenola
authors.initials: G
authors.lastname: Vernier-Massouille
authors.forename: Martine
authors.initials: M
authors.lastname: De Vos
authors.forename: Arnaud
authors.initials: A
authors.lastname: Boureille
authors.forename: Xavier
authors.initials: X
authors.lastname: Treton
authors.forename: Bernard
authors.initials: B
authors.lastname: Flourié
authors.forename: Xavier
authors.initials: X
authors.lastname: Roblin
authors.forename: Edouard
authors.initials: E
authors.lastname: Louis
authors.forename: Frank
authors.initials: F
authors.lastname: Zerbib
authors.forename: Philippe
authors.initials: P
authors.lastname: Beaune
authors.forename: Philippe
authors.initials: P
authors.lastname: Marteau
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics*; D000328:Adult; D003093:Colitis, Ulcerative / Q000097:blood / Q000188:drug therapy* / Q000235:genetics*; D016572:Cyclosporine / Q000493:pharmacokinetics / Q000627:therapeutic use*; D018432:Drug Resistance, Multiple / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D005938:Glucocorticoids / Q000627:therapeutic use*; D006801:Humans; D007166:Immunosuppressive Agents / Q000493:pharmacokinetics / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D005938:Glucocorticoids; D007166:Immunosuppressive Agents; D016572:Cyclosporine