title: Phosphatidylserine-dependent anti-prothrombin antibodies (aPS/PT) in infliximab-treated patients with inflammatory bowel diseases.
abstract: OBJECTIVE
  To (1) examine the occurrence and concentrations of aPS/PT and aPL in inflammatory bowel disease (IBD) patients at the beginning of and during anti-TNF-alpha therapy with infliximab; (2) investigate the link of the aPS/PT and aPL presence with antibodies to infliximab (ATI) formation; and (3) examine possible clinical consequences of aPS/PT and/or aPL positivity in IBD patients.
  
  
  METHODS
  Thirty (30) IBD patients treated with infliximab were analyzed regarding aPS/PT, aPL, and ATI antibody serum levels by standardized ELISAs at treatment weeks 2 (W2) and 14 (W14).
  
  
  RESULTS
  At W2, 40 % of infliximab-treated patients had elevated aPS/PT and 16.7 % had elevated aPL serum levels. At W14, the proportion of aPS/PT-positive sera decreased to 16.6 %, whereas aPL distribution remained unchanged. Moreover, concentrations of aPS/PT have shown significant differences at W2 (16.64 [10.06; 33.06] U for IgG and 18.46 [9.18; 32.48] U for IgM) and at W14 (8.24 [2.78; 19.82] U for IgG and 8.57 [5.55; 26.82] U for IgM), p = 0.009 and p = 0.003, respectively. In ATI-positive samples, aPS/PT IgG were more frequent (p = 0.001 for W2 and p = 0.003 for W14), whereas aPS/PT IgM and aPL IgG/IgM did not show such association.
  
  
  CONCLUSIONS
  Higher concentrations of aPS/PT IgG and IgM were found in IBD patients at the beginning of the biological treatment period compared to the maintenance treatment period. Moreover, aPS/PT IgG were more frequent in ATI-positive individuals, which was not observed in aPL. We speculate that there is a relationship between the aPS/PT and the severity of inflammation and auto-aggressive processes in IBD.
authors.affiliation: Laboratory of Clinical Immunology and Allergology, Institute of Medical Biochemistry and Laboratory Diagnostics, 1st Faculty of Medicine and General University Hospital, Charles University in Prague, Karlovo náměstí 32, 121 11 Prague 2, Czech Republic.
authors.forename: Karin
authors.initials: K
authors.lastname: Malíčková
authors.affiliation: Clinical and Research Center for Inflammatory Bowel Disease, ISCARE a.s. and Charles University, Prague, Czech Republic.
authors.forename: Dana
authors.initials: D
authors.lastname: Ďuricová
authors.affiliation: Clinical and Research Center for Inflammatory Bowel Disease, ISCARE a.s. and Charles University, Prague, Czech Republic.
authors.forename: Martin
authors.initials: M
authors.lastname: Bortlík
authors.affiliation: Laboratory of Clinical Immunology and Allergology, Institute of Medical Biochemistry and Laboratory Diagnostics, 1st Faculty of Medicine and General University Hospital, Charles University in Prague, Karlovo náměstí 32, 121 11 Prague 2, Czech Republic.
authors.forename: Ivana
authors.initials: I
authors.lastname: Janatková
authors.affiliation: Laboratory of Clinical Immunology and Allergology, Institute of Medical Biochemistry and Laboratory Diagnostics, 1st Faculty of Medicine and General University Hospital, Charles University in Prague, Karlovo náměstí 32, 121 11 Prague 2, Czech Republic.
authors.forename: Tomáš
authors.initials: T
authors.lastname: Zima
authors.affiliation: Clinical and Research Center for Inflammatory Bowel Disease, ISCARE a.s. and Charles University, Prague, Czech Republic.
authors.forename: Milan
authors.initials: M
authors.lastname: Lukáš
keywords: Antibodies to infliximab; Antiphospholipid antibodies; Crohn’s disease; Inflammatory bowel diseases; Phosphatidylserine-dependent antiprothrombin antibodies; Ulcerative colitis