title: Case report: induction of immune tolerance to factor VIII inhibitor after a major operation.
abstract: BACKGROUND
  We report a successful case of immune tolerance to factor VIII (FVIII) inhibitor after a major operation. An attempt was made to induce immune tolerance with inhibitor in a haemophilia A patient, who was required to undergo an above-knee amputation. We opted to give high-dose FVIII infusion with no immunosuppression.
  
  
  RESULTS
  The highest preoperative FVIII inhibitor level was 5 BU and the peak postoperative FVIII inhibitor level was 1.5 BU demonstrated on Day 9 post operation. High-dose FVIII support was provided during the perioperative period and continued with a low maintenance dose to achieve a FVIII level of 30% to 40%. The requirement of high-dose FVIII lasted from day 6 to 23 post operation and this was tailed down to a maintenance dose over the next 37 days. There were only 2 episodes of mild oozing from the wound at around Day 9, which coincided with the peak postoperative FVIII inhibitor level. Both bleeding episodes were arrested adequately by administering a single dose of FEIBA during each episode. Immune tolerance was demonstrated after around 3 months and a follow-up period of 233 days showed no recurrence of FVIII inhibitor with the normalisation of FVIII half-life study.
  
  
  CONCLUSIONS
  After immune tolerance, the patient suffered fewer episodes of joint haemorrhage and required a lower amount of FVIII infusion as well. The cost may be high initially but the longterm cost-effectiveness has to be carefully evaluated.
authors.affiliation: Department of Pathology, Singapore General Hospital, Singapore. gpthlp@sgh.com.sg
authors.forename: Liam-Pock
authors.initials: LP
authors.lastname: Ho
authors.forename: Yoke-Kum
authors.initials: YK
authors.lastname: Ho
authors.forename: Sim-Leng
authors.initials: SL
authors.lastname: Tien
mesh_terms: D000328:Adult; D000671:Amputation, Surgical; D003029:Coagulants / Q000008:administration & dosage / Q000276:immunology*; D005169:Factor VIII / Q000008:administration & dosage / Q000276:immunology*; D006467:Hemophilia A / Q000150:complications*; D006801:Humans; D007108:Immune Tolerance / Q000187:drug effects*; D008297:Male; D019990:Perioperative Care; D011182:Postoperative Care
chemical_list: D003029:Coagulants; D005169:Factor VIII