Introduction: 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. Outcome: 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. Conclusion: 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 long-term cost-effectiveness has to be carefully evaluated.
Mr ZBH was a 30-year-old man with a history of severe haemophilia A with 0% factor VIII (FVIII). He was initially supported with cryoprecipitate but was switched to FVIII concentrate in 1995. He first developed FVIII inhibitor in 1995 and his inhibitor level fluctuated between 0.3 and 2 BU. In view of his low inhibitor level, support with FVIII concentrate was continued. However, in 2003, Mr ZBH began to develop a higher inhibitor level, which peaked at 5 BU, and the factor concentrate support was subsequently changed to FEIBA, factor VIIa (FVIIa) or factor IX prothrombin complex. In the same year, he sustained a knee joint infection after the revision of his left knee replacement operation. After much deliberation, above-knee amputation was planned and the challenge was to support him during this operation.
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