Case Report on a Female Patient with Congenital Haemophilia a and An Acquired Type-2 Inhibitor to FVIII

Only rare cases of female haemophilia have been reported. Moreover, no case of congenital haemophilia A associated with an acquired type-2 inhibitor to FVIII in a female child has been described in literature yet. We report the case of a 15-year old girl, diagnosed with severe haemophilia A (FVIII:C <1%) at the age of 13 months. Her father suffered from severe haemophilia A (FVIII:C <1%) due to an intron 22 inversion. In the girl both an intron 22 inversion and a non-random X-inactivation were found. At 3 years the girl received prophylactic treatment, and recombinant FVIII (3 × 40 IU/kg/week) from 6 years of age. Bleeding episodes were rare. Aged 13 she developed two large spontaneous haematomas. In-depth analysis confirmed decreased FVIII-recovery, –half-life and an inhibitor titre of 7.6 BU following type-2 kinetics (haemophilic autoantibodies). All of the few reported children with an aquired FVIII inhibitor presented with other autoimmune diseases or had used penicillin. Our patient showed none of this, but interestingly experienced menarche 4 weeks after inhibitor detection. This lets us speculate that the ethiology of the inhibitor formation in our patient at the time of hormonal change might be similar to that in pregnant or postpartum women.

Taking into account the recommendations of Ma et al. (2006) regarding inhibitor development during pregnancy in healthy women, we initiated a modified ITI with 75 IU/kg rFVIII concentrate (4,000 IU per infusion) every other day without additional immunosuppressive therapy. After 6 weeks of ITI, inhibitor titres declined and became negative after 8 months, resulting in a normal FVIII half-life till now.