Twenty‐five years' experience of prophylactic treatment in severe haemophilia A and B

TLDR

Since 1958 Sweden has used prophylactic factor replacement in boys with severe haemophilia to shift the disease toward a milder course. The study followed 60 severe haemophiliacs (52 A, 8 B, ages 3–32) who began prophylaxis at 1–2 years old, receiving 24–40 IU/kg F VIII three times weekly (≥2000 IU/kg annually) for A or 25–40 IU/kg F IX twice weekly for B, with joint scores assessed per WHO guidelines. Results showed that 29 of 35 children aged 3–17 had zero joint scores, the oldest group had only minor defects, factor levels remained above 1 %, and all 60 patients lead normal lives, indicating that early continuous prophylaxis prevents haemophilic arthropathy.

Abstract

In Sweden, prophylactic treatment of boys with severe haemophilia has been practised since 1958 in an attempt to convert the disease from a severe to a milder form. The present study population consisted of 60 severe haemophiliacs (52 A, 8 B), aged 3–32 years. Treatment is started when the boys are 1–2 years of age, the regimens used being 24–40 IU F VIII kg −1 three times weekly in haemophilia‐A cases (i.e. > 2000 IU kg −1 annually) and 25–40 IU F IX kg −1 twice weekly in haemophilia‐B cases. The orthopaedic and radiological joint scores (maximum scores of 90 and 78, respectively) are evaluated as recommended by the World Federation of Haemophilia. Of those subjects aged 3–17 years, 29 out of 35 individuals had joint scores of zero. The oldest group had only minor joint defects. The VIII:C and IX:C concentrations had usually not fallen below 1% of normal. All 60 patients are able to lead normal lives. In conclusion, it appears to be possible to prevent haemophilic arthropathy by giving effective continuous prophylaxis from an early age, and preventing the VIII:C or IX:C concentration from falling below 1% of normal.