In order to address the question of the optimum target level for prophylactic treatment
of severe haemophilia patients, the association between endogenous clotting factor
activity and outcome was studied in a cohort of 46 patients with moderate haemophilia.
Data on treatment and outcome were collected annually.
Median follow-up was 8.0 years (range 1-26). Median joint bleed frequency was 1 per
year and median radiological score according to Pettersson was 1 point (max. 78) at
the age of 25 years. One percent increase in clotting factor level was associated
with a 4 months later onset of joint bleeds (95% Confidence Interval (CI): 2-6 months)
and a 16% lower Pettersson score (95% CI: 3-27%). No statistically significant effect
of clotting factor activity on joint bleed frequency could be demonstrated.
These findings confirm that patients with moderate haemophilia experience only mild
arthropathy, and provide evidence for a protective effect of higher clotting factor
levels on joint damage.
1
Ramgren O.
Haemophilia in Sweden III. Symptomatology, with special reference to differences between
haemophilia A and B. Acta Med Scan 1962; 171: 237-42.
5
Löfqvist T,
Nilsson IM,
Berntorp E,
Pettersson H.
Haemophilia prophylaxis in young patients – a long-term follow-up. J Intern Med 1997;
241: 395-400.
7
Bouma BN,
Starkenborg AE.
Dilution of haemophilic plasma used as a reagent in the determination of anti-haemophilic
factor A (factor VIII). Haemostasis 1974; 03: 94-7.
8
Mannucci PM,
Pareti FI,
Ruggeri ZM.
1-Deamino-8-D-arginine vasopressin: a new pharmacological approach to the management
of hemophilia and von Willebrand’s disease. Lancet 1977; 01: 869-72.
10
Pettersson H,
Nilsson IM,
Hedner U,
Norehn K,
Ahlberg A.
Radiologic evaluation of prophylaxis in severe haemophilia. Acta Paediatr Scand 1981;
70: 565-70.
12
Aledort LM,
Haschmeyer RH,
Pettersson H.
A longitudinal study of orthopaedic outcomes for severe factor-VIII-deficient haemophiliacs.
The Orthopaedic Outcome Study Group. J Int Med 1994; 236: 391-9.
13
Ahlberg A.
Haemophilia in Sweden VII. Incidence, treatment and prophylaxis of arthropathy and
other musculo-skeletal manifestations of haemophilia A and B. Acta Orthop Scand 1965;
77 (suppl) 5-99.