A High Prevalence of Ankle Arthropathy in Mild and Moderate Haemophilia A in South Australia and a Threshold Effect of FVIII Level on Its Occurrence

Abstract number: P0804

Ling^1,2 M, Heysen³ J, Duncan¹ EM, Beard³ M, Rodgers¹ SE, Lloyd^1,2 JV

^{1,2 1,21}Institute of Medical and Veterinary Science, Adelaide, Australia ¹¹Institute of Medical and Veterinary Science, Adelaide, Australia ³³Royal Adelaide Hospital, Adelaide, Australia

Ankle arthropathy due to recurrent bleeding in severe haemophilia A is well documented. Considerably less data is available on this joint for the mild and moderate group, but is known to occur in some of these patients. Our aim was to investigate the prevalence of ankle arthritis in the mild/moderate subgroup. In addition, the relationship between FVIII level and the presence of arthritis was explored. Ninety-two adult patients (21–66 years, median 45) with mild/moderate haemophilia A from the RAH/IMVS Haemophilia Centre were enrolled. The response rate from the primary survey was 63% (58/92) with 45% (26/58) reporting frequent ankle pain during the previous 4 weeks. Thirty-four individuals (16 with and 18 without ankle pain) were interviewed and a radiological (X-ray, WFH Pettersson scale) and physical evaluation (WFH scoring system) of ankle joints conducted. Using radiological diagnosis, the prevalence of ankle arthritis (score range 1–12 observed) was higher than expected at 48% (16/33). Physical evaluation tended to over-diagnose arthritis as 9 patients were positive (score range 1–6) but negative by radiology and with no pain. Forty-two percent (14/33) of these mild/moderate patients were positive for ankle arthropathy by both scoring systems, which is similar to the prevalence previously reported for severe haemophilia. In contrast to the severe patients, joints other than ankle were rarely involved in the mild/moderate cases. The symptom of ankle pain appeared to have a high sensitivity (88%) and specificity (88%) compared to radiological diagnosis. Of interest, FVIII level demonstrated a threshold effect on the presence of arthritis diagnosed by radiology: there was an abrupt increase in patients with a positive score with FVIII <15% by one-stage or <5% by two-stage assay. The results suggest the need for more aggressive prophylactic and therapeutic management of ankle joint bleeding in mild/moderate haemophilia A.