Anticoagulant antibodies in the synovial membranes of patients suffering from haemophilia, rheumatoid arthritis and other rheumatic disorders

Musculoskeletal disorders in the haemophilias

The management of the haemophilias has been improved by the advent of potent consistent clotting factor replacement therapy. The previously lethal major complications such as intracerebral haemorrhage are now rare, and the infective complications of treatment, most notably hepatitis and AIDS, are now potentially preventable with the new synthetic products. There is also the prospect of 'cure' by gene insertion therapy. Advanced arthropathy has been minimized but not prevented by early effective treatment of haemarthroses, and there is a diminishing legacy of severely affected patients many of whom may require joint replacement surgery. The present group of such patients has a high prevalence of HIV-1 infection and an increased risk of joint sepsis. The available avenues of treatment for the subacute stage of the arthropathy have not been particularly effective, emphasizing the need to prevent recurrent bleeding. The development of a multidisciplinary team-management approach in centres of expertise has been a significant factor in the improved longevity, life satisfaction and preserved mobility now available to most haemophiliacs.

Agarose gel method: its usefulness in assaying factor VIII inhibitors, evaluating treatment and suggesting a mechanism of action for factor IX concentrates

Plasmas from 14 patients with factor VIII inhibitors, 10 haemophiliacs and four non-haemophiliacs, were assayed by both the agarose gel and Bethesda methods. Good correlation was observed in 34 samples from 13 patients, but there was poor correlation in three samples from a single haemophilic patient. The sensitivity of the method was increased by diluting normal platelet rich plasma (PRP) with congenital factor VIII deficient plasma. With this modification, as little as 0.4 of a Bethesda unit (Bu) could be measured accurately. The agarose method is easier to perform and requires much less technician time than the Bethesda assay (Ba). Inhibitory activity can be measured even in the presence of large amounts of transfused factor VIII or factor IX concentrates. To study the effect of factor IX concentrates on the inhibitor, the method was modified by incorporating into the gels plasmas specifically deficient in either factor VII, IX or X. Our data suggest that factor VII is probably responsible for the 'bypassing' activity of factor IX concentrates.