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The experience with immune tolerance (IT) induction therapy for haemophilia patients with inhibitors, instituted during 1990-97 at 17 haemophilia treatment centres in the western United States, was reviewed. IT was instituted in 104 of 139 (75%) of all identified haemophilia A and haemophilia B patients with inhibitors. Doses and schedules for IT varied but most patients were treated with a daily administration of 25-200 units kg-1 day-1. Successful immune tolerance (defined as Bethesda Unit titres < 1.0) was achieved in 57 of 81 (78%) patients who completed therapy. IT success was significantly greater for those patients with historic titres < 100 BU (P < 0.0003) and those with titres of < 10 BU at initiation of IT (P < 0.0001). IT success was uniformly achieved in 16 patients with low to moderate responding inhibitors. IT in infants < 2 years of age was problematic due to the presence of high titre inhibitors and complications of venous access. Frequent complications of IT included increased bleeding during intravenous access device insertion (20%) and infections associated with venous access devices (64%). IT is widely accepted as a treatment modality for haemophilia patients with inhibitors. Patient participation in IT regimens and management during therapy is facilitated greatly by the efforts of treatment centre nurse coordinators who are knowledgeable about haemophilia and its complications. Additional clinical trials will be necessary to define better initial dose, schedule, dose adjustment and success/failure criteria for IT.

Purpose: Although intracranial hemorrhage remains a leading cause of death in hemophilia, spinal epidural hematoma is seen rarely. Decompressive laminectomy has a high associated morbidity, and recent reports have suggested that patients can be treated conservatively without surgical intervention., Patients and Methods: We present a case of spontaneous spinal epidural hematoma diagnosed by MRI scan in a 6-month-old hemophilic infant. Immediate treatment with factor VIII replacement was instituted., Results: There was rapid and complete clinical and radiographic resolution., Conclusion: This case shows that selected hemophilic patients with spinal epidural hematoma can be spared surgical decompression by prompt medical attention.

Danazol, a synthetic androgen reported to increase factor VIII and IX activity levels, was given to 6 hemophiliacs. With danazol therapy (600 mg/da) the APTTs shortened by 30-45% of pre-treatment times. However, the activity levels of the deficient factors did not increase significantly nor consistently with the APTT change. The prothrombin times and activity levels of factors XI and XII also did not change during the study period. Addition of plasma from danazol-treated patients to plasma with a known factor VIII inhibitor and to plasma from an untreated severe hemophilia A patient caused a similar shortening of the respective APTTs. Absorption of the danazol plasma with precipitating antibody against factor VIII and IX did not remove the APTT correcting principal. The data suggest that danazol may cause the de novo appearance of an intrinsic coagulation pathway activator having factor VIII and IX bypassing activity.

Current medical management programs for established joint diseases in hemophiliacs are unsatisfactory and do not modify the eventual outcome. D-penicillamine, a drug effective in the proliferative synovitis of rheumatoid arthritis, was evaluated in a rabbit model of hemarthroses-induced arthritis and in four hemophiliacs with chronic synovitis. The animals had intra-articular injections of citrate (left knees) and autologous citrated whole blood (right knees). Eight weeks later, the rabbits were divided into two groups: no treatment and D-penicillamine (50 mg/kg/day, IM) until sacrificed at 6 months. The saline-injected joints showed no inflammation and no iron deposition. The blood-injected knees showed iron deposition in both groups, the D-penicillamine animals had marked suppression of chronic inflammation. Of the four patients treated, three had clinical responses (reduction in synovial thickness, reduction in number of bleeds in the affected joint). One patient, who did not respond, developed mild-moderate proteinuria. Those patients who responded received between 5.3 and 7.1 mg/kg/day of the drug. Mild abnormalities in platelet aggregation were seen in the responders. This preliminary study suggests that D-penicillamine is beneficial in the chronic synovitis/arthritis induced by hemarthroses. Further trials are recommended.

Danazol was given orally at a dose of 600 mg/day to six hemophiliacs for eight to 14 weeks. All patients showed a significant decrease in activated partial thromboplastin time (APTT) beginning with the first measurement (two weeks) and persisting until use of the drug was discontinued. However, a corresponding increase in the deficient factor activity could not be consistently demonstrated. Despite the shortened APTT, bleeding episodes continued in the severe hemophiliacs and the patient with Christmas disease. In four patients, bleeding appeared to increase in severity or change in pattern, and in two cases the bleeding manifestations did not respond to usual factor infusions but responded to discontinuation of the drug therapy and further factor replacement. Euglobulin lysis times were measured in five patients (one hemophiliac and four with nonhemophilic conditions) who were receiving danazol. The lysis times were markedly shortened. Increased fibrinolytic activity may be responsible for the increased bleeding manifestations in danazol-treated hemophiliacs.