Summary Hemophilia is a rare disorder that is complex to diagnose and to manage. These evidence‐based guidelines offer practical recommendations on the diagnosis and general management of hemophilia, as well as the management of complications including musculoskeletal issues, inhibitors, and transfusion‐transmitted infections. By compiling these guidelines, the World Federation of Hemophilia aims to assist healthcare providers seeking to initiate and/or maintain hemophilia care programs, encourage practice harmonization around the world and, where recommendations lack adequate evidence, stimulate appropriate studies.
In patients with hemophilia A and inhibitory alloantibodies against factor VIII, various dosage schedules are used to obtain immune tolerance. In this study, we have evaluated the results of 13 years of low-dose immune tolerance induction and factors that are predictive of a positive result. The effect of immune tolerance induction in relation to age at inhibitor development, number of exposure days, age at start of therapy, maximum inhibitor titer, factor VIII products involved, and virologic status were determined. We evaluated 24 patients with severe hemophilia A and inhibitors who were treated with regular infusions with low-dose (25 U/kg every other day) factor VIII to obtain immune tolerance. In 21 of 24 patients (87%), immune tolerance induction was successful. The response time was determined by two factors: the highest inhibitor level and the age at inhibitor development. In patients with maximum inhibitor levels of less than 40 Bethesda units (BU)/mL, immune tolerance was obtained sooner than in patients with inhibitor levels exceeding 40 BU/mL (P = .005). Patients in whom an inhibitor developed before the age of 2.5 years also tended to have a quick immune response (P = .014). Immune tolerance with low-dose factor VIII is often successful in hemophilia A patients with inhibitors. Young children and patients with maximum inhibitors of less than 40 BU/mL show a relatively rapid response.
Since the introduction of clotting factor concentrates, life expectancy of haemophilia patients is increasing and now approaches that of the general male population. Increasingly, haemophilia patients are confronted with age-related co-morbidity, including ischaemic cardiovascular disease. Treatment of stable angina pectoris and the acute coronary syndrome with antithrombotic therapy and percutaneous coronary intervention in haemophilia patients is feasible, but requires a tight co-operation between all specialists involved. As evidence-based guidelines are lacking, we developed a protocol on how we will treat haemophilia patients with ischaemic heart disease.
The development of antibodies to factor VIII (inhibitors) in response to clotting-factor concentrates administration in hemophilia is common during the first few years of treatment but rare in multitransfused patients. We have investigated the possible association of a recently introduced factor VIII concentrate (Factor VIII CPS-P) in The Netherlands with the occurrence of inhibitors. To this effect, we conducted two studies. First, we performed a national multicenter study in which clinical information and inhibitor test results were obtained for 447 hemophilia A patients over the period 1988 through 1991. Secondly, for a baseline comparison we estimated the frequency of inhibitor development in a closely followed cohort of 144 patients, from 1984 through 1989. Before the introduction of Factor VIII CPS-P, the incidence of new inhibitors was 4.4/1,000 patient-years in the national study from March 1988 through May 1990, and 3.9/1,000 patient- years in the cohort followed from 1984 through 1989. These figures are similar to the incidence of new inhibitors that was found in a large cohort of patients in the United States followed in the 1970s. In the period that the new concentrate Factor VIII CPS-P was on the market, from June 1990 through November 1991, 11 clinically relevant inhibitors were detected, which yielded an incidence over this interval of 20.1/1,000 patient-years, a 4.5-fold increase compared with the previous interval (C195: 1.4 to 14.3). Nine of these 11 patients had in their lifetime received over 250 infusions with factor VIII preparations. whereas all of the inhibitors detected in the previous time interval, and all of the 24 inhibitor patients described in the US study, had received less than 250 infusions in their lifetime. All patients who developed inhibitors after June 1990 had been exposed to Factor VIII CPS-P, whereas only 75% of the patients who did not develop an inhibitor had been exposed to this product. In a prospective extension of the study, with a second inhibitor measurement after 3 months, we found that one additional inhibitor had developed during 52.5 patient-years of Factor VIII CPS-P use. In conclusion, there has been a sudden increase in the frequency of inhibitor patients, for a large part among multitransfused patients. It seems more than likely that this increase is associated with the introduction of a new factor VIII concentrate in The Netherlands.(ABSTRACT TRUNCATED AT 400 WORDS)
Because of an increased life expectancy, (age-related) co-morbidity is becoming a common occurrence in haemophilia patients. In this review, haemophilia-related and non-haemophilia-related medical problems, treatment recommendations and psychosocial consequences in ageing haemophilia patients are discussed. Haemophilic arthropathy is an important cause of pain and disability, and a frequent indication for surgery in haemophilia patients. In addition, many adult patients are infected with hepatitis C or HIV, the consequences and treatment of which can add to physical and mental discomfort. Moreover, inhibitors against factor VIII can also develop in adulthood, especially in patients with mild haemophilia. Hypertension is reported to occur more often in haemophilia patients than in the general population. Other internal problems, like renal abnormalities, overweight, diabetes mellitus and hypercholesterolemia are discussed. Haemophilia seems to protect against cardiovascular disease, although the incidence is increasing. Recommendations are given on dealing with tooth extractions, surgical interventions and sexuality problems in patients with haemophilia. In addition to haemophilia in itself, co-morbidity has a major psychological impact, and an important effect on quality of life. It can also result in complex treatment regimens, in which coordination between health care workers is essential.
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