J. G. van der Bom

Mortality and causes of death in patients with hemophilia, 1992–2001: a prospective cohort study

Summary.  Background: Clotting factor products have been safe for HIV since 1985, and for hepatitis C since 1992. Few studies have reported on mortality in the total population of hemophilia patients after the period of risk of viral infection transmission. Objectives: We studied the mortality, causes of death, and life expectancy of hemophilia patients between 1992 and 2001. We compared these findings with those of previous cohorts, together spanning the periods before, during, and after the use of potentially contaminated clotting products. Patients and methods: We performed a prospective cohort study among 967 patients with hemophilia A and B. Death rates, overall and cause‐specific, were compared with national mortality figures for males adjusted for age and calendar period as standardized mortality ratio (SMRs). Results: Between 1992 and 2001, 94 (9.7%) patients had died and two patients were lost to follow‐up (0.2%). Mortality was 2.3‐times higher in hemophilia patients than in the general male population (SMR 2.3 95% confidence interval 1.9–2.8). In patients with severe hemophilia, life expectancy decreased from 63 (1972–1985) to 59 years (1992–2001). Exclusion of virus‐related deaths resulted in a life expectancy at birth of 72 years. Conclusions: AIDS was the main cause of death (26%) and 22% of deaths were because of hepatitis C. In patients not affected by viral infections, there still appeared to be a trend toward a moderately increased mortality compared with the Dutch male population. Thus, mortality of patients with hemophilia is still increased; this is largely because of the consequences of viral infections.

Prophylactic versus on‐demand treatment strategies for severe haemophilia: a comparison of costs and long‐term outcome

Summary.  A multicentre study was performed to compare clotting factor use and outcome between on‐demand and prophylactic treatment strategies for patients with severe haemophilia. Data on treatment and outcome of 49 Dutch patients with severe haemophilia, born 1970–80, primarily treated with prophylaxis, were compared with those of 106 French patients, who were primarily treated on demand. Dutch patients received intermediate dose prophylaxis, for a median duration of 12.7 years. Patients primarily treated with prophylaxis had fewer joint bleeds per year (median 2.8 vs. 11.5), a higher proportion of patients without joint bleeds (29% vs. 9%), lower clinical scores (median 2.0 vs. 8.0), and less arthropathy as measured by the Pettersson score (median 7 points vs. 16 points). Mean annual clotting factor use was equal at 1488 ± 783 IU kg−1 year−1 (mean ± standard deviation) for patients primarily treated with prophylaxis and 1612 ± 1442 IU kg−1 year−1 for patients primarily treated on demand. These findings suggest that, compared with a primarily on‐demand treatment strategy, a primarily prophylactic treatment strategy leads to better outcome at equal treatment costs in young adults with severe haemophilia.

Long-term outcome of individualized prophylactic treatment of children with severe haemophilia.

The development of arthropathy is a serious complication of severe haemophilia. With the use of prophylaxis, bleeds can be prevented and arthropathy delayed. We investigated whether an individually tailored prophylactic regimen can prevent arthropathy and whether it had a similar effect on orthopaedic outcome compared with that of a high‐dose regimen. Efficacy was determined clinically and by radiographs of six major joints. Prophylaxis was started in 70 patients at a mean age of 4·1 years. Mean follow‐up was 15·6 years (range 8–24·5 years). The mean factor VIII consumption was 2319 IU/kg/year. The mean number of joint bleeds was 3·5/year and the mean clinical score (maximum score 90) was 1·0, with a mean Pettersson joint score (maximum score 78) of 3·0 at a mean age of 13·5 years. In conclusion, long‐term, early‐onset, individualized prophylaxis in haemophilia is feasible and prevents arthropathy.

Prophylactic treatment for severe haemophilia: comparison of an intermediate‐dose to a high‐dose regimen

Summary.  A multicentre study was performed in Sweden and the Netherlands, comparing effects of two prophylactic regimens in 128 patients with severe haemophilia, born 1970–90. 42 Swedish patients (high‐dose prophylaxis), were compared with 86 Dutch patients (intermediate‐dose prophylaxis). Patients were evaluated at the date of their last radiological score according to Pettersson. Annual clotting factor consumption and bleeding frequency were registered for a period of three years before evaluation. Patients in the high‐dose group were younger at evaluation (median 15.2 vs. 17.9 years), started prophylaxis earlier (median 2 vs. 5 years), and used 2.19 times more clotting factor kg−1 year−1. Patients treated with high‐dose prophylaxis had fewer joint bleeds (median 0.3 year−1 vs. 3.3 year−1) and the proportion of patients without arthropathy as measured by the Pettersson score was higher (69% vs. 32%), however, the age‐adjusted difference in scores (median 0 points vs. 4 points) was small and at present not statistically significant. Clinical scores and quality of life were similar. These findings suggest that, compared with intermediate‐dose prophylaxis, high‐dose prophylaxis significantly increases treatment costs and reduces joint bleeds over a period of 3 years, but only slightly reduces arthropathy after 17 years of follow‐up.

Treatment characteristics and the risk of inhibitor development: a multicenter cohort study among previously untreated patients with severe hemophilia A

Context: The development of inhibitory antibodies against infused factor (F) VIII is a major complication of treatment of patients with severe hemophilia A.Objective: This study was set up to examine the effects of treatment‐related factors on inhibitor development among previously untreated patients with severe hemophilia A.Design, setting and patients: In this multicenter cohort study, we combined individual patient data obtained from four recombinant FVIII product registration studies (Kogenate®, Kogenate Bayer®, Recombinate®, ReFacto®) that were performed between 1989 and 2001. From the databases we selected all 236 previously untreated patients with severe hemophilia A who were subsequently treated with FVIII on at least 50 days.Main outcome measures: Clinically relevant inhibitor development, defined as the occurrence of at least two positive inhibitor titers and a decreased recovery.Results: 67 patients (28%) developed clinically relevant inhibitors (44 high‐titer) at a median of ten exposure days. Age at first exposure was not associated with inhibitor development. Peak treatment moments and surgical procedures were related to an increased inhibitor risk [adjusted relative risk 1.6 (95% confidence interval 1.0–2.6) and 2.7 (95% confidence interval 1.3–5.7), respectively]. A shorter duration between exposure days was associated with an increased risk of inhibitor development. There was a possible association between dosing of FVIII and inhibitor development, which largely disappeared after adjustment for confounding factors.Interpretation: These findings show that intensive treatment periods are associated with an increased risk of inhibitor development in previously untreated patients with severe hemophilia A. Our results do not support the notion that age at first exposure is associated with the risk of developing inhibitors.

Changes in treatment strategies for severe haemophilia over the last 3 decades: effects on clotting factor consumption and arthropathy

A cohort study was performed among 214 patients with severe haemophilia, born 1944–1994, to describe changes in treatment over the last 3 decades and its effects on clotting factor consumption and haemophilic arthropathy. Data on treatment strategy, clotting factor consumption, and outcome were collected for 3567 patient years (from 1972 to 1998), and 493 Pettersson scores were analysed. Median follow up was 17 years (range 6–27 years), and median age in 1998 was 27.6 years. Since 1965, replacement therapy, prophylaxis, and home treatment have been used and treatment intensified. Over the last 3 decades, annual clotting factor consumption increased by 260%, for both prophylactic and on‐demand treatment. Annual clotting factor consumption kg–1 increased during childhood and appeared to stabilize in early adulthood for patients born 1965–79, who were treated with early replacement therapy or early prophylaxis. In contrast, clotting factor consumption increased continuously for patients born before 1965, who had had no access to replacement therapy during the early years of their life. The annual number of joint bleeds decreased over the years. Arthropathy as measured by the Pettersson score generally became apparent around the age of 15 years and was lowest in patients treated with primary prophylaxis. In conclusion, clotting factor consumption has increased and haemophilic arthropathy has decreased due to the intensification of treatment for severe haemophilia over the last 3 decades. Annual clotting factor consumption stabilizes in adulthood for patients who receive early intensive treatment.

Variability in clinical phenotype of severe haemophilia: the role of the first joint bleed

Summary.  To quantify variation in clinical phenotype of severe haemophilia we performed a single centre cohort study among 171 severe haemophilia patients. Age at first joint bleed, treatment requirement (i.e. annual clotting factor use), annual bleeding frequency and arthropathy were documented. Because treatment strategies intensified during follow‐up, patients were stratified in two age groups: patients born 1968–1985 (n = 91), or 1985–2002 (n = 80). A total of 2166 patient‐years of follow‐up were available (median 12.0 years per patient). Age at first joint bleed ranged from 0.2 to 5.8 years. Patients who had their first joint bleed later needed less treatment and developed less arthropathy. In patients born 1968–1985 during both on‐demand and prophylactic treatment, the 75th percentile of annual joint bleed frequency was consistently four times as high as the 25th percentile. In both age groups variation in annual clotting factor use between 25th and 75th percentiles was 1.4–1.5 times for prophylaxis and 3.8 times for on‐demand treatment. To conclude, the onset of joint bleeding is inversely related with treatment requirement and arthropathy and may serve as an indicator of clinical phenotype. Thus, providing a starting point for aetiological research and individualization of treatment.

The contribution of hysterectomy to the occurrence of urge and stress urinary incontinence symptoms

Objective To study the contribution of hysterectomy to the occurrence of urge‐or stress urinary incontinence symptoms

Discontinuation of prophylactic therapy in severe haemophilia: incidence and effects on outcome.

A cohort study was performed to assess adherence to early prophylactic therapy and its effects on outcome in 49 patients with severe haemophilia born 1970–1980. Median age at start of prophylaxis was 5.5 years. The majority (69%) of patients interrupted prophylactic treatment one or more times of their own accord (median total interruption 2.2 years). Patients who discontinued prophylaxis at any point tended to have more arthropathy as measured by the Pettersson scale (median 8 points versus 4 points). One‐third of these patients interrupted prophylaxis for longer periods and had permanently stopped taking prophylaxis at a mean age of 20.1 years (mean ± SD duration 4.1 ± 4 years) and consequently experienced 5.4 ± 3.4) joint bleeds per year. This subgroup could be identified by a predictive score based on age at start of prophylaxis, weekly dose of prophylaxis, and joint bleed frequency on prophylaxis. In conclusion, while on prophylaxis, more than two‐thirds of patients with severe haemophilia try to discontinue treatment, resulting in slightly more arthropathy. One‐third of these patients permanently discontinue prophylaxis in adulthood, while maintaining a low number of joint bleeds.

Elevated Plasma Fibrinogen Cause or Consequence of Cardiovascular Disease

An association between increased plasma fibrinogen and an increased risk for myocardial infarction (MI) is well established, but the nature of this association is subject to debate. Our aim was to shed light on the potentially causal nature of this association. We examined whether increased plasma fibrinogen, due to a condition that is independent of cardiovascular events, also increases the risk for MI. A case-control study was performed in 139 subjects with a history of MI and 287 control subjects selected from the Rotterdam Study, a population-based cohort of 7983 subjects aged 55 years and older. The genotype of the -455G/A polymorphism in the fibrinogen beta-gene was determined by polymerase chain reaction. Functional plasma fibrinogen levels were determined according to von Clauss. The plasma level of fibrinogen was significantly higher in subjects with one or two A alleles compared with subjects with the GG genotype: 3.8 (95% confidence interval [CI], 3.6 to 3.9) g/L and 3.6 (3.5 to 3.7) g/L, respectively. With increasing plasma fibrinogen level, the risk for MI increased gradually; a rise in fibrinogen of 1 g/L was associated with a 45% increased risk (odds ratio adjusted for age, sex, and smoking, 1.45; 95% CI, 1.12 to 1.88). There was no association between the genotype of the -455G/A polymorphism and the risk for MI. The -455G/A polymorphism is therefore associated with increased plasma fibrinogen levels but not with an increased risk for MI. These findings indicate that an increased plasma fibrinogen level due to this genetic factor does not increase the risk for MI.