Mortality in hereditary antithrombin-III deficiency--1830 to 1989

To determine whether antithrombin-III (AT-III) deficiency leads to an excess mortality, we studied 171 individuals from ten families with a proven hereditary deficiency. 73 were classified as certainly deficient either by direct measurement of AT-III concentration or by mendelian inheritance patterns. 98 individuals had a high probability (0.5) of deficiency. The 64 deaths recorded did not exceed those expected for the general population adjusted for age, sex, and calendar period. We suggest that a policy of prophylactic anticoagulation for patients with AT-III deficiency cannot be recommended.

Sex ratio of the mutation frequencies in haemophilia A: estimation and meta-analysis

A hereditary disease with excess mortality such as haemophilia is maintained in the population by the occurrence of new cases, i.e. mutations. In haemophilia, mutations may arise in female or male ancestors of a 'new' patient. The ratio of the mutation frequencies in males over females determines the prior risk of carriership of the mother of an isolated patient. An estimate of this prior risk is required for the application of Bayes' theorem to probability calculations in carriership testing. We have developed a method to estimate the sex ratio of the mutation frequencies; it does not depend on the assumption of genetic equilibrium, nor require an estimate of the reproductive fitness of haemophilia patients and carriers. Information from 462 patients with severe or moderately severe haemophilia A was gathered by postal questionnaires in a survey that included practically all Dutch haemophiliacs. Pedigree analysis was performed for the 189 patients of these 462, who were the first haemophiliacs in their family. By the maximum likelihood method, the ratio of the mutation frequencies in males and females was estimated at 2.1, with a 95% confidence interval of 0.7-6.7. In addition, we performed a meta-analysis of all published studies on the sex ratio of the mutation frequencies. When the results of six studies were pooled, it was estimated that mutations originated 3.1 times as often in males as in females. The 95% confidence interval was 1.9-4.9. This implies that 80% of mothers of an isolated patient are expected to be haemophilia carriers.

Modern haemophilia treatment: medical improvements and quality of life

Adequate replacement therapy in haemophilia has been available for two decades. This has led to considerable improvements in the life expectancy and physical status of haemophilia patients. A study was conducted to investigate whether this has also led to improvements in quality of life. With this aim, information was obtained from 935 Dutch haemophiliacs by mailed questionnaires on relationships, marriage, family life and employment. Haemophilia patients were less often married than men in the general population (13% fewer) and had a lower total number of children (30% lower, 17% for those who were married). Twenty-two per cent of the patients were not employed and received an income from the disability funds. While severity of haemophilia, joint damage and age increased the risk of disability, it was noted that home treatment was associated with a 50% reduction in this risk. Remarkably, haemophilia patients did not differ from the general population in their view of the quality of their own health. The results of this study show a positive influence of modern haemophilia treatment on quality of life. At present, AIDS overshadows all optimistic feelings one may have about this field. However, the results described here demonstrate the benefits that can be achieved with adequate replacement therapy, and justify the expectation of further improvements in the near future.

Hereditary protein S deficiency in young adults with arterial occlusive disease

Protein S is the vitamin K dependent cofactor of activated protein C. It has an important role in the regulation of blood coagulation and fibrinolysis. Hereditary protein S deficiency is associated with familial venous thrombophilia. Since a few patients with arterial occlusions have been reported to be protein S deficient, it is speculated that hereditary protein S deficiency may be also a risk factor for the development of arterial thrombosis. In a group of 37 consecutive patients with arterial occlusive disease presenting before the age of 45, three patients were found heterozygous for hereditary protein S deficiency. None of the patients had a protein C deficiency or an antithrombin III deficiency. Family investigations showed a clear association between the hereditary deficiency and venous thrombosis, but a relation between the deficiency and arterial thrombosis was less obvious. A review of previous literature on patients with arterial thrombosis and protein S deficiency revealed that more extensive studies are needed to demonstrate whether or not hereditary protein S deficiency is a risk factor for the development of arterial thrombosis.

Carrier testing and prenatal diagnosis for hemophilia: experiences and attitudes of 549 potential and obligate carriers

Experiences with and attitudes toward carrier testing and prenatal diagnosis were evaluated among 549 potential and obligate carriers of hemophilia. Almost everybody considered carrier testing to be useful. Forty-nine percent had been tested for carriership, 10% had only received limited information, and 41% had not been tested and had never received information about the heredity of hemophilia. More married women, women with severe hemophilia in their family, and women closely related to a patient with hemophilia had been tested for carriership than others. Lack of information about the probability of carriership for female relatives and a similar ignorance of the possibility of carrier testing were important reasons for not having been tested. Eleven percent of the women with one or more children had undergone prenatal diagnosis in the past. Thirty-one percent of the study population would favour prenatal diagnosis with the implication of a potential abortion in early pregnancy and half of them would choose this option even in late pregnancy. Most of the women who objected to prenatal diagnosis did so because they did not consider hemophilia to be a sufficiently serious disorder to justify an abortion.

Haemophilia protects against ischaemic heart disease: a study of risk factors

We previously reported that mortality due to ischaemic heart disease was lower in haemophilia patients than in the general male population. To support the hypothesis that this could be attributed to a protective effect of the clotting defect in haemophilia and not to differences in cardiovascular risk factors, we performed a second study. We examined 95 haemophilia patients for the presence of major risk factors for ischaemic heart disease and compared their risk factor profile with the data of epidemiologic surveys of the general Dutch population. Haemophilia patients had on average higher blood pressures than the comparison population, were more often hypertensive and used antihypertensive drugs twice as often. The mean serum cholesterol level of the patients was markedly lower than in the comparison population (4.8 versus 5.6 mmol/l, 95% confidence interval of the difference: 0.5-1.1 mmol/l). The risk factors were weighted into one theoretical risk ratio for ischaemic heart disease by application of logistic regression coefficients. The theoretical risk ratio based on the risk factor profile was 0.78. This risk ratio can only explain a moderate reduction in the incidence of ischaemic heart disease, much smaller than the mortality ratio of 0.20 we reported previously. Therefore these data support the hypothesis of a direct protective effect of haemophilia on the development of ischaemic heart disease.

[Social effects of current hemophilia treatment]

The influence of modern substitution therapy on social functioning of haemophiliacs was studied by means of surveys of education and employment in 1972, 1978 and 1985. In addition we studied the physical mobility of the patients. Non-attendance at school and educational delay decreased substantially over thirteen years and the educational level of adult patients is the same as that of the general male population. Sick leave decreased also but the number of disabled did not. Considering the general rise in the number of disabled, the general unemployment situation may be partly blamed for this. Younger patients have a better physical mobility than the older ones who did not have appropriate treatment of bleedings when they were young. Trends in reduction of joint impairment and increase of physical mobility are expected to continue in the coming decades, with a positive effect on social functioning.

Physical condition, longevity, and social performance of Dutch haemophiliacs, 1972-85

A study was carried out among haemophiliacs in The Netherlands to evaluate the effect of modern substitution treatment (replacing the missing clotting factors) on medical and social performance. Three questionnaires were sent between 1972 and 1985. The use of prophylactic treatment in the group of patients with severe and moderately severe haemophilia increased from 21% (n = 242) in 1972 to 36% (n = 559) in 1985. Home treatment programmes increased from 4% to 53%. Overall mortality was 2.1 times higher than in the general male population, which leads to a calculated life expectancy of 66 years compared with 74 years in the general male population. Severe joint impairment was prominent in the older age groups, reflecting insufficient treatment in the past. A sharp decrease in the use of inpatient and outpatient hospital facilities was observed as well as much less absence from school and work. It is concluded that the high costs of modern substitution treatment are fully justified.

Mortality and causes of death in Dutch haemophiliacs, 1973-86

Mortality figures were calculated for a group of 717 Dutch haemophiliacs over the period 1973-86. Follow-up was on average 10.9 years; no patients were lost to follow-up. The data were compared to the general male population by actuarial methods and patient-year analysis. Forty-three patients died, while 20 deaths were expected in a hypothetical group of non-haemophiliacs of the same age distribution. Hence, overall mortality was 2.1 times higher than in the general population. This leads to a calculated life expectancy of 66 years, as compared to 74 years in the general male population. Mortality did not differ much by severity of haemophilia. A possibly beneficial effect of prophylaxis on longevity was observed. Haemorrhage occurred in half of all deaths and among these traumatic bleeding was the most prevalent. The number of deaths due to ischaemic heart disease was significantly lower (80% reduction) than expected and therefore the authors conclude that haemophilia offers protection against ischaemic heart disease. Cancer mortality was significantly higher (2.5 times) than expected.

Employment of individuals with haemophilia in The Netherlands

A study was performed to determine whether improvements in the treatment of haemophilia over the past 20 years have influenced the prospects of these patients in the labour market. Surveys on the medical and social situation of haemophiliacs in The Netherlands were carried out in 1972, 1978 and 1985. Most of the patients participated in these surveys. Trends in employment do not show either an increase in the number of employed haemophiliacs or a decrease in the number administratively defined as disabled. However, considering the influence of the economic recession on the position of the chronically sick on the labour market and the rise in the number administratively defined as disabled in the Dutch population, haemophiliacs perform well. Sick leave has decreased considerably. Although the employment rate for the group of haemophiliacs is lower than that for the general male population, the level of employment in relation to educational achievements is high and most of the employed do not feel limited in their daily job activities by the haemophilia. Physical mobility is a main factor influencing the employment status but other factors, such as the type of occupation or former occupation and prejudice against people with haemophilia, have to be considered.

AIDS and haemophilia. A study among Dutch haemophiliacs on the psychological impact of the AIDS threat, the prevalence of HIV antibodies and the adoption of measures to prevent HIV transmission

More than 75% of all Dutch haemophiliacs participated in a mail survey that included a section on acquired immunodeficiency syndrome (AIDS). Although no cases of haemophilia-related AIDS had been reported in the Netherlands at the time of our survey, the threat of AIDS had caused considerable anxiety among Dutch haemophiliacs. This had led almost a third of the patients to change their therapy schedules. These changes were mostly not beneficial and possibly counterproductive, since they were not likely to reduce the risk of human immunodeficiency virus (HIV) infection. Measures that were advised to prevent HIV transmission, such as the use of condoms, were seldom carried out, even by the 17% seropositive individuals. We conclude that an increase in the informational efforts towards the patients is called for to avoid ill-advised treatment changes and to enhance preventive behaviour.