HLA class II genotype and factor VIII inhibitors in mild haemophilia A patients with an Arg593 to Cys mutation.

We evaluated inhibitor formation in a group of patients with mild haemophilia A caused by an Arg593 to Cys mutation. A remarkably high cumulative inhibitor incidence of 14% over 22 years was observed. Three of 49 patients developed transient, low-titre inhibitors, which remained below 2.0 BU mL(-1). Four patients with an Arg593 to Cys mutation developed high-titre inhibitors (>5.0 BU mL(-1)). Three of these patients have been described previously. In this study, we characterized inhibitory antibodies in a fourth patient with high-titre inhibitors. Epitope mapping studies revealed that antibodies were predominantly directed to the A2 domain of factor VIII. We addressed the role of human leucocyte antigen (HLA) class II alleles in inhibitor development in patients with an Arg593 to Cys mutation by HLA genotyping. In the group of inhibitor patients raised frequencies of HLA-DRB1*01 and HLA-DQB1*05 were observed that did not reached statistical significance. Our data suggest that inhibitor development in mild haemophilia A patients with an Arg593 to Cys mutation is not linked to HLA class II profile.

The impact of unaware carriership on the clinical presentation of haemophilia.

This study was conducted to evaluate the effect of an unaware carriership on the delay in diagnosis of haemophilia and the resulting effect of this delay on morbidity. Information on 73 haemophilia patients (<18 years) and their mothers was gathered from data of patients' medical records and completed by interviews with the parent(s). Although a positive family history was present in 52 gravidae, 16 of them (31%) were not aware of their carrier status at moment of delivery. Fifteen of these 16 unaware carriers, were carriers of a non-severe form of haemophilia. In mothers who were unaware of carriership for haemophilia instrumental delivery occurred more frequently than in mothers who knew they were carriers. This is disquieting since instrumental delivery poses a significant risk (relative risk: 17.8, 95% CI: 4.0-78.4) for intra- or extracranial bleedings in newborn haemophiliacs in comparison to spontaneous deliveries or caesarean sections. In 83% of the patients with a positive family history, diagnosis was established before the first bleeding episode. Patients diagnosed by bleedings presented more often with iatrogenic bleedings (38%) then patients who were diagnosed because of a positive family history (9%) (P < 0.05). In comparison to previous studies, more patients had a positive family history and in more haemophiliacs with a positive family history diagnosis was established before the first bleeding episode. Although this reflects the yield of improved diagnostic methods, further reduction of iatrogenic bleeding is possible by intensifying counselling of mild haemophilia carriers.

Haemophilia patients aged 0-18 years in the Western Cape.

OBJECTIVES: To record the number of haemophilicas aged 0-18 years in the Western Cape (WC), what event led to the diagnosis, the level of clotting factor, treatment, functional status of their joints and impact of the disease on the family. DESIGN: A prospective study of patients registered with the South African National Haemophilia Registry and new patients, utilising the patients' paediatricians, hospital records, patient and guardian interviews, physical examination and provincial nurse haemophilia co-ordinators. SETTING: Haemophilia care centres at the three WC academic hospitals, regional hospitals and homes of patients. Two elective medical students, MHH and JJH, collected the information. SUBJECTS: All boys with confirmed haemophilia A or B in the WC. OUTCOME MEASURES: Events that led to diagnosis, degree of haemophilia, use of clotting factor, functional status, and effect on family. RESULTS: Of 78 patients (59 haemophilia A, 19 haemophilia B) identified, 49 could be studied. Forty-three per cent had severe, 29% moderate and 22% mild disease (6% unknown). Family history was present in 49%, but led to diagnosis in only 12%. The most common first symptoms were subcutaneous and mucosal bleeding. Delay in diagnosis varied from 0 to 9 months. Twenty-nine per cent of guardians were suspected of child abuse. RSA produced clotting factor was used 'on demand' in 73% of patients, for periodic prophylaxis in 20% and as continuous prophylaxis in 7%. Joints were functionally restricted in 43% of patients. The majority of guardians (59%) said the disease had a major impact on the family. CONCLUSIONS: The diagnosis of haemophilia in children with a positive family history was often delayed. Haemophilia causes significant morbidity in our patients and their families.