Low-dose Tertiary Prophylactic Therapy for Severe Haemophilia A Adults in A Single Medical Center in Beijing Area / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the benefit of low-dose tertiary prophylaxis in adults with severe haemophilia A(SHA).</p><p><b>METHODS</b>Twenty-two SHA patients aged 18 to 60 years from the Haemophilia Centre of Peking Union Medical College Hospital, Beijing, China, were retrospectively observed from their one year on-demand treatment to one year tertiary prophylaxis using plasma derived factor 8 concentrates at 5-10 IU/kg 2-3x per week. All the patients had already developed arthropathy. Gilbert and the functional independence scores in hemophilia were used to assess the joint status and the ability in the activities of daily living of the patients.</p><p><b>RESULTS</b>Comparing with on-demand therapy,the annual bleeding frequency during low-dose tertiary prophylaxis decreased significantly by 72.7%,from 39.9 ± 21.5 to 11.1 ± 7.2 (P<0.0001),the total Gilbert score decreased from 50.5±32.1 to 45.2±29.6(P<0.05),and the total functional independence score in hemophilia score increased from 18.6 ± 5.2 to 21.7 ± 4.1 (P<0.05). CONCLUSION Low-dose tertiary prophylaxis in adults with SHA is beneficial by reducing bleeding frequency, improving the health status of joints, and improving the activities of daily living, thus raising the quality of life.</p>

Identification of seven novel mutations in the factor VIII gene in 18 unrelated Chinese patients with hemophilia A / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Hemophilia A (HA) is an X-linked inherited bleeding disorder caused by decreased activity of factor VIII (FVIII) due to heterogenous mutations in the FVIII coding gene (F8). The type of mutation plays an important role in the FVIII inhibitor formation. To date, several studies on the spectra of F8 defects have been performed in Western populations, but similar studies in Asian races are scarce. Here, we reported the distribution of the F8 gene mutations in 18 unrelated Chinese patients with HA.</p><p><b>METHODS</b>Intron 22 and intron 1 inversions in the F8 gene were screened in 158 unrelated patients with HA using a long-distance PCR and multiplex PCR method. Direct sequencing of the coding region of the F8 gene was used to identify the mutations responsible for HA in 18 unrelated Chinese HA patients who were negative for intron 22 and intron 1 inversions; sequences were compared with the HAMSTeRS database. A clotting method was used to assay the FVIII activity level and the Bethesda assay was used to detect the FVIII inhibitor.</p><p><b>RESULTS</b>A total of 18 different HA F8 mutations were identified, seven of which were described for the first time. These novel mutations included five small deletions, one point mutation and one small insertion. One novel mutation (4382-3 AC deletion) was associated with inhibitor development.</p><p><b>CONCLUSION</b>These data extend our insight into the mechanisms by which novel amino acid mutations may lead to HA and how the HA patient genotypes influence the risk of FVIII inhibitor.</p>

Frequency of factor VIII inhibitor in the patients with hemophilia A and environmental risk factors for inhibitor development / 中国医学科学院学报

<p><b>OBJECTIVE</b>To screen for factor VIII inhibitor in patients with hemophilia A (HA) and explore the environmental risk factors for inhibitor development.</p><p><b>METHODS</b>Totally 265 patients with HA were enrolled, including 107 consecutive inpatients and outpatients in Peking Union Medical College Hospital from April 2003 to April 2007 and 158 patients newly recruited from other hospitals. FVIII: C activity was measured by one-stage coagulation assay. FVIII inhibitor was determined using Bethesda method.</p><p><b>RESULTS</b>In 265 HA patients, FVIII inhibitor was detected in 22 patients (8.3%). Nine of them (86.4%) were low responders (inhibitor titers < or = 5 000 BU/L), 3 (13.6%) were high responders (the titers > 5 000 BU/L). The frequency of FVIII inhibitor was 50% in the patients aged over 50 years, which was significantly higher than those in other age groups (P = 0. 000). Among 158 newly recruited patients with full clinical data, the frequency of FVIII inhibitor was 12.8% in patients who had received infusion of FVIII products for more than 12 doses on average each year, while it was 5.8% in whom the infusion doses were less than 12 (P = 0.156). The frequency of FVIII inhibitor was 28.5% in patients with a history of continuous infusion of FVIII products whereas it was only 1.6% in patients without such history (P = 0.000). In patients who exposed to multiple-branded or single-branded FVIII products, the frequencies of FVIII inhibitor were 9.3% and 3.9%, respectively (P = 0.229).</p><p><b>CONCLUSION</b>The development of factor VIII inhibitor in patients with hemophilia A may be related to the age and the history of continuous infusion of FVIII products.</p>