RESUMO
INTRODUCTION: Inherited Factor VII (FVII) deficiency is commonest among the rare bleeding disorders. A small number of patients present in infancy with severe bleeding, and many may remain asymptomatic but detected before surgery/invasive procedures. Genetic testing may be helpful in predictive testing/prenatal diagnosis in severe cases. AIM: Characterisation of clinical and genotypic spectrum of patients with inherited FVII deficiency. METHODS: Retro-prospectively, 35 cases with prolonged prothrombin time and FVII activity (FVII:C) <50 IU/dl were subjected to targeted resequencing. After in-silico analysis, variant/s were validated by Sanger sequencing in index cases and family members. Haplotype analysis was done for F7 polymorphisms. RESULTS: Severe FVII deficiency was found in 50% of patients (FVII:C ≤1 IU/dl), and 42.9% were asymptomatic. Clinical severity assessment revealed 17% severe, 17% moderate and 22.9% patients with mild bleeds. FVII levels ranged from .3 to 38 IU/dl. Molecular analysis revealed variants in 30/35 cases, of which 17 were homozygous, 10 were compound heterozygous and 3 were heterozygous. Twelve genetic variants were identified, one promoter variant c.-30A>C; seven missense (c.215C>G, c.244T>C, c.253G>C, c.904G>A, c.961C>T, c.1109G>T, c.1211G>A), two deletions (c.21delG, c.868_870delATC), and one each of nonsense c.634C>T and splice-site variant c.316+1G>A. Recurrent variants c.1109G>T and c.215C>G were found in 17 and 8 cases, 12 of the former cases were homozygous. They had the same haplotype, indicating the founder effect in North Indians. CONCLUSION: This is the largest cohort of FVII genotyping from India, confirming heterogeneity in terms of clinical manifestations, FVII activity and zygosity of the variants with a limited genotypic phenotypic correlation.
Assuntos
Transtornos da Coagulação Sanguínea , Deficiência do Fator VII , Humanos , Efeito Fundador , Mutação , Deficiência do Fator VII/diagnóstico , Deficiência do Fator VII/genética , Fator VII/genética , HemorragiaRESUMO
INTRODUCTION: The clot waveform analysis (CWA) provide valuable information beyond clotting time. The present study was planned to assess whether the activated partial thromboplastin time (aPTT)-CWA can differentiate between hemophilia A (HA), hemophilia B (HB), or hemophilia A with inhibitors (HAWI). METHODS: The aPTT-CWA was generated by an optical detection system (ACL-TOP™ 500 coagulation analyzer) and the other tests were performed as per instructions from the manufacturer in the kit. RESULTS: A total of 75 samples (47-HA, 16-HAWI, and 12-HB) with prolonged aPTT were recruited. On analyzing the quantitative aPTT-CWA data of HA (non-inhibitors) and HB samples, the width of acceleration 1 [+] peak was the differentiating finding. Among the significant parameters, the second derivative [+] peak was lower in both mild and moderate HA, equating to HB. The time for the height of 1/2 fibrin formation and width of velocity was significantly higher in mild, moderate and severe HA. The study did not show any significant differentiating finding while comparing HAWI and hemophilia A non-inhibitors (HANI). In the subgroups of HAWI and HANI with aPTT <70 s and 70-100 s, the second derivative [+] peak (2A) was higher and the time for the height of 1/2 fibrin formation (1C) was lesser in HAWI. CONCLUSION: The aPTT-CWA parameters may be supportive for the differentiation of hemophilia including its severity and the existence of inhibitors.
Assuntos
Hemofilia A , Hemofilia B , Trombose , Humanos , Tempo de Tromboplastina Parcial , Hemofilia A/diagnóstico , Testes de Coagulação Sanguínea , Fibrina , Hemofilia B/diagnósticoRESUMO
Background: The clinical phenotype of hemophilia A (HA) does not always correlate with severity. Similarly, the presence of inhibitors does not necessarily increase the risk of bleeding. This paradox between clinical and laboratory findings may be partially attributed to non-modifiable factors, such as blood group, which is known to influence FVIII levels in healthy individuals. Our aim was to assess the effect of ABO blood group antigens on FVIII levels across the severity spectrum of HA and risk of inhibitor development. Methods: Data of consecutive patients with HA who visited the coagulation unit of a northern Indian tertiary care hospital between 2010â2021 were reviewed. Patients with missing blood group data, transfusion histories, or baseline FVIII levels were excluded. Results: Mild, moderate, and severe HA was present in 41 (6.9%), 72 (12.2%), and 479 (80.9%) patients, respectively. There were no differences in the FVIII levels among the various blood groups across the HA severity spectrum. Inhibitors were administered to 35 patients (5.9%). In the multivariate analysis, blood group A was an independent risk factor for the development of inhibitors (adjusted odds ratio 2.70, P=0.04) after adjusting for age at onset of bleeding, FVIII transfusion, age at first FVIII transfusion, and severity of HA. Conclusion: Unlike what is observed in healthy individuals, blood group did not influence residual FVIII levels across the severity spectrum of HA. Patients in group A had a higher risk of developing inhibitors.
RESUMO
Factor VIII replacement is the mainstay of treatment in hemophilia A but may lead to the development of inhibitors. While a vexing clinical problem, some observations suggest that the presence of inhibitors may not necessarily portend a higher bleeding risk. Our aim was to assess the prevalence and clinicopathological correlates of inhibitors in a well characterized cohort of Indian patients with HA patients. We retrospectively reviewed the clinical details and laboratory findings of consecutive hemophilia A patients attending a north-Indian tertiary-care center from 2010 to 2020. Among 592 patients with HA, inhibitors were detected in 35 patients (5.9%). Prevalence of inhibitors in moderate and severe hemophilia was 4.2% and 6.7%, respectively. Most patients with inhibitors had history of transfusion with factor VIII alone (54.3%) or a combination of factor VIII concentrate and other blood-products (42.9%). Intracranial bleed was significantly more frequent in patients with inhibitors compared to those without inhibitors (20% vs. 4.1%; p-0.001). Time dependent and immediately acting inhibitors were seen in 60% and 40% patients, respectively. High-titre (> 5 BU) and low-titre inhibitors (< 5 BU) were detected in 28 (80%) and 7 (20%) patients, respectively. Prevalence of inhibitors in our cohort was 5.9% and most had high-titre, time dependent inhibitors. These patients may have a higher risk of intracranial bleeding.