The prevalence of factor VIII inhibitors and genetic aspects of inhibitor development in Chinese patients with haemophilia A

Safety and Efficacy of Moroctocog Alfa (AF-CC) in Chinese Patients with Hemophilia A: Results of Two Open-Label Studies

Introduction

Moroctocog alfa albumin-free cell culture (AF-CC) increases plasma levels of factor VIII (FVIII) activity and, in China, is indicated for the control and prevention of bleeding episodes in patients with hemophilia A. This study aimed to evaluate the efficacy, safety, and recovery data of moroctocog alfa (AF-CC) in patients with hemophilia participating in two open-label studies, both conducted in China.

Methods

The authorization study (clinicaltrials.gov identifier NCT00868530) enrolled patients aged ≥6 years, previously treated with ≥1 exposure day of FVIII replacement therapy. The real-world study (clinicaltrials.gov identifier NCT02492984) enrolled patients of any age who were previously untreated or requiring surgical prophylaxis. In both studies, on-demand treatment was administered over 6 months. Key assessments included response to treatment, FVIII inhibitor development, and recovery.

Results

In the authorization study (N = 53; mean age, 23.2 years; severe hemophilia, 23%), response was excellent/good for 90% of infusions at 24 hours. Seven patients developed inhibitors. Mean (SD) FVIII recovery at the initial and final visits was 1.77 (0.50) and 1.67 (0.45) (IU/dL)/(IU/kg), respectively. In the real-world study (N = 85; mean age, 9.5 years; severe hemophilia, 58%), response was rated as excellent or good for most (87%) on-demand infusions and for all surgical prophylaxis patients (n = 14). Seven patients developed FVIII inhibitors. Mean (SD) FVIII recovery at the initial and final visits was 1.71 (0.50) and 1.68 (0.31) (IU/dL)/(IU/kg), respectively. No new safety signals were observed in either study.

Conclusion

On-demand treatment and surgical prophylaxis with moroctocog alfa (AF-CC) is safe and effective for both previously treated and previously untreated Chinese patients with hemophilia A.

Factors Involved in the Development of Inhibitory Antibodies in Patients with Hemophilia in Colombia: A Case-Control Study

Background:

The appearance of inhibitory antibodies against antihemophilic factors is one of the most serious complications related to hemophilia.

Objective:

The objective of this study was to identify variables and factors related to the development of inhibitory antibodies in a group of patients undergoing antihemophilic therapy in Colombia.

Methods:

A case-control study in patients with hemophilia treated in Specialized Healthcare Provider Institutions (IPS-E) in 21 cities of Colombia of any age and with a diagnosis of inhibitory antibodies against factor VIII or IX during 2016. Four controls per case paired by age and type of hemophilia were used. Sociodemographic, clinical, and pharmacological variables were identified and analyzed.

Results:

Seventeen patients with inhibitory antibodies and 68 controls with hemophilia were identified. The mean age was 28.3 ± 17.8 years. A total of 94.1% had hemophilia A, and 88.2% of the cases and 50.0% of the controls had severe hemophilia; 47.1% of the cases and 54.4% of the controls were receiving prophylaxis with coagulation factors. Multivariate analysis showed that having severe hemophilia (OR:17.0, 95%CI:1.32–219.60) and lack of knowledge of the coagulation factor with which the patient was treated before entering the care program in the IPS-E (OR:8.9, 95%CI:1.82–43.75) were significantly associated with a higher probability of developing inhibitory antibodies.

Conclusion and relevance:

Coagulation factors associated with the development of inhibitory antibodies were severe hemophilia and lack of knowledge of the type of factor used prior to entering the follow-up cohort.

Prevalence of FVIII Inhibitors Among Children with Hemophilia A: Experience at the Jordanian Royal Medical Services

Introduction:

Replacement therapy is constantly required by Hemophilia A (HA) patients lacking coagulation factor VIII (FVIII). The most serious complication of this treatment is the development of neutralizing antibodies (inhibitors).

Aim:

The aim of this study is to determine the frequency of FVIII inhibitors among children treated for HA at the Jordanian Royal Medical Services.

Methods:

A total of 165 diagnosed HA patients receiving on-demand treatment, were tested for FVIII inhibitors between 2003 and 2018. The age range was 6 months to 16 years. Coagulation and inhibitor screening assays were performed, followed by Bethesda assay for inhibitor-positive samples to quantify FVIII inhibitor titers.

Results:

Out of the 165 patients, 111 had severe hemophilia with FVIII level < 1%, 26 had moderate hemophilia with FVIII levels of 1–5% and 28 had mild hemophilia with FVIII levels of > 5%. Twenty patients had FVIII inhibitors, of whom 18 had high titers, 2 had low titers. The mean inhibitor level in low (titer) responders was 2.40 ± 0.85 BU, as opposed to 116.25 ±169.25 BU in high (titer) responders. In terms of disease severity, 18 of the 20 patients with FVIII inhibitors had severe HA, whereas two had moderate HA. No inhibitors were encountered in the mild HA group.

Conclusion:

Inhibitors only developed in moderate and severe cases of HA. The severity of the disease and age were the main contributing factors. The association between family history of inhibitors and the incidence of inhibitor formation warrants genetic evaluations to look for relevant mutations.

Prevalence of inhibitors and clinical characteristics in patients with haemophilia in a middle-income Latin American country

INTRODUCTION

Development of inhibitors is the most serious complication in patients with haemophilia (PWH). The prevalence of inhibitors in patients with severe haemophilia A (HA) is approximately 25%-30%. Inhibitor prevalence differs among populations. Some studies report a prevalence of almost twice in Hispanic as compared to Caucasian patients. Most data available, on the prevalence of inhibitors and their predisposing factors, originate from centres in developed countries.

AIM

Establish the prevalence of inhibitors of FVIII and FIX in Mexico.

METHODS

This was an observational, cross-sectional and descriptive study. The records of all patients diagnosed with haemophilia A (HA) or B (HB), with and without inhibitors, were included. Clinical and demographical characteristics of patients with inhibitors were assessed. Statistical analysis was performed using IBM SPSS version 22. The Ethics Committees of the various participating institutions approved this study.

RESULTS

A total of 1455 patients from the 20 participating centres were recruited, from which 1208 (83.02%) had HA and 247 (16.97%) were diagnosed with HB. The presence of inhibitors in severe HA was reported in 93/777(11.96%), and 10/162 (6.17%) in severe HB. Of them, 91.7% exhibited high titres in HA and 100% in HB.

CONCLUSION

In Mexico, the general prevalence of inhibitors varies considerably among centres. This study established a basis of comparison for future development and advances in the treatment and follow-up of patients. These findings also augment our understanding of risk factors related to inhibitor development.

Inherited Bleeding Disorders-Experience of a Not-for-Profit Organization in Pakistan

Patient registry is a powerful tool for planning health care and setting groundwork for research. This survey reports a detailed registry of inherited bleeding disorders (IBD) and their management at a not-for-profit organization in a developing country to form the basis for planning development and research. We reviewed medical records of patients with IBD from 8 hemophilia treatment centers of Fatimid Foundation located in various cities. Information collected included sociodemographic data, diagnostic tests, severity of hemophilia A and B, number of bleeding episodes per year, site and frequency of hemarthrosis, and seropositivity for viral diseases. We analyzed 1497 patients from November 1, 2015, to April 30, 2016. There were 1296 (87%) males and 201 (13%) females with a mean age of 24.5 (11) years (range, 6 months to 65 years). Hemophilia A constituted the bulk of IBD (848, 57%) followed by von Willebrand disease (172, 11%), hemophilia B (144, 10%), platelet function defect (106, 7%), and rare bleeding disorders (70, 5%). Mucocutaneous bleeding (1144, 76%) and hemarthrosis (1035 patients, 69%) were the main complications. There were 1026 (69%) patients who received only blood components for treatment of any bleeding episode while the remaining 464 (31%) were on combination therapy (blood components and factor concentrate). Seroreactivity for hepatitis C was frequent (28%), while hepatitis B (1%) and human immunodeficiency virus (0.01%) were less commonly seen. This study was an important step toward a patient registry in a hemophilia treatment center in Pakistan. Hemophilia A is the most common bleeding disorder and hepatitis C is the most frequent treatment-related complication.

Acquired factor VIII deficiency: two case reports and a review of literature

Background

Acquired factor VIII (FVIII) deficiency, or acquired hemophilia A (AHA), is a rare autoimmune disorder involving antibody-mediated depletion of coagulation FVIII, leading to severe, life-threatening bleeding. The condition is often associated with other autoimmune disorders, and its treatment involves replacement of FVIII and various modes of immunosuppression. Recently, a few noteworthy therapeutic advances have been made. We present two cases of severe AHA in Chinese women. One of these women developed this disorder in the setting of possible parvovirus B19 infection, which has not yet been reported in association with AHA. Other notable features of her case included paradoxical venous thrombosis and possible association with Sjogren’s syndrome and myositis. The other woman failed to respond to usual first-line therapies despite exhibiting a less severe clinical course, illustrating the varied but potentially stubborn behavior of this disorder.

Case 1

An 87-year-old woman presented with diffuse ecchymoses, melena, vaginal bleeding. Labs showed hemoglobin (Hgb) nadir of 5.7 mg/dL, elevated partial thromboplastin time (PTT), FVIII level <1%, mixing study consistent with an inhibitor, elevated anti-Sjogren’s-Syndrome-related antigen A antibody, elevated creatinine kinase, and elevated parvovirus IgM and IgG. Imaging of her arm showed diffuse myositis and deep venous thrombosis. After intravenous and oral steroids, her FVIII levels normalized, and her symptoms subsided.

Case 2

A 59-year-old woman presented with recurrent ecchymoses and hematomas in her extremities. Labs showed Hgb of 11.7 mg/dL, elevated PTT, FVIII level of 3%, and mixing study consistent with an inhibitor. Despite receiving a long course of steroids, several courses of IVIG, and a few courses of Rituximab, her FVIII level remained critically low.

Conclusion

The rarity of AHA limits our understanding of this disease and the ability to perform trials to discover optimal therapies. We hope that these case reports and discussion will shed further light on the varied clinical manifestations and natural histories of this disorder to guide better recognition and treatment of AHA.

The Epidemiology of FVIII Inhibitors in Indian Haemophilia A Patients

A serious complication of replacement therapy in patients with bleeding disorders is the development of 'inhibitors', particularly FVIII inhibitors in haemophilia A patients. This leads to an increase in the management cost, morbidity and mortality, especially post-operatively. The mechanism of FVIII inhibitor development is quite complex and it is difficult to predict inhibitor development, but a prompt and accurate diagnosis is critical as early therapy can save lives. The aim of this study was to screen patients with bleeding disorders in India for inhibitors, and to analyse and compare the prevalence of inhibitors in different regions in India. Patient details were recorded and blood samples were collected in sodium citrate vacutainers from 1,505 patients with bleeding disorders, in different cities in India. Coagulation and inhibitor screening assays were performed, followed by the Bethesda assay in inhibitor positive samples to quantify the FVIII inhibitor titre. Out of the 1,505 samples analysed, 1,285 were Haemophilia A patients, out of which 78 (6.07 %) were positive for 'FVIII Inhibitors'. The highest incidence of FVIII Inhibitors was seen in South India (13.04 %). The highest incidence of 20.99 % was observed in Chennai, followed by Hyderabad (13.33 %), Jammu (9.90 %) and Guwahati (8.51 %), respectively, with respect to the samples analysed. The other regions showed an inhibitor incidence <8 %. The incidence of inhibitors in haemophilia A patients is different in different regions of India; this may be due to the intensity of treatment, type of product or the genetic characteristics of these patients.

Evaluation of transfusion-related complications along with estimation of inhibitors in patients with hemophilia: A pilot study from a single center

Background:

Apart from inhibitor development in patients with hemophilia (PWH) the old problems of blood borne viral infections and red cell alloimmunization still persist in PWH from developing countries. This study was planned to detect the presence of inhibitors in our PWH and to determine the presence of transfusion transmitted infections (TTI) markers and clinically significant red cell alloantibodies in these patients.

Materials and Methods:

One hundred fourteen PWH were screened for various laboratory tests. Screening for inhibitors was done by mixing study. Blood grouping, TTI testing and red cell alloantibody detection were done as per the departmental standard operating procedures.

Results:

Out of 114 patients evaluated 98(86%) had hemophilia A and remaining 16(14%) had hemophilia B. Five (5.1%) patients of hemophilia A were positive on inhibitor screening. On Bethesda assay, one patient was high responder (14.4 BU/ml) and rest 4 were low responders (<5 BU/ml). Overall, 19 PWH were positive for TTI markers and two had clinically significant red cell alloantibody (anti-E and anti-Jk^b).

Conclusion:

This is probably first comprehensive study from our state on laboratory testing in PWH. The specialty of Transfusion Medicine can be a core part of hemophilia care. The overall prevalence of inhibitors in our hemophilia A patients was 5.1%, which is less as compared to majority of published studies.

Hemophilia care in India: a review and experience from a tertiary care centre in uttar pradesh

Approximately 14,000 people with hemophilia are registered at the Hemophilia Federation of India; however, hemophilia remains under-diagnosed and many cases are not registered. In June 2009, the Government of Uttar Pradesh made anti-hemophilic factors available at a few centers, including the Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow. Consequently, the level of hemophilia care has improved considerably in recent times. Amongst the many challenges facing people with hemophilia, the development of inhibitors, which neutralize clotting factors provided by replacement therapy, is the most feared one. Healthcare professionals who treat people with hemophilia should not only be knowledgeable about the condition and committed to bettering the management of hemophilia, but also take responsibility for the judicious allocation of resources for various aspects of managing hemophilia. This manuscript aims to raise awareness regarding the detection and management of inhibitors in hemophilia based on the experience of a tertiary care hemophilia treatment centre in Uttar Pradesh, India.