PFA-100 System: A New Method for Assessment of Platelet Dysfunction.

This is a celebratory reprint of a historical paper published in STH in 1998. The original Abstract follows.The PFA-100 system is a platelet function analyzer designed to measure platelet-related primary hemostasis. The instrument uses two disposable cartridges: a collagen/epinephrine (CEPI) and a collagen/ADP (CADP) cartridge. Previous experience has shown that CEPI cartridges detect qualitative platelet defects, including acetylsalicylic acid (ASA)-induced abnormalities, while CADP cartridges detect only thrombocytopathies and not ASA use. In this seven-center trial, 206 healthy subjects and 176 persons with various platelet-related defects, including 127 ASA users, were studied. The platelet function status was determined by a platelet function test panel. Comparisons were made as to how well the defects were identified by the PFA-100 system and by platelet aggregometry. The reference intervals for both cartridges, testing the 206 healthy subjects, were similar to values described in smaller studies in the literature (mean closure time [CT] of 132 seconds for CEPI and 93 seconds for CADP). The use of different lot numbers of cartridges or duplicate versus singleton testing revealed no differences. Compared with the platelet function status, the PFA-100 system had a clinical sensitivity of 94.9% and a specificity of 88.8%. For aggregometry, a sensitivity of 94.3% and a specificity of 88.3% were obtained. These values are based on all 382 specimens. A separate analysis of sensitivity by type of platelet defect, ASA use versus congenital thrombocytopathies, revealed for the PFA-100 system a 94.5% sensitivity in identifying ASA users and a 95.9% sensitivity in identifying the other defects. For aggregometry, the values were 100% for ASA users and 79.6% for congenital defects. Analysis of concordance between the PFA-100 system and aggregometry revealed no difference in clinical sensitivity and specificity between the systems (p > 0.9999). The overall agreement was 87.5%, with a Kappa index of 0.751. The two tests are thus equivalent in their ability to identify normal and abnormal platelet defects. Testing 126 subjects who took 325 mg ASA revealed that the PFA-100 system (CEPI) was able to detect 71.7% of ASA-induced defects with a positive predictive value of 97.8%. The overall clinical accuracy of the system, calculated from the area under the receiver operating characteristic curve, was 0.977. The data suggest that the PFA-100 system is highly accurate in discriminating normal from abnormal platelet function. The ease of operation of the instrument makes it a useful tool to use in screening patients for platelet-related hemostasis defects.

Impact of hemophilia B on quality of life in affected men, women, and caregivers-Assessment of patient-reported outcomes in the B-HERO-S study.

INTRODUCTION: Health-related quality of life (HRQoL) is impaired in patients with hemophilia; however, the impact in mild/moderate hemophilia B and affected women is not well characterized. OBJECTIVE: To evaluate factors that affect HRQoL in adults with hemophilia B and caregivers of affected children. METHODS: US adult patients and caregivers of affected children completed distinct ~1-hour online surveys including patient-reported outcome instruments. RESULTS: In total, 299 adult patients and 150 caregivers participated. Adults with moderate hemophilia reported poorer health status (median EQ-5D-5L index score, 0.63) than those with mild (0.73) or severe (0.74) hemophilia. Women reported greater pain severity than men on the Brief Pain Inventory v2 Short Form (median, 7.00 vs 5.00). Based on the Patient Health Questionnaire, mild or worse depression was observed in >50% of adult respondents, and depression was reported more often in those with moderate and severe hemophilia vs those with mild hemophilia. Most caregivers reported at least mild depression. CONCLUSION: Pain, functional impairment, and depression/anxiety are present at higher-than-expected levels in individuals with hemophilia B. The large proportion of individuals with mild/moderate hemophilia and women with reduced health status suggests significant unmet needs in this population.

Management of US men, women, and children with hemophilia and methods and demographics of the Bridging Hemophilia B Experiences, Results and Opportunities into Solutions (B-HERO-S) study.

The Bridging Hemophilia B Experiences, Results and Opportunities Into Solutions (B-HERO-S) initiative was launched in an effort to address specific gaps in the understanding of the psychosocial impact of mild-moderate-severe hemophilia B. The original Hemophilia Experiences, Results and Opportunities (HERO) qualitative study evaluated the needs of people with hemophilia A or B in multiple countries; however, a majority of participants had the more common moderate-severe hemophilia A. The B-HERO-S study was designed in collaboration with the hemophilia community to evaluate the needs of adults with hemophilia B and caregivers of children with hemophilia B, including affected women and caregivers of girls with hemophilia. The report presented here describes participant demographics and comorbidities, as well as treatment regimens and access to treatment. Bleeding symptoms were reported by 27% of mothers of children with hemophilia B who participated. Women were more likely than men to self-report arthritis and depression/anxiety as comorbidities associated with hemophilia B. More adults and children with hemophilia B were on routine treatment than on on-demand treatment, and a high percentage of adults with moderate hemophilia B received routine treatment (86%). Many adults with hemophilia B (78%) and caregivers (69%) expressed concern about access to factor in the next 5 years, and of adults with hemophilia B, women more commonly experienced issues with access to factor in the past than did men (72% vs 44%). The findings of the B-HERO-S study reveal potential unmet needs of some patients with mild-moderate hemophilia B, and the results may be leveraged to inform patient outreach by hemophilia treatment centers and education initiatives.

Assessment of acquired hemophilia patient demographics in the United States: the Hemostasis and Thrombosis Research Society Registry.

The Hemostasis and Thrombosis Research Society (HTRS) Registry was used to monitor the postapproval use of recombinant factor VIIa. The objective of this manuscript is to provide key insights on the demographics of patients with acquired hemophilia in the HTRS Registry. Acquired hemophilia patient registration in HTRS captured age; sex; comorbidities and predisposing conditions; first bleeding location; laboratory parameters; exposure to blood products, factor, and bypassing agents; and initiation of immune suppression/tolerance therapy. Overall, 166 patients with acquired hemophilia were registered in HTRS (83 women, 73 men, median age 70 years); the majority were non-Hispanic whites (61.4%). The most common comorbidities were autoimmune disease (28.4%) and malignancy (14.5%). The most common first site of bleeding was subcutaneous (27.1%); this was more common in whites (29.1%) than blacks (12.5%) and in non-Hispanics (26.4%) than Hispanics (11.8%). Blood product exposure was reported for 33.1% of patients; the most commonly reported product was packed red blood cells (28%). Of the 57 patients with outcome data available for immune tolerance therapy, 26 patients (46%) reported successful treatment, 13 reported unsuccessful treatment (23%), and 18 (32%) were receiving active treatment at the time of registration. The HTRS Registry final analysis provides the only current comprehensive look at acquired hemophilia in the US population, including details on underlying autoimmune diseases and malignancies. Pertinent to recognition and diagnosis of the disease, subcutaneous bleeding as a presenting bleeding symptom was more common in white and non-Hispanic individuals.

Improving academic leadership and oversight in large industry-sponsored clinical trials: the ARO-CRO model.

Standards for clinical trial design, execution, and publication have increased in recent years. However, the current structure for interaction among the pharmaceutical sponsor funding a drug or device development program, the contract research organization (CRO) that typically assists in executing the trial, regulatory agencies, and academicians, provides inadequate leadership and oversight of the development process. Conventional academic steering committees are not provided with the independent infrastructure by which to verify statistical analyses and conclusions regarding safety and efficacy. We propose an alternative approach centered on partnerships between CROs and university-based academic research organizations (AROs). In this model, the ARO takes responsibility for processes that address journal requirements and regulatory expectations for independent academic oversight (including oversight of Steering Committee and Data and Safety Monitoring Board activities), whereas the CRO provides infrastructure for efficient trial execution, site monitoring, and data management. The ARO engages academic experts throughout the trial process and minimizes conflicts of interest in individual industry relationships via diversification of sponsors, agents, and therapeutic areas. Although numerous models can be entertained, the ARO-CRO model is uniquely structured to meet the demand for greater assurance of integrity in clinical trials and the needs of each stakeholder in the process.