ALBERT

Description: This systematic review was designed to provide more precise effect estimates of inhibitor development for the various types of F8 gene mutations in patients with severe hemophilia A. The primary outcome was inhibitor development and the secondary outcome was high-titer-inhibitor development. A systematic literature search was performed to include cohort studies published in peer-reviewed journals with data on inhibitor incidences in the various F8 gene mutation types and a mutation detection rate of at least 80%. Pooled odds ratios (ORs) of inhibitor development for different types of F8 gene mutations were calculated with intron 22 inversion as the reference. Data were included from 30 studies on 5383 patients, including 1029 inhibitor patients. The inhibitor risk in large deletions and nonsense mutations was higher than in intron 22 inversions (pooled OR = 3.6, 95% confidence interval [95% CI], 2.3-5.7 and OR = 1.4, 95% CI, 1.1-1.8, respectively), the risk in intron 1 inversions and splice-site mutations was equal (pooled OR = 0.9; 95% CI, 0.6-1.5 and OR = 1.0; 95% CI, 0.6-1.5), and the risk in small deletions/insertions and missense mutations was lower (pooled OR = 0.5; 95% CI, 0.4-0.6 and OR = 0.3; 95% CI, 0.2-0.4, respectively). The relative risks for developing high titer inhibitors were similar.

Description: Introduction Inhibitors are considered to be the most serious complication of clotting factor concentrate (CFC) therapy in hemophilia. The incidence of inhibitors in PTPs with severe hemophilia is very low (∼ 1 per 1,000 patient years). Four cases of PTP inhibitors that developed during hospital admissions were observed at the University of North Carolina over a 14-month period during 2011 – 2012. Due to concern about the possible role of the CFC used during hospitalization, further investigation by the CDC was requested. Methods A review of hemophilia-related hospital practices and procedures, along with a medical record review of admissions from January 2008 – November 2012 was conducted to: 1) compare inhibitor incidence trends in the time periods before and after January 2011; and 2) assess patient risk factors and evaluate hospital practices relative to inhibitor occurrence. A case was a person who developed an inhibitor during a hospital admission and non-cases were inpatients with no history of inhibitor development. The prevalence of inhibitor risk factors were compared between cases and non-cases and across time periods. Unadjusted odds ratios were used to compare the prevalence of exposures between cases and non-cases and comparisons of means of continuous risk factors used parametric and non-parametric tests as appropriate. Results A check of the FDA's Adverse Event Reporting System (FAERS) revealed no identified problems of the CFC in question. The medical record review revealed 134 admissions in 49 patients (59 in period 1 and 75 in period 2) during the 5-year period (see Figure). No other cases were found during the review; however, one of the index cases was found to have developed the inhibitor as an outpatient leaving 3 cases and 45 non-cases for study. The cases ranged in age from 23 – 69 years. One had severe and one had moderate hemophilia A, while the third case had combined factor V-VIII deficiency with FV and FVIII levels of 7% and 10%, respectively. Compared to non-cases, cases had elevated odds of: an infection (OR, 95% CL=4.4, 0.3–53), continuous factor infusion (CI) (4.2, 0.04–6.4), at least one non-surgical procedure (3.9, 0.1–80.5), and used the only hospital-available CFC (2.7, 0.1–73) during the admission and a product switch prior to admission (3.5, 0.1–105) and a family history of hemophilia (2.4, 0.1–51). In addition, cases had more hospital admissions (mean 6.6 vs. 2.4, p = 0.002) and more total hospital days (mean 39.6 days vs. 14.8 days. p = 0.05) than non-cases. Finally, cases received a greater total dose of CFC than non-cases (mean 101 IU/kg vs. 69 IU/kg, p = 0.003) during admission. Two hospital practices changed in period two: 1) the method of preparation and administration of CI involved less diluent and, therefore, a more concentrated infusion solution; and 2) the hospital pharmacy stocked only one brand of CFC in period 2 whereas several brands were available in period 1. The latter change increased the proportion of inpatients using a different product than that used as an outpatient (i.e., product switch) during period 2. Compared to inpatients admitted during period 1, those in period 2 were: more likely to receive the only available CFC and to have a product switch during the admission (p 〈 0.001). No difference between time periods was seen in the proportion of patients administered CI (58.8% vs. 56.9%) or who were tested for an inhibitor during admission (25% vs. 22%). Conclusions The investigation results support an increase in incidence of inhibitors among inpatients during period 2 compared to period 1, however, the number of cases was small. Nonetheless, because inhibitors are rare in PTPs, the occurrence of 3 cases in a 14-month period after a 3-year time span with no cases is highly suggestive of an actual increase in occurrence. The apparent increase was unlikely due to enhanced surveillance since rates of inhibitor testing during the two time periods were similar. While the odds ratios for some of the risk factors were elevated, the confidence limits were wide indicative of the lack of study power. Although there was no clear indication of a preventable inciting factor and more investigation is needed, the investigation revealed that this inhibitor cluster occurred in patients who had many complications that required lengthy hospitalizations and intense treatment with CFCs, contributing factors that should be considered in future management of hemophilia patients. Disclosures: No relevant conflicts of interest to declare.

Description: A pilot project of a prospective surveillance system for coagulation factors VIII and IX inhibitors has been initiated at 9 U.S. Hemophilia Treatment Centers (HTCs). More than 500 patients have been enrolled. Risk factor and product exposure data are recorded at each HTC. A blood specimen is collected upon entry, annually, at product switch, or for clinical indication and tested centrally at the CDC, using a modified Nijmegen-Bethesda method. Plasma from specimens collected in 4.5mL evacuated tubes containing 3.2% sodium citrate is shipped overnight on cold packs. Specimens are heated to 56oC for 30 minutes to remove endogenous and infused FVIII and centrifuged. Specimens are initially screened for inhibitor using a single dilution of 3 parts patient plasma to 1 part normal pool plasma buffered with imidazole to pH 7.4 (BNPP). Specimens showing inhibition and those from previously positive patients are tested in multiple dilutions at 1 part patient dilution to 1 part BNPP. Dilution is in naturally FVIII-deficient plasma containing normal von Willebrand factor. After a 2-hour incubation at 37oC, FVIII remaining in the patient mixture is divided by FVIII remaining in a 1:1 mixture of BNPP and FVIII-deficient plasma and expressed as % residual activity (RA). %RA is converted to Nijmegen-Bethesda units (NBU) using a curve with one NBU equal to 50% RA. An inhibitor plasma of known titer is run with each assay as positive control. Split specimens shipped frozen and on cold packs showed a correlation of 0.998. 3:1 and 1:1 mixtures showed a correlation of 0.97. Almost 50% of the first 200 specimens received had measurable FVIII activity. The heating step was introduced to remove FVIII without damaging the antibody. 65 specimens went from 〉100% RA to a titer of 0–0.2 NBU after heating. Among 538 specimens tested for FVIII inhibitors, 435 (81%) were from patients with no previous history of inhibitor (shown below). 429 (98.6%) were 〈 0.5 NBU. The 6 specimens (1.4%) with 〉 0.6 NBU are under investigation as possible seroconversions. Nijmegen-Bethesda Units in Patients with No Previous Inhibitor NBU No. Pts. (%) NBU No. Pts. (%) NBU No. Pts. (%) 0 220 (50.6%) 0.4 3 (0.7%) 0.8 1 (0.2%) 0.1 127 (29.2%) 0.5 0 0.9 0 0.2 59 (13.6%) 0.6 0 1.0–4.0 2 (0.5%) 0.3 20 (4.6%) 0.7 2 (0.5%) 5.0–19.0 1 (0.2%) Among 121 specimens tested for factor IX (FIX) inhibitors, 113 were from patients with no previous history of inhibitor and all had NBU

Description: Menorrhagia occurring during adolescence and perimenopause is presumed to be associated with anovulation, and during perimenopause, with uterine pathology, such as subserosal uterine myoma, as well. The frequency of bleeding disorders in women presenting with menorrhagia at the extremes of menstruating age, ie adolescence and perimenopause, are not known. We conducted a study to evaluate the frequency and types of hemostatic defects found in adolescent and perimenopausal age women diagnosed with menorrhagia. 115 women with a physician diagnosis of menorrhagia, including 25 adolescent women, 25 perimenopausal age women, and 65 women between the ages of 20 and 44, underwent comprehensive hemostatic testing for possible bleeding disorders. There were no significant differences between the three age groups in mean hemoglobin, percentage of women with anemia, duration of menses, mean pictorial blood assessment scores, or race. Overall, 48% of women were found to have hemostatic abnormalities. Hemostatic abnormalities among women with menorrhagia Overall ≤ 19 yrs 20–44 yrs ≥ 45 yrs p-value N=115 N=25 N=65 N=25 *Platelet aggregation, Von Willebrand factor, and/or coagulation factor Platelet Aggregation 44% 44% 48% 32% 0.48 Von Willebrand Factor 7% 4% 8% 8% 0.78 Coagulation Factor 5% 8% 6% 0% 0.34 Any Abnormality* 48% 48% 54% 32% 0.32 Adolescents and perimenopausal age women diagnosed with menorrhagia were as likely as women presenting between age 20 to 44 to have underlying hemostatic defects. Among the adolescents, neither age at presentation nor time from menarche were predictive of having a bleeding disorder. The platelet aggregation defects observed were similar among the three age groups with the exception of ADP induced platelet aggregation defects which were seen significantly more frequently in adolescents compared to older women (p≤ 0.01). Ristocetin and epinephrine induced platelet aggregation defects were the most common aggregation defects in women 20 years and older and ADP induced platelet aggregation defects were the most common among adolescents. There were no significant differences in platelet ATP release abnormalities between the three age groups. Our results demonstrate that a high proportion of adolescents and perimenopausal age women presenting with menorrhagia have bleeding disorders. These results suggest that menorrhagia in the adolescent, even if presenting soon after onset of menarche, and in perimenopausal age women, even if fibroids are present, may warrant hemostatic evaluation. Further age-specific studies evaluating treatment benefits and outcomes in women with menorrhagia diagnosed with bleeding disorders are warranted.

Description: Menorrhagia is a common clinical problem among reproductive age women and annually 5% of reproductive age women seek medical attention, usually with gynecologists and other primary care physicians, for this symptom. Since underlying bleeding disorders are common in women presenting with menorrhagia, and referral for comprehensive hemostatic testing of substantial numbers of women with otherwise unexplained menorrhagia is problematic from the public health and cost perspective, a short, easy-to-administer screening tool comprised of 8 questions for identifying women with menorrhagia for hemostatic evaluation was previously developed (Am J Ob Gyn2008;198:e1–163e8). In the present study, the validity of the screening tool was evaluated in a multi-site, prospectively recruited cohort of women with menorrhagia. 232 women with menorrhagia age 18 and older with a pictorial blood assessment chart (PBAC) score 〉 100 were recruited from 5 US centers as potential subjects for a prospective cross-over study for evaluation of intranasal DDAVP versus tranexamic acid. All subjects underwent comprehensive laboratory testing for bleeding disorders, including VWF, platelet aggregation/ATP release, and factor assays. Study participants were administered a questionnaire which included the 8 screening tool questions in 4 categories, including history of duration and severity of menorrhagia, anemia treatment, excessive bleeding with hemostatic challenges, and family diagnosis of bleeding disorder. A screening tool was considered positive if there was a positive response for any of the questions in the four categories. Sensitivity of the screening tool with 95% confidence interval was calculated for bleeding disorders and also separately for low VWF (ristocetin cofactor 〈 50%), and platelet function defects.217 women with menorrhagia including 78% white and 16% black women with complete data were evaluated. In this population, a positive screening tool had a sensitivity of 89% (95% CI, 83–93) for bleeding disorders, 89% for platelet function defects (95% CI, 82–94), and 73% for low VWF (95% CI, 39–94). The sensitivity for bleeding disorders was 87% (95% CI, 79–92) among white women and 94% (95% CI, 79–99) among black women. Adding a PBAC score 〉 185 increased the sensitivity of the screening tool for bleeding disorders to 95% (95% CI, 90–98). Using a multi-site US population of adult women with menorrhagia, this study confirms the benefit of a short screening tool to assist primary care physicians in the selection of women with menorrhagia to refer for comprehensive hemostatic testing and evaluation. population of adult women with menorrhagia, this study confirms the benefit of a short screening tool to assist primary care physicians in the selection of women with menorrhagia to refer for comprehensive hemostatic testing and evaluation.

Description: Abstract 3184 Poster Board III-121 INTRODUCTION Inhibitor formation is a major complication of hemophilia A (HA). Although only 25% of new inhibitors occur in those with mild or moderate HA, they often lead to an increased frequency of bleeding with potentially devastating consequences. In contrast to severe HA, knowledge of risk factors for the development of inhibitors in those with mild and moderate hemophilia A is limited. This study was carried out to assess the role of intensive exposure to factor VIII (fVIII), in inhibitor formation in those with mild or moderate HA. METHODS A retrospective case-control design was utilized. Cases were initially identified among participants of the Universal Data Collection (UDC) surveillance system as those with mild or moderate HA (fVIII 1-40%) having a current or past inhibitor titer of 〉 1 BU/ml. Hemophilia severity and inhibitor titer were verified by the Hemophilia Treatment Center (HTC) and patients were eligible for enrollment if they had an inhibitor titer 〉 1 BU/ml on two consecutive occasions or had one inhibitor titer 〉 1 BU/ml followed by initiation of immune tolerance therapy. Additional cases were identified by the HTC. Control subjects had no history of inhibitor titer 〉 0.6 BU/ml and had previously received fVIII. Negative inhibitor status was confirmed by Nijmegen assay performed in a central laboratory. After informed consent was obtained, exposure information during the year prior to inhibitor development (cases) or the year prior to enrollment (controls) was gathered from clinical records and subject interview. The primary risk factor of interest was intensive treatment with fVIII defined as having received 6 or more consecutive days. Other risk factors investigated include: age, baseline fVIII activity, race, prior number of fVIII exposure days, vaccination within the prior year, product type and fVIII genotype. RESULTS Forty-three cases and 65 controls met eligibility criteria and were enrolled at 16 HTCs. Seven cases and three controls were not included in the analysis after genotyping demonstrated mutations typically associated with severe disease, such as intron-22 inversion. The final analysis included 36 cases and 62 controls. Ten of these cases were originally identified in the UDC system. The mean baseline fVIII activity was similar between groups (p=0.73). The median age was 31 years (Inter-quartile range (IQR), 10-51 years) in cases and 27.5 years (IQR, 18-46 years) in controls (p=0.80). The distribution of subjects having 〈 50, 50-100 or 〉 100 prior fVIII exposure days was similar between groups (p=0.40). Fifty percent of cases had received intensive treatment with fVIII compared with 17.7% of controls (p 30 years (1.55 vs. 13.54, heterogeneity p=0.02). After multivariate adjustment, intensive treatment with fVIII remained strongly associated with inhibitor formation (OR 7.65; 95% CI, 1.69-34.44). In the multivariate model, the OR for intensive treatment in those 〈 30 years of age was 3.36 (95% CI, 0.6-16.8) compared with 15.24 (95% CI, 2.38-97.2) in those 30 years of age or older. However, this interaction between age and intensive treatment did not reach statistical significance (Wald test p=0.23). CONCLUSION Intensive treatment with fVIII is a strong independent risk factor for inhibitor development in those with mild or moderate hemophilia A and the risk appears to be greater in adults 30 years of age or older. Disclosures Kempton: Biomeasure Inc: Consultancy; CSL Behring Foundation: Research Funding. Manco-Johnson:Baxter BioScience: Honoraria; Bayer HealthCare: Honoraria; CSL Behring: Honoraria; NovoNordisk: Honoraria; Octapharma: Honoraria. Abshire:CSL Behring, Novo Nordisk, Bayer Healthcare: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Description: Objective While hemarthrosis contributes to morbidity in males with Hemophilia, less is known about joint destruction in females with FVIII deficiency. Our hypothesis was that females with FVIII deficiency enrolled in the Universal Data Collection (UDC) project had a reduced mean overall joint range of motion (ROM) compared to historic controls from the Normal Joint Study. Methods We employed a cross-sectional study design utilizing the UDC dataset. The overall joint ROM was the sum of the right and left ROM measurements of the five joints (hip, ankle, elbow, knee, shoulder) for the females with FVIII deficiency from the UDC and for healthy females without the deficiency 2-69 years of age from the Normal Joint Study. Females that were very obese (BMI 〉35) were excluded from the Normal Joint Study thus they were excluded from the UDC cohort. Mean overall joint ROM between affected and normal females was assessed for statistical difference using the non-parametric Wilcoxon-rank-sum test. Results were displayed as mean overall ROM with 95% confidence interval (CI) and p-value by age group and factor deficiency. Multivariate linear regression was performed using the General Linear Model (GLM) procedure with the overall joint ROM as the dependent variable and the clinical hemophilia severity as the independent variable adjusting for age, race, body mass index (BMI) and number of joint bleeds reported over the last six months. Summary A total of 522 females were identified with FVIII deficiency; 28% (144/522) of females were removed because of inability to assign factor deficiency type and 14% (75/522) of females were removed due to being very obese (BMI〉35) or outside the age range studied in the Normal Joint Study. Final analysis was performed on 303 females with FVIII deficiency between the ages of 2-69 years for comparison to the control group. As FVIII activity decreased, the mean overall joint range of motion became reduced and in most cases was significantly lower than that of the controls (see table 1). In FVIII deficient females there was a significant (p〈 0.0001) correlation between Hemophilia severity and mean overall joint ROM. Furthermore, using multivariate linear regression analysis, stratifying by age and clinical hemophilia severity and controlling for BMI and race, females with severe (5% and

Description: More than 600 U.S. hemophilia patients have been genotyped as part of the pilot study for a prospective surveillance system for factor inhibitors conducted at 12 U.S. Hemophilia Treatment Centers. 80% of enrolled subjects had hemophilia A, 58% with severe disease, 24% moderate, and 18% mild. Age ranged from

Description: Inhibitors are now considered to be the most important complication of clotting factor replacement therapy in hemophilia. In January 2005, the Universal Data Collection (UDC) project, which includes data on over 14,000 patients with hemophilia A or B, was amended to include prospective data collection on inhibitors. We report interim results of a pilot project involving 9 selected Hemophilia Treatment Centers in the U.S. Dedicated data managers collected risk factor and product exposure data from enrolled patients on a monthly basis. Tracked infusion log submissions were used to estimate patient adherence to infusion log completion. A blood specimen is collected at baseline, annually, at product switch, or for clinical indication and is tested centrally for inhibitor using the Nijmegen modification method. Results are reported and any above a threshold value are followed up with repeat testing and clinical correlation. As of August 2007, 514 male patients with hemophilia, ages 2–84 years (mean 23 yrs SD 17) had been enrolled. Of these, 415 (81%) had FVIII deficiency (64% severe, 20% moderate, 16% mild) and 99 (19%) had FIX deficiency (35%, 43%, and 22%, respectively). 85% of the patients were caucasian, 8% black, and 4% Hispanic. A previous history of inhibitor was present at enrollment in 71 (14%). Prophylactic treatment was used by 37% and 80% received product by home infusion. Historical exposure to product collected at enrollment was as follows: 14% had 0–20 exposure days (ED), 12% had 21–100 ED, 7% had 101–150 ED, and 64% 〉 150 ED. During follow-up, 6 patients have had inhibitor titer measurements over 0.4 BU. One of these was known to have an active inhibitor at enrollment. Confirmatory testing of remaining cases is underway. Mean adherence rate for patient infusion log completion in the 9 HTC’s was 45% (range 7% to 74%). Overall adherence increased with time on study from about 40% at one month to nearly 60% for those enrolled at least 10 months. In summary, enrolled participants represent a wide range of characteristics including age, race, disease severity and number of factor exposures. Interim findings indicate that prospective collection of factor infusion data from hemophilia patients necessary to appropriately monitor inhibitor formation, is feasible but labor intensive and requires patient adherence to completion and submission of accurate infusion logs. Because inhibitor formation is rare and the potential risk factors are many, large scale studies with long-term follow-up will be needed to fully assess risk factors for inhibitors.

Description: The genetics of blood coagulation has been an ongoing area of research; and with the advent of next generation sequencing panels, there is a significant increase in the number of variants identified in coagulation factor genes. Several published reports and online databases document the variants observed in patients with bleeding disorders; however, the clinical interpretation of these variants is not always straight-forward. To enable gene-specific variant interpretation in coagulation factor deficiency disorders, the National Institutes of Health (NIH)-funded effort, Clinical Genome Resource (ClinGen), has developed the Coagulation Factor Deficiency Variant Curation Expert Panel (CFD-VCEP). The CFD-VCEP is comprised of expert clinicians, genetic counselors, clinical laboratory diagnosticians and researchers working toward the goal of developing and implementing standardized protocols for sequence variant interpretation for coagulation factor genes. The CFD-VCEP adapts the 2015 American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) guidelines for precise and consistent variant classification to genes involved in blood coagulation deficiencies. These guidelines recommend the use of 28 criteria codes based on the evidence category and the strength of the evidence (see Figure below). The first two genes under the purview of CFD-VCEP are F8 (OMIM: 300841) and F9 (OMIM: 300746). Pathogenic variants in the F8 and F9 genes resulting in the loss of protein function cause Hemophilia A and B, respectively. Owing to the similarity between these two genes with respect to their role in the coagulation cascade as well as the resulting phenotype, specification of variant curation guidelines for both genes has been undertaken simultaneously. With the completion of guideline specification for F8 and F9, the CFD-VCEP will subsequently continue this effort for other coagulation factor genes, while also curating F8 and F9 variants reported in ClinVar and other variant databases. Modifying the ACMG/AMP guidelines involves gene- and disease-informed specifications of the recommended criteria codes. This includes identifying which codes are applicable and which are not, defining gene- and disease-specific cut-offs such as for population frequency, and making code strength adjustments when appropriate. The specified guidelines are further refined based on their performance on a set of pilot variants (n = 30) for each gene compared to existing assertions of variant classification in ClinVar and by diagnostic laboratories represented in the CFD-VCEP. F8 and F9 variants classified by the CFD-VCEP will be submitted to ClinVar at the 3-star review status, with the tag of "FDA-recognized database", and the CFD-VCEP plans to begin this process by the second quarter of 2020. The considerations by the CFD-VCEP in the guideline-specification process and results from the pilot analysis will be discussed. This effort will lead to the standardized use of evidence criteria for the evaluation of variants in F8 and F9, which will reduce the number of variants of uncertain significance and those of conflicting interpretations, making genetic testing results more informative for providers and patients. The CFD-VCEP also encourages sharing de-identified data on variants among laboratories, which enables accurate and consistent curations. Figure Disclosures Lee: UNC Hemophilia Treatment Center: Employment. Carcao:Biotest: Honoraria, Membership on an entity's Board of Directors or advisory committees; Grifols: Honoraria, Membership on an entity's Board of Directors or advisory committees; Shire/Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; CSL Behring: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novo Nordisk Inc: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Octapharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; Agios: Research Funding; LFB: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bioverativ/Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bayer: Honoraria, Membership on an entity's Board of Directors or advisory committees. Kemball-Cook:European Association for Haemophilia and Allied Disorders: Other: Freelance . Leebeek:CSL Behring: Research Funding; uniQure BV: Consultancy, Research Funding; Baxalta/Shire: Research Funding. Miller:Division of Blood Disorders, National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention: Consultancy.