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Gili Kenet,1,2 Thomas Moulton,3 Brian M Wicklund,4 Sanjay P Ahuja,5 Miguel Escobar,6 Johnny Mahlangu7 1National Hemophilia Center, Sheba Medical Center, Tel HaShomer, Israel; 2The Amalia Biron Thrombosis Research Institute, Tel Aviv University, Tel Aviv, Israel; 3Bayer, Whippany, NJ, USA; 4Children’s Mercy-Kansas City, Kansas City, MO, USA; 5Rainbow Babies & Children’s Hospital, Cleveland, OH, USA; 6University of Texas Health Science Center, Houston, TX, USA; 7Hemophilia Comprehensive Care Center, Faculty of Health Sciences, Charlotte Maxeke Johannesburg Academic Hospital, University of the Witwatersrand, and National Health Laboratory Service, Johannesburg, South AfricaCorrespondence: Gili Kenet, Amalia Biron Thrombosis Research Institute, Tel Aviv University, Tel HaShomer, 52621, Israel, Tel +972-3-5307356, Fax +972-3-5351806, Email Gili.kenet@sheba.health.gov.ilIntroduction: Previous clinical trials established the efficacy and safety of sucrose-formulated recombinant factor (F) VIII (rFVIII-FS/Kogenate FS®/Helixate FS®) and octocog alfa (BAY 81– 8973/Kovaltry®; LEOPOLD trials).Aim: To report the results of a post hoc subgroup analysis assessing efficacy and safety outcomes in patients with hemophilia A who were receiving rFVIII-FS prior to enrolling into the LEOPOLD I Part B and LEOPOLD Kids Part A clinical trials and switching to octocog alfa.Methods: LEOPOLD I Part B (NCT01029340) and LEOPOLD Kids Part A (NCT01311648) were octocog alfa Phase 3, multinational, open-label studies in patients with severe hemophilia A aged 12– 65 years and ≤ 12 years, respectively. Annualized bleeding rate (ABR) was the efficacy endpoint for both studies. Safety endpoints included adverse events (AEs) and development of FVIII inhibitors.Results: Of the 113 patients in both LEOPOLD trials, 40 (35.4%) patients received rFVIII-FS prophylaxis pre-study and had data available for pre-study total ABR. In LEOPOLD I Part B (n = 22, 35.5%), median (Q1; Q3) total ABR decreased from 2.5 (0.0; 9.0) pre-study to 1.0 (0.0; 6.8), and from 1.0 (0.0; 6.0) pre-study to 0.0 (0.0; 6.02) in LEOPOLD Kids Part A (n = 18, 35.3%). Octocog alfa was well tolerated, and no patients had drug-related serious AEs or inhibitors.Conclusion: Treatment with octocog alfa prophylaxis appeared to have a favorable risk–benefit profile compared with rFVIII-FS and thus could be an effective and improved alternative strategy for individualized treatment for children, adolescent and adult patients with severe hemophilia A currently on rFVIII-FS treatment.Keywords: FVIII, hemophilia A, prophylaxis, recombinant proteins, octocog alfa

The objective of this study was to make surgeons aware of a potential pressure complication in posterior spine surgery for patients with hereditary spherocytosis (HS) and to present a plausible hypothesis for injury. Posterior spine surgery is common practice for adolescent idiopathic scoliosis (AIS). Common, less severe surgical risks include pressure ulcers; while rare, more severe pressure complications include rhabdomyolysis and compartment syndrome. In patients with HS, a familial hemolytic disorder with altered red cell deformability, it is unknown if their red cell disorder is an additional risk factor for pressure-related surgical injuries. Two patients with HS, an 18-year-old male and a 17-year-old female, were both post-splenectomy and underwent revision posterior spinal fusion and instrumentation for progressive AIS. Surgery lasted 9 hours and 7 hours respectively, with no intraoperative complications other than prolonged surgical time due to revision nature of the deformities. Thigh redness and swelling was noted in both patients directly deep to the thigh pads. Thigh myonecrosis was diagnosed with eventual recovery in both cases. Patients with HS may be at inherent more risk of pressure complications during posterior spine surgery. We propose that thigh myonecrosis occurs with decreased perfusion and hemolysis from HS erythrocytes' inherent fragility, decreased deformability within capillaries, and prolonged microvasculature compression from positioning, causing poor microvascular perfusion, tissue ischemia, and reperfusion injury. Level of veidence: IV.

Although TEG directs effective resuscitation in adult surgical patients, pediatric data are lacking. We performed a retrospective comparative review of the effect of TEG on blood product utilization and outcomes following pediatric liver transplantation in 38 patients between 2008 and 2014. Diagnoses, laboratory values, fluid and blood product use, and outcomes were examined. Nineteen patients underwent liver transplantation prior to the implementation of TEG, and 19 had perioperative TEG. The most common indications for transplant were BA (n = 14), HB (n = 7), and metabolic disorders (n = 7). Intraoperative blood loss, urine output, fluid and blood product use were similar between groups. However, the use of fresh frozen plasma decreased significantly in TEG patients within the first 24 hours (29 vs 0 mL/kg, P < .01), and between 24 and 48 hours (12 vs 0 mL/kg, P = .01) post-operatively. The total use of fresh frozen plasma during hospitalization was markedly reduced (111 vs 17 mL/kg, P < .01). Four patients in the TEG group had thromboembolic graft complications, including portal vein or hepatic artery thrombosis, and underwent retransplantation. The decreased use of fresh frozen plasma since implementation of TEG is an important finding for resource utilization and patient safety. However, the increased incidence of thromboembolic complications requires further investigation., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Essentials Immunologic methods detect factor VIII (FVIII) antibodies in some inhibitor-negative specimens. Specimens were tested by modified Nijmegen-Bethesda assay (NBA) and fluorescence immunoassay. The NBA with preanalytical heat inactivation detects FVIII inhibitors down to 0.2 NBU. IgG 4 frequency validates the established threshold for positivity of ≥ 0.5 NBU for this NBA., Summary: Background The Bethesda assay for measurement of factor VIII inhibitors called for quantification of positive inhibitors by using dilutions producing 25-75% residual activity (RA), corresponding to 0.4-2.0 Bethesda units, with the use of 'more sensitive methods' for samples with RA closer to 100% being recommended. The Nijmegen modification (Nijmegen-Bethesda assay [NBA]) changed the reagents used but not these calculations. Some specimens negative by the NBA have been shown to have FVIII antibodies detectable with sensitive immunologic methods. Objective To examine the performance at very low inhibitor titers of the Centers for Disease Control and Prevention (CDC)-modified NBA (CDC-NBA), which includes preanalytic heat inactivation to liberate bound anti-FVIII antibodies. Methods Specimens with known inhibitors were tested with the CDC-NBA. IgG 4 anti-FVIII antibodies were measured by fluorescence immunoassay (FLI). Results Diluted inhibitors showed linearity below 0.4 Nijmegen-Bethesda units (NBU). With four statistical methods, the limit of detection of the CDC-NBA was determined to be 0.2 NBU. IgG 4 anti-FVIII antibodies, which correlate most strongly with functional inhibitors, were present at rates above the background rate of healthy controls in specimens with titers ≥ 0.2 NBU and showed an increase in frequency from 14.3% at 0.4 NBU to 67% at the established threshold for positivity of 0.5 NBU. Conclusions The CDC-NBA can detect inhibitors down to 0.2 NBU. The FLI, which is more sensitive, demonstrates anti-FVIII IgG 4 in some patients with negative (< 0.5) NBU. The sharp increase in IgG 4 frequency between 0.4 and 0.5 NBU validates the established threshold for positivity of ≥ 0.5 NBU for the CDC-NBA, supporting the need for method-specific thresholds., (© 2017 International Society on Thrombosis and Haemostasis.)

Background: The development of neutralizing anti-factor VIII alloantibodies (inhibitors) in patients with severe hemophilia A may depend on the concentrate used for replacement therapy., Methods: We conducted a randomized trial to assess the incidence of factor VIII inhibitors among patients treated with plasma-derived factor VIII containing von Willebrand factor or recombinant factor VIII. Patients who met the eligibility criteria (male sex, age <6 years, severe hemophilia A, and no previous treatment with any factor VIII concentrate or only minimal treatment with blood components) were included from 42 sites., Results: Of 303 patients screened, 264 underwent randomization and 251 were analyzed. Inhibitors developed in 76 patients, 50 of whom had high-titer inhibitors (≥5 Bethesda units). Inhibitors developed in 29 of the 125 patients treated with plasma-derived factor VIII (20 patients had high-titer inhibitors) and in 47 of the 126 patients treated with recombinant factor VIII (30 patients had high-titer inhibitors). The cumulative incidence of all inhibitors was 26.8% (95% confidence interval [CI], 18.4 to 35.2) with plasma-derived factor VIII and 44.5% (95% CI, 34.7 to 54.3) with recombinant factor VIII; the cumulative incidence of high-titer inhibitors was 18.6% (95% CI, 11.2 to 26.0) and 28.4% (95% CI, 19.6 to 37.2), respectively. In Cox regression models for the primary end point of all inhibitors, recombinant factor VIII was associated with an 87% higher incidence than plasma-derived factor VIII (hazard ratio, 1.87; 95% CI, 1.17 to 2.96). This association did not change in multivariable analysis. For high-titer inhibitors, the hazard ratio was 1.69 (95% CI, 0.96 to 2.98). When the analysis was restricted to recombinant factor VIII products other than second-generation full-length recombinant factor VIII, effect estimates remained similar for all inhibitors (hazard ratio, 1.98; 95% CI, 0.99 to 3.97) and high-titer inhibitors (hazard ratio, 2.59; 95% CI, 1.11 to 6.00)., Conclusions: Patients treated with plasma-derived factor VIII containing von Willebrand factor had a lower incidence of inhibitors than those treated with recombinant factor VIII. (Funded by the Angelo Bianchi Bonomi Foundation and others; ClinicalTrials.gov number, NCT01064284; EudraCT number, 2009-011186-88.).

Subcutaneous (SQ) vs. intramuscular (IM) vaccination may cause fewer injection site complications in children with bleeding disorders, but little is known about comparative immunogenicity. To compare immunogenicity of hepatitis B virus (HBV) vaccination administered SQ or IM to individuals <2 years old with bleeding disorders, we performed a retrospective analysis of HBV surface antibody titres among patients enrolled in the universal data collection database who had received three doses of HBV vaccine solely by one route (SQ or IM). Data reviewed were from an initial visit before 24 months of age, until time of hepatitis antibody titre testing. The SQ and IM study groups did not differ in demographics, haemophilia type or severity or bleeding history. The mean age at the time of HBV surface antibody (anti-HBs) testing was 56.9 ± 20.3 months. Eighty-five of 92 subjects (92.4%) who received vaccine SQ developed a positive antibody titre (>12 IU/L), compared to 101/114 (88.6%) who received IM (P = 0.30). There was no statistically significant difference in distribution of titre values. The average age of the subjects at time of testing was 53 ± 20 months in the SQ group vs. 60 ± 20 months in the IM group (P = 0.02). The average time between the last dose of vaccine and anti-HBs testing was 47.6 ± 18.5 months among SQ vaccinated subjects vs. 51.6 ± 20.5 months in the IM group (P = 0.2). Immunogenicity to hepatitis B vaccination by the SQ and IM routes is similar., (© 2014 John Wiley & Sons Ltd.)

Background: Detection and validation of inhibitors (antibodies) to hemophilia treatment products are important for clinical care, evaluation of product safety and assessment of population trends., Methods: Centralized monitoring for factor VIII (FVIII) inhibitors was conducted for patients in the Hemophilia Inhibitor Research Study using a previously reported modified Nijmegen-Bethesda clotting assay (NBA), a chromogenic Bethesda assay (CBA) and a novel fluorescence immunoassay (FLI)., Results: NBA and CBA were performed on 1005 specimens and FLI on 272 specimens. CBA was negative on 880/883 specimens (99.7%) with Nijmegen-Bethesda units (NBU) < 0.5 and positive on 42/42 specimens (100%) with NBU ≥ 2.0 and 43/80 specimens (53.8%) with NBU 0.5-1.9. Among specimens with positive NBA and negative CBA, 58.1% were FLI negative, 12.9% had evidence of lupus anticoagulant, and 35.5% had non-time-dependent inhibition. CBA and FLI were positive on 72.4% and 100% of 1.0-1.9 NBU specimens and 43.1% and 50.0% of 0.5-0.9 NBU specimens. FLI detected antibodies in 98.0% of CBA-positive and 81.6% of NBA-positive specimens (P = 0.004). Among 21 new inhibitors detected by NBA, five (23.8%) with 0.7-1.3 NBU did not react in CBA or FLI. Among previously positive patients with 0.5-1.9 NBU, 7/25 (28%) were not CBA or FLI positive. FLI was positive on 36/169 NBU-negative specimens (21.3%)., Conclusions: FVIII specificity could not be demonstrated by CBA or FLI for 26% of inhibitors of 0.5-1.9 NBU; such results must be interpreted with caution. Low titer inhibitors detected in clot-based assays should always be repeated, with consideration given to evaluating their reactivity with FVIII using more specific assays., (© 2013 International Society on Thrombosis and Haemostasis.)

The coagulopathy of liver disease in pediatric patients presents an unusual set of challenges. Little pediatric data have been published, so this review is based largely on adult studies. There is a precarious balance between deficiencies of clotting factors and anticoagulation factors in liver disease that result in abnormal prothrombin time (PT) and activated partial thromboplastin time (aPTT) tests that would suggest a bleeding tendency, yet the patients can form a clot and are at risk of thromboembolic disease. Attention has centered on thromboelastography and thrombin-generation assays to clarify the patient's ability to control bleeding, but these tests are not routinely available to many treating physicians.

Over the past decade, an increasing number of infections due to Agrobacterium radiobacter have been reported. Observation of three cases of bacteremia due to this organism prompted a review of the English-language literature. Nineteen cases of significant disease have previously been reported. In more than one-half of the cases, bacteremia was the primary manifestation, often associated with the presence of an intravascular catheter. Other clinical syndromes (peritonitis, urinary tract infection, and endocarditis) have been described. Infection is strongly related to the presence of plastic foreign material, and effective treatment often requires removal of the device. Because antimicrobial sensitivity is variable, treatment must be based on sensitivity data for the individual isolate.

We describe the successful treatment of a neonate with severe aortic thrombosis using systemic urokinase. Current knowledge regarding the treatment of this condition, including fibrinolytic therapy, is reviewed.