| INTRODUC TI ONThe recent development of emicizumab (Hemlibra, also previously referred to as ACE910; Hoffman-la Roche) extends treatment options for haemophilia A patients, with and without anti-Factor (F) VIII inhibitors, and provides an alternative to FVIII replacement therapy for patients with severe haemophilia A. 1,2 The novel nature and mode of action of the molecule have implications for the laboratory testing of coagulation parameters in patients receiving this treatment. | WHAT IS EMI CIZUMAB AND HOW DOE S IT WORK?Emicizumab is an engineered IgG4 bispecific antibody that binds both factor IXa (FIXa) and its substrate factor X (FX). This interaction colocalises the components of the intrinsic tenase complex and improves Abstract Introduction: The factor VIII mimetic emicizumab (Hemlibra, Hoffman-la Roche, Basel, Switzerland) has a novel mode of action that affects the laboratory monitoring of patients receiving this treatment. Aim: This guideline from the United Kingdom Haemophilia Centre Doctors Organisation(UKHCDO) aims to provide advice for clinical and laboratory staff on appropriate use of laboratory assays in patients with Haemophilia A treated with emicizumab. Results:The guideline describes the effect of emicizumab on commonly used coagulations tests and provides recommendations on the use of assays for measurement of factor VIII and factor VIII inhibitor in the presence of emicizumab. The guideline also provides recommendations on measurement of emicizumab. Conclusion:Knowledge of the effect of emicizumab on coagulation tests and factor assays is required to ensure appropriate testing and monitoring of therapy in patients receiving this drug. K E Y W O R D Sbispecific antibody, chromogenic factor VIII assay, emicizumab, factor VIII assay, haemophilia, Hemlibra

Children with von Willebrand disease (VWD) in whom DDAVP is ineffective or contraindicated require treatment with a coagulation factor concentrate containing von Willebrand factor (VWF) and factor VIII (FVIII). The aim of this study was to monitor the safety, efficacy and tolerability of Wilate(®) (a VWF:FVIII concentrate with a 1:1 ratio) used across the North London Paediatric Haemophilia Network since May 2010. In total, 47 children (aged 0.0-17.0 years) with type 1 (n = 28), type 2 (n = 7), type 3 (n = 10) and acquired VWS (n = 2) have been treated for bleeds, surgery and/or prophylaxis using 260 000 IU Wilate(®). Analysis of dose and frequency of treatment show expected responses to treatment with mean doses of 55, 50 and 50 IU kg(-1) for bleeds, surgery and prophylaxis respectively. Most bleeds responded to a single treatment. Surgical procedures were covered with clinician approved dosing schedules with 95% (39/41) reported as having excellent or good efficacy. There was no accumulation of FVIII or VWF and no thromboembolic events. This case series confirms the efficacy, safety and tolerability of Wilate(®) in neonates, children and adolescents when used on-demand, prophylactically and in the surgical setting.

Children born with severe homozygous protein C deficiency do not survive beyond the neonatal period unless they receive protein C replacement. Protein C concentrate (Baxter Biosciences, Vienna) is usually given intravenously via a central venous catheter The authors describe 2 children in whom protein C concentrate was successfully administered by subcutaneous infusion after they had had recurrent central line infections. Alternate daily doses of 250-350 IU/kg resulted in trough protein C levels of > 25 IU/dL. In the follow-up period of 1-2 years neither child has had a thrombotic episode or purpuric skin lesions, and infusions are managed in the home by their parents.

Desmopressin (1-deamino-8-D-arginine vasopressin (DDAVP)) has been shown to be an effective treatment option when administered both intravenously [1,2] and subcutaneously [3] to children with inherited bleeding disorders. We demonstrate here, both the efficacy and acceptability of a new intranasal DDAVP preparation, providing a cost effective treatment with good outcomes for children with bleed disorders.

Summary Epidural abscess is a rare but life threatening condition that requires early diagnosis and prompt management. We report a case of cervical epidural abscess following an intravenous cannula site infection. The organism responsible was Methicillin Resistant Staphylococcus Aureus (MRSA). Management involved surgery, prolonged antibiotics and ventilation. Despite this, there was no return of neurological function and the patient died. We review the literature on epidural abscesses unrelated to catheterisation or instrumentation of the epidural space and discuss the aetiology and clinical features of this acute medical emergency.