Gabriele Calizzani

Inhibitor development in haemophilia according to concentrate. Four-year results from the European HAemophilia Safety Surveillance (EUHASS) project.

Inhibitor development represents the most serious side effect of haemophilia treatment. Any difference in risk of inhibitor formation depending on the product used might be of clinical relevance. It was this studys objective to assess inhibitor development according to clotting factor concentrate in severe haemophilia A and B. The European Haemophilia Safety Surveillance (EUHASS) was set up as a study monitoring adverse events overall and according to concentrate. Since October 2008, inhibitors were reported at least quarterly. Number of treated patients was reported annually, specifying the number of patients completing 50 exposure days (Previously Untreated Patients, PUPs) without inhibitor development. Cumulative incidence, incidence rates and 95 % confidence intervals (CI) were calculated. Data from October 1, 2008 to December 31, 2012 were analysed for 68 centres that validated their data. Inhibitors developed in 108/417 (26 %; CI 22-30 %) PUPs with severe haemophilia A and 5/72 (7 %; CI 2-16%) PUPs with severe haemophilia B. For Previously Treated Patients (PTPs), 26 inhibitors developed in 17,667 treatment years [0.15/100 treatment years; CI 0.10-0.22) for severe haemophilia A and 1/2836 (0.04/100; (CI 0.00-0.20) for severe haemophilia B. Differences between plasma-derived and recombinant concentrates, or among the different recombinant FVIII concentrates were investigated. In conclusion, while confirming the expected rates of inhibitors in PUPs and PTPs, no class or brand related differences were observed.

EUHASS: The European Haemophilia Safety Surveillance system

Pharmacovigilance is an essential element of any drug treatment and considering the history of adverse events due to products used to treat inherited bleeding disorders, it should be an integral component of modern haemophilia treatment. Because inherited bleeding disorders and adverse events are rare, a multicentre, preferably multinational, adverse event reporting scheme for all clotting factor products is required. EUHASS is a European, prospective, multicentre adverse event reporting scheme in the field of inherited bleeding disorders.

The role of antenatal immunoprophylaxis in the prevention of maternal-foetal anti-Rh(D) alloimmunisation.

The first description of haemolytic disease of the newborn (HDN) can be traced back to 1609 and was made by a French midwife, Louise Bourgeois, who, from 1600, worked at the royal court of King Henry IV and Queen Marie de Medicis1–4. In the treatise that Bourgeois wrote in 1609 she described the birth of two twins3: the first had hydrops and died immediately, while the second, initially in a better condition, rapidly became jaundiced and, after having developed neurological symptoms (kernicterus), died 3 days after being born. Hydrops foetalis and kernicterus were correctly interpreted as two aspects of the same pathology only in 19325, when Diamond described foetal erythroblastosis secondary to severe haemolysis, although the cause was still unknown. A few years later, in 1938, Ruth Darrow correctly identified the (antibody-related) pathogenesis of HDN6, although erroneously attributing foetal haemoglobin the role of the culprit antigen, which was suggested to have induced a maternal antibody response after crossing the placenta. The true pathogenesis of the disease was definitively clarified in 1940 with the discovery of the Rhesus (Rh) blood group system by Landsteiner and Wiener7 and with the subsequent identification, in 1941, by Levine8, of the Rh(D) antigen. This antigen was, in fact, identified, in D-negative mothers, as being the cause of the immunisation occurring following transplacental passage of foetal D-positive red blood cells. The subsequent passage of maternal anti-D immunoglobulin G (IgG) across the placenta into the foetal circulation was recognised as the final event able to cause the spectrum of clinical events that characterise HDN. It did not take long before the risk of immunisation could be quantified1,3: i) 16% in the case of a Rh(D)-negative mother and a Rh(D)-positive, ABO-compatible foetus; ii) 2% in the case of a Rh(D)-negative mother and a Rh(D)-positive, ABO-incompatible foetus (about 20% of the cases); iii) overall risk of immunisation: 13.2%. Before 1945, about 50% of all foetuses with HDN died of kernicterus or hydrops foetalis. Subsequently, thanks to the progress in treatment, in industrialised countries the mortality decreased to 2–3%; this mortality rate was then very considerably further reduced (100-fold) with the introduction of anti-D immunoprophylaxis to prevent maternal-foetal anti-Rh(D) alloimmunisation 9. At the beginning of the 1960s, Stern demonstrated experimentally that the administration of anti-D IgG could prevent sensitisation to the Rh(D) antigen10; in the same period, other studies clarified the mechanism of Rh iso-immunisation in pregnancy and introduced the clinical practice of passive immunisation with anti-D IgG to protect Rh(D)-negative women from sensitisation against Rh(D)-positive red blood cells11–14. The successes obtained in studies of Rh(D)-negative male volunteers formed the experimental basis for clinical trials in pregnant Rh(D)-negative women15; these trials demonstrated that post-partum immunoprophylaxis decreased the incidence of post-pregnancy anti-Rh(D) immunisation from 12–13% to 1–2%15,16. Subsequently, in 1977, it was shown that 1.8% of Rh(D)-negative women, despite post-natal prophylaxis, continued to develop anti-D antibodies because of small transplacental haemorrhages during pregnancy17,18. One year later, a Canadian study by Bowman et al. showed, in 1,357 Rh(D)-negative primagravida, that the incidence of Rh(D) alloimmunisation could be reduced to 0.1% by prophylaxis with antenatal anti-D IgG, in addition to post-partum prophylaxis19. There is currently sufficient evidence demonstrating that antenatal anti-D prophylaxis also reduces the risk of Rh(D) immunisation in the next pregnancy to below the level of 0.4%. Forty years after Zipursky and Israels first proposed the use of anti-D IgG to reduce the incidence of Rh alloimmunisation in pregnancy14, immunoprophylaxis has drastically reduced the cases of Rh-induced HDN; nevertheless, this pathology continues to be relevant in 0.4 of 1,000 births (0.04%)20, for various reasons21: i) the possible occurrence of anti-D immunisation during the pregnancy (which occurs in about 1% of Rh(D)-negative women carrying a Rh(D)-positive foetus22); ii) the lack of efficacy of immunoprophylaxis because of the administration of an insufficient dose of anti-D IgG that is not congruent with the volume of the foetal-maternal haemorrhage; iii) immunoprophylaxis not administered; iv) possible errors in typing the pregnant or puerperal woman or the neonate; v) possible errors in transfusion therapy in women of child-bearing age.

Human Parvovirus B19 and blood product safety: a tale of twenty years of improvements

The establishment of systems to ensure a safe and sufficient supply of blood and blood products for all patients requiring transfusion is a core issue of every blood programme. A spectrum of blood infectious agents is transmitted through transfusion of infected blood donated by apparently healthy and asymptomatic blood donors. Recent emerging-infectious-disease threats include West Nile virus1,2, chikungunya3, babesia4, dengue5, hepatitis E virus6, and variant of Creutzfeldt-Jakob disease7. Parvovirus B19 (B19V), long known to be the causative agent of erythema infectiosum (fifth disease), is not a newly emerging agent. However, it deserves discussion because it may be present in blood and in plasma products, can circulate at extraordinarily high titres, can infect recipients, and, in some cases, can cause severe disease8. Its potentially severe pathological effects have become more apparent in the past decade with the widespread use of (pooled) plasma-derived medicinal products and are the main reason for the uneasy relationship between transfusion medicine specialists and B19V9. The aim of this review is to analyse the role played by this virus in compromising safety in transfusion medicine and the progressive measures to reduce the risks associated with the virus.

Hepatitis E: an old infection with new implications.

The availability of safe blood and blood products is an important public health issue. Improvements in donor screening and testing, pathogen inactivation1 and removal methods, the use of serological tests with greater diagnostic efficacy and the introduction of nucleic acid testing (NAT) have resulted in a substantial drop in transfusion-transmitted infections over the last two decades2. Nonetheless, blood supplies remain vulnerable to emerging and re-emerging infections. In recent years, numerous infectious agents found worldwide have been identified or reconsidered as potential threats to blood supplies3–5. Hepatitis E virus (HEV) has long been considered an enterically transmitted virus causing self-limiting acute viral hepatitis. The disease is endemic in many developing countries, but in recent years an increasing number of autochthonous and sporadic HEV infections have been described in developed countries6. This virus usually causes an acute self-limiting hepatitis, but in some cases fulminant hepatic failure resulting in morbidity and mortality may occur, especially in at-risk groups such as the elderly, pregnant women and patients with pre-existing liver disease or those who are immunocompromised. Furthermore, recent seroprevalence studies are questioning the concept of the low circulation of HEV in developed countries7. This narrative review aims at providing a comprehensive view of HEV and its possible “role” in transfusion medicine.

The European standards of Haemophilia Centres.

INTRODUCTION The European haemophilia community of professionals and patients has agreed on the principles of haemophilia care to address comprehensive optimal delivery of care which is nowadays scattered throughout Europe. Many of the health facilities call themselves Haemophilia Centres despite their variation in size, expertise and services provided. Only a small number of countries have Haemophilia Centre accreditation systems in place. METHODS In the framework of the European Haemophilia Network project, following an inclusive process of stakeholder involvement, the European Guidelines for the certification of haemophilia centres have been developed in order to set quality standards for European Haemophilia Centres and criteria for their certification. RESULTS The Guidelines define the standards and criteria for the designation of two levels of care delivery: European Haemophilia Treatment Centres, providing local routine care, and European Haemophilia Comprehensive Care Centres, providing specialised and multi-disciplinary care and functioning as tertiary referral centres. Additionally, they define standards about general requirements, patient care, provision of an advisory service and establishment of network of clinical and specialised services. CONCLUSIONS The implementation of the European Guidelines for the certification of Haemophilia Centres will contribute to the reduction of health inequalities through the standardisation of quality of care in European Union Member States and could represent a model to be taken into consideration for other rare disease groups.

Inhibitor development in non-severe haemophilia across Europe

Evidence about inhibitor formation in non-severe haemophilia and the potential role for clotting factor concentrate type is scant. It was the aim of this study to report inhibitor development in non-severe haemophilia patients enrolled in the European Haemophilia Safety Surveillance (EUHASS) study. Inhibitors are reported quarterly and total treated patients annually. Incidence rates and 95% confidence intervals (95% CI) were calculated according to diagnosis and concentrate used. Between 1-10-2008 and 31-12-2012, 68 centres reported on 7,969 patients with non-severe haemophilia A and 1,863 patients with non-severe haemophilia B. For haemophilia A, 37 inhibitors occurred in 8,622 treatment years, resulting in an inhibitor rate of 0.43/100 treatment years (95% CI 0.30-0.59). Inhibitors occurred at a median age of 35 years, after a median of 38 exposure days (EDs; P25-P75: 20-80); with 72% occurring within the first 50 EDs. In haemophilia B, one inhibitor was detected in 2,149 treatment years, resulting in an inhibitor rate of 0.05/100 years (95% CI 0.001-0.26). This inhibitor developed at the age of six years, after six EDs. The rate of inhibitors appeared similar across recombinant and plasma derived factor VIII (FVIII) concentrates. Rates for individual concentrates could not be calculated at this stage due to low number of events. In conclusion, inhibitors in non-severe haemophilia occur three times more frequently than in previously treated patients with severe haemophilia at a rate of 0.43/100 patient years (haemophilia A) and 0.05/100 years (haemophilia B). Although the majority of inhibitors developed in the first 50 EDs, inhibitor development continued with increasing exposure to FVIII.

Plasma-derived medicinal products in Italy: information sources and flows.

For the purpose of a systematic analysis of the manufacturing, marketing and usage of plasma-derived medicinal products (PMPs), it is essential to define all stages of the medicinal product life-cycle and to properly identify all information sources suitable for detecting and quantifying the information related to the assessment of each stage. The PMPs present some peculiarities. Their biological active substances are obtained by an industrial extraction process of human plasma derived from voluntary donations, instead of chemical synthesis. As a raw material, plasma can be a vehicle of blood born infectious diseases. Therefore, the Italian and European legislations identified several measures aimed at reducing the risk of infection, such as: donor selection, biological validation tests, methods of pathogen removal and inactivation; moreover, the adoption of prescriptive measures is envisaged in order to guarantee both traceability and pharmacovigilance of all PMPs1–11. Another peculiar feature of PMPs is related to the ownership of the raw material and of the derived medicinal products. In Italy, as regards the national plasma collected by Regional Blood Transfusion Services, Regions and Autonomous Provinces (henceforth referred to as ‘Regions’) retain the ownership of both of them within the toll fractionation agreements with the authorised manufacturer. On the contrary, the commercial product ownership is assigned to pharmaceutical companies, which obtain the raw material from blood establishments in all other countries where plasma provision for commercial use is allowed. The aim of this manuscript is to provide an exhaustive critical description of all data sources available in Italy for the study and monitoring of the entire medicinal product life-cycle and then to highlight the degree of overlap of various information sources and to demonstrate the feasible analyses that might be developed using each of them.

Clinical use and the Italian demand for activated prothrombin complex and activated recombinant factor VII concentrates

The activated prothrombin complex concentrate (aPCC, Factor Eight Inhibitor Bypassing Activity, FEIBA, Baxter, Deerfield, IL, USA) and the recombinant activated factor VII concentrate (rFVIIa, NovoSeven, Novo Nordisk A/S, Bagsvaerd, Denmark) are the so-called “by-passing agents”, i.e. products able to promote haemostasis through mechanisms alternative to the physiological tenase complex, in which a phospholipid-dependent reaction occurs with factor (F) X as the substrate, activated (a) FIX as the enzyme and FVIIIa as a cofactor1. The mechanism(s) of action of these agents are still not completely elucidated. The aPCC, which contains activated FII, FIX, FX and small amounts of FVII, is thought to facilitate thrombin generation on the platelet surface. This product was first introduced in clinical practice in 1975, as a therapeutic agent for haemophilia B when specific FIX concentrates were not available, and in the current vapour-heated formulation in 19852. The rFVIIa concentrate was specifically developed to provide a therapeutic approach in haemophilia with inhibitors, being able at high concentrations to enhance platelet-surface FXa generation, irrespective of the presence of FVIII or FIX3. The first use of rFVIIa was reported in 1988, and the product was registered in Europe in 1996 and in the United States in 1999. aPCC and rFVIIa are the mainstay of treatment of patients with congenital and acquired haemophilia (AH) with inhibitors4–6, in whom efficacy and safety of such agents have been documented over more than three and two decades of clinical use, respectively. As a specific replacement agent, rFVIIa is indicated in patients with factor VII deficiency7 and, as an alternative haemostatic agent, in patients with Glanzmann’s thrombasthenia (GT) and alloantibodies and/or platelet transfusion refractoriness8. Because of the rarity of the other recognised indications for treatment, most clinical and literature data regarding bypassing agents have been generated in the setting of congenital haemophilia with inhibitors. Before presenting the Italian demand for aPCC and rFVIIa in this 5-yr analysis, the clinical use of bypassing agents in the management of patients with bleeding disorders, in particular in those with congenital haemophilia and inhibitors, with the numerous challenges and open issues, will be concisely reviewed.

The demand for human albumin in Italy.

Human albumin (HA) is a blood plasma protein produced in the liver. It constitutes about 60% of plasma proteins and is a physiological plasma-expander. However, its limited availability and high cost make it essential to define recommendations for its appropriate use, as an alternative to other therapeutic strategies including solutions of crystalloids and non-protein colloids. According to all official recommendations, the choice to use albumin rather than an artificial colloid strictly depends on the clinical situation of the patient1–6. HA is also used in all cases in which there is a contraindication to the use of non-protein colloids7. Based on clinical evidence, the 2009 guidance document of the Italian Society of Transfusion Medicine and Immunohaematology (SIMTI)7 recommends the use of HA in acute conditions, which call for blood volume expansion and maintenance of adequate blood flow, as well as in some chronic conditions of low serum albumin levels. “There are some widely shared and fully agreed indications for the appropriate use of human albumin and indications that are occasionally appropriate, that is, when other criteria are fulfilled”7. In addition, in haemorrhagic shock HA should only be used as a second choice [i.e. when solutions of crystalloids or non-protein colloids (first choice treatment) have already been used at maximum doses without having produced a clinically adequate response] and in cases in which non-protein colloids are contraindicated7.