Vanessa Piccinini

Reduction of the risk of bacterial contamination of blood components through diversion of the first part of the donation of blood and blood components.

The level of safety of transfusion therapy is now very high thanks to the combination of serological methods and genomic amplification used to screen for transmissible diseases and the meticulous care with which repeat, voluntary, unpaid donors are selected1–4. The main risk of transfusion-related infectious diseases is currently that of bacterial sepsis1,3–5. The risk of bacterial contamination of blood components is, in fact, estimated to be about three orders of magnitude greater than that of post-transfusional HIV and HCV infections5,6; the risk of bacterial sepsis causes by the transfusion of platelets is more than two orders of magnitude greater than the risk of the same viral infections5,6. According to a study published in 20047, the year in which bacteriological screening tests for platelet units were introduced in the USA3,8,9, the average prevalence of bacterial contamination in platelets from whole blood was 33.9/100,000 units, that of platelets from apheresis 51/100,000, while that of red cell concentrates was 2.6/100,000. The overall prevalence of bacterial contamination of units of cellular blood components was, therefore, about 1 in 3,000 donations (33.3/100,000)7,10. Table I reports the data on bacterial contamination of units of platelets and red blood cells derived from studies before 200311–19. More recent estimates indicate that bacterial culture tests on units of platelets are positive, and confirmed as such, in about 1 in 5,000 units (20/100,000)4. The risk of receiving platelet concentrates contaminated by bacteria is, therefore, considerably higher than the risk of post-transfusion infection by HIV, HCV, HBV and HTLV3,4. Table I Prevalence of bacterial contamination of cellular blood components recorded in studies before 2003

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.

Human T-lymphotropic virus and transfusion safety: does one size fit all?

Human T‐cell leukemia viruses (HTLV‐1 and HTLV‐2) are associated with a variety of human diseases, including some severe ones. Transfusion transmission of HTLV through cellular blood components is undeniable. HTLV screening of blood donations became mandatory in different countries to improve the safety of blood supplies. In Japan and Europe, most HTLV‐infected donors are HTLV‐1 positive, whereas in the United States a higher prevalence of HTLV‐2 is reported. Many industrialized countries have also introduced universal leukoreduction of blood components, and pathogen inactivation technologies might be another effective preventive strategy, especially if and when generalized to all blood cellular products. Considering all measures available to minimize HTLV blood transmission, the question is what would be the most suitable and cost‐effective strategy to ensure a high level of blood safety regarding these viruses, considering that there is no solution that can be deemed optimal for all countries.

The first data from the haemovigilance system in Italy.

BACKGROUND Haemovigilance is defined as the surveillance of adverse reactions occurring in donors and in recipients of blood components and as epidemiological surveillance of donors. The ultimate purpose of haemovigilance is to prevent the repetition of adverse events and reactions. Since the 2002/98/EC Directive came into force, the introduction of haemovigilance systems has become a priority for all countries in the European Community. The Italian haemovigilance system is essentially in line with the Directive, although it does not include surveillance of adverse events in donors and does not have a national level of registration of severe incidents connected with the collection, processing and storage of blood and blood components. Epidemiological surveillance of donors has been performed nationally since 1989 for HIV and since 1999 for HBV, HCV and Treponema pallidum. Surveillance of adverse events in recipients was started at the end of 2004. MATERIALS AND METHODS The national form proposed for notifying adverse reactions (PETRA) was prepared by the National Institute of Health and distributed to all Transfusion Structures. RESULTS The data collected (adverse reactions, errors, and near miss errors) came from 21.0% of the Transfusion Structures in 2004 and 38.4% in 2005. The system monitored 49.6 % of all the units distributed in Italy. Overall 1,495 adverse reactions were reported, which is equivalent to 0.8 reactions/1,000 units of blood components distributed. There were 16 reports of errors involving transfusions to the wrong patient. Not all the Transfusion Structures sent their data using the PETRA form. From the 986 PETRA forms received, it was possible to analyse the relevance of the transfusion, the outcome of the patient, the type of blood component involved, the type of error and the type of near miss error. CONCLUSIONS This study is the first Italian report on transfusion errors and adverse reactions.

Inhibitors in Patients with Congenital Bleeding Disorders Other Than Hemophilia

Abstract The most worrying complication of replacement therapy for severe hemophilia A and B is currently the occurrence of inhibitory alloantibodies against infused factor VIII and factor IX, respectively. Inhibitors compromise the management of hemorrhage in affected patients, with a considerable increase in complications, disability, and costs. While these alloantibodies have been extensively studied in the past years in hemophilia A and B, those occurring in patients with other inherited bleeding disorders are less well characterized and still poorly understood, mostly due to the rarity of these hemorrhagic conditions. This narrative review will deal with inhibitors arising in patients with inherited bleeding disorders other than “classical” hemophilia, focusing in particular on those developing in patients with congenital deficiency of coagulation factor V, factor VII, factor XI, and factor XIII.

The human pegivirus: A new name for an "ancient" virus. Can transfusion medicine come up with something new?

Human pegivirus (HPgV, formerly called GB virus C/hepatitis G virus) is a poorly understood RNA virus of the Flaviviridae family. The HPgV infection is common worldwide and the virus is likely transmitted by blood products. At this time, no causal association between HPgV and human diseases has been identified. While waiting for new findings to better understand the Pegivirus genus, the aim of our narrative review is to discuss the currently available information on HPgV focusing on its prevalence in blood donors and its potential threat to transfusion safety.