New insights into the natural history of hepatitis E virus infection through a longitudinal study of multitransfused immunocompetent patients in France.

Little is known about the natural history of Hepatitis E virus (HEV) infection in immunocompetent individuals. The prevalence, the course of infection and the occurrence of transmission by transfusion were investigated in multitransfused immunocompetent patients/blood donor pairs included in a longitudinal sample repository collection and followed up between 1988 and 2010. Ninety-eight subjects aged 6-89 years and suffering from acquired haemoglobinopathies were tested for HEV markers (IgM, IgG and RNA) in serial samples collected every 2 or 3 years. Eighteen patients (18.4%) were positive for HEV-IgG at baseline with a prevalence increasing from 12.5% below 26 years to 32% above 56 years. Nine patients remained IgG positive along the study and nine lost their antibodies after a mean follow-up of 7.4 years (1-22 years). One seropositive patient showed an increase of IgG level and RNA-HEV reappearance 1 year after inclusion, suggesting a reinfection and one seroconversion, probably acquired through blood transfusion was observed. This first longitudinal study including immunocompetent individuals confirms that HEV infection is common in Western Europe and that transfusion transmission occurs probably less frequently than expected. In addition, seroreversion and reinfection seem to be common. This suggests that the anti-HEV may not persist overtime naturally. However, repeat exposure to the virus related to the high prevalence of HEV infection may result in a sustainable specific IgG response.

Screening for transfusion transmissible infections using rapid diagnostic tests in Africa: a potential hazard to blood safety?

Rapid diagnostic tests (RDTs) are routinely used in African blood centres. We analysed data from two cross-sectional studies representing 95 blood centres in 29 African countries. Standardized panels of sera containing varying concentrations of anti-human immunodeficiency virus (HIV) antibodies (Ab), hepatitis B virus antigen (HBsAg) and antihepatitis C virus (HCV) Ab were screened using routine operational testing procedures at the centres. Sensitivity of detection using RDTs was high for HIV Ab-positive samples, but low for intermediately HBsAg (51·5%) and HCV Ab (40·6%)-positive samples. These findings suggest that current RDT use in Africa could pose a hazard to blood safety.

A pilot external quality assurance study of transfusion screening for HIV, HCV and HBsAG in 12 African countries.

BACKGROUND AND OBJECTIVES: Serologic screening for the major transfusion transmissible viruses (TTV) is critical to blood safety and has been widely implemented. However, actual performance as measured by proficiency testing has not been well studied in sub-Saharan Africa. Therefore, we conducted an external quality assessment of laboratories engaged in transfusion screening in the region. MATERIALS AND METHODS: Blinded test panels, each comprising 25 serum samples that were pedigreed for HIV, HBsAg, HCV and negative status, were sent to participating laboratories. The panels were tested using the laboratories' routine donor screening methods and conditions. Sensitivity and specificity were calculated, and multivariable analysis was used to compare performance against mode of testing, country and infrastructure. RESULTS: A total of 12 African countries and 44 laboratories participated in the study. The mean (range) sensitivities for HIV, HBsAg and HCV were 91·9% (14·3-100), 86·7% (42·9-100) and 90·1% (50-100), respectively. Mean specificities for HIV, HBsAg and HCV were 97·7%, 97% and 99·5%, respectively. After adjusting for country and infrastructure, rapid tests had significantly lower sensitivity than enzyme immunoassays for both HBsAg (P < 0·0001) and HCV (P < 0·05). Sensitivity also varied by country and selected infrastructure variables. CONCLUSION: While specificity was high, sensitivity was more variable and deficient in a substantial number of testing laboratories. These findings underscore the importance of proficiency testing and quality control, particularly in Africa where TTV prevalence is high.

Characterization and comparison of bone marrow and peripheral blood mononuclear cells used for cellular therapy in critical leg ischaemia: towards a new cellular product.

BACKGROUND AND OBJECTIVES: Autologous transplantation of either bone marrow (BM) or peripheral blood (PB) mononuclear cells (MNC) induces therapeutic angiogenesis in patients with peripheral arterial occlusive disease. Yet, the precise nature of the cellular product obtained from BM or PB and used in these therapeutic strategies remains unclear. MATERIALS AND METHODS: We have analysed the characteristics of BM-MNC and PB-MNC collected without mobilization and implanted in patients with critical limb ischaemia in a clinical trial of cellular therapy including 16 individuals treated by BM-MNC and eight by PB-MNC. These MNCs were characterized by cell counts, viability assessment and enumeration of leucocyte subsets, CD34 stem and endothelial progenitor cells (EPCs) (CD34+/CD133+/VEGF-R2+) by flow cytometry. Mean fluorescence intensity ratios were determined for CD34, CD133 and VEGF-R2 markers. All analyses were simultaneously performed in two laboratories. RESULTS: Accuracy and reliability between both laboratories were achieved. BM-MNCs and PB-MNCs were quantitatively and qualitatively heterogeneous and quite different from each other. Stem cells and EPCs were significantly more present in BM- compared to PB-cell products, but with similar mean fluorescence intensity ratios. A weakly positive correlation was observed between CD34+ cell counts and EPCs levels, confirming the specificity of cell identification. CONCLUSION: A great variability was observed in cell product characteristics according to their origin and also between individuals. These data stress the necessity of optimal characterization of cell products especially in multicentric clinical trials.

[Biobanks and blood transfusion in France: a tool for public health]. / Les biothèques de transfusion sanguine en France: un outil de santé publique.

Donor and recipient sample biobanks are a precious tool in hemovigilance studies as well as in epidemiological and biological research, in particular with regards to safety against blood-borne agents. This paper describes the main transfusion biobanks existing in France and gives their advantages and limits. The National blood donation biobank, organized for medicolegal reasons, preserves samples of each blood donation for a 5-year period. The biobank of the Blood and Organ Transmissible Infectious Agents (BOTIA) project stocks paired donor-recipient samples with a research objective. Preserved over a long period of time, such transfusion biobanks will be useful in terms of public health, as a reflection of the biological state of a population at a given moment.

Hepatitis G virus: a suitable marker of in vivo efficacy for pathogen inactivation.

Being an orphan virus despite a large number of investigations, hepatitis G virus is a blood-borne agent for which screening is not required in blood donations. The in vivo efficacy of pathogen inactivation methods could be assessed by the absence of hepatitis G virus markers after transfusion of pathogen-inactivated blood products, in recipients susceptible to infection before the transfusion.

[Genetic diversity of human erythroviruses: consequences on infectious safety of blood products and plasma derivatives]. / Conséquences de la diversité génétique des érythrovirus humains sur la sécurité infectieuse des produits sanguins labiles et des médicaments dérivés du sang.

Sequence analysis of human erythroviruses shows an organization into three genotypes; genotype 1 with B19 Parvovirus (B19 V) and 2 new genotypes with a genetic diversity markedly distinct from that of B19 V. The frequency of each genotype depends on geographic origin and population. Human erythroviruses infection can be transmitted by transfusion. In immunocompetent recipients, B19 V exposure is generally inconsequential, since a large proportion is immunized. However, such a contamination may have severe clinical outcome in not immunized patients with shortened red cell survival, in seronegative pregnant women and in immunocompromised patients. No prevention of blood transmission is currently performed, but a preventive strategy could be discussed for at-risk recipients. In plasma derivatives, B19VDNA screening is done with a threshold of 104 IU/mL. With recent data of a new classification on the human erythroviruses genotypes, DNA testing assays would be validated in accordance with genetic variability, in order to guarantee optimal safety.

[Blood safety: malaria and blood donation in Africa]. / Sécurité transfusionnelle: paludisme et don de sang en Afrique.

Malaria is a principal cause of mortality in Africa and represents a major blood-borne disease. The studies made on the continent show that transfusion-associated malaria is highly prevalent in blood donors groups and that some risk factors and clinical manifestations are frequently observed. The disease is mostly asymptomatic and the signs are mild, which reduces significantly an efficient selection of the blood donors during the predonation interview and a secure supply of blood products. Furthermore, the lack of appropriate screening assays of the malaria in blood banks on the continent limit the diagnosis of the disease and hamper the blood safety. However, the prevention of transfusion-associated malaria is a frequently asked question. The destruction of the parasite in the blood bag and the recipient anti-malarial prophylaxis are the described possibilities, added to local programs against the vectors of the disease.

Measures to prevent transfusion-associated protozoal infections in non-endemic countries.

To understand the risk of protozoa transmission by blood is critical as: (i) the world has become globalized with extensive travel, and increased immigration; (ii) blood-borne protozoa is common in inter-Tropical areas; (iii) protozoa develop biological means to escape hosts' immune systems, together with complicated detection, surveillance, and biological testing; and (iv) life threatening-parasites are inadequately controlled by treatment or prevention. This question is relevant in France, with it's non-continental territories, such as French Guiana, located in the Amazon Basin, which is endemic for various Plasmodium ssp. responsible for malaria, and for Trypanosoma cruzi, which is responsible for Chagas disease. In France, specific questioning of blood donors is haphazard despite the increase in population migration over the last three decades: specific questioning must be emphasized and 'at-risk' donors should be identified and subsequently excluded from donation. Donor exclusion alone would only be partially efficient, there is also a need for relevant biological testing of blood donations and in particular for T. cruzi through the CE-marked test to organize a coherent prevention policy: precise studies would thus define which blood donations are subjected to this additional qualifying test when available.

[Application of pre- and post-transfusion virological controls prior to the suppression of their recommendation]. / Application des contrôles virologiques pré- et post-transfusionnels avant la suppression de leur recommandation.

In 1996, due to a residual risk of transfusion-transmitted virus, a circular of the French Health Authorities (DGS/DH n degrees 96-609) recommended proposing to recipients of cellular blood products a test for antibodies to human immunodeficiency virus (HIV) and for antibodies to hepatitis C virus, before and three months after transfusion. We have evaluated the application of this recommendation throughout the whole transfused population of a French Hospital over a three month period. In addition, this study allowed us to establish the vaccination status against hepatitis B virus (HBV) infection in this exposed population including transfusion and nosocomial risks. The results showed a failure in the application of the 1996 circular and confirmed the validity of the abrogation of this circular by a recent circular (11 January 2006) of the French health authorities. It also showed that only a minority of patients needing a vaccination against HBV were afforded such treatment during their hospitalization.

[Safety of blood products and B19 parvovirus]. / Sécurité des produits sanguins labiles et parvovirus B19.

More than 25 years after the discovery of the parvovirus B19 (B19), the issue of the safety of blood components and the screening of this virus in blood donations is still debated. Although more often transmitted by respiratory route, B19 may also be transmitted by transfusion of blood components. This risk of exposure has been estimated to a frequency ranging from 1/625 to 1/50,000, according to the sensitivity of the detection methods and to seasonal epidemiologic circumstances. Usually, B19 is responsible for benign pathologies. However, such an infection can have a serious clinical outcome in three categories of susceptible recipients: (i) patients with shortened red cell survival (thalassemia major, sickle cell disease, other hemolytic diseases); (ii) immunocompromised patients (previously exposed to B19 or not) (iii) and pregnant women (not previously exposed the B19), with a risk of hydrops fetalis or of intrauterine death. Selected blood components, not collected during the short but highly viremic pre-seroconversion phase, could be reserved for these three groups of at-risk recipients. The screening of such viremic donations could be performed with nucleic acid testing (NAT), but an alternate strategy could be the selection of B19 immunised donors far from the primo-infection (positive for B19 IgG and negative for B19 IgM, or only positive for IgG at two controls distant of several months). However, the existence of persistently B19-infected individuals carrying B19 DNA despite the presence of specific IgG (estimated at 1% of blood donors) could constitute a potential threat for transfused immunocompromised recipients. The screening of such donors, which could be performed through a very highly sensitive NAT, would be justified only if the infectivity of such blood donations is demonstrated. If not, a screening of blood donors positive for B19 IgG would be a sufficient preventive measure.

"The Tramp", a blood donation propagandist?

The French pioneer for blood transfusion, who eventually organized the very early blood transfusion centers worldwide, went to imagine a scenario written in purpose for Charlie Chaplin, the unique character of "The Tramp" ("Charlot" in French). The movie Star was offered to feature a blood donation propagandist, and no longer the perpetual, well-known, "loser". This anecdote, besides being amusing, tells a lot on how Arnault Tzank encompassed all the difficulties in collecting blood enough to meet the demand, at all times; his proposal turns out to be extremely modern and questions nowadays marketing for blood donation.

[Blood donation in the media between 1950 and 1980]. / Le don de sang dans la presse française des années 1950-1980.

Anecdotes, such as found in the media and chiefly the humor journals and magazines aim at bringing revisited insights on society subjects, which can even be the most serious. Anecdotes reported here on blood transfusion and the transfusion environment, that were retrieved from French news released in the media press between the 1950s to 1980s give a view on what has been achieved since then, but also on what is at a standstill by some incapability in moving forward or in changing minds. Those anecdotes would be used to stimulate or refresh debates in transfusion related-ethics.

[Electronic learning: interactive learning in medicine or Socrates in electronic guise]. / Electronic learning: apprentissage interactif en médecine ou Socrate en habits électroniques.

E-learning has been widely used for training in different fields. More recently, it was introduced during medical studies or for continuous medical education. The Canadian Universities are pioneers in e-learning creating special departments dedicated to pedagogy. Developing countries like Brazil or Central Europe have made some pilot experiments, which were successful. Several electronic companies have given a free access to the programmes and sites. The use of electronic media leads to an adaptation of teaching methods making them more interactive.

[French training program for medical students in transfusion medicine. Transfusion Medicine Teachers' College]. / Programme en transfusion des étudiants en médecine. Collège des enseignants en transfusion sanguine.

In France, transfusion medicine training program has been updated. A national committee of professors in transfusion medicine propose a series of 13 items which represent the minimum knowledge that general practitioners should possess. This overview of transfusion medicine is far below the level that specialists should reach and they will need an additional specialized training. Several French universities have set up their own training program which is quite similar to the work of the committee of professors. The following recommendations are not strict guidelines but is a common basis which will be improved in 2005 according to new evidence based transfusion medicine.

Progression to AIDS in the majority of asymptomatic HIV-infected people.

Sixty-eight asymptomatic HIV-seropositive people with a CD4 lymphocyte count above 400/mm3 at the first examination were followed up every year over a 3-year period, by monitoring the biological markers of AIDS (CD4 lymphocyte decrease, loss of anti-p24 or anti-p17 antibodies, positive p24 antigenemia, increase of erythrocyte sedimentation rate, and of serum levels of immunoglobulin G. immunoglobulin A, neopterin and beta 2-microglobulin). The percentages of subjects positive for at least one marker at the first, second, third and fourth examinations were 66, 88, 94 and 97%, respectively. The increase in the number of markers with time was significant (chi-square test; P less than 0.001). This increase suggests a progression to AIDS in the majority of asymptomatic seropositive subjects, even those without a decreased CD4 lymphocyte count.

Prognostic value of an elevated CD8 lymphocyte count in HIV infection. Results of a prospective study of 152 asymptomatic HIV-positive individuals.

OBJECTIVE: To evaluate the prognostic value of an elevated CD8 lymphocyte count in the early stages of HIV infection. DESIGN: A prospective study ongoing since January 1986. METHODS: One hundred and fifty-two asymptomatic HIV-positive individuals with a CD4 lymphocyte count > 400 x 10(6)/l at enrollment were included. Disease progression was defined as a CD4 count < 200 x 10(6)/l. RESULTS: During the follow-up period, CD4 count decreased in 33 individuals; CD8 count increased to > 1500 x 10(6)/l in 38 individuals and doubled in 35. The risk of a decreasing CD4 count was estimated to be 1.7-fold higher, although not significantly so, after the elevation of the CD8 count to > 1500 x 10(6)/l than before or in the absence of such an increase. However, this predictive value disappeared when five baseline parameters found to predict the outcome (neopterin, beta 2-microglobulin, p24 antigen, anti-p18 antibody and immunoglobulin A) were adjusted. CONCLUSION: Elevated CD8 count appears to be a weak marker for disease progression.