[Immunohematologic follow-up and transfusion safety in hematopoietic stem cells allografts]. / Le suivi immunohématologique et la sécurité transfusionnelle dans les allogreffes de cellules souches hématopoïétiques.

Since 1990, specific documentation is established between the immunohematology laboratory of the French EFS Lorraine-Champagne and the marrow transplantation unit of the CHU of Nancy, for patients undergoing hematopoietic stem cells transplantation. These documents and the standardization of the immunohematologic follow-up of those patients, have contributed to the improvement of the transfusion safety.

Plateletpheresis concentrates produced with the COMTEC cell separator: the French experience.

The latest generation of cell separators such as Trima (Gambro), Amicus (Baxter) and AS-TEC 204 (Fresenius), allow the collection of leucocyte-reduced platelet concentrates without secondary filtration. Fresenius has recently developed the COMTEC cell separator whose performance has been evaluated by several teams in France. This new cell separator is an improved version of the Fresenius AS-TEC 204 cell separator, designed to allow more efficient platelet collections. This study reports on the experience of six French teams (from Bordeaux, Clermont-Ferrand, Creteil, Dijon, Lille and Nancy) who obtained 696 leucocyte-reduced plateletpheresis concentrates in the course of collection using the new Fresenius COMTEC cell separator. All healthy volunteer donors fulfilled French selection criteria for platelet apheresis. Donors were eligible if they had suitable venous accesses, if their bodyweight was *50 kg and if their pre-apheresis platelet count was >150 x 10(9) l(-1). Between 4606 and 5229 ml of blood were processed. The mean volume of the platelet concentrates was between 439 and 493 ml (mean 460 +/- 63 ml). The platelet yield was of the order of 5.18 +/- 1.02 x 10(11) with only one platelet concentrate below the norm of 2 x 10(11) platelets (0.91 x 10(11)). No plausible explanation for this was found. The residual leucocyte levels conform to current norms. The platelet concentrates contained less than 1 x 10(6) leucocytes per concentrate (mean 0.233 +/- 0.150 x 10(6) leucocytes) in more than 97% of the components produced with >95% statistical confidence. The efficacy of the cell separator (52.44 +/- 7.35%) is comparable to that of other separators. The Fresenius COMTEC cell separator makes it possible to obtain leucocyte-reduced platelet concentrates which comply with current standards both in terms of platelet content and residual leucocyte level.

Prevalence of GBV C/HGV RNA and GBV C/HGV antibodies in French volunteer blood donors: results of a collaborative study.

BACKGROUND AND OBJECTIVES: Posttransfusion hepatitis still occurs at an incidence of about 1 in 118,000 for HBV and 1 in 220,000 for HCV. This collaborative study aimed to determine the prevalence of a novel flavivirus, GBV-C/HGV, even though its role in transfusion-associated hepatitis is uncertain. MATERIALS AND METHODS: GBV-C/HGV RNA was detected by PCR using either the Boehringer detection kit or by primers previously described. HGV antibodies were detected by a serological assay from Boehringer. RESULTS: The observed GBV-C/HGV RNA frequency was 3.4%. HGV antibodies occurred in 9.5% of donors. CONCLUSION: In our study, 12. 9% of the donors had been in contact with the GBV-C/HGV virus.

Comparison of T cell depletion strategies from bone marrow, umbilical cord and peripheral blood using five separation systems.

The development of bone marrow transplantation in mismatched or matched unrelated donor situations, the recent use of peripheral blood stem cells for allogeneic transplants, the standardization and respect of good methodology practices highlight the need to evaluate new safe methods of T cell depletion (TCD). We have performed 79 in vitro TCD using five techniques: rabbit complement cytotoxicity, CD2-CD7 immunomagnetic depletion, CD5-CD8 panning system, CD34 positive purging and counterflow centrifugation elutriation (CCE). We analyzed these different approaches with regard to the degree of T and B depletion, recovery of progenitors and NK cells. In our hands, the 5 systems evaluated showed a TCD of between 1.3 and 3 log. The CCE, immunomagnetic, complement and panning methods all give similar a TCD of around 2 log. In contrast, we obtained a TCD of approximately 3 log with CD34 positive purging. The progenitor yield was around 50% regardless of the technique used. However, the degree of B and NK cell depletion was dependent on the method: specific TCD resulted in low BCD (under 0.5 log), whereas CCE or CD34 positive purging gave a BCD of greater than 1 log. Moreover, CD34 positive selection resulted in a virtually complete elimination of NK cells. CCE was the only technique allowing isolation of the small lymphocyte population which can be useful for adoptive therapy. To obtain TCD over three logarithms, double purging techniques are necessary. Because specific roles of T cells subsets in engraftment, graft versus host disease, Epstein Barr virus associated B cell lymphoproliferative disorders and disease relapse have not yet been completely elucidated, new techniques such as CD34 positive purging and double purging methods (positive and negative purging) need to be clinically evaluated, especially with respect to peripheral blood stem cells.

Infection by hepatitis C virus through contaminated intravenous immune globulin: results of a prospective national inquiry in France.

BACKGROUND: A recent hepatitis C virus (HCV) outbreak has been suspected of being caused by an infusion of intravenous immune globulin. STUDY DESIGN AND METHODS: Three laboratories were mandated by the French regulatory agency to prospectively screen on a national scale those persons having received suspected batches: 233 exposed patients were recalled and tested for HCV antibody and for HCV RNA. RESULTS: Nineteen patients (8.1%) were found positive for HCV RNA; 7 of these 19 were positive for the HCV antibody. CONCLUSION: The link between HCV infection and intravenous immune globulin was reinforced by the overrepresentation of the 2b genotype (58%), which contrasts with the low prevalence of this genotype in France (1%).

Epidemiology of HCV infection in the general population and in blood transfusion.

The prevalence of HCV seropositivity observed in various populations raise the issue of the contamination routes and the corollary exclusion criteria of risk subjects from blood donation. There are various diagnostic methods for HCV infection. The biological diagnosis is reached at three levels: circulating antibody screening by second and third generation tests; screening validation by immunoblot, to distinguish between the various HCV specific antibodies and detection of viral nucleic acids by molecular biology. In blood donors in France, 0.5% were seropositive in 1990, 0.3% in 1992 and 0.1% (essentially new donors) in 1995. This decrease is the result of improved test specificity and sensitivity and donor selection. In Europe, prevalences range from 0.1-1.5% with a North-South gradient. In other countries: 0.3% in Canada, 0.6% in the USA, 1-2% in China, Thailand and Japan, from 0.2% to 20% in Africa. In risk populations contamination by blood is manifest: HCV seropositivity in 80% of drug abusers, 10-60% of dialysis patients before 1991, more than 80% of haemophiliacs treated before 1986, 10% of labile blood product recipients before 1988. The nosocomial transmission figures are even worse: 2-5% of hospitalized patients are thought to be contaminated. Perinatal and sexual contaminations are not excluded (3-30%) and they vary according to the degree of exposure and the viral type of post-transfusional HCV infection: prevention implies several types of action: information and education of populations about risk factors; medical interview before each blood donation; systematic serological testing; manufacturing measures for stable (SD processing) and labile (deleukocytation, plasma seroattenuation) blood products; prescription recommendations and follow-up measures; haemovigilance (clinical and biological follow-up of all recipients of human blood products).

Blood group antigen survival on freeze-dried erythrocytes and ghosts after isolation.

To screen and identify irregular antibodies, whatever the technique used, fresh erythrocytes (RBCs) are needed to set up the panel. Solid-phase tests using dried blood cells are available, but the technique is based on the adherence of sensitized RBCs, which have a short life span. We have checked antigen survival on membranes with a saline test and an antiglobulin test for two methods to preserve the antigen substrate: freeze-drying of RBCs and preparation of RBC membranes. The different antigens of the ABO, Rhesus, Kell, P, Lewis, MNSs, Lutheran, Duffy, Kidd and Li systems are well recognized on the membranes after isolation and on freeze-dried cells. Demonstration of antigen survival leads us to consider using membranes or freeze-dried cells in new immunological tests.

The number of circulating CD34 positive cells is the best preleukapheresis parameter for predicting the quality of peripheral blood progenitor cell harvest.

Correlations between different peripheral blood parameters and harvesting yields of stem cells were analysed in 230 leukaphereses performed on 61 patients. According to multivariate analysis, the number of circulating CD34 positive cells was found to provide the best preleukapheresis parameter for predicting the quality of peripheral blood progenitor cell harvest. A high correlation coefficient and small 95% confidence and prediction intervals would indicate the assay of CD34 positive cells in peripheral blood to be a unique tool essential for monitoring the collection of circulating haematopoietic progenitors.

Loss of lymphocyte modulatory control by surfactant lipid extracts from acute hypersensitivity pneumonitis: comparison with sarcoidosis and idiopathic pulmonary fibrosis.

Surfactant components are recognized to exert a regulatory control on lymphocytes in physiological conditions, as testified by in vitro studies. However, what happens following lung injury has not been established. As surfactant composition is altered in interstitial lung diseases, this work was carried out to compare the modulatory impact of normal human alveolar fluids on lymphocyte proliferation, with that from inflammatory lung diseases which are characterized by distinct patterns of immunologically-mediated alterations (i.e. sarcoidosis, acute hypersensitivity pneumonitis, idiopathic pulmonary fibrosis). Thymidine incorporation of allogeneic normal human blood lymphocytes was studied in the presence of total alveolar fluids or lipid extracts from 37 subjects, and phytohaemagglutinin (PHA) as T-cell mitogen. The results show that: 1) total alveolar fluids and lipid extracts from normal subjects share a concentration-dependent suppressive activity on T-cell proliferation; 2) total alveolar fluids from diseased patients have lost this property, either by a lack of suppressive activity (i.e. idiopathic pulmonary fibrosis) or even by enhanced activity (i.e. sarcoidosis and hypersensitivity pneumonitis); 3) lipid extracts from diseased patients still retain the suppressive activity of normal subjects, except for hypersensitivity; and 4) an imbalance in surfactant phospholipids with an increase in the inducers to suppressors ratio is more likely to explain this alteration in hypersensitivity pnuemonitis than changes in total lipid content. In conclusion, alveolar lipid extracts from acute hypersensitivity pnuemonitis have lost the modulatory control normally exerted by surfactant lipids on lymphocyte proliferation in vitro. This alteration may contribute to the invasion of the lung by lymphocytes in acute hypersensitivity pnuemonitis in vivo.

[Screening tests of anti-HVC antibodies used in France. Analysis of sensitivity]. / Les trousses de dépistage des anticorps anti-VHC utilisées en France. Analyse de la sensibilité. Groupe de Travail "Hépatites Virales" de la Société Française de Transfusion Sanguine.

The results concerning the hepatitis C antibodies screening tests sensitivity are presented by Viral Hepatitis Study Group of the French Society of Blood Transfusion. This evaluation was carried out in 1993, with five tests available for Hepatitis C Viral (HCV) antibodies screening. Several panels of human blood samples, collected by members of Viral Hepatitis Study Group, were used. For those specimens the data about whole serology (various reactivities against viral antigens) clinical history and other explorations (molecular biology, liver histology, other viral infections) are described. If possible all those results are used to describe some interpretation criteria for the HCV serology and sensitivity obtained for each screening test.

[Seroprevalence of hepatitis C antibodies among blood donors. Study of second generation ELISA and RIBA tests and surrogate markers]. / Séroprévalence des anticorps contre le virus de l'hépatite c chez les donneurs de sang. Etude des tests ELISA et RIBA de 2e génération et des marqueurs indirects.

Between March and November 1991, prevalence of hepatitis C antibodies was evaluated in 60,960 blood donors from the North-East of France. Using a second generation ELISA, 424 donors (0.69%) were reactive, with no significant difference between males (0.69%) and females (0.70%). Among these 424 donors, respectively 137 (32.3%), 86 (20.3%) and 201 (47.4%) were reactive, indeterminate or nonreactive by a second generation RIBA (RIBA-2) (Recombinant Immunoblot Assay). Donors with a high ELISA ratio (> or = 4) were significantly more likely to have a reactive RIBA-2. Of the 1906 donors with anti-HBc positivity (3.12%), 44 had a reactive ELISA; of these, respectively 27, 12 and 5 had a reactive, indeterminate and nonreactive RIBA. Of the 1201 donors (1.97%) with increased serum ALAT (alanine-amino-transferase) levels (> or = 2N), 42 had a positive ELISA; of these, respectively 35, 2 and 5 had a reactive, indeterminate and nonreactive RIBA. Of the 54 donors with both indirect markers, nine had a reactive ELISA; the same nine donors had a reactive RIBA. These data show that donors with both surrogate markers and a reactive ELISA are very likely to have a positive RIBA. Seventy-seven (18.16%) of the 424 donors with a reactive ELISA had at least one surrogate marker; 67 of these donors (30.04%) were among the 223 donors with a reactive ELISA and a reactive or indeterminate RIBA.