Epidemiology of anti-HCV antibodies in France. Viral Hepatitis Study Group of the French Blood Transfusion Society.

The aim of this large survey which covered 173,038 unselected blood donors, was to determine the seroprevalence of anti-HCV antibodies and surrogate markers (ALT and anti-HBc) in France. The results revealed a frequency of 0.63% of anti-HCV positive donors. The correlation with surrogate markers was very poor but since we know nothing about the infectivity of anti-HCV negative donations, screening of surrogate markers must still be performed to prevent post-transfusional hepatitis.

Vitamin status, immunity and infections in an elderly population.

The relations between vitamin status and immunological parameters or number of infections have been investigated in self-sufficient healthy individuals aged 60 and over. A total of 411 subjects agreed to participate, but 202 were discarded from the main statistical analysis since they could have had their immune or nutritional status modified by a recent infection, vaccination or drug consumption. Plasma concentrations of retinol, alpha-tocopherol, ascorbic acid and vitamin B6 were determined. Three indices of cellular immunity were measured: percentages of T-cell subsets, lymphoproliferative response to phytohaemaglutinin and delayed-type hypersensitivity to 7 ubiquitous antigens. A questionnaire about past infections was presented. Two results, supported by previous experimental observations, should be underlined. Vitamin B6 status was positively related to percentages of T-cell subsets: the lowest percentages of CD5 and CD4 cells were observed in the low B6 status group (50.6 and 32.6 per cent) and the highest percentages in the high B6 status group (62.0 and 41.0 per cent), with intermediate values in the medium group (57.6 and 39.5 per cent). Vitamin E status was negatively related to the number of past infections: subjects with a high alpha-tocopherol plasma concentration had fewer infections during the last 3 years (1.0) than those with a medium (2.2) or a low (2.3) concentration. In spite of these two observations, cellular immunity did not seem to be strongly related to vitamin status in the supposedly healthy population studied.

Toxicity of HPA-23 (ammonium-21-tungsto-9-antimoniate) for normal human myeloid progenitor cells (GM-CFU) in vitro.

HPA-23 is a competitive inhibitor of the RNA-dependent DNA polymerase (reverse transcriptase) of the human immunodeficiency virus (HIV). It may therefore potentially benefit patients with HIV infection. This study aimed at defining the haematopoietic toxicity of this drug and particularly its effects on the normal human granulocyte-macrophage progenitor cells (GM-CFU). Our in vitro studies, in semi-solid agar, have shown an inhibitory effect of increasing concentrations of HPA-23 on colony and cluster formation. This effect is probably dose-dependent. An almost complete inhibition of colony formation was observed at doses of more than 20 micrograms/ml. Regarding cluster formation, a similar although much more progressive inhibitory effect was found. Our experimental data should be extrapolated with caution to clinical situations. However, they must be kept in mind for optimal design of HPA-23 therapy in HIV infected patients.

A Mossbauer determination of the iron core particle size distribution in ferritin.

The important biological iron bearing molecule ferritin has been studied using the 57Fe Mossbauer resonance. Natural and reconstituted ferritin samples have been studied in the temperature range 4--300 K. At low temperatures six-line magnetic hyperfine spectra are observed but with noticeably asymmetric line shapes, at high temperatures doublets are observed and in an intermediate temperature range (30--40 K) complex spectra characteristic of superparamagnetic behaviour are observed. From a theoretical study of the dependence of the hyperfine splitting parameters on particle size and from the experimental probability distributions obtained for these parameters from the Mossbauer spectra, it has been possible to derive the ferritin micelle particle size distributions for four different samples. It is found that the natural and reconstituted samples have roughly similar distributions except for the sample reconstituted from apoferritin in the presence of a phosphate environment. This sample is shown to have a slightly narrower particle size distribution centred on a smaller mean diameter. The information derived from these Mossbauer measurements are finally shown to be consistent with conclusions reached from separate biochemical experiments.

[Cellular immunity in the red fox vaccinated against rabies. Studies with the lymphocyte transformation test]. / Immunité à mediation cellulaire du renard vaccine contre la rage. Etude par le test de transformation lymphoblastique.

The best conditions for performing a lymphocyte transformation test have been studied in the red fox with three phytomitogens: phytohaemagglutinin, concanavalin A and Pokeweed (phytolacca). These assays were carried out with varying different parameters of the reaction, among which concentration of mitogens, nature and duration of the lymphocyte cultures. Isolation of fox lymphocytes gave lower yields than human lymphocytes, but were similar in number to those from other domestic animal species. The best mitogenetic reactivity was observed with concanavalin A (optimal concentration being not very different from one mitogen to another) and the maximum transformation ratio was usually observed after four days of lymphocyte cultivation in round bottom plates. Mean value of stimulation ratio is about ten times less that in man, but not very different from dogs. These results allowed the use of this technique a second time to explore specific stimulations by rabies antigen. These last were observed only in 33% of foxes recently vaccinated against rabies, either with live or inactivated virus vaccine.

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.

[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.

[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.

Analysis of blood CD4+ and CD8+ T-lymphocyte subsets with monoclonal antibodies. Comparison of the Genetic Systems CD4/CD antigen typing kit with conventional indirect immunofluorescence microscopy and the automated Technicon-H1 Enzyme Immunoassay (EIA).

The Genetic Systems Technique (GS: direct immunofluorescence microscopy with ethidium bromide counterstaining of nuclei) was tested for quantitative analysis of T-lymphocyte subsets in human peripheral blood. The monoclonal antibodies anti-CD4 and anti-CD8 were used for detection of T-helper and T-suppressor cells respectively and the results compared to those obtained by conventional indirect immunofluorescence microscopy and the Technicon Enzyme Immunoassay (EIA) with automated reading. The GS technique provided results correlating well with both indirect immunofluorescence and EIA techniques. Moreover, this method has two advantages: it is less time-consuming than the indirect immunofluorescence microscopy and necessitates less expensive and more commonly available equipment than the automated EIA technique.

[Serum antibodies to hepatitis C virus: analysis of risk factors of seropositivity in a population of blood donors in metropolitan France]. / Anticorps sériques contre le virus de l'hépatite C: analyse des facteurs de risque de séropositivité dans une population de donneurs de sang de France métropolitaine. Le Groupe "Hepatites Virales" de la Société Nationale de Transfusion Sanguine.

Risk factors were analyzed in a group of 117 blood donors seropositive for hepatitis C virus antibody. One risk factor, at least, was found in 63 (53.8%) subjects. Frequently encountered risk factors were 1) travels in developing countries (31/117); 2) blood transfusions (20/117); 3) health care works (10/117); 4) intravenous drug addiction (8/117); 5) homosexual or multiple heterosexual contacts (3/67). Our study emphasizes the high percutaneous transmission of hepatitis C in contrast with the low sexual transmission. No risk factor could be found in 54 (46.2%) of the 117 seropositive subjects: the route of transmission in these cases is an intriguing issue which certainly deserves further epidemiological investigations.

[Study of allergy to general anesthetics and muscle relaxants using the lymphoblast transformation test]. / Etude de l'allergie aux anesthésiques généraux et aux myorelaxants par le test de transformation lymphoblastique.

This study aims to test the lymphocyte response in normal subjects and patients who presented an anaphylactoid shock to various anaesthetic and muscle relaxant drugs, by using the lymphoblast transformation test (LTT). The results show that, although the LTT is a specific test, which can be carried out in vitro, it is badly adapted to the biological diagnosis of anaphylactic drug accidents on the whole, because of a possible non specific lymphoblastic transformation in controls or, on the contrary, of false negative results in anaphylaxis. As a consequence of this, and some comparative studies, the diagnosis of drug induced anaphylaxis must rely on skin tests, human basophil degranulation test (HBDT) and the Prausnitz-Küstner test.

[Comparative study of immunologic consequences of autotransfusion and homologous transfusion in lung cancer surgery]. / Etude comparative des conséquences immunologiques de l'autotransfusion et de la transfusion homologue en chirurgie carcinologique pulmonaire.

A study was carried out to determine the effects of transfusion with either autologous or homologous blood in 35 patients with lung cancer undergoing lung surgery. The patients were randomly allocated to two groups, "allo" receiving homologous blood (n = 10), and "auto" receiving autologous blood only (n = 13). A third control group included the patients (n = 12) who had not required any blood. In patients of "auto" group, two blood removals of 7 ml.kg-1 each were performed, provided their haemoglobin concentration was over 110 g.l-1 and their haematocrit over 34%. The following parameters were studied at t-1 (the day of inclusion), t0 (just before surgery and transfusion), t1 (one week after surgery), and t2 (one month later): haematocrit and haemoglobin concentration; IgG, IgA and IgM concentrations; polymorphonuclear and neutrophil leucocyte and lymphocyte numbers, lymphocyte subpopulations (CD4/CD8), activated natural killers (NK), polymorphonuclear leukocyte chemotaxis and chemoluminescence. Anaesthesia and surgery initiated initiated an early decrease in immunity in all three groups. The immune profile, and its time course in patients who received autologous blood only was similar to that of those who were not transfused at all. On the other hand, homologous blood transfusion seems to modify the recipient's non specific immune system. In group "allo", a decrease occurred in the number of auxiliary lymphocytes CD4, an increase in suppressor lymphocyte numbers CD8, with an increase in the CD4/CD8 ratio, and no increase in NK activity. These data suggest that autologous transfusion is well tolerated in cancer patients undergoing surgery.

[Cervical Pyoderma gangrenosum: treatment by plasma exchanges]. / Pyoderma gangrenosum cervical: traitement par échanges plasmatiques.

The authors report one case of Pyoderma gangrenosum whose unusual cervical localization was particularly bothering. Besides, the patient, an 18-year-old girl, had clinical symptoms of Crohn's disease confirmed by radiological investigations and bowel pathology. A benign monoclonal gammapathy and an auto-immune haemolytic anaemia were also found. After four plasma exchanges Pyoderma healed rapidly, Crohn's disease stabilized and biological abnormalities disappeared. Comments and review of the literature are reported. It appears that such a case is quite exceptional, as far as clinical, biological data and therapy (plasma exchange) are concerned.