[Severe cases of Salmonella non typhi infections on sickle cell patients in Réunion Island]. / Chocs septiques à Salmonelles non typhiques chez des patients drépanocytaires à La Réunion.

We report two cases of septic shocks due to Salmonella non typhi infection on sickle cell patients admitted to an intensive care unit. Such patients should enforce food hygiene measures, especially under tropical settings, to avoid potentially deadly severe infections.

A multicenter study on the efficiency of white cell reduction by filtration of red cells.

To evaluate accurately the current performance of filtration, the French Produits Sanguins Labiles study group, composed of 21 transfusion teams, conducted a large-scale 6-month study involving over 1400 filtrations and 3000 controls. Some 745 standard red cell concentrates (RBC concentrates) and 690 concentrates previously white cell (WBC)-reduced by removal of buffy coat (BC-poor RBC concentrates) were filtered using six commercially available filters: at least 170 results were collected per filter, spread among a minimum of three teams. Prefiltration controls show that the removal (manual and automated) of the buffy coat results in an initial WBC reduction of approximately 63 percent, along with a hemoglobin loss of 4 g (7%). After filtration, residual WBCs were counted in the Nageotte manual counting chamber. The reliability of this counting method, which is simple and adapted to low WBC concentrations, was characterized in this study by a 25-percent coefficient of variation (CV) for a concentration of 2.5 WBCs per microL (i.e, 0.6 x 10(6) WBCs/filtered unit). The analysis of the results shows that, for five of six filters (1 filter was excluded), the postfiltration median value of residual WBCs was 1.1 x 10(6) in filtered RBC concentrates (n = 590), whereas it was 0.34 x 10(6) in filtered BC-poor RBC concentrates (n = 581). The difference is significant (p less than 10(-8), Wilcoxon test). Hemoglobin loss due to filtration varies according to the filter, from 5.7 +/- 2.2 to 17.3 +/- 2.5 g.(ABSTRACT TRUNCATED AT 250 WORDS)

[Preparation of leukocyte-depleted human platelet concentrates by centrifugation and filtration of a pool of sterilely connected buffy-coats]. / Préparation de concentrés de plaquettes humaines déleucocytés par centrifugation et filtration d'un pool de buffy-coats connectés stérilement.

We describe a new method for the preparation of standardised therapeutic doses of leukocyte depleted platelets. The first step is to remove the buffy-coat from whole blood units drawn on triple Siamese ACD/SAGM bags (Maco-Pharma) by means of a Compomat (NPBI). The second step is to connect (SCD Haemonetics) six buffy-coats and one plasma to a special kit (Maco-Pharma) including a PALL PL 100 filter; after centrifugation, the supernatant platelet concentrate is extracted, filtered and recovered in a 2 litre TOTM PVC bag. The volume, the number of platelets and leukocytes of these pools are measured. A comparison of these parameters is made with therapeutic doses prepared in the same way without filtration. Besides, pH measurements up to the 6th day of storage and bacteriological checks are carried out. The results show: no platelet loss related to filtration; a synergy between the preparation process out of buffy-coats and the filtration: so each dose contains less than 10(6) leukocytes; a good pH level allowing the storage for five days as it is associated to the bacteriological safety of the functionally closed system. This technique makes it possible to transfuse only leukocyte depleted platelet concentrates. In addition, it offers new prospects for standardisation and quality improvement.

[Technical constraints in rapid vascular fluid replacement]. / Contraintes techniques du remplissage vasculaire rapide.

Rapid fluid infusion remains the cornerstone for therapy of hypovolaemic shock. The principal limitations of flow rate are governed by the four variables of Poiseuille's law: tube internal diameter and length, viscosity of the fluid passing through the tube, and the pressure gradient between the two ends of the tube. Conventional transfusion systems, with wide bore tubing (up to 5.0 mm internal diameter), large bore cannulas (8.5 French introducer catheters), high pressure (up to 300 mmHg) and diluted blood, can result in a maximum flow rate of about 1,000 ml.min-1 (for crystalloid solutions). Specific apparatus for rapid infusion can increase this to 1,500 ml.min-1 (Rapid Infusion System, Haemonetics). Dry-heat warming devices and microfiltration, to remove microaggregates and prevent non haemolytic febrile transfusion reactions, seem necessary when carrying out rapid transfusions. However, the use of microaggregate filters could be avoided by the routine production of leukocyte-poor red blood cell concentrates.

[Leukocyte removal in a closed system of human red-cell concentrates: a technic coupled with the automated extraction of the buffy coat using a sterile connector from a filtration kit]. / Déleucocytation en système clos des concentrés de globules rouges humains: une technique associant l'extraction automatisée du buffy-coat à la connexion stérile d'un kit de filtration.

A technique, integrally run in a closed system, for leucocyte depletion of human red cell concentrates is described. It associates two complementary processes: buffy-coat removal and filtration. The first step is carried out with an automated system for blood component preparation (Compomat, NPBI); its efficiency is improved by a custom made blood collection set with ACD anticoagulant solution in the primary bag. The second step is simplified by a filtration kit requiring only one sterile connection for operation (SCD 312, Dupont de Nemours) and allowing a standardised rinsing of the filter. Quality control of 33 units so prepared shows principally: --an intensive leuko-depletion (4 logs) enabling leukocyte contamination to be kept below 10(6) per unit; --a moderate red cells loss (15 ml for the first step and 20 ml for the second one). This technique provides a permanently available and very pure blood component. Moreover it offers new potential for standardisation and mastery of quality control.

[Viability of human red blood cells preserved for 35 days after leukocyte depletion (in vitro study)]. / Viabilité des globules rouges humains conservés pendant 35 jours après déplétion en leucocytes (étude in vitro).

24 leukocyte poor red cells concentrates (L.P.R.C.) were prepared by sterile connection of a leucocyte filter between the primary bag and the SAGM bag of a blood unit after centrifugation. Their quality was followed up to 42 days by means of a panel of tests including, ATP and 2,3-DPG levels, hemolysis, plasma potassium, lactate and glucose, and counts of the microaggregates. 24 standard units acted as a control group. Results showed better preservation of LPRC and especially less hemolysis, higher ATP levels and at least equal oxyphoric capacity (explored by 2,3-DPG). Microaggregate formation was dramatically reduced and bacteriologic checks (48 at day 25 and 48 at day 42) were all negative. Leucocyte depletion appears as a new way to improve functionality of erythrocytes during storage in the SAGM medium. 35 days shelf life will allow this blood product to be more available and its preparation more standardised.

Comparison between a solid-phase low-ionic-strength solution antiglobulin test and conventional low-ionic-strength antiglobulin test: assessment for the screening of antierythrocyte antibodies.

A solid-phase low-ionic strength salt antiglobulin test (LISS-SPAT) has been developed using a microplate coated with dried sera as a solid phase. Before coating, the in vitro C3d fragment generation was activated by adding heat-aggregated immunoglobulin. The LISS-SPAT was compared with low-ionic strength conventional antiglobulin test (LISS-AGT) and also with a test using polybrene or papain microplates. When detecting the IgG and IgM antierythrocyte antibodies the reaction was developed in the same way in LISS-SPAT and LISS-AGT. In routine work, the LISS-SPAT provides a fast, reliable, handy and inexpensive screening of antibodies. This method appears to be an additional method to the papain and polybrene tests in microplates.

[Assessment and value of the polybrene microplate test for study and identification of irregular anti-erythrocyte antibodies]. / Evaluation et intérêt du test au polybrène en microplaque pour la recherche et l'identification des anticorps irréguliers anti-érythrocytes.

We have adapted Lalezari's manual polybrene test for use with microplate technology for screening and identification of anti-erythrocytes antibodies with a view to future automation. The technical conditions have been standardized, firstly by using a programmable centrifuge and a sequential shaking, secondly by using a preservative medium for panel after dispensing onto microplates. This methodology has been run in parallel with papain test and LIS indirect antiglobulin test: 7,000 screenings have been performed and their results are considered here. Our results are comparable to those described for automatic and manual techniques. The polybrene-microplate test affords a fast, reliable, handy and inexpensive means of screening and identification for irregular antibodies. It appears as an additional method for enzymatic tests in microplate. An antiglobulin test can be carried out after negative tests.

[Platelet preservation in a new type of plastic material. Functional in vitro study]. / Conservation des plaquettes dans un nouveau type de matériel plastique. Etude fonctionnelle in vitro.

We report the comparison of the fonctionnal platelet criteria's evolution studied in vitro by aggregation with different agents, by osmotic stress, ATP total amount and platelet volume distribution for six days of storage in two different PVC bags. The results indicate that: platelet's evolution appears more appreciable when tested by aggregation with an important amount of collagen, by hypotonic stress and volume distribution. The difference between the two different bags is shown as early as the thirs day of storage; for quality control, we can choose some criteria despite the absence of their clear correlation with transfusion efficiency.