Biomedical subjects

J G Schrijver

Publications and source records attributed to J G Schrijver.

7 recordsLinked to original sources

PubMed2003

Crossover study of three methods for low-level white blood cell counting on two types of flow cytometer.

BACKGROUND: Flow cytometric methods were previously shown to be preferable to microscopic and volumetric methods for counting residual white blood cells (WBCs). In this study, three flow cytometric, low-level WBC counting methods were cross compared using two flow cytometers. METHODS: Double-filtered red cell and platelet concentrates were spiked with different amounts of WBC to obtain panels of unspiked and 0.3, 1.0, 3.3, and 10.0 WBC/microl. The methods of BD Biosciences (BDB), Beckman-Coulter (BC), and an in-house method were performed on flow cytometers from BDB and BC. Samples were measured in ninefold. We required that (a) r(2) be at least 0.98 (linearity), (b) at least 80% of observations fell within 20% of expected values (accuracy), and (c) the coefficients of variation be at least 20% (precision) for samples containing at least 3.3 WBC/microl. RESULTS: For the red cell panel, our requirements were met by the BDB method on both flow cytometers and by the BC and in-house methods on the BDB flow cytometer only. For the platelet panel, our requirements were met on all combinations of methods and flow cytometers, except for the in-house method on the BDB flow cytometer. Intra-assay variation was lowest for the BDB method, irrespective of the type of flow cytometer used. CONCLUSION: Based on accuracy and precision, the BDB method on the BDB flow cytometer produced the best results for counting low-level WBCs.

Cell Separation↗

PubMed2001

Comparison of five platforms for enumeration of residual leucocytes in leucoreduced blood components.

The need for quality control of leucoreduction of blood products has led to the development of various methods to count low levels of residual leucocytes. We compared five platforms side-by-side: the Nageotte haemocytometer and four based on fluorescent staining of nuclei: two flowcytometers (Beckman Coulter, BD Biosciences) with methods based on counting beads, a volumetric flow cytometer (Partec) and the microvolumic fluorimeter ImagN2000 (BD Biosciences), all according to their manufacturers' recommended methods. Analysis of double-filtered red cell concentrates (RCCs) and platelet concentrates (PCs), spiked with various numbers of leucocytes, revealed good linearity for all methods over the range of 1.6-32.7 leucocytes/microl, all with r(2) > 0.99. At the rejection level of leucocyte-reduced blood components, i.e. 1 x 10(6) per unit corresponding with approximately 3.3 leucocytes/microl, the Nageotte haemocytometer had low accuracy (0% for RCCs, 56% for PCs), and was relatively imprecise [coefficient of variance (CV) of 34% and 30% respectively]. The Partec flow cytometer gave good results for RCCs (accuracy 67%, CV 22%), but not for PCs (accuracy 0%, CV 25%). The ImagN2000 had an accuracy of 44% for RCCs and 89% for PCs, but the precision was variable (CV 32% for RCCs, 15% for PCs). The best results were obtained with the Beckman Coulter (RCCs: accuracy 86%, CV 13%, PCs: accuracy 67%, CV 16%), and BD Biosciences platforms (RCCs: accuracy 100%, CV 10%; PCs: accuracy 89%, CV 11%). We conclude that, at the rejection level of 1 x 10(6) leucocytes per unit, the widely used Nageotte haemocytometer performs poorly in terms of inaccuracy and imprecision, and that both counting-bead-based, flow cytometric methods performed best.

Flow Cytometry↗

PubMed2001

WBC content of platelet concentrates prepared by the buffy coat method using different processing procedures and storage solutions.

BACKGROUND: The number of WBCs in platelet concentrates (PCs) prepared by the buffy coat (BC) method with different storage solutions can result in low (5 x 10(6)/unit) WBC levels by the use of careful centrifugation techniques without filtration. At present, most blood banks use filtration steps to meet these requirements. The difference in processing methods and suspension solutions prompted the investigation of the influence of the various procedures on the WBC and platelet content of PCs. STUDY DESIGN AND METHODS: PCs from 5 BCs were harvested without or with inline filtration (AutoStop BC, Pall Corp.) in either plasma (PCs-plasma) or platelet additive solution (PCs-PAS-2). After preparation, samples were taken for counting WBCs and platelets and for analyzing WBC subsets by flow cytometry using specific MoAbs. The WBCs were concentrated before analysis of the WBC subsets. Results less than 2.5 cells per microL were considered below the limit of accuracy of the subset analysis. RESULTS: All filtered PCs met the AABB standard of 5 x 10(6) per unit and the European guidelines of 1 x 10(6) per unit. None of the nonfiltered PCs met the European guidelines, but all met the AABB guidelines. All filtered units gave residual WBC counts below the detection limit for subset analysis. Filtered PCs-plasma gave significantly higher platelet counts than filtered PCs-PAS-2 or nonfiltered PCs (p<0.01, ANOVA). CONCLUSION: Careful centrifugation of pooled BCs, with plasma or PAS-2, can result in PCs with low WBC contamination levels. However, filtered PCs are superior, because of better WBC removal and higher platelet counts.

Acetates↗

PubMed2000

Reactions and platelet increments after transfusion of platelet concentrates in plasma or an additive solution: a prospective, randomized study.

BACKGROUND: Reactions after platelet transfusions are rather common and frequently are caused by plasma constituents. In recent developments, the preparation and storage of platelet concentrates (PCs) in a platelet additive solution (PAS-2) have been shown to result in acceptable storage conditions. A major drawback of the use of these PCs is the progressive increase of P-selectin-positive platelets during storage. The clinical benefit of transfusions of PCs in PAS-2 was studied. STUDY DESIGN AND METHODS: PCs prepared from buffy coats were suspended in either plasma or PAS-2 and stored for up to 5 days. Clinical responses were evaluated in a prospective study in 21 patients treated with intensive chemotherapy for hematologic malignancies. Eligible patients were randomly assigned to receive prophylactic transfusions of PCs prepared in either plasma or PAS-2. Reactions and CCIs were recorded after each transfusion. RESULTS: The incidence of reactions in 12 patients given PCs in plasma (n = 192) was 12 percent. Transfusions to 9 patients of PCs in PAS-2 (n = 132) showed a reduction in the incidence of reactions to 5.3 percent (p<0.05). The average 1-hour and 20-hour CCIs after transfusion of PCs in plasma were 20.7 +/- 8. 5 and 11.5 +/- 8.0, respectively. CCIs after transfusion of PCs in PAS-2 were significantly lower: the average 1-hour CCI was 17.1 +/- 6.6 (p<0.001) and the average 20-hour CCI was 9.5 +/- 7.0 (p<0.05). Storage conditions of PCs were optimal: in each group, average 1-hour CCIs of both fresh and stored PCs were similar. The 20-hour CCIs after the transfusion of fresh and stored PCs in PAS-2 also were similar. CONCLUSION: Transfusion of PCs in PAS-2 significantly reduces the incidence of reactions. The 1-hour and 20-hour CCIs after transfusion of PCs in PAS-2 were significantly lower than the CCIs after transfusion of PCs in plasma. Because storage conditions of both PCs were found to be optimal, the decrease in CCIs after transfusion of PCs prepared in PAS-2 may be caused by rapid elimination of a subpopulation of P-selectin-positive platelets from the circulation.

Adult↗

PubMed1999

Differences in residual white blood cell subset counts in buffy coat-depleted red cell concentrates prepared with bottom and top or quadruple-bag systems.

BACKGROUND: For preparation of buffy coat-depleted red cell concentrates (RCCs) in additive solution whole blood is currently collected in The Netherlands both in quadruple-bag and bottom and top bag systems. By using the quadruple-bag system both plasma and buffy coat cells are transferred into integrated satellite bags while the red cells remain in the collection bag. When bottom and top bags are used, the buffy coat remains in the collection bag while both red cells and plasma are transferred into satellite bags. The difference in processing prompted us to perform quantitative analysis of residual WBC subsets in buffy coat-depleted RCCs. Differences in removal of specific cells with the buffy coat could improve the outcome of additional filtration procedures aiming at complete removal of specific WBC subsets. STUDY DESIGN AND METHODS: The buffy coat was removed in semiautomated procedures (Optipress I; Compomat G4) from units of whole blood collected in both bag systems. Paired samples were taken before and after removal of the buffy coat for counting and analyzing WBC subsets by flow cytometry using subset-specific monoclonal antibodies. RESULTS: All RCCs met the criteria from the guidelines of the Council of Europe. The percentage of residual total WBCs was lower (p<0.001) in RCCs processed in bottom and top bag systems (26% Compomat and 18% Optipress) as compared to RCCs processed in quadruple-bag systems (43% Compomat). WBC subset analysis in RCCs processed in quadruple-bag systems showed approximately 25% of residual T cells, B cells and monocytes and 60% of residual granulocytes. In contrast, WBC subset analysis in RCCs processed in bottom and top bag systems showed approximately 2% residual T cells, B cells, and monocytes and 35% residual granulocytes; in about 45% of units, lymphocytes and monocytes were even below the detection limit of flow cytometry analysis. CONCLUSION: Buffy coat-depleted RCCs are currently processed in bottom and top bag or quadruple-bag systems, the former being superior to the latter due to selective depletion of lymphocytes and monocytes by 98% (2 logs). The bottom and top procedure is an evident contribution to leukodepletion in blood transfusion, both with and without additional filtration.

Blood Component Removal↗

PubMed1998

Platelets stored in a new-generation container differences between plasma and platelet additive solution II.

BACKGROUND AND OBJECTIVES: In order to preserve platelet concentrates (PCs) with high yields, a new polyolefin platelet storage container (PL 2410, 1.3L, Baxter, La Châtre, France) with increased gas permeability in combination with a larger surface area has been developed. The storage capacity was studied with platelets in plasma and platelets additive solution. MATERIALS AND METHODS: Platelet concentrate pools (PCs) of different yields suspended in either plasma (PCs-PL; n = 30) or PAS II (PCs-PAS; n = 37) were prepared. For preparation of PCs with a low, intermediate and high number of platelets 3, 5 and 6 buffy coat (BCs) were pooled with different volumes of plasma and 5 and 6 BCs were pooled with different volumes of PAS II, in order to obtain PCs of equal volumes comparable with routine conditions. All PCs were stored on a flatbed shaker at 22+/-2 degrees C and evaluated on days 1, 2, 5 and 7 by determining platelet and white cell counts, pH (37 degrees C), pO2, pCO2 and swirling score. RESULTS: Platelet yields ranged from 1.5 up to 5.5 x 10(11) platelets/U. On day 7 all PCs-PL (n = 4) with platelet yields above 4.5 x 10(11)/U had a pH value below 6.8 (range 5.91-6.79). While 7 of 8 PCs-PAS units with platelet yields above 4. 0 x 10(11)/U showed a pH value below 6.8 (range 6.31-6.70). CONCLUSION: During 7 days of storage in a new 1.3-liter platelet container, the pH was maintained above 6.8 in PCs in plasma with a yield between 1.5- and 4.5 x 10(11)/U; when PAS II was used, the maximum platelet yield allowed for comparable pH maintenance was somewhat lower (4.0 x 10(11)/U).

Adult↗

PubMed1997

Improvement of platelet storage conditions by using new polyolefin containers.

BACKGROUND: Storage of pooled platelet concentrates (PCs) with yields above 3.0 x 10(11) platelets per unit in a 1-L PL-732 polyolefin container for 5 days often results in a drop in pH to below 6.0. Recently, new oxygen-permeable platelet containers (1-L PL-2410, 1-L and 1.5-L Compoflex) have been developed. The maximal platelet storage capacities of the new containers and the PL-732 were compared. STUDY DESIGN AND METHODS: Large platelet pools (n = 27) with platelet concentrations between 1.2 and 1.4 x 10(11) per L were made from 3 to 5 PCs prepared from buffy coats. The pools were divided in equal volumes among the PL-732 and the three new platelet containers. Platelet counts in the PCs ranged from 1.0 to 5.0 x 10(11) per unit. All PCs were stored on a flatbed shaker at 22 +/- 2 degrees C and evaluated on Days 1, 3, 5, and 7 by measuring platelet count, pH, pO2, pCO2, HCO3-, glucose, lactate, platelet swirling, and soluble p-selectin. RESULTS: Day 7 storage of PCs (n = 6) with yields between 3.0 and 4.0 x 10(11) platelets in PL-732 showed mean +/- SD pH values of 5.93 +/- 0.05 and lactate values of 32.3 +/- 7.9 mmol per L; in 4 of these 6 PCs, pH was below 6.0. In contrast, storage of these PCs in 1-L PL-2410 and 1.5-L Compoflex containers and of 2 of these 6 PCs in 1-L Compoflex containers showed pH values above 6.8. Lactate values were 15.5 +/- 1.3, 15.3 +/- 1.8, and 19.5 +/- 4.7 mmol per L, respectively (p < 0.001 vs. PL-732). The platelet storage capacity of the new containers with platelet yields between 4.0 and 5.0 x 10(11) per unit (n = 6) was evaluated. Day 7 storage of these PCs in the 1.5-L Compoflex showed an average pH value of 6.74 +/- 0.20; in 2 of 6 PCs, pH was below 6.8. The average pH value in the PL-2410 was 6.38 +/- 0.31, and in all PCs, pH was below 6.8. Average lactate values were 17.8 +/- 5.7 and 25.8 +/- 5.6 mmol per L (p < 0.05), respectively. Soluble p-selectin values on Day 7 of storage increased approximately twofold in all PCs. CONCLUSION: The new oxygen-permeable containers showed platelet quality comparable to that with the PL-732 and for longer storage periods and at higher platelet counts.

Blood Platelets↗