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H W Reesink

Publications and source records attributed to H W Reesink.

At least 37 records · Page 2Linked to original sources
PubMed2003

Comparison of various dimethylsulphoxide-containing solutions for cryopreservation of leucoreduced platelet concentrates.

BACKGROUND AND OBJECTIVES: Leucoreduced platelet concentrates (LR-PCs) can be stored at 20-24 degrees C for 5-7 days. When LR-PCs are cryopreserved they can be stored for several years. For cryopreservation to become applicable in blood-bank practice, an off-the-shelf cryoprotectant is needed that can be added to the LR-PC in a sterile manner. For this, we varied the composition of the cryopreservation medium and studied various parameters of cryopreserved LR-PCs for up to 24 h after thawing at room temperature. MATERIALS AND METHODS: LR-PCs in plasma or Composol were concentrated and divided into 2 units. To each unit, an equal part of 10% dimethylsulfoxide (DMSO) in plasma, Composol with or without 5% albumin, or GPO (pasteurized plasma-protein solution) was added. Freezing occurred at 1 degrees C/min and LR-PCs were placed in the vapour phase of nitrogen. LR-PCs were thawed at 37 degrees C and stored at room temperature. LR-PCs were tested for morphology, platelet recovery, swirling effect, and activation antigens at various time-points thereafter. RESULTS: LR-PCs in 100%, 65% and 50% plasma supplemented with Composol showed good morphology scores (>250), limited CD62P expression (<35%), low CD63 expression (<20%) and a swirling effect of about 2, at 24 h after thawing. At the same time-point, platelet recovery was >80% under all conditions and CD42b expression varied between 70 and 85%. Results of LR-PCs in 15% plasma and Composol, with or without plasma substitutes, were not acceptable at 24 h after thawing, i.e. the morphology score was <200 and the CD62P expression was >40%. CONCLUSIONS: A minimum of 50% plasma in the cryopreserved LR-PC is necessary to maintain an acceptable in vitro quality of platelets up to 24 h after thawing. Composol is a good candidate for using to prepare an off-the-shelf cryoprotectant.

Blood Platelets↗
PubMed2002

Prevalence of and risk factors for HIV infection in blood donors and various population subgroups in Ethiopia.

The aim was to determine the prevalence of HIV infection and risk factors for HIV infection in various population subgroups in Ethiopia. Serum panels from blood donors (n = 2610), from various population subgroups in Ethiopia were tested for anti-HIV-1/2 by ELISA. All ELISA repeatedly reactive samples were subjected for confirmation by immunoblot (IB) and anti-HIV-1 and anti-HIV-2 specific ELISAs. 155/2610 (5.9%) blood donors were HIV-1 infected. Of pregnant women, 84/797 (10.5%) were HIV-1 infected, and 1/797 (0.1%) was HIV-2 infected. 1/240 (0.4%) individuals from the rural population were HIV-1 infected. 198/480 (41.3%) female attendees, and 106/419 (25.3%) male attendees at sexual transmitted disease (STD) clinics were HIV-1 infected. One (0.2%) male, and 2 (0.4%) female STD patients were infected with both HIV-1 and HIV-2. It was concluded that the prevalence of HIV-1 infection varied from 0.4% among urban residents to 25.3-41.3% among STD attendees. There is a low prevalence of HIV-2 present in Ethiopian subjects. Risky sexual behaviour is significantly associated with HIV-infection in Ethiopia.

Adolescent↗
PubMed2001

Variation of pH-measurement in platelet concentrates.

To measure pH in platelet concentrates, blood gas analysers with different calibration principles may be used. In this study, variances observed in pH measurements with two types of blood gas analysers were investigated. pH was measured in crystalloid solutions (platelet additive solution (PAS-II), phosphate-buffered solutions) and two types of platelet concentrates (containing 100% plasma, or 65% PAS-II/35% plasma) with two blood gas analysers: either using liquid and gas calibration (AVL 945), or only liquid calibration (AVL OMNI). These measurements were compared with a reference method. Especially for PAS-II, large variation in pH was observed between AVL 945, AVL OMNI and the reference method: 6.91 +/- 0.02, 7.35 +/- 0.02 and 7.188 +/- 0.010, respectively (mean +/- SD; n = 12, P < 0.0001, paired t-test). A significant difference in pH was also found for platelet concentrates in 65% PAS/35% plasma (6.88 +/- 0.09 on AVL 945 and 7.02 +/- 0.09 on AVL OMNI, n = 134, P < 0.0001). Comparison with the reference method revealed minor differences with AVL 945, whereas AVL OMNI gave a mean difference in pH of + 0.17. Platelets in 100% plasma revealed smaller differences (6.93 +/- 0.13 for AVL 945 and 6.99 +/- 0.13 for AVL OMNI, n = 95, P < 0.0001). We conclude that different blood gas analysers can yield different pH values, especially in weak buffered solutions such as platelet concentrates in PAS-II. Validation of blood gas analysers for pH measurement of these solutions is therefore mandatory.

Blood Gas Analysis↗
PubMed2001

Comparison of two platelet additive solutions.

The use of an additive solution for substitution of plasma for storage of leukodepleted platelet concentrates can have many advantages. In this study, a comparison was made between two platelet additive solutions: one containing citrate and acetate (PAS-II), the other also supplemented with additional salts such as magnesium, and with gluconate (Composol-PS). Donor-dependent differences were avoided by applying a paired experimental design (n = 10). The platelet concentrates were prepared by pooling five buffy coats and the additive solution, and prestorage filtration was utilized to remove leucocytes to well below 1 x 106. Storage of platelet concentrates up to 9 days after blood collection revealed that platelet concentrates in Composol-PS maintained an almost constant pH of on average 6.93 from day 2 through day 7, and at 6.90 at day 9. This was in contrast to PAS-II, which showed a gradually decreasing pH from on average 6.97 at day 1 to 6.86 at day 9. In all units stored in both solutions the swirling effect was present during 9 days of storage. In conclusion, both additive solutions allow storage of platelets, derived from pooled buffy coats, for up to 9 days after collection of the whole blood, with maintenance of good quality in vitro. Composol-PS has a slightly better buffering capacity, reflected as a more constant pH throughout the storage period.

Acetates↗
PubMed2001

Influence of temperature, filter wettability, and timing of filtration on the removal of WBCs from RBC concentrates.

BACKGROUND: The efficacy of the removal of WBCs from buffy coat-reduced RBC concentrates by filtration is determined by many variables. The aim of this study was to investigate the influence of the filtration temperature, the wettability of the filter material, and the timing of the filtration after collection. STUDY DESIGN AND METHODS: The investigation used commercially available filters: 3 dry "online" filters (Cellselect FR, Fresenius Hemocare; BioR-01-max, Fresenius; Leucoflex LCG1, MacoPharma) and one wet "inline" filter (Leucoflex LCR4, MacoPharma) that contained saline-adenine-glucose-mannitol additive solution for RBCs and differed from the online version only in wettability. After buffy coat removal and suspension in saline-adenine-glucose-mannitol, filtrations were performed immediately at room temperature (RT) and after 2 hours' storage of the RBC concentrates at 4 degrees C, while the Leucoflex LCR4 was also tested after 24 hours' storage of the RBC concentrates at 4 degrees C. Sets of 12 pooled experiments were performed to prevent donor-dependent differences. RESULTS: The Cellselect FR gave significantly better WBC removal from RBC concentrates at 4 degrees C than at RT, with residual WBCs of 1.44 +/- 0.58 x 10(6) and 2.78 +/- 1.23 x 10(6), respectively (p<0.001). The BioR-01-max gave no significant difference: 0.62 +/- 0.27 x 10(6) WBCs (at 4 degrees C) versus 0.61 +/- 0.25 x 10(6) WBCs (at RT). Filtration with the Leucoflex LCG1 resulted in 0.06 +/- 0.03 x 10(6) and 0.07 +/- 0.07 x 10(6) WBCs at 4 degrees C and RT, respectively, which is not a significant difference. The Leucoflex LCR4, however, gave 2.08 +/- 0.84 x 10(6) WBCs at RT, 0.52 +/- 0.44 x 10(6) WBCs at 4 degrees C after 2 hours' cooling, and 0.05 +/- 0.10 x 10(6) WBCs at 4 degrees C after 24 hours' cooling (all p<0.001). CONCLUSION: Temperature, filter wettability, and timing of filtration after collection influence the efficacy of a filter for RBC concentrates. These variables need to be established, validated, and controlled before a filter can be selected for routine use.

Blood Component Removal↗
PubMed2001

WBC-reduced platelet concentrates from pooled buffy coats in additive solution: an evaluation of in vitro and in vivo measures.

BACKGROUND: The use of a platelet additive solution (PAS-II, Baxter) may have benefits over plasma for storage of platelets. It was the aim of this study to develop a method to produce WBC-reduced platelet concentrates (PCs) in PAS-II with >240 x 10(9) platelets and <1 x 10(6) WBCs per unit, which can be stored for 5 days at pH >6.8 and that will give sufficient platelet increments after transfusion: a 1-hour CCI of >7.5 and a 20-hour CCI of >2.5. STUDY DESIGN AND METHODS: PCs were made from five pooled buffy coats and 250 g of PAS-II. After centrifugation the PCs were WBC-reduced with a filter (Autostop BC, Pall Biomedical) and stored in a 1000-mL polyolefin container. CCIs were assessed in stable hemato-oncologic patients after 5-day old PCs were transfused. RESULTS: Routinely produced PCs contained a median of 310 x 10(9) platelets (n = 5,363) with 3.5 percent containing <240 x 10(9) platelets, in a median volume of 320 mL (n = 11,834). The median number of WBCs was <0.03 x 10(6) (n = 694). The WBC count exceeded 1 x 10(6) in three PCs, but it was always <5 x 10(6), giving 99-percent confidence that more than 99.5 percent of the units will contain <1 x 10(6) WBCs. The pH remained >6.8 on Day 8, provided the concentration was below 1.1 x 10(9) platelets per mL (n = 32). After 28 transfusions in 28 patients, the 1-hour CCI was 12.6 +/- 4.3 (mean +/- SD, with 2/28 CCIs <7.5) and the 20-hour CCI was 8.9 +/- 5.6 (with 4/28 CCIs <2.5). Limitations of this study include the absence of a control group of patients receiving platelets stored in plasma and of in vivo radiolabeled survival studies, but a comparison of these data with previously published data suggested that the in vivo survival of platelets stored in PAS-II is less than that of platelets stored in plasma. CONCLUSION: The WBC-reduced PCs conformed to specifications. These WBC-reduced PCs could be stored at least 5 days with maintenance of pH, and they gave sufficient increments after transfusion to patients.

Adenine↗