Overnight storage of whole blood: a comparison of two designs of butane-1,4-diol cooling plates.

BACKGROUND: Whole blood (WB) can be stored overnight before processing, provided that it is quickly cooled to room temperature (20-25 degrees C), for example, with butane-1,4-diol plates. A new design of cooling plates became available (CompoCool-WB, Fresenius HemoCare), where WB must be placed vertically against the plates, versus placing of WB under plates in the current version (Compocool). This study compared cooling efficiency and in vitro quality of plasma and of stored white cell (WBC)-reduced red cells (RBCs) from overnight-stored WB, cooled with either of the systems. STUDY DESIGN AND METHODS: Temperature curves following cooling with Compocool or CompoCool-WB were studied with a 25 percent glycerol solution as simulated WB. WB from voluntary donors was cooled with Compocool or CompoCool-WB, stored overnight at room temperature, centrifuged, and separated into components. WBC-reduced RBCs in SAGM were stored until Day 42 with measurement of in vitro parameters (n=23/group). RESULTS: Simulated WB reached a temperature of less than 25 degrees C after 2:15+/-1:04 hours for Compocool versus 1:39+/-0:38 hours for CompoCool-WB (p=0.02). On Day 35, RBCs had a hemolysis of 0.3+/-0.2 percent in both groups, and ATP levels were 3.3+/-0.5 and 3.6+/-0.5 micromol per g hemoglobin for Compocool and CompoCool-WB, respectively (not significant). Factor VIII content in plasma was 1.05+/-0.25 and 0.97+/-0.18 IU per mL for Compocool and CompoCool-WB, respectively. CONCLUSION: WB can be cooled to room temperature within 2 hours with both Compocool and CompoCool-WB butane-1,4-diol plates, improving temperature uniformity in WB donations. Application of either design for overnight storage of WB at room temperature had no adverse effects on the composition of subsequently prepared blood components.

The effect of interruption of agitation on in vitro measures of platelet concentrates in additive solution.

BACKGROUND: Interruption of agitation results in lower in vitro quality of platelet concentrates (PCs). The rates at which the deleterious effects occur, however, are unknown. Therefore, in vitro parameters of PCs in additive solution (AS) during various periods without agitation have been investigated. STUDY DESIGN AND METHODS: PCs from five buffy coats in AS (Composol, Fresenius HemoCare) were white cell (WBC)-reduced by filtration. Four PCs were pooled and divided to obtain paired samples. Beginning immediately after processing, three PCs were stored without agitation and placed on an agitator after 16, 20, and 24 hours. The fourth PC was agitated throughout storage and served as reference (n = 10 paired experiments). RESULTS: pH(37 degrees C) on Day 7 was greater than 6.8 in reference PCs, and in PCs that were not agitated for 16 hours, longer interruption resulted in lower pH values. During interruption of agitation, metabolic rates were significantly higher in the study groups: glucose consumption was 12.5 +/- 1.6 micromol per 10(11) platelets (PLTs) per hour in PCs during the first 24 hours without interruption versus 2.0 +/- 0.4 micromol per 10(11) PLTs per hour in the reference group (p < 0.01). Lactate formation was 24.7 +/- 4.2 versus 3.9 +/- 0.4 micromol per 10(11) PLTs per hour in the above-mentioned groups, respectively (p < 0.01). Once replaced on the agitator, the metabolic rates lowered, but remained significantly elevated during consecutive storage days compared to the reference. CONCLUSION: WBC-reduced PCs in Composol AS may experience 16 hours without agitation with no permanent effects on in vitro measures compared to reference units. During interruption of agitation, glucose and lactate metabolism is elevated, resulting in lower pH values in the subsequent storage period.

Applications of real-time PCR in the screening of platelet concentrates for bacterial contamination.

Although there have been major improvements over the past few decades in detection methods for blood-borne infectious agents, platelet concentrates are still responsible for most cases of transfusion-transmitted bacterial infections. To date, real-time PCR is an indispensable tool in diagnostic laboratories to detect pathogens in a variety of biological samples. In this article, the applications of this powerful technique in the screening of platelet concentrates for bacterial contamination are discussed. Next to pathogen-specific (real-time) PCR assays, particular attention is directed to the recently developed 16S rDNA real-time PCR. This assay has been proven as a convenient way to detect bacterial contamination of platelet concentrates. The assay is sensitive and enables rapid detection of low initial numbers of bacteria in platelet concentrates. The short turnaround time of this assay allows high-throughput screening and reduction of the risk of transfusion of bacterially contaminated units. As with every method, real-time PCR has its advantages and disadvantages. These and especially limitations inherent to generation of false-positive or -negative results are emphasized. The universal nature of detection of the assay may be suitable for generalized bacterial screening of other blood components, such as red blood cells and plasma. Therefore, it is necessary to adapt and optimize detection in red blood cells and plasma with real-time PCR. Further sophistication, miniaturization and standardization of extraction and amplification methods should improve the total performance and robustness of the assay. Hence, real-time PCR is an attractive method in development as a more rapid screening test than currently used culture methods to detect bacterial contamination in blood components.

Comparison of two sterile connection devices and the effect of sterile connections on blood component quality.

BACKGROUND: Sterile connection devices (SCDs) are used to connect pieces of polyvinylchloride tubing between blood bag systems. After observing a slight decrease in inner diameter of tubing welded with the CompoDock S2 SCD, the effect of welded tubing on storage characteristics of white blood cell (WBC)-reduced red blood cells (RBCs) and platelet (PLT) concentrates was studied. Welds were made with Terumo SCD (T-SCD) or CompoDock S2, and unwelded tubing served as reference. STUDY DESIGN AND METHODS: Three WBC-reduced RBC units or 3 PLT concentrates were pooled and divided to prevent donor-dependent differences. The units were transferred 10 times over (1) tubing with a T-SCD weld, (2) a CompoDock S2 weld, or (3) unwelded tubing. RBCs were stored for 42 days and free hemoglobin (Hb) was measured; PLT concentrates were stored for 8 days and CD62P expression was measured, as markers for blood component quality (n = 10 paired experiments). RESULTS: WBC-reduced RBC units had similar hemolysis at the end of storage: 0.47 +/- 0.28, 0.47 +/- 0.35, and 0.49 +/- 0.38 percent of total Hb, for tubing with a T-SCD weld, a CompoDock S2 weld, or no weld, respectively (not significant). CD62P expression of stored WBC-reduced PLT concentrates was not significantly different between the groups: 20.3 +/- 5.1, 19.8 +/- 5.1, and 22.3 +/- 9.8 percent for tubing with a T-SCD weld, a CompoDock S2 weld, or no weld, respectively. CONCLUSION: The quality of blood components, measured as RBC hemolysis and platelet CD62P expression, is not adversely affected by the presence of a sterile connection in the tubing, made by either the CompoDock S2 or the T-SCD.

Detection of bacteria in platelet concentrates: comparison of broad-range real-time 16S rDNA polymerase chain reaction and automated culturing.

BACKGROUND: Based on real-time polymerase chain reaction (PCR) technology, a broad-range 16S rDNA assay was validated and its performance was compared to that of an automated culture system to determine its usefulness for rapid routine screening of platelet concentrates (PCs). STUDY DESIGN AND METHODS: The presence of bacteria in pooled PCs was routinely assessed in an automated culturing system (BacT/ALERT, bioMerieux). The PCR assay was performed with DNA extracted from the same samples as used for culturing. DNA extraction was performed with a automated extraction system (MagNA Pure, Roche Diagnostics). PCR amplification was performed with a set of universal primers and probe targeting eubacterial 16S rDNA. RESULTS: A total of 2146 PCs were tested. Eighteen (0.83%) samples were found to be contaminated. These samples were positive for the presence of bacteria by both methods. All contaminants were identified as bacteria belonging to the common human skin flora. These included Propionibacterium spp. (n = 7), Staphylococcus spp. (n = 6), Bacillus spp. (n = 2), Micrococcus spp. (n = 2), and Peptostreptococcus spp. (n = 1). Estimation of the bacterial load in PCs by real-time PCR showed that the initial levels of contamination varied between 13.6 and 9 x 10(4) colony-forming unit equivalents per PCR procedure. CONCLUSIONS: Compared to culture in the BacT/ALERT system, the PCR assay had a sensitivity of 100 percent and a specificity of 100 percent. This real-time PCR assay has a much shorter turnaround time of 4 hours, which offers the possibility to test and obtain results on PCs before release or the day they are transfused. This would permit the withdrawal of contaminated PCs before transfusion.

Preparation and storage of white blood cell-reduced split apheresis platelet concentrates for pediatric use.

BACKGROUND: White blood cell (WBC) reduction and bacterial screening induce unacceptable product loss when platelet (PLT) concentrates (PCs) for pediatric transfusion are prepared from whole blood. The aim was to investigate PCs, WBC reduced and bacterially screened, from single-donor apheresis procedures, divided in 3 or 4 pediatric units and stored up to 5 days. STUDY DESIGN AND METHODS: PCs were collected with an apheresis machine and WBC reduced by in-process filtration. The PCs were sampled for bacterial screening and subsequently divided in 70-mL products. Initially, storage characteristics of split units in 400-mL polyvinylchloride (PVC) bags with 17 split PCs originating from five apheresis donations were studied. When a 600-mL container made of the more gas-permeable polyolefin became available, a paired comparison was performed with 9 split PCs from nine donations and with a higher-yield PLT collection procedure. RESULTS: Split PCs contained 69 x 10(9) +/- 14 x 10(9) PLTs in 69 +/- 1 mL of plasma, and storage in the PVC containers gave a pH value of 6.86 +/- 0.10 on Day 6 (mean +/- SD, n = 17). When comparing the containers, the PVC bag contained 98 x 10(9) +/- 15 x 10(9) PLTs in 72 +/- 4 mL versus 102 x 10(9) +/- 18 x 10(9) PLTs in 74 +/- 8 mL for the polyolefin bag (n = 9, not significant). This gave pH values on Day 6 of 6.12 +/- 0.50 in the PVC container, whereas pH remained acceptable in the polyolefin container: 6.85 +/- 0.10 on Day 6 (p < 0.01). CONCLUSION: PCs for pediatric use from split single-donor apheresis concentrates, WBC reduced and bacterially screened, can be stored for up to 5 days in a 600-mL polyolefin container with maintenance of good in vitro storage variables.

Multicenter evaluation of two flow cytometric methods for counting low levels of white blood cells.

BACKGROUND: Flow cytometric methods can be used to count residual white blood cells (WBCs) in WBC-reduced blood products, which should contain fewer than 1 x 10(6) WBCs per unit (approximately 3.3 WBCs/ microL). In this study two flow cytometric methods for counting WBCs under routine conditions in nine laboratories were evaluated. STUDY DESIGN AND METHODS: Panels of red blood cells (RBCs), platelets (PLTs), and plasma were prepared containing 33.3, 10.0, 3.3, 1.0, and 0.3 WBCs per microL and counted with flow cytometric methods (either LeucoCOUNT, BD Biosciences, four laboratories; or LeukoSure, Beckman Coulter, five laboratories). Requirements were that at the level of 3.3 WBCs per microL, coefficient of variation was < or =20 percent and accuracy was > or =80 percent. Routine flow cytometric quality control (QC) data of WBC-reduced blood products from two laboratories were analyzed. RESULTS: At the level of 3.3 WBCs per microL, none of the laboratories met the requirements for all three blood products. The LeucoCOUNT method met requirements at more laboratories than the LeukoSure method for RBCs and PLTs, but the opposite was true for plasma. Routine QC data showed that >99 percent of the flow cytometric measurements for WBC-reduced products was below the 95 percent prediction interval at 3.3 WBCs per microL. CONCLUSION: None of the laboratories met the requirements for accuracy and precision for all three blood products. Nevertheless, routine results showed that in >99 percent of the products, WBC counts were below guideline limits. Therefore, both flow cytometric methods are suitable for QC with pass-fail criterion.

Storage of platelets in additive solution for up to 12 days with maintenance of good in-vitro quality.

BACKGROUND: Storage of PLT concentrates (PCs) may be extended beyond 5 days, provided in-vitro and in-vivo variables allow longer storage and bacterial screening is performed. The aim of this study was to examine in-vitro storage characteristics of PCs in various storage solutions: plasma only, or mixtures of plasma with PAS-II, PAS-III, PAS-IIIM, and Composol. STUDY DESIGN AND METHODS: PCs from five pooled buffy-coats and WBCs reduced by filtration were stored in 1.3-L butyryl-tri-hexyl-citrate-plasticised PVC containers. First, a paired comparison was made between PAS-II and Composol, with 35-percent final plasma concentration (n = 10). Then, plasma, PAS-III with 30-percent plasma, PAS-IIIM with 20- and 30-percent plasma, and Composol with 20 and 30-percent final plasma concentration were compared (n = 5 pairs). Finally, 50 PCs in Composol with 35-percent final plasma concentration were studied. RESULTS: PCs in PAS-II or Composol had a mean +/- SD pH of 6.95 +/- 0.09 and 6.96 +/- 0.08 at Day 12, respectively. For PCs in PAS-IIIM and Composol with 30-percent final plasma concentration, pH on Day 7 was 7.00 +/- 0.02 and 6.83 +/- 0.05. With 20-percent final plasma concentration, pH was 6.98 +/- 0.02 and 6.81 +/- 0.03 for PAS-IIIM and Composol, respectively. PCs in PAS-III with 30-percent plasma had a pH on Day 7 of 6.87 +/- 0.03, whereas PCs in 100-percent plasma had a pH of 7.05 +/- 0.03. PCs in Composol with 35-percent plasma maintained pH greater than 6.8 in 48 of 50 of the units (96%), averaging 7.00 +/- 0.10 on Day 8. CONCLUSION: In-vitro quality of PCs in AS with at least 35-percent plasma can be maintained for 7 to 12 days after collection.