Prestorage white cell reduction in saline-adenine-glucose-mannitol red cells by use of an integral filter: evaluation of storage values and invivo recovery

Laboratory and clinical comparison of the efficacy of prestorage leukoreduction of red cells at cold versus room temperature

BACKGROUND

The temperature at which filtration takes place has been reported to influence the efficacy of leukoreduction. We aimed to compare the residual leukocyte count (RLC) in red cell units (RCUs) filtered at cold (CT) versus room temperature (RT) and to assess whether this correlates clinically with a difference in the incidence of acute transfusion reactions (ATRs).

METHODS AND MATERIALS

In the first part of the study, whole blood units collected were randomly allocated for subsequent filtration at CT and RT, respectively. RLC postfiltration was assessed using flow cytometry. The second part of the study was a nonrandomized clinical trial in which incidence of ATR was compared between RCUs filtered at RT and CT for 6 months each.

RESULTS

Thirty-five RCUs each underwent leukofiltration at CT and RT, respectively. The median RLCs in the filtered units at CT and RT were 0.02 × 10⁶ and 0.1 × 10⁶ leukocytes/unit, respectively (p = .0001), with no difference in red blood cell (RBC) recovery (p = .41). During the second part, 3455 RCUs filtered at RT and 3539 RCUs filtered at CT were transfused to patients. The rate of febrile non-hemolytic transfusion reaction (FNHTR) among transfused patients was less with units filtered at CT (1 per 2000 transfusions) in comparison to RT (1 per 588 transfusions). The difference was, however, not significant (p = .14).

CONCLUSION

If change in temperature alone can cause significant reduction in leukocytes, then it is a simple way to curtail the rate of this common yet unpleasant reaction and reduce the reaction rate at minimal cost.

[The life span of red blood cell in patients with severe/very severe aplastic anemia]

Objective: To explore the life span of red blood cells (RBC) in patients with severe/very severe aplastic anemia (SAA/VSAA). Methods: Clinical data of 128 SAA/VSAA patients from November 2016 to April 2017 were retrospectively analyzed, and 13 healthy volunteers in the same period was used as normal control. The endogenous Breath Carbon Monoxide (CO) test was used to detect the life span of RBC in SAA/VSAA patients, and the effect of immunosuppressive therapy (IST) on the life span of RBC in these patients was explored. Results: The mean life span of RBC in 51 untreated SAA/VSAA patients was (50.69±21.43) d, which was significantly shorter than that in normal controls[(111.85±31.55) d](t=-6.611, P<0.001). The mean life span of RBC in 77 patients treated with IST was (87.14±39.28) d. The mean life span of RBC in complete responses (CR), hematologic response (HR) and non-response (NR) patients were (106.15±32.12) d, (92.00±38.60) d and (50.44±21.56) d, respectively. The life span of RBC in patients with HR was significantly longer than that in newly diagnosed and NR patients (t=7.430, P<0.001; t=4.846, P=0.002), which was similar to that in the normal controls (t=-1.743,P=0.085). There was no statistical significance between CR patients and the normal controls in the mean life span of RBC (t=-0.558, P=0.579). No factor affecting the RBC life span was found in univariate logistical regression analyses in the newly diagnosed SAA/VSAA patients. The serum levels of IL-2R and IL-6 were much lower in HR patients than NR patients[IL-2R: 4.3×105 U/L vs 6.5×105 U/L, z=-2.733, P=0.006; IL-6: 2.6 (2.0-17.7) ng/L vs 6.1 (2.0-14.4) ng/L, z=-2.968, P=0.003]. Of the 51 newly diagnosed patients, 38 received IST and their 3-month curative effect was evaluated. Receiver operator characteristics (ROC) curve was used to analyze the predictive effect of RBC life span of untreated patients on the efficacy of IST before treatment. The cut-off point was 60 days with sensitivity of 37.5% and specificity of 86.4%. In 9 cases with life span of RBC>60 d before IST, 6 cases acquired HR, while in 29 cases with life span of RBC ≤ 60 d before IST, 10 cases acquired HR, the difference was not statistically significant (P=0.128). Conclusion: The life span of RBC in SAA/VSAA patients was shortened, which can be improved even recovered to the normal after IST. Elevated cytokines might play a role in the pathophysiology of the shortened RBC life span in SAA/VSAA.

Evaluation of the red cell hemolysis in packed red cells during processing and storage

Introduction:

Storage of red cells causes a progressive increase in hemolysis. In spite of the use of additive solutions for storage and filters for leucoreduction, some amount of hemolysis is still inevitable. The extent of hemolysis, however, should not exceed the permissible threshold for hemolysis even on the 42^nd day of storage.

Study Design and Methods:

Eighty units of packed red cells, 40 stored in SAGM post leucoreduction and 40 in ADSOL without leucoreduction filters, were evaluated for plasma hemoglobin by HemoCue Plasma Hemoglobin analyzer on the day of collection and on the 7^th, 14^th, 21^st, 28^th, 35^th and 42^nd days thereafter. The hemoglobin and hematocrit were also noted for all these units by the Beckman and Coulter analyzer. Percentage hemolysis was then calculated.

Observations:

Hemolysis progressively increased with the storage period in all the stored red cell units (SAGM as well ADSOL). However, on day 42^nd of storage, free hemoglobin in all the red cell units was within the permissible level (which is 0.8% according to the Council of Europe guidelines and 1% as per the US FDA guidelines). The mean percentage hemolysis was slightly higher in the SAGM-containing bags with an integral leucoreduction filter as compared to the bags containing ADSOL. However this difference was marginal and not statistically significant.

Conclusion:

Hemolysis of the red cells increases with storage. However, maximum hemolysis does not exceed the permissible limits at any time thereby indicating the effect of optimum processing and storage conditions on red cell hemolysis.

Characterization of blood components prepared from whole-blood donations after a 24-hour hold with the platelet-rich plasma method

BACKGROUND

The preparation of platelet (PLT) concentrates (PCs) from PLT-rich plasma (PRP) requires that whole blood (WB) be processed within 8 hours of collection. Increasing WB storage time to 24 hours would be logistically attractive. This study compares the in vitro quality of blood components prepared from WB stored for 8 and 24 hours at room temperature before processing with the PRP method.

STUDY DESIGN AND METHODS

WB units were collected from ABO-matched blood donors. To reduce individual variations, paired donations were drawn in parallel, pooled, and split back in the collection bag. One unit was held for 6 to 8 hours and the other for 22 to 24 hours at 20 to 24 degrees C. Prestorage leukoreduced components were prepared with the PRP as intermediate product and analyzed during storage.

RESULTS

RBC units prepared after an 8- or 24-hour hold were comparable in terms of hemolysis, sodium, pH, and ATP levels. RBC 2,3- diphosphoglycerate (2,3-DPG) was significantly lower in RBCs prepared from 24-hour hold donations immediately after processing but not after 20 days of storage. Residual white blood cells were approximately fivefold higher (p < 0.05) in 24-hour RBC units. For PCs, measurements for glucose, ATP, lactate, pH, extent of shape change, hypotonic shock response, and CD62p activation were similar. No differences were observed in the von Willebrand factor, factor (F)V, FVIII, and fibrinogen content of fresh-frozen plasma.

CONCLUSIONS

The decrease in FVIII and RBC 2,3-DPG can be acceptable as a compromise to improve blood component logistics, but leukoreduction efficiency must be improved before considering the adoption of an overnight storage of WB before PRP processing.

Prestorage leukoreduction and low-temperature filtration reduce hemolysis of stored red cell concentrates

BACKGROUND

Universal prestorage leukoreduction in Canada created the perception that stored red cells (RBCs) are more hemolyzed than their unfiltered predecessors. A pool-split design tested the effects of leukoreduction on hemolysis of stored RBCs.

STUDY DESIGN AND METHODS

Two ABO-matched units were pooled, divided, and then processed into leukoreduced (LR) and nonleukoreduced (NLR) units with the Pall LT-WB or RC-PL systems and sampled during standard processing and storage for testing of sterility, counts, hemolysis, and osmotic fragility.

RESULTS

Room temperature (RT) filtration of 10 pairs of LT-WB-LR and -NLR units showed significantly different percentage of hemolysis (0.39%) and osmotic fragility (0.643%) at 42 days. Cold-stored and -filtered units (2 days at 4 degrees C before processing) were less hemolyzed, but showed a similar proportional decrease of hemolysis in LR units (0.13% vs. 0.25% at 42 days). RBCs from RC-PL systems showed the lowest hemolysis although there was a filtration effect (0.05% vs. 0.12%, 42 days). Osmotic fragility paralleled hemolysis. Segment samples gave inaccurate results. Two-day prefiltration cold storage reduced hemolysis from 0.36 to 0.07 percent (42 days, p < 0.001). RT-LR hemolysis became significantly higher by Day 10 and 4 degrees C LR by Day 12. NLR units showed hemolysis by Day 7. LR units filtered cold were less hemolyzed (p < 0.05) than RT-LR but osmotic fragility was unchanged.

CONCLUSIONS

LR-RBCs prepared by any of three methods (LT-WB, RT or cold; RC-PL), filtered at 4 degrees C, were less hemolyzed during storage than nonfiltered concentrates: 4 degrees C leukoreduction is beneficial for RBCs and does not cause hemolysis or enhance fragility.

Visual assessment of hemolysis in red blood cell units and segments can be deceptive

BACKGROUND

Blood components that appear hemolyzed are discarded. However, visual inspection is subjective and criteria for excessive hemolysis are poorly defined.

STUDY DESIGN AND METHODS

Packed RBCs (10 CPDA-1, 10 Adsol) were collected. Half of each unit was leukoreduced. Plasma Hb was measured and compared in segments and units by three methods: 1) a HemoCue Plasma/Low Hb Photometer system; 2) a tetramethyl-benzidine (TMB) chemical method, and 3) a free Hb visual comparator.

RESULTS

Visual assessment tended to overestimate hemolysis. Chemical methods were comparable (r(2)= 0.894; HemoCue = 0.043 +[0.770]x TMB; n = 400; range, 0.01-0.5 g/dL), although the mean plasma Hb (g/dL) for the HemoCue method was higher than that of the TMB method (0.12 vs. 0.10 g/dL, respectively; p < 0.001). No units would have been discarded based on a hemolysis level of at least 0.6 g/dL (approx. 1%) if measured by a chemical method. However, 50 percent of CPDA-1 and 10 percent of Adsol units would have been discarded if only visual criteria were used. Leukoreduction did not increase plasma Hb levels. Discrepancies in plasma Hb levels were noted between units and their corresponding segments.

CONCLUSION

Visual assessment of hemolysis can result in unnecessary wastage of blood components. HemoCue offers an alternative, objective method to assess plasma Hb in the setting of blood collection and processing facilities for routine quality control and process validation, and may aid in the development of objective criteria for excessive hemolysis in blood components.

Influence of prestorage leucocyte depletion and storage time on rheologic properties of erythrocyte concentrates

BACKGROUND AND OBJECTIVES

Rheological blood properties were studied during storage.

MATERIALS AND METHODS

Blood viscosity, erythrocyte morphology and ATP levels were determined in filtered samples (Leukotrap WB filter system) and their unfiltered counterparts during storage with saline-adenine-glucose-mannitol (SAG-M) for 42 days.

RESULTS

Prestorage leucocyte depletion decreased blood viscosity at a high shear rate and reduced the degree of anisocytosis of erythrocytes. During storage, erythrocytes underwent a time-dependent echinocytic shape transformation, which increased the suspension viscosity at high and low shear rates. On day 42, high shear viscosity in filtered units remained lower than in unfiltered counterparts, the mean cellular volume and red blood cell distribution width (RDW) were lower and erythrocytic ATP levels were higher.

CONCLUSIONS

Prestorage leucocyte depletion by Leukotrap WB filters improves biophysical properties of erythrocyte concentrates throughout storage, which is, however, outweighed by a time-dependent echinocytic shape transformation and deterioration of these properties.

Prestorage WBC filtration of RBC units with soft-shell filters: filtration performance and impact on RBCs during storage for 42 days

BACKGROUND

The introduction of universal WBC filtration of RBCs prior to storage is currently under consideration in many countries, as it is thought to minimize the incidence of transfusion-associated adverse effects. Centrifugation of blood containers with newly developed soft-shell WBC filters is more convenient, and so of great interest.

STUDY DESIGN AND METHODS

Two different quadruple blood pack systems with integrated soft-shell WBC filters were compared (Sepacell OptiPure RC, Baxter Biotech, vs. LCR 5, Maco Pharma). Buffy coat-depleted RBC units were investigated from whole-blood donations that were held for 2 to 3 hours before centrifugation and subsequent filtration at 22 degrees C (Group 1, OptiPure RC, 450 mL; Group 2, LCR 5, 450 mL; Group 3, OptiPure RC, 500 mL; Group 4, LCR 5, 500, mL, n = 12 per group). Filtration performance was analyzed, and the impact of WBC filtration on hemolysis rate, Hb content, pH, supernatant potassium, ATP, and 2,3 DPG was investigated weekly during storage for 42 days.

RESULTS

Filtration reduced the WBC count by 4.4 to 5.1 log. Mean +/- SD Hb content was 44.7 +/- 3.0, 41.2 +/- 3.3, 53.1 +/- 5.0, and 51.5 +/- 6.3 g per unit, respectively, with a corresponding mean RBC recovery after filtration of 71.0 +/- 3.0, 68.3 +/- 3.3, 76.6 +/- 1.7, and 68.9 +/- 4.5 percent. WBC filtration resulted in a significant reduction of Hct (0.10-0.14) in all four groups. Investigation of all RBC storage variables revealed acceptable values throughout the storage for 42 days.

CONCLUSION

WBC filtration with two newly developed soft-shell filters showed acceptable WBC-reduction efficacy without any difference between filter types in buffy coat-depleted RBCs from 450- and 500-mL whole-blood donations. However, the application of both filters resulted in an unacceptably low RBC recovery after filtration, which was particularly evident with the LCR5 filter. Our findings raise concern that WBC reduction with these filters may result in the production of RBCs with an inappropriately low Hb concentration.

[Consequences for labile blood products of leukocyte depletion by whole blood filtration using the Leucoflex LST1 in-line filter. Evaluation of the Leucoflex LST1 filter]

The aim of this study is to evaluate the effects of whole blood filtration after a storage time of 20-24 hours at laboratory temperature using the in line filter Leucoflex LST1. The study concerns 49 blood donations in which we studied leukocyte depletion, proteins (IgG, IgA, IgM, haptoglobin, C3, C4), coagulation factors (fibrinogen, factors XII, XI, IX, VIII, V, proteins S and C, plasminogen, tPA, D-Dimers, PDF) at day 1, the parameters of conservation (ATP, 2-3 DPG, extra cellular potassium, haemolysis, pH) of red blood cell concentrates (RCCs) and bacteriological sterility at day 1 and 42. Despite a correct leukocyte depletion (mean depletion of 3.96 log), a 10 fold higher mean level of residual leukocytes/unit than with buffy coat poor RCC filtration (0.514.10(6) vs 0.051.10(6)) is observed. Moreover a lot of concentrates are not in accordance with French regulations (7/42 with more than 1.10(6) leukocytes/unit). The variation of the rates of IgG, IgA, IgM, haptoglobin, C4 and protein C is not significant. For the others there is a slight decrease with a mean level remaining in a physiological range. No sign of activation is noted. The sterility assays remain negative and the RCC conservation is not altered. In conclusion, even if the quality of the leukocyte depletion is not satisfactory in our study and has to be stated more precisely by multicenter studies, the whole blood filtration does not alter the quality of the derived components and allows us obtain RCC in a bigger volume and containing more haemoglobin than with the classical procedure after removing the buffy-coat [10].

Prestorage leukocyte reduction with in-line filtration of whole blood: evaluation of red cells and plasma storage

OBJECTIVES

Prestorage filtration of blood components appears to be an effective method to reduce leukocyte-induced adverse reactions and other complications. To determine whether it is better to filter whole blood before component separation, we compared the efficiency of in-line filtration of whole blood with that of postseparation filtration.

METHODS

Blood was collected from normal, healthy donors into either regular triple-bag containers or into whole-blood integral-filter container systems. We then compared the in vitro storage values of leukocyte-depleted red blood cell concentrates (RBCC) kept at 4 degrees C, and plasma frozen for 1 year with nonfiltered blood components as control.

RESULTS

All counts of white blood cells after filtration were < 1 x 10(6) per unit. For almost all storage parameters no significant differences were found between leukocyte-reduced RBCC and control units. The plasma fibrinopeptide A values below 30 ng/ml prior to freezing indicate that filtration does not activate the coagulation factors. Furthermore, the filtration did not influence either the biological values or the coagulation factors of plasma units.

CONCLUSIONS

Whole blood filtration prior to component preparation seems to offer a useful alternative technique for obtaining leukocyte-reduced RBCC and plasma.