Automated collection of double red blood cell units with a variable-volume separation chamber.

BACKGROUND: Automated collection of blood components offers multiple advantages and has prompted development of portable devices. This study sought to document the biochemical and hematologic properties and in vivo recovery of red cells (RBCs) collected via a new device that employed a variable-volume centrifugal separation chamber. STUDY DESIGN AND METHODS: Normal subjects (n = 153) donated 2 units of RBCs via an automated blood collection system (Cymbal, Haemonetics). Procedures were conducted with wall outlet power (n = 49) or the device's battery source (n = 104). Units were collected with or without leukoreduction filtration and were stored in AS-3 for 42 days. The units were assessed via standard biochemical and hematologic tests before and after storage, and 24 leukoreduced (LR) and 24 non-LR RBCs were radiolabeled on Day 42 with Na(2)(51)CrO(4) for autologous return to determine recovery at 24 hours with concomitant determination of RBC volume via infusion of (99m)Tc-labeled fresh RBCs. RESULTS: Two standard RBC units (targeted to contain 180 mL of RBCs plus 100 mL of AS-3) could be collected in 35.7 +/- 2.0 minutes (n = 30) or 40.3 +/- 2.7 minutes for LR RBCs (n = 92). An additional 31 collections were conducted successfully with intentional filter bypassing. RBC units contained 104 +/- 4.1 percent of their targeted volumes (170-204 mL of RBCs), and LR RBCs contained 92 percent of non-LR RBCs' hemoglobin. All LR RBCs contained less than 1 x 10(6) white blood cells. Mean hemolysis was below 0.8 percent (Day 42) for all configurations. Adenosine triphosphate was well preserved. Mean recovery was 82 +/- 4.9 percent for RBCs and 84 +/- 7.0 percent for LR RBCs. CONCLUSIONS: The Cymbal device provided quick and efficient collection of 2 RBC units with properties meeting regulatory requirements and consistent with good clinical utility.

In vitro and in vivo evaluation of LEUKOSEP HRC-600-C leukoreduction filtration system for red cells.

BACKGROUND: Documentation of the benefits of leukoreduction has led to the increased use of this technique and the need for development of efficient and effective techniques for its accomplishment. This study investigated the in vitro properties and in vivo autologous radiolabeled recovery of leukoreduced red cells (RBCs) produced through a leukoreduction filtration system for RBCs (LEUKOSEP HRC-600-C, Hemerus Medical). STUDY DESIGN AND METHODS: Normal subjects donated 36 units of RBCs that were leukoreduced on Days 0, 3, or 5 through a "hands-off" technique. Biochemical studies were performed before and after filtration and at the end of 42 days of storage. Units leukoreduced on Days 0 or 5 were held until Day 42 and used for autologous radiolabeled return to determine recovery with 51Cr single-label radiolabeling techniques. RESULTS: Leukoreduction filtration was accomplished in 16.3 +/- 2 minutes on Day 0 at room temperature or 27 to 30 minutes on Days 3 or 5 after refrigeration. Leukoreduction efficiency was 4.6 +/- 0.6 log with a median residual white blood cell (WBC) content of fewer than 3.3 x 10(4) WBCs per unit. RBC recovery was 90 +/- 2 percent. Hemolysis was 0.34 +/- 0.16 percent at the end of 42 days of storage. The in vivo recovery of radiolabeled RBCs 24 hours after autologous return was 80.6 +/- 4.5 percent for RBC units leukoreduced on Days 0 and 5 combined. CONCLUSION: The LEUKOSEP HRC-600-C WBC reduction filtration system produced leukoreduced RBCs efficiently and effectively with acceptable poststorage biochemical measures and posttransfusion recovery after 42 days of storage.

Efficacy of apheresis platelets treated with riboflavin and ultraviolet light for pathogen reduction.

BACKGROUND: Pathogen reduction technologies for platelet (PLT) components offer a means to address continued viral transmission risks and imperfect bacterial detection systems. The efficacy of apheresis PLTs treated with riboflavin (vitamin B2) plus ultraviolet (UV) light (Mirasol, Navigant Biotechnologies) was investigated in a single-blind, crossover study in comparison to untreated PLTs. STUDY DESIGN AND METHODS: Normal subjects (n = 24) donated PLTs by apheresis on two occasions at least 2 weeks apart. Units were randomized to control or test arms, the latter receiving the addition of 28 mL of 500 micromol per L B2 and exposure to 6.2 J per mL UV light. PLTs were stored for 5 days with biochemical and hematologic analyses performed before and after illumination on Day 0 and at the end of storage. An aliquot of each unit was radiolabeled and returned to determine recovery and survival. RESULTS: The PLT content of treated units was maintained from Day 0 (4.1 x 10(11) +/- 0.4 x 10(11)) to Day 5 (4.0 x 10(11) +/- 0.4 x 10(11)). Treatment with B2 plus UV light was associated with an increase in lactate production with concomitant increases in glucose consumption. pH (control, 7.38 +/- 0.07; test, 7.02 +/- 0.10) was well maintained throughout storage. Recovery of treated PLTs (50.0 +/- 18.9%) was reduced from that of control PLTs (66.5 +/- 13.4%); survival was similarly shortened (104 +/- 26 hr vs. 142 +/- 26 h; p < 0.001). CONCLUSIONS: PLTs treated with B2 plus UV light demonstrate some alterations in in vitro measures but retain in vitro and in vivo capabilities similar to pathogen-reduced and licensed PLT components that have been shown to have useful clinical applicability. The recovery, survival, and metabolic properties of Mirasol PLTs should provide sufficient hemostatic support in thrombocytopenia to justify patient clinical trials.

Further evaluation of a new standard of efficacy for stored platelets.

BACKGROUND: The proposal to assess the viability capabilities of platelets (PLTs) collected, treated, or stored in a developmental system against "fresh" PLTs from the same subject poses several important methodologic issues pertaining to the timing and manner of the collecting and separating the fresh PLTs. This study extended the previous validation of this method of comparing fresh and stored PLTs, applying it to an assessment of apheresis PLTs stored for 7 days with a newly standardized radiolabeling protocol. STUDY DESIGN AND METHODS: Eighteen normal subjects donated 1 unit of leukoreduced PLTs, pheresed with a standard, approved system. They received an aliquot radiolabeled with 51Cr on Day 7 simultaneously with 111In-labeled fresh PLTs that had been separated by a manual method. Recovery and survival were compared to determine whether the stored PLTs were not inferior to the criterion of 67 percent of recovery and 50 percent of survival of fresh PLTs. Separate studies were undertaken to document the similarity of recovery and survival with 51Cr and 111In radiolabeling in PLTs stored to 8 days and to determine the importance of correcting the radioactivity in timed samples for the activity remaining in blood beyond the life span of the retransfused PLTs. RESULTS: PLTs stored for 7 days demonstrated 88.7 +/- 35.2 percent of the recovery and 89.9 +/- 21.2 percent of the survival of PLTs collected via a nonproprietary, manual system and thus met the comparative criterion. In a separate study (n = 12), labeling Day 8 PLTs with 51Cr or 111In resulted in recoveries and survivals that were not different. Radiolabel eluted from labeled PLTs in vitro was taken up by cellular blood elements in a reuptake incubation. CONCLUSION: Apheresis PLTs stored for 7 days met the criterion proposed for comparison with fresh PLTs. This analytic approach is feasible with PLTs collected and prepared via a manual method. A standardized protocol for radiolabeling PLTs with 51Cr and 111In and analyzing the results in a standardized fashion was employed successfully, with the two radioisotopes yielding similar results. The importance of correcting for residual activity after disappearance of injected cells was noted.

Preliminary validation of a new standard of efficacy for stored platelets.

BACKGROUND: Platelet preparation and storage systems, unlike those for RBC, lack an objective, absolute performance criterion to determine acceptability. Recently, a criterion based on paired comparison with the radiolabeled recovery and survival of "fresh" platelets has been proposed, namely, recovery = two-thirds and survival = half of "fresh" platelets. STUDY DESIGN AND METHODS: Eleven normal subjects donated a unit of leukoreduced apheresis platelets using a standard, approved system. They received an aliquot radiolabeled with 111In or 51Cr (random selection) 4 to 20 hours after donation and, using the other radioisotope, on Day 5 of storage. The recovery was calculated based on the injectate radioactivity. The survival was determined using the multiple-hit model. The area under the platelet survival curve was calculated using the COST program. RESULTS: Reinfusion of platelets less than 20 hours after collection resulted in a recovery of 74.7 +/- 12.3 percent and a survival time of 7.5 +/- 1.1 days. Reinfusion on Day 5 resulted in a recovery of 58.2 +/- 12.0 percent and a survival time of 6.9 +/- 1.4 days, values that were 77.9 +/- 9.5 percent and 91.8 +/- 16.1 percent of the observation using "fresh" platelets, respectively. The area under the curve using Day 5 platelets was 67.8 +/- 11.5 percent of that using "fresh" platelets. CONCLUSION: The proposed criterion for objective evaluation of platelet preparation and storage systems appears applicable to a commonly accepted approach, leukoreduced apheresis platelets stored in plasma for 5 days, and merits evaluation using other collection, treatment, and storage systems.

Seven-day storage of single-donor platelets: recovery and survival in an autologous transfusion study.

BACKGROUND: Bacterial screening may effectively reduce the morbidity and mortality risk associated with extended storage of platelets. Platelet viability then becomes the primary determinant of acceptable storage time. This study evaluates the effectiveness of platelets stored in plasma for 7 days. STUDY DESIGN AND METHODS: WBC-reduced, single-donor platelets (n = 24) were collected and stored by standard methods at two sites. Standard in vitro platelet biochemical and functional parameters were monitored over the storage period. On Days 5 and 7 of storage, platelets were alternately labeled with 51Cr and (111)In and returned to the subject, and recovery and survival were determined. RESULTS: Component pH(22 degrees C) was maintained in the range 6.2 to 7.61 through 7 days and did not detrimentally affect either in vitro or in vivo outcomes. In vitro platelet characteristics were adequately maintained over 7 days. Day 5 platelets had better recovery (63.0 +/- 4.36 vs. 53.9 +/- 4.36%, p < 0.0001) and survival (161 +/- 8.1 vs. 133 +/- 8.1 hr, p = 0.006) than Day 7 platelets adjusting for radioisotope, center, and donor effects. CONCLUSION: Although declines in recovery and survival were noted, these are less than used previously to gain licensure of 7-day storage and are unlikely to be clinically significant. Extension of storage to 7 days could be implemented with bacterial screening methods to select out contaminated components without a significant effect on the platelet efficacy compared to 5-day components.

Production of pathogen-inactivated RBC concentrates using PEN110 chemistry: a Phase I clinical study.

BACKGROUND: Despite extensive reductions in risk, donor selection and testing cannot eliminate pathogen transmission. The objective of this study was to evaluate clinically the viability of pathogen-inactivated RBCs. STUDY DESIGN AND METHODS: Twelve healthy subjects each donated two units of blood that were handled as additive system control units or were inactivated using the PEN110 process (INACTINE, V.I. Technologies) in randomized order. PEN110, which inactivates pathogens by reacting with nucleic acid bases, was incubated with RBCs for 6 hours, followed by washing and quenching with sodium thiosulfate. Radiolabeled RBC recovery and survival determinations were undertaken after 28 days of storage; biochemical and hematologic variables were assessed over 42 days. RESULTS: After 28 days, treated units had a 24-hour double-label ((51)Cr/(99m)Tc) recovery (85.0 +/- 5.0%) that was indistinguishable from control units (85.9 +/- 2.7%); the times required for reduction of radioactivity of labeled cells to half the Day 1 activity (T(50)) were similar for both groups (treated, 31.9 +/- 8.2 days; control, 32.9 +/- 3.3 days). No deleterious effects of PEN110 treatment were found on RBC antigens tested. Treatment reduced 2,3-DPG levels by half and slightly lowered pH levels. Throughout the 42-day storage period, treated RBCs had a lower level of lactate production and a trend toward lower glucose consumption. Hemolysis remained below 1 percent; supernatant potassium and ATP levels were lower than those seen in control RBCs. CONCLUSION: PEN110-treated RBCs stored for 28 days meet all critical requirements for therapeutically useful units.