RBC storage for 11 weeks

BACKGROUND: Increasing the length of RBC storage can increase both RBC availability and quality. This work addresses 11-week RBC storage in experimental ASs (EASs). STUDY DESIGN AND METHODS: Three studies were performed. In the first, 24-hour in vivo recovery of (51)Cr-labeled autologous RBCs was measured in nine volunteers after storage of their RBCs for 11 weeks in EAS 67. In the second study, 4 units of blood were divided and stored in aliquots with an EAS containing 0, 15, 30, or 45 mmol per L of mannitol; then hemolysis, RBC morphology, and microvesicle protein were measured. In the third study, 6 full units were stored for 12 weeks in the EAS containing 30 mmol per L of mannitol, with weekly sampling for morphologic and biochemical measures of RBC quality. RESULTS: RBCs stored for 11 weeks in EAS-67 had a mean 24-hour in vivo recovery of 79 +/- 5 percent, but the hemolysis was 1.35 +/- 0.68 percent. Increasing mannitol content of the EAS reduced hemolysis but increased microvesiculation. EAS-76, with 30 mmol per L of mannitol allowed 11-week storage with 0.48 +/- 0.10 percent hemolysis at 11 weeks and 0.62 +/- 0.14 percent hemolysis at 12 weeks. CONCLUSION: It is possible to store RBCs for 11 weeks in EAS with greater than 75 percent recovery and less than 1 percent hemolysis.     

The effects of phosphate, pH, and AS volume on RBCs stored in saline-adenine-glucose-mannitol solutions

BACKGROUND: RBC ATP concentrations are the most important correlate of RBC viability. Tests were performed to determine whether increased AS volume, pH, and phosphate content increased stored RBC ATP concentrations. STUDY DESIGN AND METHODS: In three studies, packed RBCs were pooled in groups of 3 or 4 units and realiquoted as combined units to reduce intradonor differences. Pooled units were stored in the licensed ASs, AS-1 or AS-5, which contain saline, adenine, glucose, and mannitol (SAGM), or in experimental ASs (EASs) containing SAGM and disodium phosphate. Ten pools were stored in AS-1 at RBC concentrations equivalent to 100, 200, or 300 mL of AS. Six pools were stored in 100, 200, 300, or 400 mL volumes of EAS-61. Ten pools were stored in 100 mL of AS-5, 200 mL of EAS-61, or 300 mL of EAS-64. RBC ATP concentration and other measures of RBC metabolism and function were measured weekly. RESULTS: RBC ATP concentrations decreased sooner with storage in increasing volumes of AS-1. In EAS-61 and EAS-64, RBC ATP concentrations initially increased and stayed elevated longer with increasing AS volume. CONCLUSIONS: The addition of disodium phosphate to SAGM AS increases the RBC ATP concentrations. Reducing storage Hct appears to have a separate beneficial effect in reducing hemolysis.     

Successful storage of RBCs for 10 weeks in a new additive solution

BACKGROUND: The effect of storing packed RBCs suspended in 300 mL of an alkaline, experimental additive solution (EAS 64) was explored. STUDY DESIGN AND METHODS: RBC units prepared from blood collected from healthy donors into CPD were WBC reduced and stored for 10 weeks under blood bank conditions after the addition of 300 mL of EAS 64 (adenine, 2 mM:; dextrose, 50 mM:; mannitol, 20 mM:; NaCl, 75 mM:; Na(2)HPO(4), 9 mM:). For comparison, non-WBC-reduced units from the same donors were stored in a different additive solution (AS-1, Baxter Healthcare) for 6 weeks. Standard methods were used for the in vitro assays. The 24-hour in vivo recoveries were measured by using (51)Cr- and (99m)Tc-labeled RBCs. RESULTS: Mean recovery in the EAS 64 units after 10 weeks was 84 +/- 8 percent, the same as in the AS-1 units stored for 6 weeks. For EAS 64 and AS-1 units, respectively, the ATP of the RBCs was 85 percent and 64 percent of the initial value, hemolysis was 0.43 percent and 0.63 percent, supernatant potassium was 24 mEq per L and 44 mEq per L, and the morphologic index was 98 and 71. CONCLUSION: RBCs suspended in 300 mL of EAS 64 can be stored satisfactorily for 10 weeks. Longer RBC storage should reduce outdating, increase availability of transfusions in remote locations, and improve the efficiency of autologous donor programs.     

Successful storage of RBCs for 9 weeks in a new additive solution

BACKGROUND: This study explored the effect of storing packed RBCs suspended in 200 mL of an alkaline, hypotonic, experimental additive solution (EAS 61). STUDY DESIGN AND METHODS: Packed RBC units prepared from RBCs collected from healthy donors in CPD were stored for 8 (n = 10) and 9 (n = 10) weeks under blood bank conditions after the addition of 200 mL of EAS 61 (adenine, 2 mM:; dextrose, 110 mM:; mannitol, 55 mM:; NaCl, 26 mM:; Na(2)HPO(4), 12 mM:). Standard methods were used for in vitro assays. The 24-hour in vivo autologous recoveries were measured with (51)Cr. RESULTS: Mean +/- SD recoveries at 8 and 9 weeks were 81 +/- 7 and 77 +/- 7 percent. After 9 weeks, the ATP of the RBCs was 81 percent of the initial value, hemolysis was 0.35 percent, supernatant potassium was 46 mEq per L, and the morphologic index was 94.1. CONCLUSION: Packed RBCs suspended in 200 mL of EAS 61 can be stored satisfactorily for 9 weeks. Longer RBC storage should reduce outdating, increase availability of transfusions in remote locations, and improve the efficiency of autologous donor programs.     

RBC antibody persistence

BACKGROUND: A person exposed to foreign blood group antigens may produce antibodies. The persistence of antibodies varies among people and among antibodies. A study was performed to investigate the persistence of clinically significant RBC alloantibodies over a period of 20 years. STUDY DESIGN AND METHODS: A retrospective examination was performed of all records of RBC antibodies in the transfusion laboratory computer database from 1978 through 1997. Records of patients who underwent at least one antibody investigation after an antibody had been detected were studied. The study included all antibodies against the Rh, K, Fy, Jk, and MNs blood group systems. An antibody was regarded as not persistent if, after previous detection, the screening or panel studies became negative for the antibody under study. Anti-D due to RhIg administration was excluded. RESULTS: An analysis was performed of 480 records consisting of 593 antibodies that fulfilled the criteria. Median antibody follow-up was 10 months (range, 1-240). In 137 patients, 153 (26%) antibodies became undetectable over the course of time. After initial negative screening investigations, 310 antibodies were formed. The antibodies that were still detectable had a median follow-up of 7 months (range, 1-193). A patient's age, sex, and antibody specificity were of no influence on the length of time that antibodies were detectable. Antibodies detected with a more sensitive screening technique were less persistent (p = 0.0002). For 28 patients, detection of antibodies was highly irregular. CONCLUSIONS: About 25 percent of all antibodies became undetectable over the course of time. The antibody screening technique used, rather than the antibody specificity, affected these results. To prevent delayed hemolytic transfusion reactions, precise antibody documentation is of great importance.     

WBC reduction in RBC concentrates by prestorage filtration: multicenter experience

BACKGROUND: As universal leukocyte (WBC) reduction (ULR) is being considered as a new standard, few data are available on the performance of WBC-reduction filtration in routine practice. The performance of WBC-reduction in RBCs, using varied filtration practices, in meeting the current FDA requirement (<5 x 10(6)), Council of Europe (EC) recommendation, the proposed FDA requirement (<1 x 10(6)), and a more stringent proposal (<5 x 10(5)) for residual WBCs per RBC unit was assessed and compared. STUDY DESIGN AND METHODS: Participating facilities were the 11 sites of the Viral Activation Transfusion Study (VATS), a prospective study of the impact of transfusion with and without WBC-reduction on survival and HIV viral load in HIV-1-infected patients. Patients randomly assigned to undergo WBC reduction were required to receive RBCs < or =14 days old that had undergone prestorage (within 72 hours of collection) WBC-reduction filtration by a method devised to achieve a postfiltration WBC count of <5 x 10(6). Residual WBC quantitation was performed by PCR in the central VATS laboratory by using frozen WBC-reduced RBC samples obtained at issue for transfusion. RESULTS: A total of 1869 WBC-reduced RBC units were studied. Filtration practices varied within and between sites. There were significant differences in mean residual WBC counts at the 11 sites (p<0.001). Among the WBC-reduced RBC units, 0.8 percent exceeded 5 x 10(6) WBCs per unit, 8.3 percent exceeded 1 x 10(6) WBCs per unit, and 14.3 percent exceeded 5 x 10(5) WBCs per unit. CONCLUSION: Residual WBCs in WBC-reduced RBC units vary within and between sites. WBC reduction was successful, in that over 99 percent and 91 percent of VATS WBC-reduced RBC units met US and EC thresholds, respectively. However, the small but measurable failure rate indicates that not every unit will meet these guidelines.     

Differential expression of the duffy antigen receptor for chemokines according to RBC age and FY genotype

BACKGROUND: The Duffy (Fy) blood group (also known as Duffy antigen receptor for chemokines, or DARC) may be involved in regulation of the level of circulating proinflammatory chemokines, and it is an obligatory receptor on RBCs for the human malaria parasite Plasmodium vivax. STUDY DESIGN AND METHODS: Because quantification of Fy expression by using RBCs of various ages will not detect acute changes associated with inflammatory states, and because P. vivax exclusively invades reticulocytes, a flow cytometric method was developed to measure the level of surface expression of Fy. Reticulocytes and mature RBCs from persons with different genotypes (GATA-1 T-->C promoter mutation at nt -46; FY*A and FY*B in the ORF) were used. RESULTS: Expression of the Fy6 epitope, which is required for P. vivax invasion, was 49 +/- 19 percent higher on reticulocytes than on mature RBCs, regardless of donor genotype (p<0.0001). Fy6 levels were approximately 50 percent lower in persons who were heterozygous for the GATA-1 promoter mutation and were significantly lower on reticulocytes and mature RBCs of the FY*B/FY*B genotype than on those of the FY*A/FY*A or FY*A/FY*B genotype. CONCLUSION: Fy has greater expression on reticulocytes than on mature RBCs in flow cytometry. This method may be useful in further studies of this antigen, such as characterization of reticulocytes and RBC phenotypes across populations, in response to chemokine regulation, and in the context of susceptibility to P. vivax and other parasites.     

Duck hepatitis B photoinactivation bydimethylmethylene blue in RBC suspensions

BACKGROUND: Dimethylmethylene blue (DMMB) has been used to photoinactivate a number of model viruses, including VSV, in RBC suspensions under conditions that preserve in vitro RBC properties during storage. The relative sensitivity of duck HBV (DHBV) and VSV to photoinactivation by DMMB was investigated by performing an indirect immunofluorescence assay (IFA) using primary duck hepatocyte (PDH) cultures or a standard plaque assay for the respective viruses. STUDY DESIGN AND METHODS: DMMB was added to 45-percent Hct, WBC-reduced, oxygenated AS-3 RBCs at 10-, 1-, and 0.1-microM concentrations. Samples (1-mm thick) were illuminated with 5.4-mW per cm(2) of red light for 2 or 9 seconds. Unilluminated samples without DMMB or with 10 microM DMMB served as control. RESULTS: DHBV and VSV were rapidly photoinactivated by DMMB in a concentration and light-dose-dependent fashion. Neither virus was substantially inactivated by incubation with DMMB in the dark. For a given light exposure, DHBV required a concentration of DMMB one-one hundredth that of VSV to achieve approximately the same level of inactivation. CONCLUSION: DHBV appears to be considerably more sensitive than VSV to DMMB photoinactivation. Photoinactivation in 45-percent Hct RBCs can be achieved in seconds by using micromolar quantities of dye.     

Validating billing data for RBC transfusions: a brief report

BACKGROUND: Administrative data are used often for research, but without validation of their accuracy. The validity of the billing for blood transfusion was assessed in one tertiary-care hospital. MATERIALS AND METHODS: Patient discharge data were retrieved from a database containing demographics, diagnoses, and charges. There was random selection of 358 patients who were billed for RBC transfusion and 358 who were not, within a 2-month period. The blood bank's transfusion records were reviewed. Sensitivity was defined as the proportion of transfused patients who were billed, and specificity as the proportion of nontransfused patients who were not billed. Patient characteristics were compared by using Wilcoxon's rank sum test and the chi-square test. RESULTS: Sixty-one transfused patients were not billed for the transfusion. No patient was billed without transfusion. Thus, the sensitivity and specificity were 83 percent (95% CI, 79-87%) and 100 percent, respectively. Nine patients who were not issued RBCs were appropriately not billed for RBCs, although the billing record suggests they had a procedure involving transfusion. These patients were called true-negative. The patients not billed were older (58 years vs. 55 years; p = 0.046) and less likely to have commercial insurance (5% vs. 15%; p = 0.035) than billed patients. CONCLUSIONS: The billing for RBC transfusion in one large institution is reassuringly valid. The specificity is excellent, and the sensitivity is higher than that seen in other studies of coding validity.     

Prestorage universal WBC reduction of RBC units does not affect the incidence of transfusion reactions

BACKGROUND: Febrile nonhemolytic transfusion reaction (FNHTR) has been identified as a pivotal reason for prestorage universal WBC reduction. A regional blood center implemented universal prestorage WBC reduction for RBCs on January 1, 2000. Whether prestorage universal WBC reduction of RBC units will affect FNHTR is not known. STUDY DESIGN AND METHODS: All reports of RBC transfusion reactions at Barnes-Jewish Hospital submitted for evaluation to the blood bank, before and after the implementation of WBC reduction of RBCs, were retrospectively evaluated. RESULTS: For the 36,303 allogeneic RBC transfusions administered in 1999, 85 reactions (0.23%) were reported. These reactions were classified as FNHTR in 43 cases, allergic in 13, delayed hemolytic in 19, and miscellaneous in 10. For the 31,543 non-WBC-reduced RBC transfusions performed in 1999, 78 reactions (0.25%) were reported. These reactions were classified as FNHTR in 39 cases, allergic in 13, delayed hemolytic in 19, and miscellaneous in 7. In the first half of 2000, 32 reactions (0.20%) were reported for 16,093 prestorage WBC-reduced RBC transfusions (p = 0.41). There were 13 FNHTRs and 10 allergic, 7 delayed hemolytic, and 2 miscellaneous reactions. The use of prestorage WBC-reduced RBCs did not significantly affect the rate of reactions classified as allergic (0.04% in 1999; 0.06% in 2000; p = 0.43) or as FNHTR (0.12% in 1999; 0.08% in 2000; p = 0.33). For all patients, universal WBC reduction in 2000 did not reduce the rate of FNHTR from the rate seen with selective bedside WBC reduction, the practice used in 1999 (0.12% in 1999; 0.08% in 2000; p = 0.36). CONCLUSION: No significant difference was found in the incidence of transfusion reactions in patients receiving prestorage WBC-reduced RBCs and non-WBC-reduced RBCs. In addition, no difference was found in transfusion reaction rates when periods of prestorage universal WBC reduction were compared to those of selective WBC reduction.     

Potassium-adsorption filter for RBC transfusion: a phase III clinical trial

BACKGROUND: Within the past 2 years, three cases of cardiac arrest just after rapid transfusion of RBCs preserved for over 7 days after 15-Gy irradiation were found. This severe complication caused transient hyperkalemia. To prevent potassium (K(+)) overload by RBC transfusion at the bedside, a K(+)-adsorption filter made of sodium polystyrene sulfonate was developed. STUDY DESIGN AND METHODS: After in vitro and animal safety and efficacy tests, a Phase III clinical trial was conducted with 65 patients given transfusions via the newly developed filter (filter group) and 37 patients in whom the filter was not used (control group) and transfusions were given at twice the usual flow rate (20 mL/min). RESULTS: More than 85-percent (94.4+/-3.8%) removal of K(+) in RBCs in mannitol-adenine-phosphate (MAP) that had been preserved for more than 14 days or that were used 3 days after 15-Gy irradiation (calculated K(+): 3.8+/-1.3 mEq/bag) was achieved in 82 of 83 bags of MAP RBCs in the filter group, with 79.6 percent removed in the other, even in rapid transfusions. RBC recovery 1 day after transfusion, determined by increments in RBCs, Hb, and Hct, were 24 and 0.4 x 10(4) per microL, 0.7 and 0.3 g per dL, and 1.6 and 0 percent, respectively, in the filter and control groups. No adverse transfusion reactions, such as hypotension, anaphylactoid reactions, or asthma-like attacks, were observed, except for one case of urticaria in the filter group. Mild fever (within 1 degrees C) after transfusion was observed in both groups. Serologic markers of hemolysis rose slightly in both groups, but there was no significant difference between the two groups. CONCLUSION: The newly developed K(+)-adsorption filter is useful, especially in a rapid transfusion setting.     

Prospective RBC phenotype matching in a stroke-prevention trial in sickle cell anemia: a multicenter transfusion trial

BACKGROUND: Most sickle cell anemia patients undergo transfusion therapy to prevent complications. The Stroke Prevention Trial in Sickle Cell Anemia showed that transfusion therapy is effective in the primary prevention of stroke. Despite its efficacy, transfusion therapy is limited by alloimmunization. The purpose of this study was to determine if a multicenter trial could implement a transfusion program utilizing phenotypically matched blood to reduce alloimmunization. STUDY DESIGN AND METHODS: One hundred thirty children underwent RBC phenotyping and antibody screening with review of blood bank records. The protocol required use of WBC-reduced RBCs, which were matched for E, C, and Kell. Monthly alloantibody testing and review of transfusion forms were performed to determine compliance and the occurrence of any adverse events. RESULTS: Patient RBCs expressed a low frequency of Kell (2%), E (20%), and C (25%) antigens. Sixty-one patients received 1830 units. Ninety-seven percent of all units were WBC reduced. Only 29 units were inadvertently not matched for E, C, and Kell. Five patients (8%) developed a clinically significant alloantibody. Four developed a single antibody to E or Kell. Three patients (5%) developed a warm autoantibody. There were 11 transfusion reactions and 8 transfusion-associated events. Transfusion reactions included 6 febrile reactions (0.33%/unit), 3 allergic (0.16%/unit), and 2 hemolytic (0.11%/unit). Associated events included 4 episodes of hypertension (0.22%/unit), 3 crises (0.16%/unit), and 1 transient ischemic attack (0.05%/unit). CONCLUSION: This is the first multicenter study to show that extended RBC phenotyping can be implemented nationwide. Compared to studies, the alloimmunization rate dropped from 3 percent to 0.5 percent per unit, and hemolytic transfusion reactions dropped by 90 percent. It is recommended that all transfused sickle cell anemia patients be antigen matched for E, C, and Kell. Patients should be closely monitored during transfusions to avoid preventable risks.     

The effect of two additive solutions on the postthaw storage of RBCs

BACKGROUND: Sterile systems for freezing and for washing thawed blood will allow the storage of RBCs for more than 24 hours after removal of the cryoprotectant glycerol. This study assessed the effect of two ASs in maintaining deglycerolized RBCs. STUDY DESIGN AND METHODS: Twenty-four RBC units were stored for 6 days, pooled in groups of 4, realiquoted, sterilely glycerolized, and frozen. One month later, the units were thawed, sterilely deglycerolized by using an automated system (H215; Haemonetics), and stored for 5 weeks in either 100 or 200 mL of AS-3 or an experimental AS (EAS-61). Sterile samples were taken weekly for chemical and morphometric analysis. RESULTS: The glycerolization and deglycerolization process produced highly comparable RBC units, but it caused a marked reduction of RBC pH, to about 6.4 at the beginning of storage. The addition of acidic AS-3 further reduced the pH, which in turn reduced glucose consumption, lactate formation, and RBC ATP concentrations. Alkaline EAS-61 increased these measures. Hypotonic EAS-61 caused increased cell swelling and hemolysis, despite better RBC morphology. CONCLUSIONS: Automation of sterile glycerolization and deglycerolization with the H215 works well, but the solutions should be reformulated for extended postthaw storage. This would best be accomplished by raising the pH of the wash solutions by the addition of disodium phosphate or sodium bicarbonate or both, by using alkaline ASs, and by matching the osmolality of the wash solution and ASs.     

RBC transfusion and postoperative length of stay in the hospital or the intensive care unit among patients undergoing coronary artery bypass graft surgery: the effects of confounding factors

BACKGROUND: Data on the independent association between perioperative allogeneic blood transfusion (ABT) and postoperative length of stay at the hospital or in the intensive care unit (ICU) are sparse. STUDY DESIGN AND METHODS: The records of 421 consecutive patients undergoing coronary artery bypass graft (CABG) operations at the Massachusetts General Hospital were reviewed. The effect of perioperative ABT in explaining the variation in the postoperative length of stay (LOS) at the hospital or in the ICU was calculated after adjustment for the effects of 20 confounding factors that pertained to severity of illness, difficulty of operation, and risk of postoperative wound infection or pneumonia. RESULTS: Postoperative LOS averaged (mean +/- SE) 8.0 +/- 0.3 days in the hospital and 50.0 +/- 4.1 hours in the ICU. After adjustment for the effects of confounding factors, the postoperative length of hospitalization increased by 0.837 percent (95% CI, 0.249-1.425%) per RBC unit transfused (p<0.001), and the postoperative length of stay in the ICU increased by 0.873 percent (95% CI, -0.068-1.814%) per RBC unit transfused (p<0.10). CONCLUSION: Allogeneic blood transfusion was independently associated with longer postoperative stays in the hospital or the ICU, but the observed independent association is perhaps too small to be clinically relevant. This independent association may be due to a relationship between ABT and a higher incidence of septic complications of surgery, or it may reflect the function of blood transfusion as a surrogate marker for severity of illness.     

The utility of < or =3-day-old whole-blood platelets in reducing the incidence of febrile nonhemolytic transfusion reactions

BACKGROUND: Febrile nonhemolytic transfusion reactions (FNHTRs) to platelet transfusions have been linked to the presence of cytokines in supernatant plasma. Cytokine concentration is directly related to WBC content and storage time. This study evaluated the effect of limiting the storage time of random-donor platelet concentrates on the FNHTR rate. STUDY DESIGN AND METHODS: FNHTR rates were calculated retrospectively for single-donor apheresis platelet (SDP) and pooled random-donor platelet (PP) transfusions given during three consecutive 5-month study periods (November 1995 to February 1997) to patients on a single hematology/oncology/bone marrow transplant unit. Transfusion practice policies were: Baseline Period, SDPs preferred; Study Period A, PPs preferred; and Study Period B, < or =3-day-old PPs preferred. FNHTR rates were calculated from physicians' interpretations of reported reactions and the total number of SDP and PP transfusions in each period. SDPs were collected on two cell separators. All platelet components were filtered at issue in the laboratory by WBC-reduction filters. RESULTS: FNHTR rates for PP transfusions were: baseline, 11.1 percent (3/27); Study Period A, 4.6 percent (22/481); and Study Period B, 1.1 percent (3/282). The rates for SDP transfusions were 0. 15 percent (1/650), 0.75 percent (2/267), and 0.36 percent (1/273), respectively. The FNHTR rate for < or =3-day-old PPs was significantly less than the rate for older PPs (p = 0.0086 for Study Period A vs. Study Period B), and was not significantly different than that for SDPs (p = 0.33 for PPs vs. SDPs in Study Period B). CONCLUSION: Limiting transfusion of PPs to those stored 相似文献   

The expression of NA antigens in people with unusual Fcgamma receptor III genotypes

BACKGROUND: The Fcgamma receptor IIIb (FcgammaRIIIB) genes that encode neutrophil-specific antigens NA1 and NA2 differ at 5 nucleotides (nts); in 4, the result is an amino acid (AA) difference between the two alleles. The role of each of these differences in antigen expression is not known. Persons with FcgammaRIIIB genes that differ from NA1-FcgammaRIIIB and NA2-FcgammaRIIIB by 1 nt have been described. This study compared NA1 and NA2 expression on granulocytes in persons with variant FcgammaRIIIB genes and in healthy blood donors. STUDY DESIGN AND METHODS: Reactions of NA1- and NA2-specific MoAbs and alloantibodies with granulocytes were assessed by flow cytometry in 74 healthy blood donors and 6 persons with known variant FcgammaRIIIB genes. The granulocytes were tested with 1 NA1-specific MoAb, 1 NA2-specific MoAb, 4 NA1-specific alloantibodies, and 4 NA2-specific alloantibodies. RESULTS: Analysis of granulocytes from persons with variant NA genotypes found that single-base substitutions in FcgammaRIIIB at 141 and at 349 are important in NA1 expression and those at 227 and 277 are important in NA2 expression. Among blood donors, neither age, sex, nor race affected the expression of NA1 or NA2. The NA2-specific MoAb reacted more intensely with granulocytes from NA2-double-dose cells than with those from NA-single-dose cells, but this was not true for the NA2-specific alloantibodies. There was no difference in the reactions of the NA1-specific MoAbs and alloantibodies with donor samples of known NA1-double-dose or NA-single-dose cells. The intensity of reactions of both the NA1- and NA2-specific MoAbs and alloantibodies were strongly correlated on double-dose cells but not on single-dose cells. In fact, granulocytes from 7 healthy blood donors, phenotyped as NA-single-dose with the MoAbs, were phenotyped as NA2-double-dose with the alloantibodies. Variations in FcgammaRIIIB are common in blacks, but 5 of the 6 donors were white. These results suggest that FcgammaRIIIB variations may be common in both whites and blacks. CONCLUSIONS: NA2 expression is affected by polymorphisms in FcgammaRIIIB 227 and FcgammaRIIIB 277, both of which are involved in an FcgammaRIIIb N-glycosylation site. Polymorphisms in FcgammaRIIIB at 141 and 349 appear more important to NA1 expression.     

Longitudinal monitoring of WBC subsets in packed RBC units after filtration: implications for transfusion transmission of infections

BACKGROUND: Specific subsets of peripheral blood WBCs are reservoirs for infectious agents, such as CMV and EBV, and can serve as vectors for transfusion transmission of these agents. While filter WBC reduction has been used to prevent transfusion transmission of infections, its effectiveness has not been documented for many infectious agents and in some instances may be difficult to demonstrate in clinical trials. Because the effectiveness of filtration depends on the number of infected WBCs remaining at transfusion, WBC subpopulations in packed RBC units were quantitated after filtration and storage. STUDY DESIGN AND METHODS: Packed RBC units (n = 14) were filtered and stored at 4(o)C for 42 days or were stored without filtration. Serial samples were subjected to flow cytometric immunophenotyping of WBC subsets: neutrophils, monocytes, CD4+ and CD8+ T cells, B cells, and NK cells. RESULTS: Filtration produced a mean reduction in total WBCs of 3.2 log. Monocytes, lymphocytes, and neutrophils were reduced by 4.1, 3.8, and 2.5 log, respectively. Lymphocyte subsets also demonstrated differential reduction with filtration. All WBC subsets showed ongoing loss during storage. CONCLUSIONS: Monocyte and lymphocyte subsets are removed most effectively by prestorage filtration. Postfiltration storage leads to further significant reductions in WBC subsets. The implications of these findings for the mitigation of transfusion transmission of infection are discussed.     

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.     

Variations in genes encoding neutrophil antigens NA1 and NA2

BACKGROUND: Neutrophil-specific antigens NA1 and NA2 are located on Fcgamma receptor IIIb (FcgammaRIIIb). NA1 and NA2 forms of FcgammaRIIIb differ by four amino acids and the corresponding genes by five nucleotides. Variations in NA gene frequencies are encountered among ethnic groups. Altered forms of the genes are expected among individuals. STUDY DESIGN AND METHODS: RFLPs associated with four recognition sites were used to determine NA genotypes of 232 individuals. When atypical NA genotypes were identified, FcgammaRIIIB and FcgammaRIIIA regions were sequenced. RESULTS: NA1 FcgammaRIIIB frequency in 100 Japanese (0.66) was greater than that in 53 African Americans (blacks) (0.40; p<0.01) and 79 whites (0.32; p<0.001). Sequencing of atypical FcgammaRIIIB in 16 people confirmed that four blacks had G-->A substitutions at 227; 7 blacks had A-->G substitutions at 277; and 1 Japanese person had C-->G at 141 and G-->T at 227. A at 227 and G at 277 represent expected nts of NA1 FcgammaRIIIB. One black had an NA1 FcgammaRIIIB with a G-->A substitution at 349; A is normally found in NA2 FcgammaRIIIB at 349. Sequencing atypical FcgammaRIIIA in three persons revealed that two blacks had G-->A substitutions at 277 plus C-->A substitutions at 266 and 1 white had previously described T-->G at 230. Two blacks with atypical NA2 FcgammaRIIIB had T-->G FcgammaRIIIA at 230. One black was NA(null). CONCLUSION: NA2 FcgammaRIIIB is more polymorphic in blacks than in whites or Japanese persons. Chimeric FcgammaRIIIB alleles are most similar to NA2 FcgammaRIIIB. One alternate allele of NA1 (NA1*02) and four alternate alleles of NA2 (NA2*02, NA2*03, NA2*04, and NA2*05) are described.