Reactions and platelet increments after transfusion of platelet concentrates in plasma or an additive solution: a prospective, randomized study

BACKGROUND: Reactions after platelet transfusions are rather common and frequently are caused by plasma constituents. In recent developments, the preparation and storage of platelet concentrates (PCs) in a platelet additive solution (PAS-2) have been shown to result in acceptable storage conditions. A major drawback of the use of these PCs is the progressive increase of P-selectin-positive platelets during storage. The clinical benefit of transfusions of PCs in PAS-2 was studied. STUDY DESIGN AND METHODS: PCs prepared from buffy coats were suspended in either plasma or PAS-2 and stored for up to 5 days. Clinical responses were evaluated in a prospective study in 21 patients treated with intensive chemotherapy for hematologic malignancies. Eligible patients were randomly assigned to receive prophylactic transfusions of PCs prepared in either plasma or PAS-2. Reactions and CCIs were recorded after each transfusion. RESULTS: The incidence of reactions in 12 patients given PCs in plasma (n = 192) was 12 percent. Transfusions to 9 patients of PCs in PAS-2 (n = 132) showed a reduction in the incidence of reactions to 5.3 percent (p<0.05). The average 1-hour and 20-hour CCIs after transfusion of PCs in plasma were 20.7 +/- 8. 5 and 11.5 +/- 8.0, respectively. CCIs after transfusion of PCs in PAS-2 were significantly lower: the average 1-hour CCI was 17.1 +/- 6.6 (p<0.001) and the average 20-hour CCI was 9.5 +/- 7.0 (p<0.05). Storage conditions of PCs were optimal: in each group, average 1-hour CCIs of both fresh and stored PCs were similar. The 20-hour CCIs after the transfusion of fresh and stored PCs in PAS-2 also were similar. CONCLUSION: Transfusion of PCs in PAS-2 significantly reduces the incidence of reactions. The 1-hour and 20-hour CCIs after transfusion of PCs in PAS-2 were significantly lower than the CCIs after transfusion of PCs in plasma. Because storage conditions of both PCs were found to be optimal, the decrease in CCIs after transfusion of PCs prepared in PAS-2 may be caused by rapid elimination of a subpopulation of P-selectin-positive platelets from the circulation.     

Development of non‐ABO RBC alloantibodies in patients undergoing allogeneic HPC transplantation. Is ABO incompatibility a predisposing factor?

BACKGROUND: Data from the appearance of RBC antibodies other than ABO in patients undergoing HPC transplantation are limited. STUDY DESIGN AND METHODS: The incidence and specificity of non-ABO RBC alloantibodies are described in a series of 217 patients undergoing allogeneic HPC transplantation because of various hematologic malignancies. RESULTS: Eight patients (3.7%) developed 10 antibodies after transplant. None of these patients had previously been immunized. Seven patients had one RBC antibody and one patient had three RBC antibodies. Antibody specificity were anti-Jk(b) (2 patients), -Kell (2), -M (2), -Le(b) (1), and -D (1). Finally, two patients had a panagglutinin. The mean time between transplant and antibody detection was 23 days (range, 16-672). The source of the HPCs, the conditioning regimen administered, and the type of GVHD prophylaxis administered did not influence the rate of antibody formation. On multivariate analysis, ABO blood group incompatibility (p = 0.005) and patient's age (p = 0.02) were the only two variables significantly associated with the development of RBC alloantibodies. CONCLUSION: Patients undergoing allogeneic HPC transplantation are at risk of developing RBC-specific antibodies despite the immunosuppressive therapy administered. Antibody formation was more frequently observed in ABO-mismatched cases, which suggests a potential role of this incompatibility in facilitating antibody production.     

Transfusion of buffy coat-depleted blood components and risk of postoperative infection in orthopedic patients

BACKGROUND: Allogeneic blood transfusions have been reported to increase susceptibility to postoperative infection, but the findings were inconclusive. This study was designed to investigate the effect of buffy coat-depleted allogeneic and autologous transfusion on postoperative infection in patients undergoing orthopedic surgery. STUDY DESIGN AND METHODS: Patients (n = 385) undergoing elective orthopedic surgery (primary and revision joint replacement, spinal, or pelvic surgery) were included in a prospective observational study of the incidence of postoperative infection between April and December 1996. Infection rates in patients who received allogeneic buffy coat-depleted blood transfusions were compared with those in patients who received no transfusion or only autologous (buffy coat-depleted) blood. RESULTS: Patients without exposure to allogeneic blood (no blood or only autologous blood) had an infection rate of 3.9 percent, as compared to a rate of 12.2 percent for those with exposure to allogeneic blood (allogeneic blood, autologous plus allogeneic blood) (odds ratio 3.442; 95% CI, 1.349-10.40; p = 0.006). Of the 385 study patients, 309 underwent primary hip or knee replacement surgery. In this homogeneous subgroup, the postoperative infection rate was 4.6 percent after no transfusion or autologous transfusion and 11.9 percent after allogeneic transfusion (odds ratio 2.827; 95% CI 1.059-8.799; p = 0.036). Multivariate regression analysis confirmed buffy coat-depleted allogeneic blood transfusion as an independent variable associated with high risk for postoperative infection. CONCLUSION: Buffy coat-depleted allogeneic blood transfusion increases the incidence of postoperative infection in patients undergoing uncontaminated orthopedic surgery.     

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.     

Platelet transfusion refractoriness associated with HPA-1a (Pl(A1)) alloantibody without coexistent HLA antibodies successfully treated with antigen-negative platelet transfusions

BACKGROUND: Alloimmune-mediated refractoriness to platelet transfusion is most commonly due to antibody to HLA antigens in multiply transfused or multiparous patients. Published reports of poor transfusion response due to antibodies to platelet-specific antigens are rare and often confounded by the presence of coexistent antibodies against HLA antigens. CASE REPORT: A case is presented of a multiparous woman with acute myelogenous leukemia whose sole cause of transfusion refractoriness was antibody to platelet antigen HPA-1a. She responded dramatically to HPA-1a-negative platelet transfusion. CONCLUSION: This case provides strong serologic and clinical evidence that platelet transfusion refractoriness may result from antibodies to platelet-specific antigens.     

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.     

Assessment of blood administration procedures: problems identified by direct observation and administrative incident reporting

BACKGROUND: Adverse events in blood administration frequently involve the identification of transfusion recipients or components. This report details the results of an investigation of the efficacy of direct observation and that of a hospital-wide incident-reporting system in detecting standard operating procedures (SOPs) for deviations in blood administration. STUDY DESIGN AND METHODS: A process-driven audit form targeting 19 blood administration steps was developed for direct observation monitoring of blood administration. Over 18 months, 202 transfusions were observed in selected hospital locations. Data from this audit were compared with data collected from the incident reporting system. RESULTS: Through direct observation, 334 events were identified for a rate of 1.65 SOP deviations per transfusion. The incident reporting system identified 52 adverse events. Deviations were categorized as being related to the patient or component information, transfusion, patient monitoring, record documentation, and ordering or delivery of the component. Fifty-five percent of the events detected with direct observation related to identification of the patient or component, compared with 17 percent of incident reports. Using direct observation, 9 percent of transfused patients had wristband identification deviations. Such SOP deviations were not detected with the incident reporting system. Transfusion SOP deviations represented 15 percent of direct observation reports and 38 percent of incident reports. Direct observation identified deviations in monitoring practices and record documentation not detected by incident reporting. CONCLUSION: Direct observation appears to be an effective means for identifying deviations related to patient identification, patient monitoring, and record documentation.     

Patients with neoplastic and nonneoplastic hematologic diseases acquire CTLA-4 antibodies after blood transfusion

BACKGROUND: The presence of antibodies to CTLA-4, a negative regulator of T-cell activation, was investigated in multiply transfused patients with malignant and non- malignant hematologic diseases. A previous study showed that, in multiply transfused patients, an immune response against nuclear matrix proteins can be induced by WBCs undergoing apoptosis during RBC unit storage. This study evaluated whether the same phenomenon could be involved in the induction of CTLA-4 antibodies in the patients analyzed. STUDY DESIGN AND METHODS: Patient sera were tested for binding to the recombinant full-length CTLA-4 beta-galactosidase fusion protein by an ELISA. Immuno-fluorescence stainings were performed to analyze the CTLA-4 epitopes recognized by the antibodies and to detect such epitopes in the apoptotic cells present in the RBC units. RESULTS: CTLA-4 antibodies were found in multiply transfused patients with beta-thalassemia (40%) and with other hemolytic diseases (33%) including leukemias (42%). A higher incidence of CTLA-4 antibodies was found in patients receiving non-WBC-reduced blood (88%) than in those receiving WBC-reduced blood (26%). Immunofluorescence staining showed that WBCs undergoing apoptosis in the RBC unit expressed CTLA-4 epitopes. CONCLUSIONS: The apoptotic WBCs present in the RBC units, after cold storage, express CTLA-4 epitopes. These epitopes can be released and induce formation of CTLA-4 antibodies with profound implications in the development of autoimmune disorders and in facilitating tumor dissemination and metastasis.     

Platelet alloantibodies in transfused patients

BACKGROUND: Patients receiving cellular blood components may form HLA antibodies and platelet-specific alloantibodies. STUDY DESIGN AND METHODS: Serum samples from a cohort of 252 patients with hematologic or oncologic diseases who are receiving cellular blood components were studied for platelet-reactive antibodies. Specificity of platelet alloantibodies was determined with a panel of typed platelets RESULTS: Platelet-reactive antibodies were detected in the sera of 113 patients (44.8% of 252), HLA antibodies in the sera of 108 (42.9%), and platelet-specific antibodies in the sera of 20 (8%). The following platelet-specific antibodies were identified: anti-HPA-5b (n = 10), anti-HPA-1b (n = 4), anti-HPA-5a (n = 2), anti-HPA-1a (n = 1), anti-HPA-2b (n = 1), anti-HPA-1b+5b (n = 1), and anti-HPA-1b+2b (n = 1). Fifteen sera from the 108 patients with anti-HLA (13.9%) contained additional platelet-specific alloantibodies, while in 5 sera, platelet-specific alloantibodies only were detected: anti-HPA-5b (n = 4) and anti-HPA-1a (n = 1). Of the 108 sera with HLA antibodies, 29 (26.9%) showed discordant results when studied with the lymphocytotoxicity test and the glycoprotein-specific immunoassay. Ten sera contained panreactive antibodies against platelet glycoproteins (GP) IIb/IIIa, GPIa/IIa, and/or GPIb/IX. Alloimmunization occurred in 58.3 percent of female patients with previous pregnancies, but in only 23.3 percent of those without previous pregnancies (p = 0.0049). CONCLUSION: Platelet alloantibody specificities in transfused patients (predominantly anti-HPA-5b and -1b with antigen frequencies <30% among whites) differ significantly from those observed in patients with neonatal alloimmune thrombocytopenia or posttransfusion purpura, in whom anti-HPA-1a (antigen frequency >95%) is the most prevalent specificity. HLA antibody detection yields discordant results when the lymphocytotoxicity assay and a glycoprotein-specific immunoglobulin-binding assay are used.     

Immunoglobulin administration to fetuses with anemia due to alloimmunization to D

BACKGROUND: The purpose of this study was to examine fetal tolerance of high-dose intravenous immunoglobulin (IVIG), given directly at the time of intravascular transfusion, and its effects on fetal hemolysis and pregnancy outcome in the setting of alloimmunization to D.
STUDY DESIGN AND METHODS: Thirteen consecutive D+ fetuses requiring transfusion for maternal alloimmunization received high-dose IVIG (1.0 g/kg) and red cell transfusions. Twenty-four previous, consecutive fetuses with maternal anti-D served as controls. The schedules for subsequent transfusions were the same in the two groups.
RESULTS: High-dose IVIG was well tolerated by all fetuses. In the IVIG group, daily decreases in hematocrit were smaller than those in controls after the second administration of IVIG (mean hematocrit decrease, 0.72 percent/day vs. 1.45 percent/day; p = 0.007). No significant difference was found in the total number of fetal transfusions, the gestational age at delivery, the duration of neonatal intensive care, the number of neonates requiring postnatal transfusion therapy, and perinatal mortality.
CONCLUSION: In this small pilot study, direct administration to fetuses of IVIG with red cell transfusions was well tolerated and appeared to have a beneficial effect on fetal hemolysis.     

Blood transfusion in a random sample of hospitals in France

BACKGROUND: Representative information on blood use is scarce. A large-scale study of blood recipients and blood use in France was conducted. STUDY DESIGN AND METHODS: Based on a random sampling, this study was carried out in teaching and other hospitals between March and December 1997. In each hospital, a patient was included if he or she received an allogeneic or an autologous transfusion during the observation period for that hospital. For each recipient, product and patient characteristics for 24 hours after inclusion were collected. RESULTS: From the 175 hospitals that had given a transfusion to at least one patient during the observation period, 3206 patients were included. Most transfusion recipients (57%) were over 65 years old; 42 percent were in teaching hospitals and 53 percent in medical wards. Among the 3044 adults, 91 percent received an allogeneic transfusion. Fifty-three percent of allogeneic units were WBC reduced. The indications most frequently reported for allogeneic transfusion were neoplasms (48%) and those for autologous transfusion were disorders of musculoskeletal (63%) or circulatory (15%) systems. The patients in nonteaching hospitals were more often transfused during surgery and were more likely to be aged and to have a musculoskeletal disorder than were patients in teaching hospitals. CONCLUSION: General collection of such data, within a system of traceability, could provide relevant denominators from which to interpret adverse-reaction data.     

Single-donor platelets reduce the risk of septic platelet transfusion reactions

BACKGROUND: Septic platelet transfusion reactions (SPTRs) are the most common, serious risk of transfusion. Because SPTRs result from donor skin flora or asymptomatic bacteremia, the use of single-donor platelets (SDPs) has been proposed to reduce the risk of SPTRs from the risks with pools of platelet concentrates (PCs). STUDY DESIGN AND METHODS: Beginning in 1986, all febrile transfusion reactions were evaluated by culture of the platelet bag. Confirmed SPTRs were identified by isolation of the same bacteria from the bag and the patient's blood or by positive Gram's stain of the bag that confirmed a positive platelet culture. In 1987, a program to minimize PC use in favor of SDP use was initiated as a means of reducing SPTRs. RESULTS: In 12 years, the use of SDPs increased from 51.7 percent to 99.4 percent of all platelet transfusions at one institution. SPTRs fell from three events in 1 year to the current rate of one event per year. The incidence of SPTRs decreased from 1 in 4,818 transfusions to 1 in 15,098 transfusions. The rate of SPTRs due to PCs was 5.39 times higher than that of SPTRs due to SDPs (95% CI, 1.89,12.9). CONCLUSION: The use of SDPs is a simple means of reducing SPTRs. Other measures such as sterilization will be required to eliminate all SPTRs.     

Antibodies to private and public HLA class I epitopes in platelet recipients

BACKGROUND: Transfusions or pregnancies can cause immunization against private HLA determinants and public epitopes shared by more than one private HLA antigen. HLA antibodies are correlated with febrile transfusion reactions, lower platelet response following platelet transfusion, and an increased rate of renal transplant rejection. Until now, antibody specificities in alloantisera from platelet recipients have been poorly characterized. STUDY DESIGN AND METHODS: Consecutive serum screens from platelet recipients were analyzed for antibodies against private HLA class I antigens and public HLA epitopes using a serum analysis program based on the 2 x 2 table analysis of correlations. Serum screens of highly immunized patients and of patients with new alloimmunization events were reviewed separately. RESULTS: Of the serum screens from 566 platelet recipients, 1577 indicated alloimmunization (panel-reactive antibodies >5%). The program assigned a specificity in 1024 of these screens (64.9%) and at least once in 522 of 566 patients (92.2%). In 267 patients, antibodies detecting public epitopes in the combined A- or B-locus cross-reacting groups were found; other public markers were detected in 39 patients. Patterns of reactivity were remarkably less stable than in patient groups previously studied. In many patients, antibodies with apparent private epitope specificity preceded the identification of antibodies against a shared marker of the same cross-reactive group. However, the disappearance of antibodies (whether or not this was followed by a new antibody against a private or public marker belonging to another cross-reacting group) was also observed. CONCLUSION: The computerized analysis of microlymphocytotoxicity tests enhances the rate of antibody specification in sera from platelet recipients with lymphocytotoxic antibodies. The identified antibodies should be taken into account in the selection of platelet donors. The data confirm and extend previous observations on HLA class I antibodies and elucidate new alloimmunization events.     

Incidence of red cell antibodies after multiple blood transfusion

A retrospective study was performed to estimate the frequency of alloimmunization against red cell (RBC) antigens in a multiply transfused group. Patients (n = 186) were studied who had received at least six blood transfusions during a period of at least 3 months. Some 6944 units of blood were transfused. One hundred forty patients had hematologic disorders. The patients' sera were investigated every 3 months with indirect antiglobulin tests and enzyme-treated RBCs. Twenty-two patients (11.8%) made 33 antibodies. Seven patients made more than one antibody. Eight of the 22 patients (36.4%) made their first antibody before or at the 10th transfusion. The risk of immunization increased with the number of transfusions. Influence of gender and age was not demonstrable. Nor was a relationship demonstrated between blood transfusion reactions and RBC antibody formation; no delayed hemolytic transfusion reactions occurred. Anti-E was demonstrated in 12 patients and anti-K in 15. When the gene frequencies were taken into account, it appeared that anti-E was made by 11.5 percent of E-negative patients, most of whom were immunized after an estimated three transfusions with E-positive blood. Anti-K was made by 8.7 percent of the K-negative patients, after an estimated 2.1 units of K-positive blood. It might be desirable to match red cell units for the E and K antigens in patients at relatively high risk. These are primarily patients who have already formed an antibody and are going to receive many transfusions and women of childbearing age who are to receive more than 4 units of blood.     

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   

Immunoglobulin administration to fetuses with anemia due to alloimmunization to D

BACKGROUND: The purpose of this study was to examine fetal tolerance of high-dose intravenous immunoglobulin (IVIG), given directly at the time of intravascular transfusion, and its effects on fetal hemolysis and pregnancy outcome in the setting of alloimmunization to D. STUDY DESIGN AND METHODS: Thirteen consecutive D+ fetuses requiring transfusion for maternal alloimmunization received high-dose IVIG (1.0 g/kg) and red cell transfusions. Twenty-four previous, consecutive fetuses with maternal anti-D served as controls. The schedules for subsequent transfusions were the same in the two groups. RESULTS: High-dose IVIG was well tolerated by all fetuses. In the IVIG group, daily decreases in hematocrit were smaller than those in controls after the second administration of IVIG (mean hematocrit decrease, 0.72 percent/day vs. 1.45 percent/day; p = 0.007). No significant difference was found in the total number of fetal transfusions, the gestational age at delivery, the duration of neonatal intensive care, the number of neonates requiring postnatal transfusion therapy, and perinatal mortality. CONCLUSION: In this small pilot study, direct administration to fetuses of IVIG with red cell transfusions was well tolerated and appeared to have a beneficial effect on fetal hemolysis.     

Efficacy of donor screening for HTLV-I and the natural history of transfusion-transmitted infection

BACKGROUND: It has been 10 years since the implementation in Japan of donor blood screening for human T-cell lymphotropic virus type I (HTLV-I). This report reviews the effectiveness of screening in preventing transmission of HTLV-I through blood transfusion and the current status of patients with confirmed seroconversion due to transfusions given before the implementation of screening. STUDY DESIGN AND METHODS: Patients who received blood at Kyushu University Hospital from 1990 to 1997 were followed. Serum samples were collected before transfusion and 60 days or more after transfusion. Seroconversion was determined by a second-generation particle agglutination test. Confirmation tests were an immunofluorescence assay, enzyme-linked immunosorbent assay, and immunoblotting. Confirmed seroconverted patients were followed by a search of hospital records. RESULTS: Seroconversion was found in one of 4672 transfused patients, but the donor was identified and confirmed to be negative for anti-HTLV-I and virus genome by nested polymerase chain reaction. A total of 23,323 red cell concentrates and 17,237 platelet concentrates were transfused to these 4672 patients. Therefore, the anti-HTLV-I prevalence in blood for transfusion after screening was estimated at 1 in 45,560 (0.0022%; the upper 95% CI was 0.0080%). One hundred two seroconverted patients who were transfused before donor screening for HTLV-I were followed. One patient developed HTLV-I-associated myelopathy, diagnosed 18 weeks after seroconversion, and another patient developed uveitis 1 month after seroconversion. No patients developed adult T-cell lymphoma, and the survival rate of seroconverted patients was 92.5 percent 15 years after transfusion. CONCLUSION: This study confirmed that the present donor screening program for HTLV-I by the new particle agglutination test can almost completely prevent virus transmission by transfusion. Complications of HTLV-I transmission were at lower rates than expected.     

Antibodies provoked by the transfusion of biotin-labeled red cells

BACKGROUND: Biotin-labeled (biotinylated) red cells (B-RBCs) offer a technique by which to study RBC volume and circulating kinetics without in vivo radiation. The immunogenicity of B-RBCs is undefined. STUDY DESIGN AND METHODS: To determine if biotinylation renders RBCs immunogenic, autologous B-RBCs were transfused to 20 healthy subjects, and plasma samples were obtained before transfusion and serially for up to 6 months after transfusion. These serial samples, plus plasma from 20 normal control subjects not given B-RBCs, were screened for antibodies to B-RBCs by use of an antiglobulin technique against aliquots of group O RBCs from a single donor-one aliquot biotinylated and one aliquot not biotinylated (i.e., test and control RBCs). Posttransfusion recovery and survival of B-RBCs were also determined. RESULTS: Plasma from none of 20 normal nontransfused subjects reacted with B-RBCs. Similarly, none of the 20 subjects given autologous B-RBC transfusions exhibited antibodies before transfusion. However, 3 of the 20 subjects transiently produced antibodies to B-RBCs after transfusion. Antibodies disappeared within 6 months in 2 of these 3 subjects and within 12 months in the third. Antibody reactivity was not reduced by dithiothreitol, but in 2 of the 3 subjects, B-RBC antibodies were neutralized by incubation with biotin solution. Circulating RBC kinetics were not altered in the 3 subjects with antibody. The significance of these observations is unclear, because antibodies were just beginning to emerge during the studies. CONCLUSIONS: Biotinylation does not render RBCs reactive with normal human plasma (i.e., presumably does not evoke neoantigens). Transfused B-RBCs occasionally provoke IgG antibodies in healthy subjects. Because the biologic effects of B-RBC antibodies currently are unknown, testing for them is recommended when multiple B-RBC transfusions are given to study RBC volume or circulating kinetics.     

The importance of antibodies against low-incidence RBC antigens in complete and abbreviated cross-matching

BACKGROUND: It is common practice to perform an antiglobulin cross-match only when unexpected RBC alloantibodies are present, to detect antibodies against additional RBC antigens. In this study, the incidence of unexpected antibodies to low-incidence antigens (Ab-LIA) over a period of 23 years was investigated. STUDY DESIGN AND METHODS: Records of RBC antibodies and the accompanying transfusion history from 1978 through 2000 was retrospectively examined. Complete cross-matches were performed for all RBC transfusions before 1991. As of 1991, the type-and-screen policy was applied. To study the incidence of anti-Wra, a prospective study was conducted on sera from 462 patients sent to the transfusion laboratory and 486 blood donors. RESULTS: The records of 1795 patients containing 2257 RBC antibodies were examined. In 89 patients, a total of 94 Ab-LIAs was found. Anti-Wra was the most frequently encountered Ab-LIA. Thirty-nine patients had Ab-LIA in combination with other antibodies, 20 of which were autoantibodies. Eighty percent of these Ab-LIA were found at the first positive antibody screening test. Fifty-one solitary Ab-LIA were found in 50 patients, 37 during antibody screening tests, and 14 after positive complete cross-matches conducted before 1991. After an RBC antibody was detected, 664 patients received a total of 7792 RBC transfusions. Since the introduction of the type-and-screen policy, only one anti-Wra has been discovered during complete cross-matching. No transfusion reactions due to Ab-LIA were reported during the study period. In the prospective study, 12.3 percent of patients and 4.3 percent of blood donors had anti-Wra. CONCLUSIONS: Although Ab-LIAs are found coincidentally in the sera of only 2 to 3 percent of patients with other RBC antibodies, they are formed often. Because we found no difference in serologic incompatibility, due to Ab-LIAs, between patients with and without other blood group antibodies, we conclude that blood can be transfused safely to patients without performing a complete cross-match.     

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.