RESUMEN
BACKGROUND: Most very low birth weight (<1.0 kg) infants receive RBC transfusions. Several reports have demonstrated that RBCs stored up to 42 days can be transfused safely in small volumes to preterm infants to decrease donor exposure without consequent hyperkalemia, acidosis, or other adverse effects. Although biologic parents are likely candidates as donors of blood for their neonates, it has been suggested that their blood may be serologically incompatible with that of their infants. STUDY DESIGN AND METHODS: A two-arm randomized study was conducted to compare the feasibility and immediate safety of two single-donor programs for providing small-volume RBC transfusions to preterm infants: in one arm, infants received RBCs collected from unrelated donors and stored up to 42 days, and in the other arm, RBCs were collected from one of the biologic parents and stored identically. All infants received compatible RBCs that were WBC reduced before storage, stored in AS-3, and gamma-radiated. All transfusions were given uniformly as 15 mL per kg of RBCs transfused over 5 hours, during which time the infants were closely observed for clinical reactions. In addition, laboratory studies were performed shortly before and after each transfusion. RESULTS: A total of 40 preterm infants received 120 RBC transfusions. Biologic parents experienced several donor eligibility problems. However, once enrolled as donors, they were able to supply all RBCs needed by their infants. Significant differences in rates of clinical transfusion reactions and laboratory abnormalities were rare and had no apparent clinical importance, regardless of whether RBCs were donated by biologic parents or unrelated donors. CONCLUSION: A single-donor system, in which AS-3 RBCs were collected either from unrelated blood donors or from biologic parents and then stored up to 42 days, was able to supply small-volume RBC transfusions needed by individual preterm infants without immediate, adverse effects. Because the risk of infectious disease transmission is likely reduced by limiting donor exposure, it is logical to conclude that single-donor programs should increase transfusion safety and that biologic parents should be considered as blood donors for their infants.
Asunto(s)
Donantes de Sangre , Transfusión de Eritrocitos/normas , Recien Nacido Prematuro/sangre , Padres , Femenino , Humanos , Recién Nacido , MasculinoRESUMEN
BACKGROUND: Preterm infants are among the most heavily transfused of patient groups, yet multiply transfused infants only rarely produce alloantibodies against RBC or WBC antigens. It is not known whether rates of alloimmunization might be increased by repeated exposure to RBCs and WBCs from the same donor, as in limited-donor-exposure programs, or whether infants might benefit from WBC-reduced RBC components as a means of diminishing the risk of possible alloimmunization. STUDY DESIGN AND METHODS: Preterm infants (birth weight 0.6-1.3 kg) received prestorage WBC-reduced RBCs from dedicated donors, collected in AS-3 as a means of limiting donor exposures. Blood samples were collected serially from infants shortly after birth until either discharge or age 6 months and were studied for RBC and WBC antibodies-the latter with reactivity against either HLA class I or neutrophil-specific antigens. RESULTS: Thirty preterm infants received 139 transfusions (mean, 4.6; median, 4 transfusions per infant), with 81 percent of transfusions obtained from one donor per infant. Eighty-four blood samples (mean, 2.7/infant) were studied, and no infant produced RBC antibodies. Twenty-seven percent of infants exhibited WBC antibodies, but only 13 percent actually produced WBC antibodies (passive maternal antibody excluded). Of the WBC antibodies produced by infants, three were against HLA class I and one was against neutrophil-specific antigens; none were linked to adverse effects. CONCLUSIONS: Because infants only rarely produce RBC antibodies, no changes in blood banking practices are necessary for limited-donor-exposure programs. Although the production of WBC antibodies by infants occurs, it seems to be uncommon; thus, the possible benefits, if any, of WBC reduction are uncertain, and further study is required before changes in practice can be justified.
Asunto(s)
Donantes de Sangre , Transfusión de Eritrocitos , Recien Nacido Prematuro/sangre , Recien Nacido Prematuro/inmunología , Isoanticuerpos/sangre , Isoanticuerpos/inmunología , Transfusión de Leucocitos , Recuento de Eritrocitos , Humanos , Inmunización , Recién NacidoRESUMEN
BACKGROUND: Very-low-birthweight infants have typically been given fresh red cells (RBCs), a practice in which aliquots of RBCs for several infants were issued each day from a single unit. Recently, to limit donor exposures, large volumes of RBCs are reserved for the long-term transfusion support of individual infants. STUDY DESIGN AND METHODS: Medical records were examined retrospectively to assess the costs of a limited-donor program for providing RBC transfusions to very-low-birthweight infants. Costs of multiple- and limited-donor programs were compared by using two samples of 30 consecutive infants treated at The University of Iowa Hospitals and Clinics in 1993 and 1997. Effectiveness was evaluated with respect to the number of donor exposures per infant. RESULTS: The cost, in 1997 dollars, of preparing each small-volume transfusion in the multiple-donor program was $27.86 per transfusion, while that in the limited-donor program was $34.83. This difference was largely attributable to use of white cell reduction in association with the limited-donor program in 1997. Eliminating the costs associated with white cell reduction rendered the costs of the limited- and multiple-donor transfusions comparable. The limited-donor program had donor exposures of 2.0 per infant, while the multiple-donor program had 3.6 exposures per infant (p<0.002). CONCLUSION: The limited-donor blood program reduces donor exposure without adversely affecting costs.
Asunto(s)
Donantes de Sangre , Transfusión de Eritrocitos , Análisis Costo-Beneficio , Transfusión de Eritrocitos/economía , Transfusión de Eritrocitos/métodos , Humanos , Lactante , Recién Nacido de Bajo Peso/sangre , Recién Nacido , Sensibilidad y EspecificidadRESUMEN
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.
Asunto(s)
Biotina , Transfusión de Eritrocitos , Isoanticuerpos/inmunología , Biotina/farmacología , Ditiotreitol/farmacología , Eritrocitos/efectos de los fármacos , Eritrocitos/inmunología , Humanos , Isoanticuerpos/análisis , Isoanticuerpos/efectos de los fármacos , Valores de Referencia , Factores de TiempoRESUMEN
PURPOSE: To compare the occurrence of red blood cell (RBC), platelet (PLT), and white blood cell (WBC) antibodies in preterm infants after transfusions. METHODS: A randomized, blinded trial was conducted in which preterm infants were transfused either with stored RBCs, prepared by prestorage leukocyte reduction and transfused throughout 42 days of storage to limit donor exposure (n = 18), or with fresh RBCs prepared without leukocyte reduction and transfused within 7 days after collection from as many donors as needed to guarantee freshness (n = 17). Nontransfused preterm infants of comparable birth weight were control subjects (n = 11). RESULTS: No RBC antibodies were detected in serial blood samples taken during the first 6 months of life. Similarly, no definite WBC antibodies were found, although weak reactivity was detected transiently in sera from two infants. Accordingly, RBC and WBC antibody production did not differ among groups. In all, 11% of the transfused the infants exhibited platelet antibodies: 14% of the infants given stored leukocyte-reduced RBCs and 7% of the infants given fresh nonleukocyte-reduced RBCs (difference not statistically significant). CONCLUSIONS: Preterm infants rarely produce antibodies to blood cell antigens after RBC transfusions, regardless of whether the exposure is to fresh unmodified RBCs from several donors or to stored leukocyte-reduced RBCs from a limited number of donors. Therefore, efforts to limit donor exposures or to remove WBCs from blood components cannot be justified simply for purposes of preventing alloimmunization in neonates.
Asunto(s)
Células Sanguíneas/inmunología , Conservación de la Sangre , Transfusión Sanguínea , Recien Nacido Prematuro/inmunología , Isoanticuerpos , Formación de Anticuerpos , Plaquetas/inmunología , Eritrocitos/inmunología , Humanos , Recién Nacido , Leucocitos/inmunologíaRESUMEN
BACKGROUND: Despite recent optimism about the use of erythropoietin therapy to treat the anemia of prematurity, very-low-birth-weight infants who are severely ill receive multiple red cell (RBC) transfusions. Many physicians transfuse relatively fresh RBCs to newborn infants, exposing them to multiple donors and possibly increasing their risk of acquiring transfusion-transmitted infections. STUDY DESIGN AND METHODS: A randomized, single-blind clinical trial was conducted to determine, as the primary endpoint, whether RBCs collected from one dedicated donor and stored for < or = 42 days in AS-1 storage media could safely supply all small-volume RBC transfusions (15 mL/kg/dose) needed by very-low-birth-weight infants (0.6-1.3 kg) during the first 84 days of life. Secondary endpoints were the assessment of the possible adverse clinical and biochemical effects of transfusing AS-1 RBCs stored for < or = 42 days. Control infants received identical nursery care, except they received fresh RBCs stored < or = 7 days in CPDA-1. RESULTS: Infants transfused with AS-1 RBCs were exposed to a mean of 1.6 donors,-compared with an exposure to 3.7 donors for infants given CPDA-1 RBCs (p < 0.05). Neither clinical transfusion reactions nor the results of multiple laboratory tests were significantly different in infants who received slow transfusions (15 mL/kg) of AS-1 RBCs stored for < or = 42 days and in infants who received the same volume of CPDA-1 RBCs stored < or = 7 days. CONCLUSION: AS-1 RBCs, usually from only one dedicated donor, can safely supply all RBCs needed by most very-low-birth-weight infants-a practice that decreases donor exposure and likely increases transfusion safety.
Asunto(s)
Anemia Neonatal/terapia , Donantes de Sangre , Conservación de la Sangre/normas , Transfusión de Eritrocitos/normas , Adenina , Femenino , Glucosa , Humanos , Recién Nacido , Recién Nacido de muy Bajo Peso , Masculino , Manitol , Cloruro de SodioRESUMEN
Reducing leukocyte (WBC) contamination of platelet (PLT) concentrates diminishes some adverse effects associated with transfusions. To provide WBC-reduced PLTs, we initiated a program using bedside filtration. However, the inability to easily quantitate WBC removal and PLT loss at the bedside prompted us to perform filtration in the blood bank. To establish optimal methods, production of WBC-reduced PLTs using the CS-3000 PLUS was studied in three phases, during which technical modifications were made. During phase 1, prestorage WBC reduction was performed using the PALL LRF-10H filter, sterilely connected. WBC reduction was satisfactory, but PLT loss was excessive. During phase 2, the PLT-30 collection chamber and Fenwal Closed System Apheresis Kit with Integral Sepacell Leukocyte Reduction Filter were used. PLT yields were improved, but now WBC contamination was excessive. During phase 3, the interface offset was reduced from 10 to 6, and both PLT yields and WBC reduction were satisfactory. Using this final method (CS-3000 PLUS, PLT-30 collection chamber, integral filter and offset setting of 6), the mean PLT yield per unit is 4.29 x 10(11) (N = 1,146), and the mean WBC contamination is 0.50 x 10(6) (N = 32).
Asunto(s)
Separación Celular/instrumentación , Recuento de Leucocitos , Transfusión de Plaquetas/efectos adversos , Plaquetoferesis/instrumentación , Garantía de la Calidad de Atención de Salud , Bancos de Sangre , Filtración , HumanosRESUMEN
Premature neonates require multiple red blood cell (RBC) transfusions. Single-donor programs have been proposed as a means to limit donor exposures, but methods must be developed to collect, store long-term and issue multiple aliquots of RBCs from a single donor. We evaluated a method by which RBCs could be collected, leukocyte depleted, repeatedly centrifuged for issuance as multiple small aliquots of high-hematocrit cells and then resuspended for continued storage throughout 42 days. The quality of RBCs handled by the method were compared to cells stored in standard fashion. Leakage of intracellular potassium, hemoglobin and lactic dehydrogenase into the extracellular fluid from RBCs processed by either method was comparable-indicating maintenance of RBC integrity. Multiple cultures, taken throughout the period of storage, were sterile to document that extensive handling did not introduce contamination. This new method appears promising as a means to provide RBCs for neonates.
Asunto(s)
Conservación de la Sangre/métodos , Recolección de Muestras de Sangre/métodos , Transfusión de Eritrocitos , Recien Nacido Prematuro , Donantes de Sangre , Hematócrito , Humanos , Recién NacidoRESUMEN
Autoanti-Jkb and a transient autoanti-E were identified in a patient with autoimmune hemolytic anemia, and red blood cells negative for Jkb and E antigens were transfused. Twelve weeks after transfusion, the autoantibody appeared to have developed broad specificity. However, autoadsorption studies revealed that the broad reactivity was due to the development of alloanti-Jka in addition to the autoanti-Jkb. Distinguishing this combination of alloanti-Jka plus autoanti-Jkb from an autoantibody with broad specificity will be important in selecting Jka antigen-negative red cells for subsequent transfusions. This case emphasizes the importance of additional serologic testing to detect alloantibodies in patients with broadly reactive warm autoantibodies.
Asunto(s)
Anemia Hemolítica/sangre , Autoanticuerpos/análisis , Enfermedades Autoinmunes/sangre , Isoanticuerpos/análisis , Sistema del Grupo Sanguíneo de Kidd/inmunología , Adulto , Anemia Hemolítica/inmunología , Enfermedades Autoinmunes/inmunología , Eritrocitos/inmunología , Femenino , HumanosRESUMEN
Anti-Sda, an antibody not usually considered to cause of hemolytic transfusion reactions, possibly was related to hemolysis following transfusion of red blood cells expressing strong Sda antigen. Prior to transfusion, the antiglobulin antibody screen performed in LISS and an immediate spin crossmatch were negative. Retrospectively, after hemolysis was detected, an antiglobulin crossmatch with red cells from the transfused unit revealed microscopic incompatibility. The transfused unit proved to have strong expression of Sda antigen-facilitating identification of a weak Sda antibody in our patient. In addition, this case represents an unusual instance in which an antibody screen plus an immediate spin crossmatch failed to detect an incompatibility that would have been apparent had an antiglobulin crossmatch been performed.
Asunto(s)
Tipificación y Pruebas Cruzadas Sanguíneas/métodos , Hemólisis/inmunología , Isoanticuerpos/inmunología , Reacción a la Transfusión , Femenino , Humanos , Persona de Mediana EdadRESUMEN
Abbreviated pretransfusion testing, although permitted by American Association of Blood Banks Standards for unimmunized patients, is not widely practiced. Concerns remain about optimal antibody screening methods, antibodies missed by deleting the antiglobulin crossmatch, and cost-effectiveness. The authors prospectively tested 3,380 serum samples for blood type, antibody screen, and antiglobulin crossmatch. Antibody screens for 2,000 samples, performed with the use of a two-cell screen, were compared with 1,380 samples studied with a three-cell screen. Also, all 3,380 sera had major crossmatches performed carried through the antiglobulin phase. Two and three screening cells gave comparable results, with 5.45% of patients tested by two-cell and 5.22% by three-cell screens having a positive antibody screen. Of those with negative screens, 0.5% screened by two-cell screens and 0.8% by three-cell screens had a positive major crossmatch. Among these (negative antibody screen, positive crossmatch), only 0.03% (1 of 3.380) had a clinically significant alloantibody (anti-Kpa); 0.27% (9 of 3,380) had antiglobulin crossmatch positive with polyspecific antisera but negative with anti-IgG; and 0.12% (4 of 3,380) had positive crossmatch because of passive anti-A. By cost accounting of labor and reagents, 84 per unit would be saved using abbreviated versus complete pretransfusion testing. Blood banks now performing complete pretransfusion testing should reconsider abbreviated crossmatching for unimmunized patients as a safe, efficacious means of cost-containment.
Asunto(s)
Tipificación y Pruebas Cruzadas Sanguíneas/métodos , Transfusión Sanguínea/economía , Tipificación y Pruebas Cruzadas Sanguíneas/economía , Control de Costos , Humanos , Estudios Prospectivos , Seguridad , Factores de TiempoRESUMEN
Serum-to-red cell ratio (volume:volume) significantly affects the sensitivity of antibody detection. Obtaining sufficient serum quantity can be a problem when testing blood from transported neonates not accompanied by maternal samples. Reducing serum volumes used for testing might result in missed antibodies. The authors studied 1,177 sera for unexpected red cell antibodies by comparing one versus two drops of patient serum using a technique with LISS at 37 degrees C through the antiglobulin phase. The serum-to-red cell ratio using two drops was approximately 50: 1. Results of 60% (58/96) of samples containing antibody benefited by the use of increased serum. Eighteen percent; (17/96) had antibodies detected only with two drops that were missed entirely by one, and 43% (41/96) showed stronger positive reactions using two drops versus one. Importantly, antibodies detected only with or enhanced by two drops were clinically significant (anti-D, anti-K, anti-M, anti-c, anti-E). Thus, reducing serum-to-cell ratio is potentially dangerous, and blood banks should insist on adequate sample size to ensure patient safety.
Asunto(s)
Antígenos de Grupos Sanguíneos/inmunología , Sangre , Isoanticuerpos/análisis , Humanos , Recién Nacido , Valores de Referencia , Factores de RiesgoRESUMEN
We report a patient with an erythrocyte autoantibody in whose serum a broadly reactive antibody was transiently replaced by a monospecific autoanti-Jka. On preoperation evaluation, a 49-year-old man, who had never been transfused, exhibited both a positive antibody screen and a positive direct antiglobulin test. Although a broadly reactive antibody had been present 2 years earlier, only anti-Jka was found in the serum on preoperative testing. In contrast, an acid eluate prepared from the patient's red cells at the time was reactive with all cells from a 10-cell panel--a finding consistent with the broadly reactive autoantibody noted earlier. Repeat testing of a sample obtained 1 week later revealed only a broadly reactive autoantibody in both serum and eluate. This patient is notable in two respects. He exhibited a rare autoantibody, monospecific anti-Jka, and the specificity of the autoantibody changed from broadly reactive when first detected to anti-Jka and then back to broadly reactive. Thus, antibodies directed against specific antigens, in the setting of autoimmune hemolytic anemia, may be part of the autoimmune process and not always alloantibodies.