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.

Cost-effectiveness of a limited-donor blood program for neonatal red cell transfusions

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.

Blood banking issues pertaining to neonatal red blood cell transfusions

Many preterm infants are given multiple red blood cell transfusions during the early weeks of life. Because firm standards for neonatal transfusions do not exist, it is important to consider the pathophysiology of the anemia of prematurity, the goals of transfusion therapy and blood banking practices that best provide safe and effective neonatal transfusions. There is increasing agreement that efforts continue to minimize phlebotomy blood losses, to transfuse per conservative indications and to limit donor exposure by transfusing stored red blood cells from a single unit reserved for an infant--rather than insisting on fresh blood.

Comparing alloimmunization in preterm infants after transfusion of fresh unmodified versus stored leukocyte-reduced red blood cells

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.

An international view of hydroxyethyl starches

Hydroxyethyl starch (HES) is one of the most frequently used plasma substitutes. A variety of different HES solutions exist worldwide, which differ greatly in their pharmacological properties. HES is classified according to its manufactured or in vitro molecular weight (MW) into high MW (450-480 kDa), medium MW (200 kDa), and low MW (70 kDa) starch preparations. However, this is not sufficient, because as HES is metabolized in vivo, its MW changes, and it is the in vivo MW which is responsible for the therapeutic and adverse effects of each HES. The rate of metabolization depends mainly on the degree of hydroxyethyl substitution (ranging from 0.4 to 0.7), and the C2/C6 ratio of hydroxyethylation. A high degree of substitution and a high C2/C6 ratio lead to a slow metabolization of HES, resulting in a large in vivo MW. Slowly degradable high MW HES 450/0.7 and medium MW HES 200/0.62 have a high in vivo MW and are eliminated slowly via the kidneys. As a result, these starches have a relatively long-lasting volume effect. When infusing higher volumes (>1500 ml) are infused, large molecules accumulate in the plasma. This can result in bleeding complications due to decreased factor VIII/von Willebrand factor, platelet function defects, incorporation into fibrin clots, and an unfavorable effect on rheological parameters. Rapidly degradable medium MW HES 200/0.5 or low MW HES 70/0.5 are quickly split in vivo into smaller, more favorable molecule sizes, resulting in faster renal elimination, shorter volume effect, and fewer adverse effects on coagulation and rheological parameters. For historical and marketing reasons, only slowly degradable, high MW HES (480/0.7) is available in the United States. In Europe, a large variety of HES solutions are available, dominated by medium MW, easily degradable HES (200/0.5). Because of increasing international competition and the availability of newly developed starches, it is important to be aware of the pharmacological properties of HES and the advantages and disadvantages of the individual preparations.

Measurement of circulating red cell volume using biotin-labeled red cells: validation against 51Cr-labeled red cells

BACKGROUND

Anemia is a serious problem in the fetus and preterm infant. To investigate the physiology and pathophysiology of anemia and to assess responses to blood transfusions or erythropoietin therapy, measurement of circulating red cell volume would be useful. Because the standard 51Cr method exposes the subject to radiation, a method of measuring circulating red cell volume without radiation exposure, sufficiently sensitive for use in fetuses and infants, was developed.

STUDY DESIGN AND METHODS

In 10 healthy adults whose body mass ranged from 56.8 to 115.9 kg, aliquots of autologous red cells were labeled with biotin or with 51Cr, mixed, and transfused intravenously. Circulating red cell volume was measured in posttransfusion blood by quantitating the in vivo dilution of biotinylated red cells. Biotinylated red cells were detected by two methods: 1) 125I-streptavidin and 2) fluorescein-labeled avidin with flow cytometry.

RESULTS

Circulating red cell volume measured by 125I-streptavidin detection agreed well with that measured by 51Cr (slope = 1.07, y-intercept = -97, correlation = 0.987). Similarly, circulating red cell volume measured by flow cytometry agreed well with that measured by 51Cr (slope = 1.05, y-intercept = -20, correlation = 0.987).

CONCLUSIONS

Circulating red cell volume measured by the use of biotin with either 125I-streptavidin or flow cytometry agrees with that measured by 51Cr. Each system provides a method of performing these studies without exposing the subject to radiation.

Measurement of red cell survival using biotin-labeled red cells: validation against 51Cr-labeled red cells

BACKGROUND

Anemia is a serious problem in the fetus and preterm infant.To investigate the physiology and pathophysiology of anemia and to assess responses to blood transfusions and erythropoietin therapy, measurement of circulating red cell survival would be useful.

STUDY DESIGN AND METHODS

Because the standard 51Cr method exposes the patient or subject to radiation, a practical, accurate method for measuring red cell survival was developed on the basis of determining the number of biotin-labeled red cells that persist in the circulation by using fluorescein-labeled avidin and flow cytometry. In addition, disappearance of total biotin label was measured by using 125I-streptavidin. Results of each detection method were compared to red cell survival measured by the standard 51Cr method.

RESULTS

Biotinylated cells persisted in circulation with life spans approaching normal. Despite near-normal persistence in circulation of the biotin-labeled cells, about one-half of the biotin label left the circulation over the first few weeks, causing early curvilinear disappearance. This observation is consistent with the hypothesis that about one-half of the biotin label leaves the red cells. However, about one-half of the biotin was permanently attached, which produced linear disappearance and approximately normal life span estimates for the linear survival curve appearing after the first few weeks.

CONCLUSION

Red cell survival can be measured accurately in humans using enumeration of biotinylated red cells. The method is practical and does not expose the patient to radiation.

Circulating red cell volume and red cell survival can be accurately determined in sheep using the [14C]cyanate label

The sheep commonly serves as an animal model for investigation of human fetal and newborn erythropoiesis and red blood cell kinetics. Measurement of red cell volume (RCV) and survival (RCS) in sheep would be useful for studying mechanisms of neonatal anemia. Unfortunately 51Cr, the standard method for RCV, is not suitable for RCS in sheep because 51Cr leaves the red cell too rapidly. We developed and validated the permanent label [14C]cyanate as a method for measuring both RCV and RCS in sheep. In 19 sheep, RCV was determined simultaneously using [14C]cyanate and 51Cr. RCV determined by [14C]cyanate agreed almost perfectly with RCV by 51Cr; correlation coefficient = 0.990. The line of regression had a slope of 0.94 and an intercept of 40; these parameters are not significantly different from a line of identity. In nine sheep, RCS was determined using [14C]cyanate. Survival after d 1 accurately fit a model containing two components: 1) an early exponential loss likely related to damage caused by labeling and handling and 2) a linear decrease that reflected normal survival of undamaged red cells. Mean potential life span (MPL) determined from the linear phase was 114 +/- 12 d (mean +/- 1 SD). These results agree with reported MPL values determined either by 59Fe or differential hemolysis. Together, these observations establish [14C]cyanate-labeled red cells as a tool for measuring both RCV and RCS in sheep and enhance the value of the ovine model for investigating neonatal anemia.

Practical issues in neonatal transfusion practice

Small premature infants frequently require transfusions of blood components, particularly red blood cells (RBCs), during the first weeks of life. Although great efforts have been made during the past few years to optimize the transfusion of blood components to these tiny patients, several questions have not been definitively answered. Accordingly, transfusion practices vary among neonatologists. The purpose of this article was to assess the available data critically. The findings indicated that stored RBCs can be transfused safely into premature infants to diminish donor exposures. It was also found that leukocyte-reduced blood components can be used to prevent the transmission of cytomegalovirus; thus, cellular components do not need to be obtained exclusively from donors negative for antibodies to cytomegalovirus. However, gamma-irradiation of cellular blood components cannot be justified for all neonatal transfusions. Obviously, as new information is reported, these findings may require revision.

Randomized study of prophylactic platelet transfusion threshold during induction therapy for adult acute leukemia: 10,000/microL versus 20,000/microL

PURPOSE

We designed and conducted a randomized single-institution trial comparing two common prophylactic platelet transfusion thresholds in patients undergoing induction therapy for acute leukemia.

PATIENTS AND METHODS

Seventy-eight patients undergoing induction therapy for acute leukemia were randomized to receive prophylactic apheresis platelet concentrates when the platelet count was either < or = 10,000/microL or < or = 20,000/microL.

RESULTS

There was no significant difference in the total number of bleeding episodes per patient with a median of four in the < or = 10,000/microL arm and two in the < or = 20,000/microL arm (25th to 75th percentiles of 2, 7 and 1, 5, respectively; P = .12). Patients randomized to the < or = 10,000/microL arm received more platelet transfusions for bleeding [one (0, 2) v zero (0, 0); P = .0003]. In contrast, patients on the < or = 20,000/microL arm received more platelet transfusions for prophylactic indications [10 (5, 14) v six (3, 8); P = 0.001], as would be expected, but less for bleeding. Nevertheless, the total number of platelet transfusions given to patients on the < or = 20,000/microL arm was higher and nearly significant [11 (6, 15) v seven (5, 11); P = .07]. There were no statistically significant differences between the groups with regard to RBC transfusion requirements, febrile days, days hospitalized, days thrombocytopenic, need for HLA-matched platelets, remission rate, or death during induction chemotherapy. No patient in either group died from hemorrhage or underwent major surgery for bleeding complications.

CONCLUSION

Giving prophylactic platelets at a threshold of < or = 10,000/microL compared with < or = 20,000/microL can decrease the total utilization of platelets with only a small adverse effect on bleeding, and no statistically significant effect on morbidity.

[14C]cyanate labeling of sheep red cells: covalent binding to hemoglobin continues in vivo for a day

The sheep is a useful model to study fetal and newborn physiology including perinatal erythropoiesis and red cell kinetics. A practical, economical method for measuring red cell survival (RCS) in sheep would be very valuable. However, 51Cr is unsatisfactory, and suitable alternatives have not been published. In the course of investigating [14C]cyanate as a label for sheep red cells, we observed continued covalent labeling over 24 h in vivo that was great enough to introduce a substantial artifact into two commonly used parameters of RCS: posttransfusion recovery (PTR24) and time to 50% decrease (T50) when referenced to time zero. In a simulation of in vivo conditions, the amount of 14C bound to Hb increased 26 +/- 6% (mean +/- 1 SD, n = 11) over 24 h. To investigate the mechanism of the increasing 14C bound, acid-acetone extraction, molecular sieve chromatography, and density gradient separation were used separately or in combination to quantitate intracellular free 14C and 14C covalently bound to intracellular proteins. Free 14C decreased as protein-bound [14C]cyanate increased. These studies provide evidence that covalent binding of [14C]cyanate to intracellular Hb continues in vivo for the first 24 h and that the source of the increase is intracellular free [14C]cyanate. We conclude that 1) PTR24 cannot be accurately determined by [14C]cyanate unless labeled red cells are incubated before infusion to allow the cyanate reaction to approach completion and 2) RCS by [14C]cyanate should be referenced to blood concentrations at 24 h.

A survey of Canadian neonatal blood transfusion practices

In 1990, the Pediatric Hemotherapy Committee of the American Association of Blood Banks developed and distributed a questionnaire addressing neonatal blood transfusion practices. The same questionnaire was subsequently sent to Canadian university-affiliated hospitals (n = 92). This report describes the results of the Canadian survey. Seventy-two percent (n = 66) of institutions contacted responded. Of these 42% (n = 28) had sufficient experience with neonatal transfusions and provided sufficient data for analysis. Although the majority of stated practices did follow published guidelines, several areas of variability and/or suboptimal practices were identified. With respect to component selection and preparation, suboptimal practices included excessive pretransfusion testing, unnecessary routine washing of RBC concentrates for small-volume transfusions, routine volume reduction of platelet concentrates and the use of suboptimal granulocyte preparations. With respect to transfusion practices, a disturbingly high percentage of respondents indicated that frozen plasma would be given in situations generally considered inappropriate. There was a great deal of variability in the provision of blood components at low risk for CMV, in the use of gamma irradiation and in the platelet count used for prophylactic platelet transfusions. The data collected in this survey provide information concerning practices that require improvement, identify areas where further research is desirable and provide a basis for comparison with current and future neonatal blood transfusion practices.

Changing patterns of red blood cell transfusion in very low birth weight infants

OBJECTIVE

Anemia develops in increasing numbers of critically ill very low birth weight (VLBW) infants who survive the neonatal period, and they receive multiple red blood cell (RBC) transfusions. Despite their need for prolonged medical treatment, we hypothesized that VLBW infants presently receive fewer RBC transfusions as a result of the growing awareness of transfusion risks and improvement of neonatal care.

METHODS

RBC transfusion practices and clinical outcomes in infants with birth weights of 1.5 kg or less were analyzed retrospectively in three selected years: 1982, before awareness of the human immunodeficiency virus; 1989, before surfactant availability; and 1993, before erythropoietin approval.

RESULTS

Progressive declines in RBC transfusions, donor exposures, and transfusion volumes occurred concurrently with decreases in morbidity and mortality rates. Transfusions per infant (mean +/- SD) declined from 7.0 +/- 7.4 in 1982 to 5.0 +/- 5.8 in 1989 to 2.3 +/- 2.7 in 1993 (p < 0.001). This decline was associated with a decrease in pretransfusion hematocrit (33.6% +/- 2.8% in 1982, 34.2% +/- 3.7% in 1989, and 29.8% +/- 5.1% in 1993; p < 0.001). The distribution of RBC transfusions given by week of life among study years did not change; 70% of RBC transfusions were given within the first 4 weeks, when infants are sickest. Although the percentage of VLBW infants weighing more than 1 kg at birth and never receiving any RBC transfusions increased with time (17% in 1982, 33% in 1989, and 64% in 1993), more than 95% of infants weighing 1 kg or less in all years received transfusions.

CONCLUSIONS

Overall administration of neonatal transfusions has decreased markedly, most likely because of multiple factors. Because most RBC transfusions are given to infants weighing 1 kg or less in the first weeks of life, therapeutic strategies should focus on this group of VLBW infants during this critical period. The temporal changes observed in transfusion patterns emphasize the importance of including concurrent controls in future studies evaluating transfusion interventions.

AS-1 red cells for neonatal transfusions: a randomized trial assessing donor exposure and safety

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.

Cadaver skin allografts and transmission of human cytomegalovirus to burn patients

BACKGROUND

The potential role of cadaver skin as a vehicle for CMV transmission to burn patients has never been clearly defined. We sought to determine if a cytomegalovirus (CMV)-positive cadaver allograft transmits CMV infections to CMV-seronegative burn patients.

STUDY DESIGN

All patients in this study were CMV seronegative on admission. They received CMV-seronegative blood products, and cadaver allografts for temporary wound closure and management without regard to the donor's CMV serum status (positive or negative).

RESULTS

Of 493 patients admitted from 1989 to 1993, 22 were CMV seronegative on admission and required cadaver allografts for their burn wounds. Five (22.7 percent) of 22 patients seroconverted during hospitalization: one of five had CMV pneumonia develop, two had CMV viruria develop, and three had persistent fever, abnormal liver enzymes, and diarrhea not ascribable to bacterial or other viral agents.

CONCLUSIONS

Cytomegalovirus infections result from using CMV-seropositive cadaver allografts on seronegative burn patients.

Providing leukocyte-reduced platelets using the CS-3000 PLUS

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).

Mechanisms of adverse effects during hemapheresis

For over 20 years blood components have been collected from normal donors by automated hemapheresis. Cell separators have become increasingly sophisticated, and relatively pure component "concentrates" can be obtained quite safely. Cytapheresis donors are monitored carefully, and serious reactions are very rare. In contrast, therapeutic apheresis procedures may be technically demanding and frequently are performed on very sick patients. Large volumes of blood are rapidly removed from the patient, anticoagulated, and separated into components by the automated cell separator. The blood component containing the pathogenetic factor (e.g., plasma containing an antibody) is retained outside of the body, and the remaining components (e.g., red cells, white cells, and platelets) plus the replacement fluid are reinfused. Complications can occur in normal cytapheresis donors because of the technical challenges of the procedure (e.g., extracorporeal circuit to be filled, use of citrate anticoagulant, need for large bore intravascular access, and rapid blood flow rates). All of these factors apply also to therapeutic patients plus the additional requirement for replacement fluids, and the clinical features of the underlying illness for which each patient is being treated. Fortunately, even with therapeutic patients, most complications are of modest severity and are easily managed with only temporary slowing or interruption of the hemapheresis procedure.

Bacterial contamination rates following processing of bone marrow and peripheral blood progenitor cell preparations

BACKGROUND

The performance of cultures to assess possible bacterial contamination of bone marrow and peripheral blood progenitor cell preparations is required by the standards of the American Association of Blood Banks.

STUDY DESIGN AND METHODS

Consecutive (n = 893) bone marrow and peripheral blood progenitor cell preparations were cultured for assessment of possible contamination by microorganisms.

RESULTS

Consecutive bone marrow and peripheral blood progenitor cell preparations (n = 893) were cultured; the overall positive rate detected was 2.5 percent (22/893). The isolates predominantly were skin contaminants (gram-positive cocci) and so-called water-borne organisms (gram-negative rods). The 6.0-percent rate of positivity in 317 bone marrow preparations was higher than the 0.5-percent rate in 576 peripheral blood progenitor cell preparations (p < 10(-6)). Culture-positive preparations were transfused to 16 patients at this institution; however, none of these transfusions led to documented sepsis with the contaminating organism.

CONCLUSION

The culture method described here complies with the standards of the American Association of Blood Banks. Contamination can be detected in both bone marrow and peripheral blood progenitor cell preparations. When contaminated preparations are transfused, there are few complications that can be attributed to the contamination.

A cost analysis comparing erythropoietin and red cell transfusions in the treatment of anemia of prematurity

BACKGROUND

Anemia of prematurity is invariably observed in very low birth weight infants and may become symptomatic enough to be treated with packed red cell transfusions. Recently, treatment of this condition with recombinant human erythropoietin has been advocated.

STUDY DESIGN AND METHODS

To compare the costs of training symptomatic anemia in hospitalized premature infants with transfusions alone or with erythropoietin plus red cell transfusions as needed, cost estimates were derived from local hospital and published cost data. Decision analysis and sensitivity analysis were applied to a "base case." The base case was derived from results of a multicenter erythropoietin trial in the United States in which premature infants received 500 U of erythropoietin per kg of body weight each week. Because erythropoietin treatment began on average at 3 weeks of life, when infants were clinically stable, they had already received 3.5 red cell transfusions. During the 6-week treatment period, erythropoietin-treated infants received significantly fewer additional transfusions: a mean of 1.6 versus 1.1.

RESULTS

The base-case cost in 1993 dollars for treating anemia in hospitalized premature infants with erythropoietin and transfusions was $1,326. This was nearly twice the cost of conventional treatment with transfusions alone ($721). If the 6-week treatment period alone is considered, erythropoietin is 3.6 times more costly: $840 versus $235.

CONCLUSION

The largest available US study using erythropoietin to treat anemia in premature infants has demonstrated a small, but significant, reduction in transfusion needs. However, this study's cost data alone do not justify the widespread use of erythropoietin in premature infants. When this issue is probed in great depth, sensitivity analyses demonstrate that major reductions in erythropoietin's cost and/or improvements in its effectiveness quite possibly will make its use economically more attractive.