Identification of RHD allelic variants discovered by atypical typing results on the NEO/Echo platforms.

Some individuals are at risk of anti-D alloimmunization if they inherit D antigens that are qualitatively and/or quantitatively different than wild-type D. We hypothesized that patients who showed serologically inconsistent, weak, or historically discordant D typing results by microplate direct agglutination (MDA) on NEO or Echo (Immucor, Norcross, GA) might be at risk of carrying RHD allelic variants. The present study was designed to evaluate patients with RHD allelic variants if they presented with weakly reactive D typing results on the NEO or Echo. Patients were selected for RHD genotyping if their specimens showed weak reactivity with either series 4 or series 5 anti-D typing reagent, if the strength of reactivity was ≤1+ on the NEO or Echo, or if historical or current D typing results were discordant with current results. Patients selected for RHD genotyping were also tested by saline tube testing using the same anti-D series 4 and 5 reagents. Genotyping was performed by the Immucor genotyping laboratory in Warren, NJ. Of 80 patients whose samples met study inclusion, 52 (65.0%) were found to have RHD allelic variants. Sixteen patients (20.0%) expressed possible Ceppellini effect reactivity. Most importantly, 51.25 percent of the patients who presented with weakly reactive D typing results by MDA testing on the NEO (≤1+) or Echo (≤1+) had RHD allelic variants that were associated with the potential for anti-D alloimmunization. Laboratories that use MDA testing on the Neo or Echo for D typing should consider that female patients of childbearing age might be at risk of anti-D alloimmunization if they are classified as D+ based on weakly reactive D typing results.Some individuals are at risk of anti-D alloimmunization if they inherit D antigens that are qualitatively and/or quantitatively different than wild-type D. We hypothesized that patients who showed serologically inconsistent, weak, or historically discordant D typing results by microplate direct agglutination (MDA) on NEO or Echo (Immucor, Norcross, GA) might be at risk of carrying RHD allelic variants. The present study was designed to evaluate patients with RHD allelic variants if they presented with weakly reactive D typing results on the NEO or Echo. Patients were selected for RHD genotyping if their specimens showed weak reactivity with either series 4 or series 5 anti-D typing reagent, if the strength of reactivity was ≤1+ on the NEO or Echo, or if historical or current D typing results were discordant with current results. Patients selected for RHD genotyping were also tested by saline tube testing using the same anti-D series 4 and 5 reagents. Genotyping was performed by the Immucor genotyping laboratory in Warren, NJ. Of 80 patients whose samples met study inclusion, 52 (65.0%) were found to have RHD allelic variants. Sixteen patients (20.0%) expressed possible Ceppellini effect reactivity. Most importantly, 51.25 percent of the patients who presented with weakly reactive D typing results by MDA testing on the NEO (≤1+) or Echo (≤1+) had RHD allelic variants that were associated with the potential for anti-D alloimmunization. Laboratories that use MDA testing on the Neo or Echo for D typing should consider that female patients of childbearing age might be at risk of anti-D alloimmunization if they are classified as D+ based on weakly reactive D typing results.

Major non-ABO incompatibility caused by anti-Jk(a) in a patient before allogeneic hematopoietic stem cell transplantation.

A 49-year-old white man with blood group AB, D+ was found to have alloanti-Jk(a) and -K when he developed a delayed hemolytic transfusion reaction before allogeneic hematopoietic stem cell transplant (HSCT). Given that his stem cell donor was blood group O, D+, Jk(a+), K-, rituximab was added to his conditioning regimen of fludarabine and melphalan to prevent hemolysis of engrafting Jk(a+) donor red blood cells. The patient proceeded to receive a peripheral blood stem cell transplant from a matched unrelated donor with no adverse events. To our knowledge, this is the first case of successful management of major non-ABO incompatibility caused by anti-Jk(a) in a patient receiving an allogeneic HSCT reported in the literature.

TRALI due to granulocyte-agglutinating human neutrophil antigen-3a (5b) alloantibodies in donor plasma: a report of 2 fatalities.

BACKGROUND: TRALI is usually an immunologic reaction to WBC antibodies in infused plasma and ranks second only to ABO mismatch as a cause of transfusion-associated death. Implicated donors are usually multiparous women (>/=3 pregnancies). STUDY DESIGN AND METHODS: Two fatal cases of TRALI were evaluated by reviewing clinical and laboratory findings and characterizing alloantibodies present in donor plasma. Investigation for WBC antibodies was by lymphocytotoxicity (LCT), FlowPRA (FlowPRA, One Lambda, Inc.) and granulocyte immunofluorescence and agglutination assays. Patient 1 was a 62-year-old man with chronic T-cell lymphocytic leukemia, and Patient 2 was a 54-year-old woman undergoing a cadaveric kidney transplant. Both patients developed acute respiratory distress and hypotension during (Patient 1) and approximately 30 minutes after (Patient 2) transfusion. Fulminant pulmonary edema ensued in both cases necessitating mechanical ventilation and both patients died within 24 hours of the onset of respiratory complications. RESULTS: The donors of the implicated blood components were women with a history of two pregnancies but no blood transfusions. Weak apparently panreactive granulocyte antibodies were detected with flow cytometry. However, in the granulocyte agglutination test, strong antibodies specific for human neutrophil antigen (HNA)-3a (5b) were identified in both donors. CONCLUSION: It is concluded that female blood donors with only two previous pregnancies can form clinically important granulocyte-reactive alloantibodies leading to fatal TRALI reactions in recipients. The sometimes devastating consequences of TRALI should prompt the development of strategies to prevent or reduce its incidence. Further research is warranted to investigate recipient and donor factors responsible for TRALI, including whether 5b (HNA-3a) alloantibodies are especially prone to cause severe reactions, and to better characterize the HNA-3a (5b) antigen, particularly at the molecular level.

Pretransfusion compatibility testing for red blood cell administration.

The purpose of pretransfusion compatibility testing is to prevent incompatible red blood cell transfusions that could lead to immune mediated hemolytic transfusion reactions. Some hemolytic transfusion reactions may have serious sequelae including hemoglobinemia, disseminated intravascular coagulation, renal failure, and death. This article reviews the most comprehensive recent analyses of the laboratory methods used during pretransfusion compatibility testing in the United States. Most of the laboratory practice data have been published in the College of American Pathologists Transfusion Medicine Survey Sets and in a national survey called the Pre-Transfusion Testing Survey. This article couples and trends the data of these comprehensive surveys with an assessment of the literature to present the current practice of pretransfusion compatibility testing.

Monitoring for underutilization of RBC components and platelets.

BACKGROUND: Monitoring blood transfusion for overutilization is standard practice at most institutions. STUDY DESIGN AND METHODS: This study monitored for underutilization of blood transfusion over a 14-month period, by evaluating patients who had Hb levels that were reported to be <5 g per dL or platelet counts <10 x 10(9) per L and who did not receive an RBC or platelet transfusion within 24 hours of the reported results. RESULTS: During the study period, 24,004 units of RBCs and 3,967 units of apheresis platelets were transfused. There were 148 patients who had a Hb level that was reported to be <5 g per dL or a platelet count reported to be <10 x 10(9) per L and who did not receive a transfusion during the 24 hours after the reporting of these results. In 5 cases, the patients died before the reporting of the low Hb or platelet counts, which precluded the low Hb or low platelet count reports from triggering transfusion therapy. In 8 cases, an underutilization review investigation could not be done, because of the unavailability of patient charts. Of the remaining 135 cases, investigation revealed justifiable reasons for withholding transfusion in 133. In 2 cases, the withholding of transfusion was deemed by peer review to be inappropriate, as the patients should have received a transfusion. Overall, there was one documented underutilization of RBC transfusion therapy during a period when 24,004 units were transfused and one underutilization of platelet transfusion therapy during a period when 3,967 units of apheresis platelets were transfused. CONCLUSION: Monitoring for underutilization of transfusion therapy fulfills the requirements of the Joint Commission on the Accreditation of Healthcare Organizations: While the underutilization of transfusion therapy did not appear to be a significant problem at this medical center, determining the reasons for withholding transfusions shed light on important patient care-related issues, including preexisting causes of falsely low platelet counts and Hb levels, delays in investigating critical laboratory values, and the need for policies for the treatment of patients who refuse transfusion for personal or religious reasons.

Assessing blood administering practices.

The risk that a red blood cell unit will be associated with an ABO-incompatible transfusion is currently slightly greater than the aggregate risk of acquiring human immunodeficiency virus, human T-cell lymphotropic virus, hepatitis B virus, or hepatitis C virus by transfusion. Since the most common cause for ABO-incompatible transfusion is the failure of transfusionists to properly identify a patient or a blood component before a transfusion, transfusion services are encouraged to evaluate and monitor the processes of dispensing and administering blood. In addition, a proposal of the Health Care Financing Administration of the Department of Health and Human Services would require hospitals to use a data-driven quality assessment and performance improvement program that evaluates the dispensing and administering of blood and that ensures that each blood product and each intended recipient is positively identified before transfusion. The Los Angeles County+University of Southern California Medical Center assesses the blood dispensing and administering process as proposed by the Health Care Financing Administration. During the fourth quarter of 1997, 85 blood transfusions were assessed for compliance with the Los Angeles County+University of Southern California Medical Center policies and procedures: 55 transfusion episodes had no variance from institutional protocol and 30 had one or more variances. Of the transfusions with at least one variance, 16 had one or more variances involving the identification of the patient, the component, or the paperwork. The remaining 14 transfusions had one or more variances involving other criteria (nonidentification items). The most frequent variance was the failure to document vital signs during the first 15 minutes after a transfusion was started or after 50 mL of a component had been transfused. No variances in patient or blood component identification were noted in nursing units whose staff routinely performed self-assessment of blood administering practices. Based on these findings, a corrective action plan was implemented. Follow-up assessments (n = 63) were conducted after 3 months (during the second quarter of 1998). The compliance with the pretransfusion identification protocol improved from 81% to 95%. The most common reason for noncompliance continued to be a lack of checking vital signs. This report demonstrates the value of using a data-driven program that assesses blood administering practices.

Survey on pretransfusion testing.

BACKGROUND: Hospitals and blood centers throughout the United States use a variety of reagents and methods to perform pretransfusion testing. A survey was developed to determine the reagents and methods in use and their relative prevalence in different work settings. STUDY DESIGN AND METHODS: A national survey on pretransfusion testing was conducted. Surveys were distributed to state and regional blood bank associations, which then distributed them to hospitals and blood centers within their region. In most instances, the blood centers distributed the survey to the local hospitals. Completed surveys were returned to the authors for review, and all information was entered into a database for analysis. RESULTS: Analysis of the data shows that the majority of blood banks use monoclonal reagents for ABO testing and monoclonal-polyclonal blended reagents for Rh testing. The data show that anti-IgG and polyclonal antihuman globulin reagents are used almost equally for antibody screening (detection) tests and that most blood banks use a three-cell antibody-screening test. Slightly more than 50 percent of hospitals use an immediate-spin crossmatch in the absence of unexpected antibodies. CONCLUSION: A number of approved reagents and methods are used by blood bank laboratories for pretransfusion testing. Facility size (number of beds) and type tend to influence the choice of methods and reagents employed. This survey provides an opportunity for blood bank laboratories to compare their current practices with those of their peers.

Practice parameter for the use of red blood cell transfusions: developed by the Red Blood Cell Administration Practice Guideline Development Task Force of the College of American Pathologists.

A practice parameter has been developed to assist physicians in the therapeutic use of red blood cell transfusions. The developers of this parameter used the best available information from the medical literature, as well as clinical experience and the extensive reality testing required by the College of American Pathologists for approval. In acute anemia, a fall in hemoglobin values below 6 g/dL or a rapid blood volume loss of more than 30% to 40% requires red blood cell transfusions in most patients. However, tissue oxygenation provides a better indication of physiologic need in situations where invasive monitoring provides this information. When these data are not available, heart rate and blood pressure measurements and the nature of bleeding (active, controlled, uncontrolled) supplement the hemoglobin value in guiding the transfusion decision. In sickle cell disease and thalassemias, red blood cells are transfused to prevent acute or chronic complications. Red blood cell transfusions are used in chronic anemias unresponsive to pharmacologic agents based on the patient's symptoms. Guidelines must be altered for neonates who require an increase in hematocrit to above 0.30 to 0.35 when respiratory distress is present. Indications for red blood cell transfusion for the pregnant or postpartum patient are similar to those for the nonpregnant patient. Risks of transfusion, particularly transmissible disease and incompatibility, remain but have been reduced. Thus, red blood cell transfusion continues to be a powerful therapeutic tool when used judiciously and carries less risk than in the recent past.

Single donor platelets: can we afford to use them? Can we afford not to use them?

One of the strategies to reduce the risk of harming a patient by transfusion therapy is to limit the overall risk of transfusion-transmitted disease. Central to this approach is minimizing the number of allogeneic blood products with which a patient is transfused. The usual dose of platelets for an adult patient is either six to 10 random donor platelets vs. one unit of platelets, pheresis (so-called single donor apheresis platelets). Consequently, the transfusion services at the University of Southern California Health Sciences Campus (USC University Hospital, the Norris Cancer Hospital, and Los Angeles County + USC Medical Center) routinely use single donor apheresis platelets (SDPs) rather than random donor platelets (RDPs) in an effort to minimize allogeneic platelet transfusions, and thereby reduce risk of transfusion-transmitted infection. Although there are other compelling medical, technical, and medical-legal reasons to use SDPs instead of RDPs, the authors believe that a decrease in allogeneic donor exposures alone is sufficient reason to make SDPs the platelet component of choice at their institutions.

Specific antibodies to Trypanosoma cruzi among blood donors in Los Angeles, California.

BACKGROUND: Trypanosoma cruzi, the cause of Chagas' disease, is often transmitted by transfusion in Latin America. Previous studies showed that at least 1 in 1000 eligible blood donors at the Los Angeles County+University of Southern California (LAC+USC) Medical Center Blood Bank had specific antibodies to T. cruzi. In June 1993, serologic screening of prospective allogeneic donors at epidemiologic risk for T. cruzi infection was begun voluntarily. STUDY DESIGN AND METHODS: The risk of T. cruzi infection in all eligible donors was assessed by questionnaire. At-risk donors were screened serologically for antibodies to T. cruzi with an enzyme immunoassay, and confirmatory testing was done with a radioimmunoprecipitation assay. RESULTS: During the 29-month study period 1311 (39.5%) of 3320 donors were judged to be at risk for T. cruzi infection. Seven donors (1/475) were reactive by an enzyme immunoassay, and six of these seven (1/ 553) were positive in a radioimmunoprecipitation assay. All radioimmunoprecipitation assay-positive donors had been born in countries in which Chagas' disease is endemic. One person in this group had received a transfusion in his homeland. CONCLUSION: These results demonstrate that a substantive proportion of eligible blood donors at our institution have antibodies specific for T. cruzi and that a commercially available assay can be used to detect these antibodies. Our data suggest that the risk of transmission of T. cruzi by transfusion could be eliminated by serologic testing limited to persons born in or transfused in countries in which Chagas' disease is endemic.

Effectiveness of a prospective physician self-audit transfusion-monitoring system.

BACKGROUND: The purpose of this study was to search for a more effective transfusion-monitoring system than the existing system of retrospective peer review. STUDY DESIGN AND METHODS: This research used a study-control, preintervention and postintervention design, to evaluate the effectiveness of a prospective physician self-audit transfusion-monitoring system that functioned without the direct involvement of transfusion service physicians. This research also evaluated the effectiveness of issuing to physicians a memo with transfusion guidelines. Three process indicators were used to assess physician behavior at various stages of the blood-ordering process: 1) the number of crossmatches ordered per admission, 2) the transfusion-to-crossmatch ratio, and 3) the number of blood units returned to the laboratory after physician self-auditing. The study used two outcome indicators to reflect overall blood utilization: 1) the percentage of patients who received red cell transfusions and 2) the number of blood units transfused per recipient each month. RESULTS: The prospective physician self-audit system implemented at the study hospital did not reverse physician transfusion decisions, and the process of issuing to physicians a memo with transfusion guidelines at the control hospital failed to reduce blood usage. However, a transient reduction in blood utilization was observed at the study hospital. CONCLUSION: The reduction was hypothesized to be due to a Hawthorne effect, in which observed behavior is affected by the subject's awareness of the research study.

Practical aspects of the self-assessment of the issue and administration of blood: a review of two hospitals' experiences.

The transfusion of blood and blood components is usually carried out by personnel who are not under the direct supervision of the transfusion service medical director. Quality assessment and quality improvement processes were described to show how transfusion service medical directors can participate in the initiation, oversight, and assessment of transfusion practices. Such involvement by a transfusion service director is appropriate and consistent with the concept that the responsibility for proper transfusion does not end with the issuance of blood and components by transfusion service personnel. The results and a discussion of the self-assessment studies at two hospitals were also presented.

Practical issues when confronting the patient who refuses blood transfusion therapy.

Caring for the Jehovah's Witness patient poses unique challenges to the medical community. Understanding the patient's viewpoint regarding the refusal of blood and blood products is an essential component in treating these patients effectively. There are currently numerous alternatives to allogeneic blood products that can be used in a variety of settings. The intent of this article is to present the beliefs of Jehovah's Witnesses regarding blood transfusion and to review the use of crystalloids, colloids, hemostatic drugs, erythropoietin, hemodilution, blood salvaging, intraoperative blood-conserving strategies, and artificial blood solutions as alternative treatments for these patients.

The sickle cell hemolytic transfusion reaction syndrome.

BACKGROUND: Patients with sickle cell anemia may develop serious, life-threatening hemolytic transfusion reactions (HTRs). More severe anemia may develop after the HTR than was present before transfusion, which suggests the possibility of an increased rate of hemolysis of autologous red cells. STUDY DESIGN AND METHODS: The signs and symptoms occurring during eight severe HTRs that occurred in five patients with sickle cell anemia were reviewed, as were published reports by other investigators. Calculations of red cell production and destruction incorporating known correction factors for reticulocyte maturation were performed to determine the most probable mechanism for the striking drop in hematocrit observed in several instances. RESULTS: A characteristic constellation of findings was recognized in some severe HTRs in patients with sickle cell anemia. Calculations of daily red cell production and senescence indicated that a marked drop in hematocrit occurs when erythropoiesis is suppressed in a patient with a short red cell life span and that this could account for severe posttransfusion anemia when donor red cells are hemolyzed during an HTR. CONCLUSION: A sickle cell HTR syndrome was defined. A rapid increase in the severity of anemia occurs in patients with sickle cell anemia when all donor red cells are hemolyzed during an HTR and when there is suppression of erythropoiesis, as commonly occurs as a result of transfusion or concomitant illness. Although an increased rate of hemolysis of autologous red cells may also occur, more definitive data are required to document that in these patients.

Are retrospective peer-review transfusion monitoring systems effective in reducing red blood cell utilization?

OBJECTIVE: This research used a study-control group design and examined data collected from five hospitals to evaluate the effectiveness of retrospective peer-review systems on reducing utilization of red blood cells (RBCs). DESIGN: The effects of retrospective peer-review systems were studied in three parts: (1) trends of RBC utilization were compared by the slopes of linear regression lines that assessed the effect of time on RBC utilization among four study hospitals and one control hospital, (2) diagnosis-specific RBC utilization was compared between the control hospital and one matched study hospital, and (3) the effect of the retrospective review system of one study hospital was assessed by linear regression using data accumulated 1 year before and 2 years after implementation of the program. RESULTS: Three study hospitals showed no significant changes in RBC utilization during the 10-month study period. One study hospital and the control hospital demonstrated trends of reduced RBC use with negative slopes of regression lines; however, there was no difference in the degree of the two slopes, and the diagnosis-specific RBC utilization was not lower at the study hospital than at the control hospital. Furthermore, implementation of the retrospective peer-review system at one study hospital demonstrated no effect on RBC utilization. CONCLUSIONS: We conclude that the retrospective peer-review systems implemented at these four hospitals had no effect on reducing red blood cell utilization.

The routine use of Rh-negative reagent red cells for the identification of anti-D and the detection of non-D red cell antibodies.

BACKGROUND: Before 1987, fewer than 50 patients per year at the authors' laboratory had a positive antibody detection test due to antepartum Rhesus immunoprophylaxis. However, after 1987, a marked increase was observed in the number of patients who had received Rh immune globulin (RhIG) during pregnancy as part of routine antepartum Rh immunoprophylaxis. In anticipation that an increased use of RhIG during pregnancy would increase the number of patients in whom anti-D was detected by this laboratory, a protocol was developed to abbreviate the process required to identify anti-D. Although this protocol was adopted primarily to address an anticipated increase in antenatal RhIG usage in women, it was also applied to alloimmunized Rh-negative males. STUDY DESIGN AND METHODS: When an Rh-negative patient (male or female) had a reactive screening test for unexpected antibodies and met certain other criteria, the patient's serum was tested with a three-vial set of Rh-negative reagent red cells (Rh-negative screening RBCs), instead of with panels of typed RBCs (panel RBCs), for the identification of anti-D or the detection of non-D antibodies. If the serum under test did not agglutinate or hemolyze Rh-negative screening RBCs, anti-D was identified and no further testing was performed. If the serum agglutinated or hemolyzed Rh-negative screening RBCs, conventional testing with panel RBCs was done to determine the antibody specificity. RESULTS: Rh-negative patients (n = 1174) who had reactive screening tests for unexpected antibodies were tested with Rh-negative screening RBCs; 1079 were found to have anti-D as a single antibody. Seven of these patients subsequently developed a non-D alloantibody, after transfusion or pregnancy, and one patient had anti-C that escaped detection at the time of initial testing with Rh-negative RBCs (a false-negative result). Ninety-two patients had anti-D in combination with a non-D antibody, and three patients had a non-D antibody but not anti-D. Use of the anti-D identification protocol actually reduced the laboratory workload by 176 College of American Pathologists workload units per month, in spite of a marked increase in the number of patients in whom anti-D was detected. No hemolytic transfusion reaction was attributed to the abbreviation of anti-D identification. CONCLUSION: The identification of anti-D may be abbreviated without jeopardizing patient safety. Such a protocol can reduce laboratory workload and might be particularly appealing to health care facilities that perform antibody detection testing on large numbers of Rh-negative pregnant women, especially if antepartum RhIG is administered routinely.