Evaluation of methods for detecting alloantibodies underlying warm autoantibodies

Red Cross, Washington, Washington, D.C., United States
Transfusion (Impact Factor: 3.23). 02/1999; 39(1):11-6. DOI: 10.1046/j.1537-2995.1999.39199116889.x
Source: PubMed


In pretransfusion testing of patients whose sera contain autoantibodies reacting optimally at 37 degrees C, it must be determined whether alloantibodies are also present. Two approaches, testing a 1-in-5 dilution of patients' sera and the adsorption of sera in the presence of polyethylene glycol (PEG), have been proposed as alternatives to the time-consuming approach of adsorbing sera with ficin- or ZZAP-treated red cells (RBCs). The three approaches were compared.
Patients' sera containing warm autoantibodies, with and without alloantibodies, were retested 1) after dilution (1-in-5) and 2) after adsorption with allogeneic RBCs in the presence of PEG. Results were compared to those after adsorption with ZZAP-treated allogeneic RBCs.
Dilution (1-in-5): Twenty-seven of 119 sera (7/26 [27%] with and 20/93 [22%] without alloantibodies) did not react; one example each of alloanti-D, -E, -e, -Fy(a), and -Jk(a), and two examples of anti-Jk(b) were not detected at a dilution of 1 in 5. Alloantibodies were identified in 5 (19%) of 26 1-in-5 diluted sera containing alloantibodies; 87 (73%) of 119 sera still reacted with all cells and would have required further workup. PEG adsorption: Thirty-nine sera were tested after parallel PEG and ZZAP adsorptions. The PEG adsorptions required a total of 55 aliquots of adsorbing cells and 13.75 hours, whereas ZZAP adsorptions required 61 aliquots and 30.5 hours. All alloantibodies (anti-D [3], -C [2], -c [1], -E [4], -K [2], -Fy(a) [1], -Jk(a) [2], -Jk(b) [1]) reacted in the adsorbed serum-PEG mixtures at a strength equal to or greater than that in the ZZAP-adsorbed sera.
Although the 1-in-5 dilution approach is convenient, only 22 percent of warm autoantibodies without alloantibodies were nonreactive, and 27 percent of alloantibodies of potential clinical significance were not detected. PEG adsorption appears to give similar results to those of ZZAP adsorption, but it has the advantages of eliminating the cost and time of prior treatment of the allogeneic adsorbing cells and of a reduction of at least a 50 percent in adsorption time.

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    • "The delay in issuing blood was observed more when special techniques like elution and adsorption has to be done or when more blood has to be crossmatched due to high autocontrol strength (≥3+). Approximately 12-40% of transfused patients develop clinically significant alloantibodies inducing rapid hemolysis and causing hemolytic transfusion reactions.[1516] History of blood transfusions in all our patients necessitated adsorption study. "
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    ABSTRACT: Background and Aim: Autoimmune hemolytic anemia (AIHA) is characterized by the production of autoantibodies directed against red cell antigens. Most patients of AIHA arrive in the emergency or out-patient department (OPD) with severe anemia requiring urgent blood transfusion. Here we share our experience of managing these patients with incompatible blood transfusions and suggest the minimal test required to assure patient safety. Materials and Methods: A total of 14 patients admitted with severe anemia, diagnosed with AIHA and requiring blood transfusion urgently were included in the study. A series of immunohematological investigations were performed to confirm the diagnosis and issue best match packed red blood cells (PRBC) to these patients. Results: A total of 167 PRBC units were crossmatched for 14 patients of which 46 units (28%) were found to be best match ones and 26 (56.5%) of these units were transfused. A mean turn around time of 222 min was observed in issuing the “best match” blood. Severe hemolysis was observed in all patients with a median hemoglobin increment of 0.88 g/dl after each unit PRBC transfusion. Conclusion: Decision to transfuse in AIHA should be based on the clinical condition of the patient. No critical patient should be denied blood transfusion due to serological incompatibility. Minimum investigations such as direct antiglobulin test (DAT), antibody screening and autocontrol should be performed to ensure transfusion safety in patients. All transfusion services should be capable of issuing “best match” PRBCs in AIHA.
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    • "Experimentally, it consists of testing diluted serum sample against a panel of RBC reagents. Although dilution should be performed only when the alloantibody titer is higher than the autoantibody titer, the dilution technique has been used in some laboratories that do not have the capability to perform the adsorption methods (e.g., ZZAP and PEG) [1]. "
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    ABSTRACT: The aim of this study was to investigate the frequency of autoantibodies with mimicking specificity by using the dilution technique, to assess the usefulness of the combination of the dilution technique and red blood cell (RBC) phenotyping, and to establish a pre-transfusion testing algorithm in patients with warm autoantibodies. Serum samples from 71 patients with warm autoantibodies were tested using the dilution technique. Among them, 25 samples were adsorbed with allogeneic ZZAP (a combination of dithiothreitol and enzyme) or polyethylene glycol (PEG) and their RBC phenotypes were determined. Thirty-nine patients were transfused with our pre-transfusion testing algorithm using a combination of dilution technique and RBC phenotyping. Autoantibodies with mimicking specificity were detected by the dilution technique in 26.8% (19/71) of the patients and most of them were directed against Rh system antigens. The agreement of the results obtained with the dilution technique in combination with RBC phenotyping and those from ZZAP or PEG adsorption was 100% (18/18) in patients who have autoantibodies with mimicking specificity and/or alloantibodies. No clinical symptoms indicating severe acute or delayed hemolytic transfusion reactions were reported in the 39 patients transfused with our pre-transfusion testing algorithm. Autoantibodies with mimicking specificity detected by the dilution technique in patients with warm autoantibodies are relatively frequent, can be discriminated from alloantibodies by employing a combination of dilution technique and RBC phenotyping, and might not appear to cause severe acute or delayed hemolytic transfusion reactions.
    Full-text · Article · Sep 2013 · Annals of Laboratory Medicine
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    • "However, there is no assurance that a patient's alloantibody will react more strongly than the autoantibody. These techniques are easy and rapid, but are unreliable (Leger & Garratty, 1999) so other, more effective procedures should be performed except in very urgent situations. "
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    ABSTRACT: Patients with autoimmune haemolytic anaemia (AIHA) frequently have anaemia of sufficient severity as to require a blood transfusion. However, it is impossible to find compatible blood when, as is frequently the case, the autoantibody in the patient's serum reacts with all normal red blood cells. Further, the autoantibody may mask the presence of a red cell alloantibody capable of causing a haemolytic transfusion reaction. Optimal patient management in this clinical setting requires special compatibility test procedures in the transfusion service laboratory. Equally important is that clinicians must understand the principles of the compatibility tests performed. Provided appropriate compatibility tests are performed, the indications for transfusion in patients with AIHA are not significantly different than for similarly anaemic patients without AIHA. Communication between clinicians and laboratory personnel are important to review the urgency of transfusion and the compatibility test methods used to select the optimal unit of red blood cells for transfusion.
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