Daratumumab Interference in Pretransfusion Testing Is Overcome by Addition of Daratumumab Fab Fragments to Patients' Plasma

Is drug interference still an issue for pretransfusion testing of patients on anti CD38 and other monoclonal antibody therapies?

Certain therapies that target CD markers on some blood cells can affect pretransfusion testing. Key examples are anti-CD38, CD47 monoclonal antibody (mAb) therapies such as daratumumab (DARA) and magrolimab, which have presented a challenge for transfusion medicine laboratories around the globe. Scientists have been faced with not only introducing a protocol to provide safe blood to patients but also investigating the most effective method to remove the pretransfusion pan-agglutinating interference caused. A number of papers in the last 5 years have reported on various methods to remove pretransfusion interference; however, most of these studies have been conducted only in a few countries. Most recent reviews on this topic have focused on techniques and reagents to remove pretransfusion interference, and dithiothreitol is currently the gold standard for removing DARA interference. However, it was clear from this review that while many laboratories have developed processes for addressing interference in pretransfusion testing, and DARA interference may not be a major issue, there are still laboratories around the world, that may not have adequately addressed this issue. In addition, the impact of mAb interference on widely used techniques such as flow cytometry is unclear.

Refractory cold agglutinin disease successfully treated with daratumumab. A case report and review of literature

BACKGROUND

Cold agglutinin disease (CAD) is immune-mediated hemolytic anemia. The disease is caused by cold reactive autoantibodies that induce hemolysis through the activation of the complement pathway. Most patients with CAD are elderly, and half may have refractory CAD that may not respond to the first-line treatment option (i.e. rituximab). Some cases are refractory to multiple lines of therapy, including chemotherapeutic agents, which might be toxic, especially for elderly patients. Daratumumab is a human monoclonal antibody targeting CD 38 glycoprotein, a transmembrane protein highly expressed in lymphoid and plasma cells. Daratumumab is currently approved for treating multiple myeloma and is used mainly as a combination therapy with other agents.

CASE PRESENTATION

Our patient is a 69-year-old female diagnosed with CAD after presenting with severe anemia and significant circulatory symptoms. Rituximab was not effective in controlling her disease, and she refused other available chemotherapeutic agents due to their side effects profile. We used daratumumab combined with erythropoietin, which led to a dramatic response measured by stabilizing her hemoglobin levels and transfusion independence.

CONCLUSION

Our case is the third reported case of refractory CAD successfully treated with daratumumab, which suggests that daratumumab might be a potential agent for the treatment and control of refractory Cold Agglutinin Disease.

Mitigation of therapeutic anti-CD38 antibody interference with fab fragments: How well does it perform?

BACKGROUND

Administration of anti-CD38 antibodies is a state-of-the-art therapy for patients diagnosed with multiple myeloma (MM). However, this treatment frequently leads to pan-agglutination of red blood cells (RBCs) in patients' serological testing making accurate blood typing and timely transfusion of compatible blood a challenging effort. The antigen masking indirect antiglobulin test (AMIAT) is an approach to address this diagnostic challenge.

STUDY DESIGN AND METHODS

A new reagent, called DaraEx plus, uses anti-CD38 Fab fragments to mitigate the anti-CD38 antibody interference in serological assays by masking CD38 on the cell surface. Its performance is extensively examined with commercial sera as well as with patient samples, and compared to the current standard method using dithiothreitol (DTT), which denatures the CD38 antigens on test panel erythrocytes.

RESULTS

In the Bio-Rad ID System, DaraEx plus effectively mitigated the interference caused by anti-CD38 antibodies in 86% of patient samples tested while DTT was successful in only 68%. Moreover, there was no negative influence on DTT-sensitive blood group systems such as KEL upon DaraEx plus treatment. The agglutination reactions of all tested anti-CD38 antibodies (Daratumumab, Felzartamab, and Isatuximab) were inhibited by DaraEx plus. The treatment was successful only if DaraEx plus was added to the test cells before the sample. Some of the other gel card systems tested showed background reactions with DaraEx plus-treated cells.

CONCLUSION

DaraEx plus treatment is straightforward and quick to perform. In the Bio-Rad ID System, it is superior to DTT treatment in the prevention of anti-CD38 antibody interference.

FTL004, an anti-CD38 mAb with negligible RBC binding and enhanced pro-apoptotic activity, is a novel candidate for treatments of multiple myeloma and non-Hodgkin lymphoma

Anti-CD38 monoclonal antibodies (mAbs), daratumumab, and isatuximab have represented a breakthrough in the treatment of multiple myeloma (MM). Recently, CD38-based mAbs were expected to achieve increasing potential beyond MM, which encouraged us to develop new anti-CD38 mAbs to meet clinical needs. In this study, we developed a novel humanized anti-CD38 antibody, FTL004, which exhibited enhanced pro-apoptotic ability and negligible binding to red blood cells (RBCs). FTL004 presented a better ability to induce direct apoptosis independent of Fc-mediated cross-linking against lymphoma and MM cell lines as well as primary myeloma cells derived from MM patients. For instance, FTL004 induced RPMI 8226 cells with 55% early apoptosis cells compared with 20% in the isatuximab-treated group. Of interest, FTL004 showed ignorable binding to CD38 on human RBCs in contrast to tumor cells, even at concentrations up to 30 μg/mL. Furthermore, with an engineered Fc domain, FTL004 displayed stronger antibody-dependent cellular cytotoxicity (ADCC) against CD38+ malignant cells. In vivo MM and non-Hodgkin lymphoma tumor xenograft models showed that FTL004 possessed an effective anti-tumor effect. Cryo-electron microscopy structure resolved two epitope centers of FTL004 on CD38: one of which was unique while the other partly overlapped with that of isatuximab. Taken together, FTL004 distinguishes it from other CD38 targeting mAbs and represents a potential candidate for the treatment of MM and non-Hodgkin lymphoma.

A Rare Case of Acute Hemolytic Anemia in a Patient with Newly Diagnosed Multiple Myeloma: Maintaining a Fine Balance between Occam's Razor and Hickam's Dictum

Anemia is a common feature in multiple myeloma and is multifactorial. A 52-year-old lady was admitted to our hospital with complaints of fatigue, exertional dyspnea, paresthesia, and a recent-onset confusion state. Fundus examination revealed features of hyperviscosity. The patient received 2 units of packed red blood cell transfusion (PRBC) before the present hospital admission. Laboratory investigations revealed severe anemia and thrombocytopenia. The M-protein was 5.8 g/dL. Bone marrow showed sheets of plasma cells. Immunofixation electrophoresis confirmed the presence of an IgAλ band. FISH was positive for IgH-FGFR3 fusion. The investigations confirmed multiple myeloma R-ISS stage III. The patient was immediately started on CyBorD chemotherapy regimen. The patient had indirect hyperbilirubinemia and symptomatic anemia. Initial testing of the patient's sample showed blood grouping discrepancy with DCT, ICT, and auto control positive. The symptomatic anemia persisted requiring PRC transfusions. Further antibody study revealed the presence of anti-Jka antibody—a warm IgG antibody and cold antibody. Subsequently, the patient received Jka antigen-negative B-positive compatible PRBC transfusions and the hemoglobin normalized. Our patient had transfusion-associated alloimmunization along with hyperviscosity. The timely recognition and early institution of plasmapheresis and myeloma-directed therapy along with transfusion of compatible Jka antigen-negative PRBC lead to rapid improvement.

Effect of clinical application of anti-CD38 and anti-CD47 monoclonal antibodies on blood group detection and transfusion therapy and treatment

BACKGROUND

To investigate the effect of anti-CD38 monoclonal antibodies (mAb) (daratumumab, DARA) and anti-CD47 mAb combined with azacytidine on blood transfusion compatibility tests, transfusion effects in the treatment of multiple myeloma or acute myeloid leukemia and the corresponding management strategy.

MATERIALS AND METHODS

Among the 19 patients who were treated with DARA and anti-CD47 mAb, 4 patients with cross matching incompatibility were selected. The ABO blood group, the Rh blood group, irregular antibody screening and direct antiglobulin test (DAT) and cross matching testing were performed before and after the application of mAbs using serological methods. Then, irregular antibody screening and microcolumn gel cross matching tests were performed with donor and recipient erythrocytes and serum treated with DL-dithiothreitol (DTT) and Immucor kit, respectively. The transfusion effect was monitored.

RESULTS

21.05% (4/19) patients had mismatched cross-matching results after mAb treatment. The agglutination intensity of irregular antibody screening tests (3 + ∼ 4 +) after anti-CD47 mAb was higher than that (1 + ∼ 2 +) after DARA. In the DARA group, treating RBCs with 0.2 mol L^-1 DTT eliminated the DARA interference with antibody screening. In the anti-CD47 mAb group, the antibody screening, cross-matching test and DAT had been strongly interfered, and using Immucor kit eliminated the interference with antibody screening testing. There was no difference in the transfusion effect.

CONCLUSION

The application of mAb drugs led to incompatibility of cross matching tests, and the transfusion effect was not affected.

Panagglutination on the indirect antiglobulin test... this is the challenge!

Panagglutination on the indirect antiglobulin test is one of the most challenging dilemmas of pretransfusion testing. It occurs when patient sera react with all red blood cells tested, that is, with both screening and identification panel cells. Two main questions must be answered. The first is to determine whether panagglutination results from the presence of autoantibody and/or alloantibody (single alloantibody or multiple alloantibodies or antibody to high-incidence antigen). The second problem is to detect the possible concomitant presence of clinically significant alloantibodies masked by panagglutination. The purpose of this mini-review is to describe the situations that can cause panagglutination and to develop algorithms which can resolve the problem. The two main points in the evaluation of panagglutination involve the assessment of the intensity of reactivity with the reagent red cells used and whether the autocontrol is positive or not. It is imperative to understand the laboratory results and the techniques available that guide the investigative process.

Review: Effects of anti-CD38 monoclonal antibodies on red blood cell transfusion and interventions

BACKGROUND

Highly expressed in almost all myeloma cells, CD38 is an attractive treatment target.

AIM

Anti-CD38 monoclonal antibodies have been approved for first-line treatment in non-transplantable multiple myeloma (MM) patients.

MATERIALS AND METHODS

However, it has been found in clinical use that anti-CD38 monoclonal antibodies bind to CD38 on red blood cells (RBCs) and cause panagglutination in indirect antiglobulin test (IAT), resulting in false positives of IAT (Transfusion, 55, 2015 and 1545; Transfusion, 55, 2015 and 1555).

RESULT

Thereby, interfering with blood bank testing and leading to the delay of further diagnosis and treatment.

CONCLUSION

With more and more patients receiving anti-CD38 treatment, it is of great importance to recognize this problem and optimize relevant diagnosis and treatment procedures to prevent RBC transfusion delays and reduce laboratory costs.

Immunhämatologische Daratumumab-Interferenz im Verlauf einer Myelomtherapie

Anti-CD38-Antikörper werden vermehrt in der Klinik zur Behandlung von multiplen Myelomen und weiteren Indikationen eingesetzt. CD38 ist ein Oberflächenmolekül, das auf einer Reihe von Zellen und Geweben exprimiert wird, auch auf Erythrozyten. Nach Verabreichung von Anti-CD38-Antikörpern wie Daratumumab kommt es regelmäßig zur Interferenz im indirekten Antihumanglobulintest (IAT), was die Bestimmung irregulärer Antikörper behindert sowie auch die Zuverlässigkeit von Serumverträglichkeitsproben stark einschränkt. Mehrere Verfahren zum Umgang dieser Interferenz werden derzeit von der Deutschen Gesellschaft für Transfusionsmedizin und Immunhämatologie (DGTI) empfohlen. Wir stellen hier einen Vergleich zwischen der DTT-Methode und der Maskierung von CD38 durch ein neues Reagens an einem Patienten mit asekretorischem multiplen Myelom vor.

Preanalytic depletion of medicinal anti-CD38 antibody from patient plasma for immunohematology testing

Monoclonal antibodies such as daratumumab that target antigens that are also expressed on red blood cells impede blood group typing. The preferred approach to potential transfusion is to do prior extensive antigen typing of patients' red cells; however, this is not always possible. Ehrend et al describe a technique for absorbing the antibodies from serum to allow accurate red cell typing for transfusion.

Alloimmunisation rate of patients on Daratumumab: A retrospective cohort study of patients in England

OBJECTIVE

Whilst small-scale studies on rates of alloimmunisation of patients on Daratumumab have been undertaken, no large-scale study has been performed to date on this cohort of patients.

BACKGROUND

Patients with multiple myeloma (MM) who are relapsed or refractory to standard treatment are treated with the anti-CD38 therapeutic monoclonal antibody, Daratumumab. Due to the complexity of pre-transfusion compatibility testing, many MM patients in England are referred to Red Cell Immunohaematology (RCI) laboratories for investigation and provision of Red Blood Cell (RBC) components.

METHODS

Over a 4-month period, patients due to commence, or currently on anti-CD38 therapy were identified and flagged on the RCI Laboratory Information Management System (LIMS). Data was identified and extracted for further analysis. Interrogation of data was performed independently by two subject matter experts, with discrepancies resolved through further enquiry.

RESULTS

Of 734 English MM patients, we report an alloimmunisation rate of 0.4% whilst on an anti-CD38 TMAb. This is in line with other smaller cohort studies.

CONCLUSION

Given the low rate of RBC alloimmunisation, consideration should be given to revising the pre-transfusion testing regimen in this cohort. This may improve testing costs, turn-around times and evidence-based patient care.

2-Mercaptoethanol (2-ME)-based IATs or Polybrene method mitigates the interference of daratumumab on blood compatibility tests

OBJECTIVES

Treating red blood cells (RBCs) with dithiothreitol (DTT) is a wildly-recommended to overcome the interference of the daratumumab (DARA) with blood compatibility testing. Nevertheless, DTT can be hard to obtain in the clinical laboratory, while its use in routine practice may be time-consuming. In the following study, we explored the feasibility of using a commercial 2-mercaptoethanol (2-ME) working solution or the time-saving Polybrene method to mitigate DARA interference.

METHODS

Antibody screening and cross-matching were performed using 2-ME or DTT-based indirect antiglobulin tests (IATs) and Polybrene method (with human IgG anti-E same IATs titer as DARA as positive control) on 37 samples. Most clinically important blood group antigens on RBCs were detected after treatment with 2-ME or DTT.

RESULTS

Treating RBCs with 2-ME eliminates the DARA interference with the antibody screening or cross-matching; yet, K antigen is denatured during treatment. DARA does not interfere with antibody screening and cross-matching via Polybrene method, while 2+ agglutinations of anti-E antibody with the same titer (IATs method) as DARA could be observed in the positive controls via this method.

CONCLUSION

2-ME-based IATs or Polybrene method could replace DTT-based IATs to mitigate DARA interference.

Impact of new myeloma agents on the transfusion laboratory

Monoclonal antibody (mAb) therapy targeting CD38 and CD47 antigens expressed on cancer cells has transformed therapy options for patients with multiple myeloma as well as other haematological and non-haematological malignancies. While the on target effects of these new drugs highlight the promise of precision cancer therapeutics, the unintended, off target binding of drugs to red blood cells (RBCs) and platelets has required transfusion service laboratories (TSL) and immunohaematology reference laboratories (IRL) to innovate and rapidly set up processes and testing protocols to overcome the significant interference in routine pre-transfusion tests caused by these agents. Binding of anti-CD38 and anti-CD47 drugs to reagent RBCs leads to false positive pan-agglutination during the antihuman globulin phase of testing, making it difficult to rule out underlying alloantibodies, and leading to delays in setting up compatible units for RBC transfusion. Anti-CD47 agents can also interfere with ABO/Rh typing studies. Several methods to successfully mitigate interference have been described, such as treatment of reagent RBCs with reducing agents or enzymes, allogeneic RBC adsorption studies and drug specific neutralisation assays; all methods have limitations. TSLs should select an approach that best fits their workflow and expertise and takes into consideration their level of access to specialised outside testing, local blood supplier capabilities, and the type of patient population served. For platelet refractory patients, samples should be tested by platelet antibody assays that are known to be unaffected by drug therapy. RBC transfusion support for multiple myeloma patients receiving anti-CD38 or anti-CD47 drugs can be optimised by establishing good communication between the clinical teams and TSLs, building electronic notification processes, and ensuring timely completion of baseline pre-transfusion testing and RBC phenotype/genotype prior to starting therapy. Staff education, standardisation of laboratory mitigation measures, and implementation of testing algorithms that consider mAb-induced interference when working up a pan-agglutinin help to significantly decrease delays that would otherwise result if standard methods were employed to complete antibody identification studies.

New method for overcoming the interference produced by anti-CD38 monoclonal antibodies in compatibility testing

BACKGROUND

Plasma of patients taking anti-CD38 monoclonal antibodies (MoAbs) leads to panagglutination in the indirect antiglobulin test (IAT), that can mask clinically significant alloantibodies. Dithiothreitol (DTT) treatment of test RBCs is the more widespread method for avoiding this interference. Current DTT 0.2 mol/L method is time consuming and damages several red blood groups antigens. This study aims to evaluate low concentration DTT treatment of RBCs adapted for gel testing.

MATERIALS AND METHODS

Four DTT concentrations (0.01, 0.02, 0.03, and 0.04 mol/L), and three gel test brands were evaluated on six DARA patient's samples. Briefly, the method consists of pipetting 50 μL of 0.8% RBCs on AHG micro columns, followed by 25 μL of DTT, thoroughly mixing and 15 min incubation at 37 °C. Then, 25 μL of serum/plasma is added to proceed to IAT. In order to asses the effect of DTT 0.04 mol/L on different blood group antigens, serial dilutions of sera containing anti-K, -k, -Kp^b, -Lu^b, -Yt^a and anti-JMH antibodies were tested against DTT-RBCs. One sample of a DARA patient with known alloantibodies as well as samples of two patients inoculated with anti-K and anti-Fy^a were evaluated.

RESULTS

RBCs treatment with DTT 0.04 mol/L for 15 min completely eliminated anti CD38 panagglutination in all samples studied and worked with different reactivity intensities in IAT and gel brands. The new method allowed the detection of underlying anti-D, anti-E, anti-K and anti-Fy^a alloantibodies. Titration assays demonstrated no denaturation of Kell, Lutheran, Cartwright and JMH antigens.

DISCUSSION

The new DTT method adapted for gel testing is efficacious, simple and only adds 15 min over regular IAT. Pheno/genotyping before DARA treatment or transfusion of K negative RBCs may be unnecessary.