Applications of murine and humanized chimaeric monoclonal antibodies for red cell phenotyping

Abstract

Summary The limited supply of reagent human polyclonal antibodies to high prevalence antigens, like Jsb, is driving the search for alternative reagents. Murine immunoglobulin G (IgG) monoclonal antibodies (Mabs) and their humanized chimaeric IgM isoforms can now be used for typing patients and screening donors. Antigen typing of red blood cells (RBC) with a positive direct antiglobulin test (DAT) is also possible using these antibodies. Blood from patients with sickle cell disease and African donors were tested with reagent anti‐Jsb, murine Mab IgG anti‐Jsb [murine immunochemistry monoclonal antibody‐8 (MIMA‐8)], and humanized chimaeric IgM anti‐Jsb [human immunochemistry monoclonal antibody‐8 (HIMA‐8)] by haemagglutination and gel cards. RBC samples that were DAT positive were used to evaluate the humanized chimaeric IgM monoclonal anti‐Fya (HIMA‐19). RBC samples (n = 243) of known Jsb type were tested in parallel with MIMA‐8 and reagent anti‐Jsb, and 132 samples were tested with MIMA‐8 in gel cards and HIMA‐8 by direct tube testing. No discrepant results were obtained. DAT‐positive RBC samples (n = 27) were correctly phenotyped using HIMA‐19. We conclude that MIMA‐8 is suitable for screening donors and typing patient RBCs. Testing MIMA‐8 with gel cards containing anti‐mouse IgG enables the screening of donors by automated methods. Humanized chimaeric IgM anti‐Jsb and anti‐Fya are suitable as typing reagents by direct agglutination methods.

High‐throughput multiplex single‐nucleotide polymorphism analysis for red cell and platelet antigen genotypes

“…The skewed "demand versus availability" of government-regulated antisera is so great that an industry has emerged to manufacture murine monoclonal or human heterohybridoma monoclonal antibodies. [14][15][16][17] Therefore, the cost to phenotype repeat blood donors routinely adds to the financial burden of the blood supplier. To reduce the cost of phenotyping blood, some blood collection facilities use unregulated antibodies and automated or semiautomated techniques to mass screen donations.…”

“…For higher incidence antigens, the likelihood of obtaining plasma for antisera manufacture is low (e.g., anti‐S or anti‐HAP‐1a) and is limited by virtue of the paucity of well‐characterized antibodies from alloimmunized transfusion recipients (anti‐S). The skewed “demand versus availability” of government‐regulated antisera is so great that an industry has emerged to manufacture murine monoclonal or human heterohybridoma monoclonal antibodies 14‐17 . Therefore, the cost to phenotype repeat blood donors routinely adds to the financial burden of the blood supplier.…”

‘Chameleonic' Serological Findings Leading to Life-Threatening Hemolytic Transfusion Reactions

“…The patient presented here appeared to had developed a potent auto-anti-D that resulted in the so-called blocked Rh(D) phenomenon. This phenomenon has been described in newborn hemolytic disease [ 9 , 10 , 11 ] and by the use of murine monoclonal antibodies [ 12 , 13 , 14 ]. To our knowledge, this is the first report describing this phenomenon in AIHA and serological transfusion reactions.…”

Characterization of a new human monoclonal antibody directed against the Vel antigen

“…Pooled RBCs were treated with enzymes or 200 m m DTT (Sigma‐Aldrich), including papain (0·2%) and α‐chymotrypsin (5 mg/ml) as already described . Briefly, 300 μl of three different RBCs was pooled and washed with physiological serum.…”