• Transfusion · Feb 2019

    Monoclonal anti-CD47 interference in red cell and platelet testing.

    • Randall W Velliquette, Judith Aeschlimann, Julie Kirkegaard, Gayane Shakarian, Christine Lomas-Francis, and Connie M Westhoff.
    • Immunohematology and Genomics Laboratory, New York Blood Center, New York, New York; and the Community Blood Center, Kansas City, Missouri.
    • Transfusion. 2019 Feb 1; 59 (2): 730-737.

    BackgroundAnti-CD47 (Hu5F9-G4) is a human monoclonal immunoglobulin G (IgG)4 antibody that is in clinical trials to treat hematologic or solid malignancies. CD47, a glycoprotein expressed on all cells, binds to signal-regulatory protein α on macrophages and regulates phagocytosis. Blocking CD47 is thought to enhance phagocytosis and promote antitumor responses. Here, we evaluate drug interference in pretransfusion testing, determine mitigation strategies, and compare interference with anti-CD38 (Daratumumab).Study Design And MethodsSamples from four patients were tested by standard methods. Anti-IgG (Immucor monoclonal Gamma-clone and Ortho BioClone) were used, and dithiothreitol and enzyme-treated RBCs were tested. Allo-adsorption was performed with papain treated RBCs, pooled platelets, or with commercial human platelet concentrate. Platelet antibody testing was performed according to manufacturer's instructions.ResultsAll plasma samples reacted 3+ to 4+ in all phases with all red blood cells (RBCs) by all methods including immediate spin. Stronger reactivity was observed with D- RBCs with titers as high as 16,384 at indirect antiglobulin testing. Reactivity at indirect antiglobulin testing using Gamma-clone anti-IgG (which does not detect IgG4) was only weakly positive and confirmed to be carryover agglutination. Plasma reacted with dithiothreitol, trypsin, papain, α-chymotrypsin, or warm autoantibody removal medium (W.A.R.M., Immucor) treated RBCs. Direct antiglobulin testing and autocontrol were negative or weak with 3+ reactive eluates. Reactivity was removed by multiple alloadsorptions with papain-treated cells or pooled platelets. Polyethylene glycol adsorption was invalid due to precipitation of antibody.ConclusionAnti-CD47 (Hu5F9-G4) interferes with all phases of pretransfusion testing, including ABO reverse typing. To remove interference requires multiple RBC alloadsorptions and/or the use of monoclonal Gamma-clone anti-IgG in the indirect antiglobulin testing.© 2018 AABB.

      Pubmed     Full text   Copy Citation     Plaintext  

      Add institutional full text...

    Notes

     
    Knowledge, pearl, summary or comment to share?
    300 characters remaining
    help        
    You can also include formatting, links, images and footnotes in your notes
    • Simple formatting can be added to notes, such as *italics*, _underline_ or **bold**.
    • Superscript can be denoted by <sup>text</sup> and subscript <sub>text</sub>.
    • Numbered or bulleted lists can be created using either numbered lines 1. 2. 3., hyphens - or asterisks *.
    • Links can be included with: [my link to pubmed](http://pubmed.com)
    • Images can be included with: ![alt text](https://bestmedicaljournal.com/study_graph.jpg "Image Title Text")
    • For footnotes use [^1](This is a footnote.) inline.
    • Or use an inline reference [^1] to refer to a longer footnote elseweher in the document [^1]: This is a long footnote..

    hide…