Monoclonal anti-CD47 interference in red cell and platelet testing.
Journal
Transfusion
ISSN: 1537-2995
Titre abrégé: Transfusion
Pays: United States
ID NLM: 0417360
Informations de publication
Date de publication:
02 2019
02 2019
Historique:
received:
20
07
2018
revised:
17
09
2018
accepted:
23
09
2018
pubmed:
6
12
2018
medline:
30
7
2019
entrez:
6
12
2018
Statut:
ppublish
Résumé
Anti-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). Samples 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. All 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. Anti-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.
Sections du résumé
BACKGROUND
Anti-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 METHODS
Samples 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.
RESULTS
All 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.
CONCLUSION
Anti-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.
Substances chimiques
Antibodies, Monoclonal
0
CD47 Antigen
0
CD47 protein, human
0
Immunoglobulin G
0
daratumumab
4Z63YK6E0E
Types de publication
Journal Article
Langues
eng
Pagination
730-737Commentaires et corrections
Type : CommentIn
Type : CommentIn
Informations de copyright
© 2018 AABB.