Autoantibodies in immune thrombocytopenia affect the physiological interaction between megakaryocytes and bone marrow extracellular matrix proteins

GRODZIELSKI, MATÍAS; DI BUDUO, CHRISTIAN A.; GOETTE, NORA P.; LEV, PAOLA R.; SOPRANO, PAOLO M.; HELLER, PAULA G.; BALDUINI, ALESSANDRA; MARTA, ROSANA F.

BRITISH JOURNAL OF HAEMATOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2018

0007-1048

Although autoantibodies from immune thrombocytopenia (ITP) were described to interfere with megakaryocyte and platelet production, their effect on several aspects of megakaryocyte physiology has not been completely elucidated. Herein, we demonstrate that MK adhesion, spreading, downstream signal activation and proplatelet formation on type I collagen, fibrinogen and von Willebrand factor are affected in the presence of ITP plasmas bearing autoantibodies against GPIaIIa, GPIIbIIIa and GPIbIX, respectively. Our results demonstrate autoantibodies block the physiological interaction between MKs and these extracellular matrix proteins, and suggest they could alter normal megakaryocyte functions within the bone marrow microenvironment, contributing to thrombocytopenia in ITP.