Autoreactive B-cell receptor specific for Glycoprotein Ib alpha (GPIbα) (Anti-GPIbα BCR)

Autoreactive B-cell receptors specific for Glycoprotein Ib alpha (GPIbα) are membrane-bound immunoglobulins on B cells that recognize the CD42b subunit of the platelet GPIb-IX-V complex (Stasi et al., 2008, Blood). In Immune Thrombocytopenia (ITP), these BCRs drive the expansion of B-cell clones that produce anti-GPIbα autoantibodies, which are a major cause of platelet destruction (Zhu et al., 2015, Journal of Thrombosis and Haemostasis). Unlike anti-GPIIb/IIIa antibodies, anti-GPIbα antibodies often cause platelet clearance in the liver via an Fc-independent mechanism involving platelet desialylation (Li et al., 2015, Nature Communications). This specific subset of BCRs is a critical therapeutic target because anti-GPIbα-mediated ITP is frequently resistant to standard treatments like intravenous immunoglobulin (IVIg) and corticosteroids (Peng et al., 2014, Blood). Current therapeutic strategies involve broad B-cell depletion using agents like Rituximab, though research into more selective approaches like Chimeric Autoantibody Receptor (CAAR) T-cells is ongoing to specifically eliminate these autoreactive clones (Kudernatsch et al., 2021, Frontiers in Immunology).

Other names

GPIbα-specific B-cell receptorAnti-CD42b B-cell receptorAutoreactive BCR (GPIbα)Anti-GPIb alpha B-cell receptor

Therapeutic intervention typically involves the depletion of B cells expressing these receptors using anti-CD20 monoclonal antibodies like Rituximab, which induces antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) (Arnold et al., 2017, NEJM). Other approaches include inhibiting B-cell activating factor (BAFF) with Belimumab to reduce the survival of autoreactive B-cell clones (Ghanima et al., 2019, Blood).