Anti-glycoprotein Ib alpha B-cell receptor (anti-GPIbα BCR)

The anti-GPIbα B-cell receptor is a membrane-bound immunoglobulin expressed on the surface of B lymphocytes that specifically recognizes Glycoprotein Ib alpha (GPIbα), a primary component of the platelet GPIb-IX-V complex (Quach et al., 2018). In patients with immune thrombocytopenia (ITP), these B cells differentiate into plasma cells that produce autoantibodies against platelets, leading to their premature destruction and impaired production (Zhu et al., 2021). A distinctive feature of anti-GPIbα-mediated ITP is that platelet clearance often occurs via an Fc-independent pathway, where antibodies trigger platelet desialylation and subsequent removal by the Ashwell-Morell receptor in the liver (Li et al., 2015). This mechanism makes the disease particularly resistant to standard treatments like intravenous immunoglobulin (IVIg) and splenectomy, which primarily target Fc-dependent clearance (Nieswandt et al., 2000). Consequently, the anti-GPIbα B-cell receptor has emerged as a high-value target for precision therapies such as Chimeric Autoantibody Receptor (CAAR) T-cells, which use the GPIbα protein as an extracellular domain to selectively identify and eliminate pathogenic B cells (Ellebrecht et al., 2016). By specifically targeting the BCR of the disease-causing clones, these therapies aim to provide a durable cure for ITP while avoiding the risks of broad immunosuppression.

Other names

GPIbα-specific B-cell receptorAnti-CD42b B-cell receptorAnti-platelet glycoprotein Ib alpha BCRAnti-GPIb alpha BCR

Selective depletion of B-cell clones expressing the anti-GPIbα BCR through antigen-mediated recognition or inhibition of downstream BCR signaling.