B cells in primary antiphospholipid syndrome: Review and remaining challenges

Autoimmun Rev. 2021 May;20(5):102798. doi: 10.1016/j.autrev.2021.102798. Epub 2021 Mar 13.


It is now widely accepted that antiphospholipid antibodies (aPL) have direct pathogenic effects and that B cells, notably through aPL production, play a key role in the development of antiphospholipid syndrome (APS). Recent findings strengthened the implication of B cells with the description of specific B cell phenotype abnormalities and inborn errors of immunity involving B cell signaling in APS patients. In addition, it has been shown in preclinical models that cross-reactivity between APS autoantigens and mimotopes expressed by human gut commensals can lead to B cell tolerance breakdown and are sufficient for APS development. However, B cell targeting therapies are surprisingly not as effective as expected in APS compared to other autoimmune diseases. Elucidation of the B cell tolerance breakdown mechanisms in APS patients may help to develop and guide the use of novel therapeutic agents that target B cells or specific immune pathway.

Keywords: Antiphospholipid syndrome; Autoantibody; Autoimmunity; B cell; Thrombosis; Tolerance.

Publication types

  • Review

MeSH terms

  • Antibodies, Antiphospholipid
  • Antiphospholipid Syndrome*
  • Autoimmune Diseases*
  • B-Lymphocytes
  • Humans
  • Phenotype


  • Antibodies, Antiphospholipid