CVID is a multifactorial antibody deficiency that can be associated with autoimmunity, which some studies have proposed to be secondary to altered CD21 expression.
With this novel tool, we show that disruption of the critical C3d-CR2 ligand-receptor binding step alone substantially ameliorates autoimmunity and renal disease in the MRL/<i>lpr</i> model of SLE.
Although the reduced expression of complement receptor 1 (CR1, CD35) and 2 (CR2, CD21) on the B cells of RA patients has been known for a long time, their exact role in B-cell tolerance and autoimmunity is not yet fully understood.
While we identified new single nucleotide polymorphism (SNP) and confirmed previously reported SNPs, none of the SNPs was associated with MS. Our findings demonstrate that sCD21 expression is altered in MS patients similar to other autoimmune diseases although no evidence was found for a specific role of the CD21 gene in MS.
A subset of patients with common variable immunodeficiency (CVID), group 1a of the Freiburg classification, is characterized by increased B cells expressing low levels of CD21 (CD21(low) ), lymphoproliferation and autoimmunity.
Complement receptor 2-negative (CR2/CD21(-)) B cells have been found enriched in patients with autoimmune diseases and in common variable immunodeficiency (CVID) patients who are prone to autoimmunity.
Human complement receptor type 2 (CR2/CD21) is a B lymphocyte membrane glycoprotein that plays a central role in the immune responses to foreign Ags as well as the development of autoimmunity to nuclear Ags in systemic lupus erythematosus.