Receptor editing and receptor revision in rheumatic autoimmune diseases.

Receptor editing is a key mechanism of B cell tolerance that modifies the B cell receptor (BcR) specificity of self-reactive lymphocytes. It acts through initiation of secondary immunoglobulin rearrangements, through generation of newly rearranged endogenous lambda chains that displace kappa chains, or through isotypic and allelic inclusion of dual BcRs (kappa(+)/lambda(+) or kappa(+)/kappa(+) B cells). Mounting evidence indicates that receptor editing is either impaired or accelerated in patients suffering from rheumatic autoimmune diseases. Remarkably, both alterations can promote the pathogenesis of autoimmune disorders by favoring the uncontrolled emergence and/or persistence of autoreactivity. Whereas impaired secondary rearrangements might result in ineffective silencing of B cells, exacerbation of receptor editing can give rise to autoreactive receptors from clones that were initially devoid of autoreactivity.