Anti-ribosomal P antibodies and lupus nephritis.

Increasing attention has been paid to the relationship of autoantibodies to ribosomal P proteins (anti-P) with lupus nephritis. Several mechanisms of involvement of anti-P in lupus nephritis have been proposed, including cross-reactivity with anti-dsDNA and anti-endothelial cell antibodies (AECA). In addition, it is also suggested that anti-P might play a role in the development of lupus nephritis through induction of T helper 1 responses. Of note, recent studies have disclosed that the presence of isolated anti-P antibodies may discriminate patients with pure class V lupus nephritis, whereas the simultaneous presence of anti-dsDNA antibodies suggests class V disease with concomitant proliferative lesions. These observations lead to the hypothesis that anti-P and anti-dsDNA might result in membraneous changes and proliferative changes, respectively, although further investigation is required for confirmation.