T- and B-cell abnormalities in systemic lupus.

A wealth of T- and B-cell abnormalities has been described in systemic lupus erythematosus (SLE). In general, T and B cells manifest evidence of intense in vivo activation, yet perform poorly when tested for in vitro responsiveness to exogenous antigen. The immune system behaves as if its commitment to self-responsiveness overrides the normal capacity to respond to immunogenic challenges. Many immunoregulatory abnormalities have been characterized, but their relation to disease remains controversial. Although a widely accepted unifying hypothesis for the vigorous autoantibody production and associated immune deficiency of SLE is lacking, it seems certain that the profound abnormalities of T and B cells in SLE are intertwined with the fundamental cause of this illness.