[Clinical application of autoantibody idiotypes].

Idiotypes (Id) are unique antigenic determinants in hypervariable regions of immunoglobulins. This paper describes the clinical usefulness of Id for the determination of pathogenic autoantibodies. O-81-Id, human anti-DNA antibody idiotypes, were specifically detected in circulating and renal glomeruli-deposited immune complexes of patients with active lupus nephritis. Anti-idiotypic antibodies to anti-DNA antibodies could be also detected in human sera. Anti-Id antibodies to O-81-Id occurred spontaneously during the remission of systemic lupus erythematosus (SLE) but rarely during an acute episode. Monoclonal anti-Id antibodies had an ability to suppress in vitro anti-DNA antibody production by SLE lymphocytes. We also presented specific manipulation of anti-DNA production though the elimination of anti-DNA-Id-positive cells by using anti-Id-cytotoxic agent conjugates.