OBJECTIVE
To identify anti-idiotype antibody activity against a regulatory anti-Sm idiotype (4B4) in pooled human IgG (IVIG).
METHODS
ELISA were used to determine anti-idiotype antibody activity in IVIG.
RESULTS
Anti-idiotype antibody activity to 4B4 was detected in IVIG. The anti-idiotypic activity in IVIG could be inhibited by antigen, Sm, and rabbit anti-idiotypic antiserum. The idiotypic binding activity was predominately directed against the 4B4 VH region.
CONCLUSION
IVIG contains antibodies against a lupus-associated crossreactive idiotype. These antibodies represent Ab2 beta type antibodies. The anti-idiotypic activity in IVIG may be relevant to the efficacious use of IVIG in treating rheumatic diseases.