POOLED HUMAN-IMMUNOGLOBULINS CONTAIN ANTIIDIOTYPES WITH REACTIVITY AGAINST THE SLE-ASSOCIATED 4B4 CROSS-REACTIVE IDIOTYPE

Objective: To identify anti-idiotype antibody activity against a regul atory anti-Sm idiotype (4B4) in pooled human IgG (IVIG). Methods: ELIS A were used to determine anti-idiotype antibody activity in IVIG.Resul ts: Anti-idiotype antibody activity to 4B4 was detected in IVIG. The a nti-idiotypic activity in IVIG could be inhibited by antigen, Sm, and rabbit anti-idiotypic antiserum. The idiotpic binding activity was pre dominately directed against the 4B4 V-H region. Conclusion: IVIG conta ins antibodies against a lupus-associated crossreactive idiotype. Thes e antibodies represent Ab(2 beta) type antibodies. The anti-idiotypic activity in IVIG may be relevant to the efficacious use of IVIG in tre ating rheumatic diseases.