complement-fixing antibody

An antibody that combines with antigen leading to the binding & activation of complement. IgM strongly fixes complement (4+) by the classical pathway. IgG also fixes complement (1+) by the classical pathway. Among the subtypes of IgG: - IgG3 is the most effective binder of complement (3+) - IgG1 also binds complement (2+) - IgG2 is a weak binder of complement (+/-) - IgG4 does not bind complement

Specific

immunoglobulin-G1 (IgG1) immunoglobulin-G2 (IgG2) immunoglobulin-G3 (IgG3) immunoglobulin-M (IgM)

References

Clinical Diagnosis & Management by Laboratory Methods, 19th edition, J.B. Henry (ed), W.B. Saunders Co., Philadelphia, PA. 1996, pg 919