BACKGROUND: Intravenous immunoglobulin (IVIg) is an effective treatment in @entity2646 ( @entity2646 ). In most @entity1 , the optimal IVIg dose and regime is unknown. Polyvalent immunoglobulin (Ig) G form idiotypic/anti-idiotypic antibody pairs in serum and IVIg preparations. We determined IgG dimer levels before and after IVIg treatment in @entity2646 @entity1 with the aim to explore their utility to serve as a surrogate marker for treatment response. METHODS: IgG was purified from serum of five controls without treatment, as well as from serum of 16 @entity2646 @entity1 , two @entity1 with @entity4894 ( @entity4894 ), and one @entity1 with @entity1737 before and after treatment with IVIg. IgG dimer levels were determined by size exclusion chromatography. IgG dimer formation was correlated with clinical response to IVIg treatment in @entity2646 . Re-monomerized IgG dimer fractions were analyzed for immunoreactivity against peripheral nerve tissue. RESULTS: IgG dimer levels were significantly higher in post- compared to pre-IVIg infusion samples. Low post-treatment IgG dimer levels in @entity2646 @entity1 were associated with clinical worsening during IVIg treatment. Re-monomerized IgG dimer fractions from @entity2646 @entity1 showed immunoreactivity against peripheral nerve tissue, whereas similarly treated samples from @entity4894 @entity1 showed immunoreactivity against GQ1b. CONCLUSION: Assessment of IgG dimer levels could be a novel approach to monitor @entity2646 @entity1 during IVIg treatment, but further studies in larger cohorts are warranted to explore their utility to serve as a potential therapeutic biomarker for IVIg treatment response in @entity2646 .

@entity2646 ( XXXX ): change of serum IgG dimer levels during treatment with intravenous immunoglobulins.

@entity1 :: ('9606', 'Species') :: ['patients', 'patient'] @entity2646 :: ('MESH:D020277', 'Disease') :: ['CIDP', 'chronic inflammatory demyelinating polyneuropathy'] @entity1737 :: ('MESH:D009157', 'Disease') :: ['myasthenia gravis'] @entity4894 :: ('MESH:D019846', 'Disease') :: ['MFS', 'Miller Fisher syndrome']
@entity2646 :: (MESH:D020277,Disease) :: ['CIDP']
