Pharmacokinetics of intravenous immunoglobulin in multifocal motor neuropathy.
Autor(es): Vlam Lotte; Cats Elisabeth A.; Willemse Eline; Franssen Hessel; Medic Jelena; Piepers Sanne.; Veldink Jan H.; van den Berg Leonard H.; van der Pol W-Ludo
Resumo: Multifocal motor neuropathy (MMN) is often responsive to treatment with intravenous immunoglobulin (IVIg), but the optimal dose and intervals of IVIg maintenance treatment have not been established. Increase in IgG concentration (?IgG) after IVIg infusion has recently been identified as determinant of outcome in Guillain-Barré syndrome. ?IgG may therefore represent a potentially useful biomarker to optimise IVIg dosing in patients with MMN. The aims of this study were to determine variability of IVIg pharmacokinetics in patients with MMN in relation to treatment response, and to establish whether interindividual differences in IVIg pharmacokinetics were associated with genetic polymorphisms of the endothelial IgG receptor (FcRn) which determines IgG half-life. Twenty-three patients with MMN receiving their first IVIg treatment at a cumulative dose of 2.0 g/kg in 5 days were included. A good treatment response was defined as an increase in muscle strength of at least one Medical Research Council point in minimally two muscle groups. IgG concentrations in serum were determined at baseline, at day 1 and day 5 of the IVIg course, and 3 weeks after treatment. FcRn copy number variation and differences in repeat length of the variable number of tandem repeats in the FcRn gene were determined by quantitative PCR and Sanger sequencing. Seventeen patients (74%) had a good response to treatment. Total IgG and ?IgG levels showed large variation between patients. Mean ?IgG was higher in IVIg responders than in non-responders, with the largest difference on day 1 (11.1 g/L vs 4.5 g/L, p=0.06), but our study lacked power to show statistically significant differences. Genetic variation in the FcRn gene was not associated with ?IgG levels or response to treatment. IVIg pharmacokinetics varies in patients with MMN and may be associated with clinical response.
Palavras-Chave: Neuroimmunology, Neuropathy
Imprenta: Journal of Neurology, Neurosurgery, and Psychiatry, v. 85, n. 10, p. 1145-1148, 2014
Identificador do objeto digital: 10.1136/jnnp-2013-306227
Descritores: Guillain-Barre Syndrome - DNA ; Guillain-Barre Syndrome - Genome ; Guillain-Barre Syndrome - Molecular Structure ; Guillain-Barre Syndrome - Pathogenesis ; Guillain-Barre Syndrome - Proteins ; Guillain-Barre Syndrome - Antibodies ; Guillain-Barre Syndrome - Clinical examination
Data de publicação: 2014
