Efficacy of Subcutaneous and Intravenous Immunoglobulin in Patients with Multifocal Motor Neuropathy: A Systematic...

Multifocal motor neuropathy (MMN) is an uncommon chronic autoimmune disorder in adults. Several randomized and non-randomized studies with small sample sizes have shown promising results with subcutaneous immunoglobulin (SCIg) in MMN patients who have a stable disease course with intravenous immunoglobulin (IVIg). This systematic review aimed to compare the efficacy of SCIg and IVIg treatment in MMN patients in terms of changes in muscle power, grip strength, motor function, disability, quality of life, as well as adverse effects.

Random- or fixed-effect model was used, as appropriate, to determine the pooled weighted estimates for outcome variables, depending on the degree of heterogeneity. A total of 11 publications from nine studies (110 patients, mean age 54.3 ± 3.4 years, 57% males, duration of illness 9.7 ± 2.4 years) were included in the review.

Changes in the Medical Research Council sum score (MRC-SS), grip strength, dexterity, and disability due to neuropathy following IVIg and SCIg administration were comparable ( P = 0.30, I ² = 9%; P = 0.51, I ² = 0%; P = 0.45, I ² = 0%; and P = 0.57, I ² = 0%, respectively). Changes in health-related quality of life were numerically better with SCIg, although the difference did not reach statistical significance ( P = 0.17, I ² = 72%,). Over the long term, there was a trend toward fewer disease fluctuations compared to IVIg ( P = 0.43), and the efficacy comparable to IVIg was maintained in terms of muscle strength, disability, and quality of life parameters ( P = 0.83, 0.85, and 0.59, respectively). The incidence of moderate to severe systemic adverse effects was significantly lower with SCIg infusion compared to previous years when patients received IVIg ( P = 0.03).

SCIg can be considered an acceptable alternative to IVIg in patients with MMN, with a better safety profile.