Subcutaneous versus intravenous immunoglobulin in multifocal motor neuropathy: a randomized, single-blinded cross-over trial

For treatment of multifocal motor neuropathy (MMN), we hypothesized that (i) infusion of equivalent dosages of subcutaneous immunoglobulin (SCIG) is as effective as intravenous immunoglobulin (IVIG) and that (ii) subcutaneous infusion at home is associated with a better quality of life. In a randomized single-blinded cross-over study, nine IVIG responsive patients were allocated to receive either SCIG or IVIG for a period equivalent to three IVIG treatment intervals and, subsequently, crossed over to the other treatment. Primary end-points were (i) dynamometric strength of affected muscles and (ii) the SF-36 quality of life questionnaire. The two treatments were equally effective, the mean change in muscle strength after SCIG being 3.6% (95% CI -3.6% to 10.9%) vs. 4.3% (-1.3% to 10.0%) after IVIG (P = 0.86). One patient had sustained erythema and oedema at the injection sites for a few weeks. All other adverse effects during SCIG were mild and transient. No differences between treatments of health-related quality of life occurred. In MMN, short-term subcutaneous infusion of immunoglobulin is feasible, safe and as effective as intravenous infusion. Subcutaneous administration is an alternative option that adds flexibility to the treatment schedule.