High-dose intravenous immunoglobulin therapy for scleromyxoedema: a prospective open-label clinical trial using an objective score of clinical evaluation system

Background: Scleromyxoedema is a primary fibro-mucinosis whose therapy is still challenging. Objective: To evaluate the safety and efficacy of high-dose intravenous immunoglobulin (IVIg) for the management of scleromyxoedema prospectively using an objective score. Methods: In a prospective open-label study, IVIg was administered to eight patients with scleromyxoedema in a dose of 2 g/kg per month. The patients were followed-up to a minimum of 6 months, and their disease activity and response to treatment were assessed using the Physician's Global Assessment of disease severity (PGA) and a modified objective skin scoring system for patients with scleroderma (modified Rodnan score system for scleromyxoedema or mRSSS). We used a stringent statistical nonparametric test, the Mann-Whitney U-test, to assess the changes in the mRSSS following therapy with IVIg. Results: Eight patients were included (five males) with a mean age of 59 years. Mean duration of scleromyxoedema was 19 months (6-37 months). The mean duration of treatment was 36.5 months (range 7-74 months).The patients were followed-up for a minimum of 15 months to a maximum of 87 months (mean 44 months). The mean baseline mRSSS of our cohort was 82.38 (37-145, SD 40.763) at the start of treatment, and this significantly decreased to 14.88 (0-37, SD 12.988) (P = 0.012) at the last clinical evaluation with a decrease in mRSSS of 81.6%. No considerable side effects were noted. Paraproteinemia remained substantially unchanged. In six cases, maintenance infusions were required to preserve disease control, while in two patients, therapy was stopped after 7 and 11 months. Relapses, however, occurred, respectively, after 6 and 25 months. Conclusions: Our study is the first to demonstrate a statistically clinical objective improvement of clinical symptoms of scleromyxoedema with IVIg.