High-Dose IVIG Effective in Painful Diabetic Polyneuropathy Resistant to Conventional Treatments

Italian investigators at eight participating sites conducted a randomized, double-blind, placebo-controlled trial to assess the safety and efficacy of intravenous immune globulin (IVIG) in treatment-resistant painful diabetic polyneuropathy (DPN). Eight participating sites enrolled 26 diabetic patients with DPN who reported baseline pain severity greater than 60 units (mm) on a visual analog scale (VAS) at enrollment, and were resistant to antidepressants and antiepileptic drugs. Twenty-three of these patients were randomized (11 in the IVIG arm and 12 in the placebo arm), 21 of whom had a diagnosis of type II diabetes.

IVIG at a dose of 0.4 g/kg per day was administered for five consecutive days. Pain intensity reported using a VAS and qualityof-life assessments were performed at the baseline visit, at the start of therapy one week later, at the end of therapy five days thereafter, and at four- and eight-week follow-up.

The study achieved its prespecified primary end point of greater than or equal to 50 percent pain reduction at four weeks after IVIG administration, achieved in seven of 11 patients (63.6 percent) in the IVIG group versus zero of 12 in the placebo group (P = 0.0013). Only two adverse events were reported during the study: one patient in the treatment arm with a mild dermatitis psoriasiform, and one patient in the placebo arm with a mild influenza.

The investigators concluded treatment with high-dose IVIG appears to be efficacious and safe for patients with DPN resistant to standard therapies.