From the Guidelines
The recommended dosage of Privigen (Intravenous Immunoglobulin, IVIG) for dermatomyositis is 1 to 2 g/kg of ideal body weight, usually given over 2 consecutive days (1 g/kg each on day 1 and day 2) once a month for 1 to 6 months. This dosage is based on the study published in the Mayo Clinic Proceedings 1, which suggests that IVIG treatment can lead to improvement in muscle strength, rash, and activities of daily living (ADL) in patients with dermatomyositis.
Key Considerations
- The serum IgA level should be checked before administering IVIG because IgA deficiency may lead to fever, infusion reactions, and/or severe anaphylaxis 1.
- If IgA deficiency is detected, the patient should receive an IVIG preparation with reduced IgA levels 1.
- If the dose of IVIG is higher than 80 g, it may be administered over 3 to 5 days at 0.4 g/kg 1.
Mechanism of Action
- IVIG works by blocking of Fc receptors, inhibition of complement activation, influencing antigen recognition by sensitized T cells, and modulation of Fc-receptor mediated activity leading to down-regulation of phagocytosis 1.
Clinical Response
- Treatment duration varies, but many patients require 3-6 months of therapy before reassessment, with some needing maintenance therapy for longer periods.
- Prior to administration, patients should be well-hydrated, and premedication with acetaminophen, diphenhydramine, and sometimes corticosteroids may help reduce infusion reactions.
From the Research
Privigen IVIG Dosage for Dermatomyositis
The recommended dosage of Privigen (Intravenous Immunoglobulin, IVIG) for dermatomyositis is as follows:
- The standard dose is 2 g/kg, given in two to five individual daily doses 2
- The course of IVIG treatment is usually 3~6 months 2
- In some studies, IVIG was administered at a dose of 2.0 g/kg every 4 weeks 3
Efficacy of IVIG in Dermatomyositis
The efficacy of IVIG in improving skin symptoms in patients with dermatomyositis has been demonstrated in several studies:
- A double-blind, randomized, multicenter, Phase 3 study (ProDERM) showed that IVIG significantly improved dermatological symptoms in patients with DM, regardless of disease severity before treatment 3
- A retrospective review of 42 patients treated with IVIG for refractory cutaneous DM found that 83% of patients had cutaneous DM improvement, including 87% treated for refractory skin disease alone and 81% treated for refractory skin/muscle/lung disease 4
- A study of 23 patients with dermatomyositis/polymyositis treated with IVIG found that IVIG treatment resulted in significant improvement in muscle strength, reduction of creatinine phosphokinase levels, and steroid dosage 5
Predictors of Response to IVIG
Some studies have investigated predictors of response to IVIG in dermatomyositis: