Which myositis patients are good candidates for IVIG?

Good candidates for IVIG in myositis include any patient with refractory dermatomyositis, refractory necrotizing myopathy, anti-HMGCR antibody-positive patients, as well as patients with dysphagia, pregnancy, infection or malignancy. In general, it can be added to 1st-, 2nd- or 3rd-line treatment in any form of myositis as an adjuvant therapy to boost the response rate and lower the steroid dose.

IVIG is also useful in calcinosis, malignancy and pregnancy.

Based on the recently published ProDERM Trial, patients with dermatomyositis, especially those with muscle involvement are good candidates. However, additional published literature have demonstrated that myositis patients who have immune-mediated necrotizing myopathy (HMGCR+) in particular are good candidates for IVIG.

Amyopathic DM, the phenotype which can look like spongiotic dermatitis histologically, consistently responds to IVIG. I have not treated patients with myositis or interstitial lung disease as I defer monitoring of response to relevant specialists. But for cutaneous symptoms, IVIG will provide months of remission, sometimes years.