A new study from France found that treatment with intravenous immunoglobulins (IVIG), known to have anti-fibrotic activity, is effective in improving muscle, joint and digestive tract function in patients with systemic sclerosis (SSc).
The study, “Intravenous immunoglobulins in systemic sclerosis: data from a French nationwide cohort of 46 patients and review of the literature,” was published in the journal Autoimmunity Reviews.
Current treatments for SSc are aimed at minimizing symptoms caused by general organ failure. There is no therapeutic strategy to hinder or reverse the excessive synthesis of collagen fibers (fibrosis) in the tissues.
IVIG exhibit immunomodulatory and anti-fibrotic properties, and could be a promising treatment for SSc.
Researchers recruited 46 SSc patients across France who received at least one IVIG cycle. Most of them were middle-age women diagnosed with SSc in the last four years. Their most frequent complications included digestive tract involvement (89%), muscle involvement (78%), interstitial lung disease (ILD; 57%), digital ulcers (52%), and joint involvement (50%).
The patients analyzed received a mean of 14.5 IVIG cycles administered over more than one year (mean 14.8 months). The administration protocols differed between them, but most (91%) were given the usual dosage of 2.0 g/kg each cycle.
By comparing symptoms before the first and after the last IVIG cycle, researchers found that IVIG cycles significantly improved muscle pain (74% vs. 20%), muscle weakness (45% vs. 21%), and joint pain (44% vs. 19%). There was a trend toward improvement of gastro-esophageal reflux disease (68% vs. 53%) and bowel symptoms (42% vs. 27%), but skin and cardiorespiratory involvements remained stable.
Levels of creatine kinase (CK) and C-reactive protein (CRP) also decreased after treatment, which indicates improved muscle function and less inflammation, respectively.
Interestingly, at the end of treatment, patients were taking lower levels of corticosteroids. “We found that corticosteroid daily doses were significantly lower at the end of IVIG treatment than at the beginning. A potential corticosteroid-sparing effect of IVIG has been reported in SSc and in other autoimmune diseases. Whether these results reflect an actual efficacy of this treatment on corticoresistance remains unclear,” the team wrote.
Only two severe adverse events were reported in the group, showing that IVIG treatment is globally well-tolerated in SSc patients.
“Our work suggests that IVIG are a safe therapeutic option that may be effective in improving musculoskeletal involvement, systemic inflammation, [and] digestive tract symptoms, and could be corticosteroid sparing,” the team concluded.
Researchers do not know the exact mechanism of IVIG’s beneficial action in SSc patients. It may target fibrotic and inflammatory processes that contribute to SSc. Also, it remains unclear whether IVIG treatment is effective in improving skin and lung function. Future clinical trials will help answer these questions.