Intravenous antibodies can be used as add-on therapy to reduce the dosage of corticosteroids and achieve disease remission in people with scleroderma-associated myopathy (SScAM), or muscle disease, a study suggests.
The study, “Corticosteroid-sparing benefit of intravenous immunoglobulin in systemic sclerosis-associated myopathy: A comparative study in 52 patients,” was published in the journal Autoimmunity Reviews.
Muscle involvement is one of the most serious symptoms of scleroderma. Depending on the definition of SScAM, the prevalence of this complication may be as high as 96% among people with scleroderma.
SScAM is associated with poor outcomes, including disability, and still lacks consensus on appropriate treatment.
Researchers suggest that therapy should focus on muscle inflammation, or myositis, as this approach has been associated with good prognosis. Corticosteroids are commonly used for the treatment of myositis in scleroderma. However, high doses are often necessary, which may carry a risk of kidney disease.
Intravenous immunoglobulins (IVIg), which are antibodies administered directly into the bloodstream, reduce inflammation and have been used in the treatment of myasthenia gravis and other autoimmune diseases. However, IVIg is not a recommended for scleroderma.
Researchers in France evaluated the use of IVIg to treat SScAM using data from patients seen at Cochin University Hospital between 1993 and 2017.
Their study included 52 patients with scleroderma: 18 with limited scleroderma (affecting the skin, including hands and face) and 34 with diffuse disease, which typically affects internal organs such as the heart, lungs, and intestinal tract.
SScAM occurred at a median of one month (maximum 15 months) after the diagnosis of scleroderma.
Thirty-four (65.4%) participants developed muscle weakness, 28 (53.8%) had myalgia, or muscle pain, and 24 (46.2%) showed dysphagia (problems swallowing). Fifty patients (96.2%) showed elevated levels of creatine kinase, a marker of muscle inflammation.
Results from muscle biopsy showed abnormalities in 49 of the 50 patients who underwent the procedure. The most predominant findings were that inflammation was found in 32 patients (64%) and necrosis (cell death) in 31 (62%).
Eighteen patients (34.6%) received IVIg, which was mainly prescribed in combination with corticosteroids. The median duration of IVIg treatment was 10 months.
Patients were followed up for a median of 79 months (about 6.5 years). Forty-six participants (88.5%) achieved remission, including all who had received IVIg and 28 patients (82.4%) who did not receive the treatment.
Eight patients (15.4%) experienced a relapse, half of whom were receiving IVIg. The median time to relapse was longer in those on IVIg (23 months) compared with participants not receiving the therapy (13 months). However, this was not a statistically significant difference.
Severe adverse events were found in three of the 18 patients, or 16.7%, who were treated with IVIg. This is a similar rate as previously described in other autoimmune diseases, the researchers said.
Importantly, when compared to patients who received corticosteroids but not IVIg, those who received both treatments were able to lower their dosage of corticosteroids at one year and at the end of follow-up — median dosage of 5 mg/day in people on IVIg vs 7.5 mg/day in those on corticosteroids only.
“This study suggests the benefit of IVIg as adjunctive therapy, with an acceptable tolerance profile, and supports its use as a [corticosteroid]-sparing agent, in SScAM,” the scientists wrote.