What is the treatment dosage for Interstitial Lung Disease (ILD) in patients with Mixed Connective Tissue Disease (MCTD)?

From the Guidelines

The treatment of interstitial lung disease (ILD) associated with mixed connective tissue disorder (MCTD) should begin with glucocorticoids as a first-line ILD treatment, according to the 2023 American College of Rheumatology (ACR)/American College of Chest Physicians (CHEST) guideline 1. The dosage of glucocorticoids typically starts with prednisone at 0.5-1 mg/kg/day (typically 30-60 mg daily) for 4-6 weeks, followed by a gradual taper over several months based on clinical response. For patients with moderate to severe disease or those who don't respond adequately to steroids, immunosuppressive agents such as mycophenolate mofetil (1-3 g/day in divided doses) or azathioprine (1-2 mg/kg/day) may be added 1. Alternatively, cyclophosphamide (1-2 mg/kg/day orally or 500-750 mg/m² IV monthly for 6 months) may be used for rapidly progressive disease. Rituximab (1000 mg IV on days 1 and 15, repeated every 6 months) may be considered for refractory cases. Tocilizumab is also conditionally recommended as a first-line ILD treatment option for people with MCTD-ILD 1. Supportive care includes oxygen therapy for hypoxemia, pulmonary rehabilitation, vaccination against pneumococcal disease and influenza, and management of gastroesophageal reflux. Treatment should be individualized based on disease severity, progression rate, and organ involvement, with regular monitoring of pulmonary function tests and high-resolution CT scans to assess response. The goal is to stabilize lung function and prevent irreversible fibrosis, as MCTD-associated ILD can significantly impact quality of life and survival if left untreated. Some key points to consider in the treatment of ILD in MCTD include:

• The use of nintedanib is conditionally recommended against as a first-line ILD treatment option for people with MCTD-ILD 1.
• The use of pirfenidone is also conditionally recommended against as a first-line ILD treatment option for people with MCTD-ILD 1.
• JAK inhibitors are not recommended as a first-line ILD treatment option for people with MCTD-ILD, except for those with IIM-ILD 1.
• CNIs are not recommended as a first-line ILD treatment option for people with MCTD-ILD, except for those with IIM-ILD 1. The treatment approach should prioritize the patient's quality of life, morbidity, and mortality, and be guided by the most recent and highest-quality evidence, such as the 2023 ACR/CHEST guideline 1.

From the Research

Treatment Dosage in ILD with Mixed Connective Tissue Disorder

• The treatment dosage for Interstitial Lung Disease (ILD) in patients with Mixed Connective Tissue Disorder (MCTD) is not explicitly stated in the provided studies, but various treatment options are discussed 2, 3, 4, 5, 6.
• A study published in 2021 compared the effect of rituximab ± mycophenolate mofetil (MMF) with MMF only on pulmonary function and prednisone dosage in patients with CTD-related ILD, including those with MCTD 2.
• The study found that rituximab ± MMF did not significantly change pulmonary function compared with MMF alone, but it did result in a relative decrease in average daily prednisone dose in a population with recalcitrant CTD-ILD 2.
• Another study published in 2005 evaluated the frequency and clinical picture of ILD in patients with MCTD and found that 66.6% of patients had active ILD, which was treated with corticosteroids (CS) or CS in combination with cyclophosphamide (CPH) 6.
• The study found that after 6 months of therapy, 69.8% of patients showed a negative HRCT pattern, and the carbon monoxide diffusion capacity (DLCO) was improved in some patients 6.
• A review published in 2024 discussed the treatment options for ILD, including antifibrotic therapy with nintedanib or pirfenidone, and immunomodulatory therapy with tocilizumab, rituximab, and mycophenolate mofetil for connective tissue disease-associated ILD 4.
• The review also mentioned that lung transplant may be considered for patients with advanced ILD, and that exercise training and oxygen therapy can improve symptoms and quality of life in patients with ILD 4.

Treatment Options

• Rituximab ± mycophenolate mofetil (MMF) 2
• Mycophenolate mofetil (MMF) alone 2, 5
• Corticosteroids (CS) or CS in combination with cyclophosphamide (CPH) 6
• Antifibrotic therapy with nintedanib or pirfenidone 4
• Immunomodulatory therapy with tocilizumab, rituximab, and mycophenolate mofetil 4
• Lung transplant 4
• Exercise training and oxygen therapy 4