[Refractory dermatomyositis associated with chronic organizing pneumonia treated with rituximab: report of one case]

Area of Science:

• Rheumatology and Pulmonology
• Immunotherapy and Autoimmune Diseases

Background:

• Chronic organizing pneumonia (COP) is a known pulmonary manifestation of collagen vascular diseases, predominantly rheumatoid arthritis.
• The association between COP and dermatomyositis (DM) is infrequently documented in medical literature.
• Standard treatments for refractory autoimmune-related lung disease often include corticosteroids and other immunosuppressants.

Observation:

• A 55-year-old woman with established dermatomyositis presented with refractory COP.
• The patient showed poor response to steroids, cyclophosphamide, and azathioprine therapies.
• Initial treatment with rituximab resulted in improved muscle strength and normalized inflammatory markers.

Findings:

• A relapse occurred after 6 months, characterized by elevated muscle enzymes, fever, and muscle weakness.
• A second course of rituximab led to significant clinical improvement, including increased muscle strength and reduced creatine kinase levels.
• High-resolution chest CT scans demonstrated substantial resolution of pulmonary abnormalities post-rituximab treatment.

Implications:

• B-cell depletion therapy using rituximab may represent a viable therapeutic strategy for patients with dermatomyositis and refractory COP.
• Rituximab, alone or in combination with other immunosuppressants, shows promise for managing complex autoimmune-related pulmonary conditions.
• This case highlights the potential of targeted immunotherapies in challenging autoimmune-associated lung diseases.