Pleural effusion during interferon treatment for chronic hepatitis C

Area of Science:

• Hepatology
• Immunology
• Pulmonology

Background:

• Chronic hepatitis C treatment often involves interferon therapy.
• Recombinant interferon-alpha 2a is a common therapeutic agent.

Observation:

• A 54-year-old male developed moderate right pleural effusion during interferon-alpha 2a treatment.
• The effusion appeared 14 days after initiating 9 megaunits/day dosage.
• No symptoms of pulmonary involvement or autoimmune disease were present.

Findings:

• Pleural fluid was serous, slightly bloody, turbid, with a positive Rivalta test.
• Elevated lactic dehydrogenase or adenosine deaminase levels were absent.
• Anti-nuclear antibody titer increased to 80, but anti-DNA and anti-LKM-1 antibodies remained negative.
• No criteria for autoimmune diseases like systemic lupus erythematosus were met.

Implications:

• This is the first reported case of interferon-induced pleural effusion without other autoimmune manifestations.
• The findings suggest interferon may trigger immunological activation leading to pleuritis.
• Discontinuation of interferon led to gradual resolution of pleural effusion.