Autoimmune Interstitial Lung Disease and Hepatitis C, An Interesting Association: Two Case Reports

The hepatitis C virus (HCV) is a hepatotropic and lymphotropic virus. Its infection generates a chronic stimulus to the immune system, giving rise to a wide range of systemic diseases with rheumatological, hematological, neurological, renal, and pulmonary manifestations. Interstitial lung disease (ILD) is one of the most common and harmful direct effects of chronic HCV infection in the lung. However, polyarthralgia and arthritis are the most common rheumatic conditions associated with this infection. There are also less common ones, such as myopathies, including anti-synthetase syndrome (ASS). Although immune syndromes are common in patients with chronic HCV infection, their pathogenesis for some illnesses is often unclear. This case report discusses the association between ILD, hepatitis C, and rheumatologic diseases. We cover clinical manifestations, theories of pathogenesis, and the importance of selecting appropriate treatment for these patients. Two clinical cases are presented, both diagnosed with ILD associated autoimmune diseases in patients with HCV infection. The first case is a 76-year-old man with progressive dyspnea, dry cough, muscle weakness, and joint pain in both hands. Physical examination revealed dry velcro-type crackles and the presence of clubbing. Laboratory studies showed a hepatitis C viral load detectable by PCR, positive rheumatoid factor (RF), and anti-CCP. Chest CT scan showed a usual interstitial pneumonia pattern (UIP). Therefore, this patient was diagnosed with interstitial lung disease and concomitant rheumatoid arthritis (RA) due to HCV infection. The second case is a 44-year-old woman complaining of dry cough and dyspnea, chest tightness, odynophagia, itching, and nasal congestion. On physical examination, bilateral subscapularis fine crackles, mechanic's hands. Blood laboratory analyses revealed a positive hepatitis C antibody test with hepatitis C virus viral load undetectable by PCR, RF: (+), anti-Ro-52 (+); anti-PL-12 (+), anti-Ro/SSA 52 (+). Chest CT scan showed a pattern of organizing pneumonia (OP). As a result, we diagnosed the patient with ILD, ASS, and past infection with the HCV. HCV and autoimmune diseases affect multiple systems, with lung involvement being a poor prognosis in both cases. Our case reports demonstrate positive outcomes in treating challenging diseases through close patient monitoring and individualized treatment decisions based on their needs, despite the absence of treatment guidelines for these patients.