Abstract Introduction Pulmonary manifestations of autoimmune hepatitis (AIH) represent a rare complication which is believed to share a common pathophysiologic basis. A very little association has been published between AIH and ILD. We present a rare case of progressive ILD associated with previously treated AIH. Case A 65-year-old male, former smoker, with a history of AIH treated and off therapy, presented with 6 months of progressive dyspnea, cough worsening over month. He denied systemic symptoms and environmental exposure other than Mold exposure. On arrival, he was tachycardic, and hypoxic. HRCT demonstrated diffuse pulmonary fibrosis with reticulation, traction bronchiectasis, airway centered fibrosis, upper lobe predominant emphysema, and early posterior basal honeycombing. Differentials for ILD remained broad and further work up with PFT showed severe restriction and decreased DLCO, ECHO showed elevated Pulmonary artery pressure, Labs showed ANA 1:1280, p-ANCA positive, elevated aldolase, negative MPO, PR3, and ENA panels. Liver and renal function were normal. He was treated for an ILD flare with steroids and antibiotics, later transitioned to inhaled bronchodilators. Up on multidisciplinary team review it was favored the diagnosis is Pulmonary fibrosis and emphysema with AIH-related progressive fibrosing ILD. Antifibrotic treatment was initiated along with evaluation for lung transplant. Discussion This rare case demonstrates progressive ILD developing years after remission of AIH. The differential diagnosis of conditions underlying ILD is a fascinating topic involving multidisciplinary team pulmonology, rheumatology and radiology. There are very few reports in the literature describing the association between AIH and pulmonary interstitial involvement which may represent a systemic autoimmune extension of AIH suggesting a possibility of shared immune dysregulation affecting both tissues. In this case, anti-RNP positivity raises the possibility of IPAF but HRCT pattern showing features suggestive of UIP. Distinguishing AIH associated ILD from other forms of ILD is challenging. The lack of systemic autoimmune features and negative autoimmune work up points towards AIH related progressive ILD as the most appropriate diagnosis. Management remains controversial as evidence guiding therapy is limited. Given the progressive disease, evaluation for lung transplantation is appropriate. Conclusion It is important to determine which type of AIH shares common pathophysiological mechanism with ILD, because it has diagnostic and therapeutic implications and may have prognostic significance. This case illustrates the potential link between AIH and fibrosing ILD, underscoring need for awareness of pulmonary complications in AIH. Early multidisciplinary evaluation, pulmonary function monitoring, and timely referral for advanced therapies are crucial to improving outcomes. This abstract is funded by: None
Komminni et al. (Fri,) studied this question.