Hepatopulmonary Syndrome in a Patient With Autoimmune Hepatitis Without Liver Cirrhosis: A Case Report.

Intrapulmonary vasodilation leads to impaired arterial oxygenation, a hallmark of hepatopulmonary syndrome (HPS), a common pulmonary complication in end-stage liver disease. We present a case of HPS primarily diagnosed due to orthodeoxia in a 62-year-old ex-smoker with autoimmune hepatitis, under immunosuppressive treatment, but without liver cirrhosis. The patient reported dyspnea at rest that improved when supine. A recent chest CT scan showed no pulmonary embolism but indicated small nodules, bronchiectasis, and emphysema lesions. Functional breath monitoring revealed a low diffusing capacity for carbon monoxide (48% predicted). Blood gas analysis showed an increased alveolar-arterial difference, and contrast-enhanced echocardiography confirmed HPS with bubbles in the left heart chambers after the fourth cardiac cycle. Lung perfusion scintigraphy was negative for thromboembolic disease, but kidney imaging reinforced the HPS diagnosis. Our case is, to the best of our knowledge, the first presentation of HPS in a patient with autoimmune hepatitis without evidence of liver cirrhosis. This case highlights a rare instance of HPS in a patient with autoimmune hepatitis without liver cirrhosis, where orthodeoxia was the first clinical manifestation.