Clinical Images: Severe interstitial lung disease in Sjögren disease - What happens in the lungs? Inflammation or fibrosis?

The patient, a 66-year-old woman, was fi rst diagnosed with idiopathic pulmonary fi brosis (IPF) in 2015, and therapy with nintedanib was initiated. In 2020, the patient presented to our clinic for differential diagnosis. The laboratory tests revealed an elevated antinuclear antibody titer as well as anti-Ro/SSA and anti-La/SSB antibodies. Lip mucosal biopsy revealed fi ndings of lymphoplasma cellular in fi ltration of the salivary glands consistent with Sjögren disease (SD) ( A-1 and A-2 ). High-resolution computed tomography (HRCT) of the lungs showed marked bronchiectasis, subpleural and basal reticulations, and peripherally basally accentuated ground-glass opacities, but no signi fi cant honeycombing ( B-1 and B-2 ). According to the international IPF guideline, the pattern could be classi fi ed as “ probable usual interstitial pneumonia (UIP) ” (1,2). Because of the patient ’ s poor general health condition, an invasive diagnostic was not possible. Based on these fi ndings, the diagnosis of SD with severe interstitial lung disease (ILD), not responding to nintedanib, was con fi rmed. We then initiated an immunosuppressive induction therapy with cyclophosphamide and glucocorticoids, followed by a switch to mycophenolate mofetil. Due to the rapid and severe pulmonary deterioration, a single lung transplantation was performed. Microscopically, the central and peripheral lung parenchyma revealed a patchy fi brous proliferation with an extensive fi brosis pattern and lymphohistiocytic in fi ltration, especially peripheral with