Interstitial pneumonia and nephritis with Sjögren's syndrome: successful treatment with corticosteroid therapy

A Sixty-eight-year-old man complained of shortness of breath on exercise since the spring of 2001. An abnormal lung shadow was pointed out on chest X-ray and progression of renal dysfunction and high γ globulinemia were detected out on blood examination. He was admitted to the Department of Respiratory Disease in our hospital in March 2003, because of bilateral lower lung interstitial shadow, severe anemia (Hb 7.9g/dl), and renal dysfunction (S-Cr 1.9mg/dl). He was found to have hypergammaglobulinemia (IgG 2, 997mg/dl), positive RO/SS-A antigen, high serum KL-6 level (2, 050U/ml), and increased urinary excretion of β2-microglobulin (β2MG). Both Gum test and Schirmer test results were positive. Lip biopsy showed cell infiltration to the salivary glands and he was diagnosed as having Sjögren's syndrome. Renal biopsy showed diffuse interstitial cell infiltration and a Trans Bronchoscopic Lung Biopsy (TBLB) showed fibrotic thickness and lymphocyte infiltration in the alveolar septum. Accordingly, he was diagnosed as having Sjögren's syndrome complicated with both interstitial nephritis and interstitial pneumonitis. He was treated by high-dose corticosteroid therapy and anticoagulant heparin. His laboratory data showed that both serum KL-6 and urinary β2MG were reduced. Chest CT showed remarkable improvement of the interstitial shadow. A second renal biopsy performed at ten weeks after the beginning of treatment showed remarkable improvement of the interstitial cell infiltration. This is a rare case of Sjögren's syndrome complicated with interstitial nephritis and interstitial pneumonitis, treated successfully with high dose corticosteroid therapy. Both complications showed immediate improvement with high-dose corticosteroid therapy, suggesting that early steroid therapy is effective for both complications.