A Case of Sjögren's Syndrome Complicated with Interstitial Nephritis and Delayed Onset Autoimmune Hepatitis.

A 61-year-old woman was admitted to our hospital because of muscle paralysis and was found to have severe hypokalemia. A gallium-67 scintigram revealed a positive accumulation in the bilateral salivary glands, and a labial minor salivary gland biopsy demonstrated a massive lymphocyte infiltrate around the salivary ducts. She was diagnosed with Sjögren's syndrome (SS) associated with renal tubular acidosis. Renal biopsy revealed tubulointerstitial nephritis with a mild focal infiltration of lymphocytes and plasma cells. These pathological features were compatible with SS with renal involvement. Acidosis and hypokalemia were corrected with sodium bicarbonate and potassium chloride, which relieved the patient's symptoms. Although steroid therapy has been reported to be effective in SS-associated tubulointerstitial nephritis, the patient's serum potassium level could be controlled without administering steroids during the first admission. Five years later, she was admitted again because of severe liver dysfunction attributed to autoimmune hepatitis. Oral administration of prednisolone resulted in the normalization of her transaminase levels, and the control of her serum potassium level became easier. It has been reported that patients with SS with salivary gland involvement tend to have hepatic complications, and those with hepatic complications tend to have renal involvement. Physicians should be aware of hepatic involvement, even if there is no liver dysfunction at the initial diagnosis of SS with salivary gland and renal involvement. It remains uncertain whether the administration of a low dose of steroids before the onset of autoimmune hepatitis might have prevented the development of liver dysfunction in our patient.