The kidneys filter waste products from the blood and remove them from the body through urine. The most common kidney problem in people with Sjögren's is interstitial nephritis, or inflammation of the tissue around the kidney's filters, which can occur even before dry eyes and dry mouth. Inflammation of the filters themselves, called glomerulonephritis, is less common. Some people develop renal tubular acidosis, which means they can't get rid of certain acids through urine. The amount of potassium in their blood drops, causing an imbalance in blood chemicals that can affect the heart, muscles, and nerves.
Often, doctors do not treat these problems unless they start to affect kidney function or cause other health problems. However, they keep a close eye on the problem through regular exams, and will prescribe medicines called alkaline agents to balance blood chemicals when necessary. Corticosteroids or immunosuppressants are used to treat more severe cases.