Tubulointerstitial nephritis and uveitis syndrome with transient hyperthyroidism in an elderly patient

Abstract

A 69-year-old Japanese woman without any specific medical or family history was admitted to our hospital for renal insufficiency with proteinuria. On laboratory examinations, deteriorated renal function (blood urea nitrogen level was 34.9 mg/dL and creatinine level was 1.78 mg/dL) and elevated urinary levels of N-acetyl-β-D-glucosaminidase (23.4 U/L) and β2-microgloblin (20200 μg/L) were observed. We performed a renal biopsy. The biopsied specimen showed severe diffuse infiltration of mononuclear cells into the interstitium, with normal glomeruli, and these findings were compatible with acute tubulointerstitial nephritis (ATIN). At that time, ATIN seemed to be idiopathic. We performed gallium scintigraphy, and the results revealed uptake by the bilateral kidneys, thyroid gland, and right parotid gland. Serum thyroid stimulating hormone (TSH) was undetectable, free triiodothyronine was normal (3.11 pg/mL), and free thyroxine was elevated to 2.4 ng/dL. The titers of antithyroglobulin and antithyroid microsomal and TSH-receptor antibodies were not elevated. Two months later, burning pain and conjunctival congestion developed in both eyes. She had uveitis, as diagnosed by slit-lamp examination. Topical corticosteroid was used for the uveitis with success. We could not detect any cause of the uveitis, so a diagnosis of tubulointerstitial nephritis and uveitis syndrome (TINU syndrome) with associated hyperthyroidism was made. Treatment was started with 15 mg/day of prednisolone. Now her renal function is slowly recovering. There are few reports of TINU syndrome with transient hyperthyroidism. This case suggests the possibility of thyroid dysfunction in patients with TINU syndrome. A laboratory evaluation of thyroid function should be considered in the diagnostic evaluation of TINU syndrome.