Tubulointerstitial nephritis and uveitis syndrome (TINU) is a rare disorder occuring in less than 2% of cases of uveitis. Diagnosis requires the presence of both tubulointerstitial nephritis and uveitis.
We present a 14-year old boy with TINU confirmed by renal biopsy. Persistent impairment of renal function required the use of oral corticosteroids for a total of 33 weeks, which resulted in overall improvement.
TINU syndrome is probably an underdiagnosed disorder and must be actively searched in either patients with uveitis or tubulointerstitial nephritis. Symptoms of uveitis and nephritis are not always present at the same time.
Tubulointerstitial nephritis in our patient very probably preceded the manifestation of uveitis by several months.