[Tubulo-interstitial nephritis and uveitis syndrome--TINU syndrome]

Acute tubulo-interstitial nephritis and uveitis (TINU syndrome) in a 53-year-old woman is reported. This rare syndrome was described 27 years ago by Dobrin et al. Since then about 50 cases have been described. The syndrome can appear at any age but most patients are under 20 years; about 75% are females. Clinical characteristics include fatigue, general malaise, weight loss, fever, night sweats, anorexia, nausea and vomiting, pallor, nocturia, polyuria, arthralgia and skin rash. Ocular involvement usually includes anterior uveitis but is sometimes posterior; in most cases the uveitis is bilateral. The characteristic laboratory findings are anemia, rapid sedimentation rate, decreased glomerular filtration rate with increased serum creatinine and urea. Total protein is increased because of polyclonal gammopathy and elevated beta 2-microglobulin. Urinalysis characteristically reveals proteinuria and beta 2-microglobulinuria. The histopathologic features on renal biopsy are characteristic of tubulo-interstitial nephritis. Uveitis can precede, accompany or follow onset of the nephropathy. The pathogenesis and etiology of the syndrome are as yet unknown. Treatment consists of large doses of corticosteroids, but the necessity for treatment is unclear, since there is evidence of spontaneous improvement. Although the prognosis of the nephropathy is favorable and most cases are reversible, the uveitis tends to recur.