A 15-year-old female was admitted with a 20-day history of extreme fatigue, loss of appetite, and weight loss (7 kg in 1 month). She also had red eyes and decreased vision for 10 days. Her past medical history, as well as family history, were unremarkable. There was no history of any drug use. On physical examination at admission, her weight was 47 kg (3 to 10 percentile), height was 162 cm (50 to 75 percentile), and her blood pressure was 110/70 mmHg. Other physical examination findings were normal. Her visual acuity was 0.4 in the right and 1.0 in the left eye. Slit-lamp examination revealed a marked diffuse ciliary injection, mild corneal edema, large granulomatous keratic precipitates distributed in the Arlt's triangle, 4+ cells in the anterior chamber, Busacca nodules, posterior synechiae, and 0.5+ cells in the anterior vitreous in the right eye (Figure
1). There were fine keratic precipitates, 3+ cells in the anterior chamber, mobile pupil, and 0.5+ cells in the anterior vitreous in the left eye. Anterior chamber flare measured by laser flare photometry was 378 ph/ms in the right eye and 11 ph/ms in the left eye. Intraocular pressure was 10 mmHg in the right and 14 mmHg in the left eye. There was no vitreous haze and the fundus was normal in both eyes. Intensive topical corticosteroid therapy was started. Her laboratory findings suggested mild renal insufficiency findings: serum urea was 76 mg/dl, creatinine level was 1.2 mg/dl (glomerular filtration rate (GFR) 55.8 ml/min/1.73 m
2) both of which were elevated. The patient's erythrocyte sedimentation rate [112 mm/h] and C-reactive protein (CRP) level (2 mg/dl) were increased. Complete blood count was normal. Antinuclear antibodies were positive in speckled pattern. Anti-ds-DNA (35.45 U/ml) was elevated (normal value <25). C3 (1.5 gr/l), and C4 (0.28 gr/l) levels were found to be normal. Urinalysis showed low urine density (1005), normoglycemic glycosuria (+++, urine dipstick), and nonnephrotic proteinuria (+, urine dipstick). Spot urine protein level was 112.7 mg/dl; urinary creatinine level was 75.5 mg/dl. We found a high protein to creatinine ratio which was 0.67 (
n < 0.2) and high urinary β2-microglobulin levels (45.3 mg/l, normal values 0.02 to 0.25 mg/l). Urinary tract ultrasound examination was normal. Viral serology was noncontributory. QuantiFERON test was done to rule out tuberculosis as a possible cause of granulomatous uveitis, which was found to be negative. Chest X-ray was normal; angiotensin-converting enzyme (ACE) and lysozyme levels were normal. A renal biopsy was performed. The biopsy specimen showed dense lymphocytes, plasmocytes, and variable eosinophiles in the interstitium and tubulitis in the tubule as well as focal debris and hyaline cylinders in the tubule (Figure
2). Glomerular structures were preserved. There were no vascular lesions. There was no immune complex nephritis. These findings were consistent with acute tubulointerstitial nephritis, and the patient was diagnosed as TINU syndrome. The patient received 2 mg/kg of prednisone for 3 weeks, and then the dose was tapered and discontinued within 1 month. Her kidney function normalized after prednisone therapy. After about 3 weeks of treatment, sedimentation rate (24 mm/h) and CRP level (0.11 mg/dl) decreased. Urea (39 mg/dl) and creatinine (0.9 mg/dl) (GFR 74.3 ml/min/1.73 m
2) levels returned to normal. Urine analysis, proteinuria, and glycosuria improved rapidly. Uveitis promptly responded to systemic and local corticosteroid treatment, and visual acuity increased to 1.0 within 6 days in the right eye. There were no relapses of uveitis or ocular complications during follow-up of 20 months.