A Unique Physical Exam Finding in a Case of Tubulointerstitial Nephritis and Uveitis Syndrome: An Abstract from Akron Children’s Hospital Resident and Fellow Academic Day

Tubulointerstitial nephritis and uveitis (TINU) syndrome is a rare autoimmune disease mostly affecting adolescents. It’s challenging to diagnose, as presenting symptoms are often non-specific, and involvement of the kidneys and eyes may not occur concurrently. As a diagnosis of exclusion, there are multiple diseases on the differential that mimic TINU, including lupus, sarcoidosis, tuberculosis, and Sjogren syndrome. A previously healthy 16-year-old male presented with a 2-month history of weight loss, malaise, orthostatic dizziness, fatigue, and headaches. Three weeks prior to admission, laboratory evaluation revealed renal injury (Cr 4.59 mg/dL) and mild anemia (Hgb 10.7 g/dL). One week later, he developed bilateral eye redness with photophobia, treated as bacterial conjunctivitis with no improvement. On admission, he was afebrile and normotensive. Growth curve confirmed a 14 kg weight loss in 2 months. Physical exam revealed pallor, bilateral conjunctival injection, decreased visual acuity, and irregularly shaped pupils (Figure 1). Ophthalmology was consulted, and their evaluation demonstrated bilateral granulomatous panuveitis, synechiae, and papilledema without vasculitis. Labs confirmed persistent renal injury, anemia, elevated inflammatory markers, and proteinuria with elevated urine beta-2 microglobulin (Table 1). MRI brain/orbits and renal ultrasound were unremarkable. Lumbar puncture revealed normal opening pressure (14 cmH2O). Kidney biopsy showed diffuse eosinophilic and lymphocytic tubulointerstitial inflammation with moderate interstitial fibrosis. The constellation of interstitial nephritis with bilateral uveitis confirmed the diagnosis of TINU syndrome. He was treated with systemic steroids and steroid and atropine eye drops. Renal function and pain improved prior to discharge. Visual acuity normalized, synechiae resolved, and renal function returned to baseline. He transitioned to mycophenolate mofetil for long-term immunosuppression. This case highlights the importance of careful physical examination and a broad differential when multisystem findings evolve over time. The irregular pupil reflected synechiae–abnormal adhesions between the iris and adjacent structures of the eye–a key diagnostic clue linking ocular inflammation to systemic disease. In the absence of surgery or trauma, synechiae should prompt further evaluation for kidney disease and systemic conditions, as severe cases can progress to glaucoma and vision loss. TINU is a rare autoimmune syndrome primarily affecting adolescents, and diagnosis is often delayed as initial symptoms are non-specific and renal and ocular symptoms may not occur concurrently. Early recognition and treatment are essential to decrease morbidity, as 20% of patients will have long-lasting effects on vision and 11-60% develop renal fibrosis and chronic kidney disease. Numerous diagnoses exist on the differential that require exclusion prior to diagnosis. Timely identification and early treatment may limit morbidity caused by delayed diagnosis.