Tubulointerstitial nephritis uveitis syndrome with Fanconi syndrome: Two case reports and literature review.

RATIONALE: Tubulointerstitial nephritis uveitis syndrome (TINU) is a rare form of acute interstitial nephritis accompanied by uveitis. However, few cases of TINU associated with Fanconi syndrome (FS) have been reported, and the clinical characteristics and optimal management of this rare association remain poorly defined.

PATIENT CONCERNS: In this case report, we aimed to describe 2 cases of TINU associated with FS and their management, emphasizing the importance of recognizing FS as a potential complication in patients with TINU.

DIAGNOSES: Two adult patients with TINU and FS were evaluated. Both presented with renal insufficiency, hypouricemia, hypophosphatemia, hypokalemia, renal glycosuria, low-molecular-weight proteinuria, and uveitis. One patient also had renal tubular acidosis. Renal biopsy revealed acute interstitial nephritis in both cases, with one case additionally showing immunoglobulin A nephropathy.

INTERVENTIONS/OUTCOMES: Systemic and ocular topical corticosteroids were administered, and potassium citrate was used to correct renal tubular acidosis. Renal function, electrolyte levels, and urinalysis results normalized in both patients.

LESSONS: In patients with TINU and renal tubular dysfunction (such as low-molecular-weight proteinuria, hypophosphatemia, and hypouricemia) the possibility of secondary FS should be considered. Along with corticosteroid therapy, timely treatment of renal tubular acidosis is essential.