TUBULOINTERSTITIAL NEPHRITIS WITH UVEITIS (TINU) UNRESPONSIVE TO CORTICOSTEROIDS AND MYCOPHENOLATE MOFETIL
Dr Shyamalee Crocker1
1North Canberra Hospital, Bruce, Australia
Background: Tubulointerstitial nephritis with uveitis (TINU) is a rare condition with concurrent ocular and renal involvement. There are case reports associated with a number of triggers inclusive of viral, bacterial, medications, endocrine and rheumatological aetiologies. Published reports support the use of corticosteroids as first-line treatment with alternative immunosuppressive steroid-sparing options such as calcineurin inhibitors, azathioprine, and mycophenolate mofetil. Treatment course is variable and often leads to a progression to chronic kidney disease in up to 70% of cases.
Case Report: A 63 year old female was referred for her acute kidney injury with a relative increase in her creatinine from baseline 73umol/L to 129umol/L in the context of bilateral uveitis. The patient had a recent diagnosis of subclinical hyperthyroidism and was known to have bilateral cataracts. She had a positive dipstick for haematuria, in the absence of casts on microscopy and minimal proteinuria with a urine albumin-creatinine ratio of 10.9mg/mmol with an increase in her ESR to 44mm/hr and a mild anaemia of Hb 114g/L. Her father had rheumatoid arthritis. The patient had been commenced on topical steroid eye drops by her ophthalmologist. Renal biopsy was attended and demonstrated tubulointerstitial nephritis with negative immunofluorescence. High-dose prednisolone was started with marked clinical improvement in the uveitis, however, no change in serum creatinine. A 3-month trial of steroids did not improve her renal parameters and hence mycophenolate was used with no improvement to serum creatinine but was ceased due to rash. Her latest creatinine has improved to 90umol/L without treatment.
Conclusions: Tubulointersittial nephritis with uveitis (TINU) is a heterogenous disorder with a complex aetiology and requires further investigation into management options.