Idiopathic Interstitial Nephritis: An Autoimmune Disease with a Chameleon Presentation and High-Potential for Kidney Loss

ABSTRACT

Data on the clinical picture, prognosis and management of 12cases of idiopathic interstitial nephritis (IIN) are presented.Clinically; 5 patients had acute renal failure (ARF) with suddenfluid overload and azotemia, 2 had ARF on top of chronicrenal disease (CRD) and 6 with unexplained CRD. Theoutcome of the 5 patients with ARF and short duration ofillness was better. One had infrequent relapses, 1 hadfrequent relapses and 3 were steroid-dependent. The latter 4patients had required maintenance immunosuppression (IS)initially with Prednisone, Mycophenolate and finally withRituximab. The 2 patients with ARF on top of CRD werestabilized after IS. The remaining 5 patients with CRD becamestable and/or improved while 1 patient progressed to endstage kidney disease since her IS was late and inadequateprior to inclusion with us. In conclusion: IIN can mimic anykidney disease and can only be diagnosed with kidney biopsy.Aggressive IS can control the disease at its early stagesotherwise, the prognosis is poor.