The missing 'interstitial vasculitis'

To the Editor: In a recent review on acute interstitial nephritis (AIN),1 the authors state that AIN may be associated with systemic disorders such as sarcoidosis, Sjogren, or systemic lupus erythematosus, but they did not mention the ‘interstitial vasculitis’, that is, AIN as the only expression of renal vasculitis.However, the occurrence of an involvement confined to the capillaries of renal tubular and interstitial structures in the setting of systemic vasculitides has been clearly stated in previous papers published by the European Vasculitis Study group2 and others.