Idiopathic acute granulomatous interstitial nephritis leading to renal papillary necrosis.

There was no history of diabetes, sickle cell anaemia Renal papillary necrosis (RPN) is a clinicopathological nephrolithiasis, sarcoidosis, or exposure to tubercuentity characterized by necrotic lesions of the kidney losis. He had no unusual environmental or occupaconfined to the distal parts of the pyramids. The first tional chemical exposures and there had been no description dates back to 1877 by Friedreich [1]. This significant exposure to acetaminophen, non-steroidal condition has also been referred to as ‘renal medullary anti-inflammatory drugs or any recreational drugs. necrosis’, ‘suppurative necrotizing pyelonephritis’, and Physical examination was unremarkable except for ‘renal necrotizing papillitis’ [2 ]. some right-sided costovertebral angle tenderness. He The fundamental mechanism in the pathogenesis of was afebrile (temperature 36.8°C ) and haemoRPN is ischaemia of the inner medulla and papillae of dynamically stable (blood pressure 155/85, no postural the kidney, areas which have ordinarily low oxygen drop; pulse rate 80/min). Admission laboratory data content and pH. The clinical course is variable. The were as follows: CBC revealed haemoglobin, 133 g/l subacute form of RPN (most common) usually presents (130–180 g/l ) with normal white blood cell and platelet insidiously over months to years with symptoms such count; prothrombin time and partial-thromboplastin as lumbar pain, haematuria, fever, and chills. There is time were normal; serum electrolytes were normal as also a rare acute fulminating type with acute onset of were blood urea nitrogen, 5.1 mmol/l (2.8–7.0 mmol/l ) renal failure and sepsis and a latent form manifesting and creatinine 106 mmol/l (60–110 mmol/l ); glucose as asymptomatic passage of blood and papillary and calcium were also normal; and the rest of the material. biochemical screen was unremarkable. His urine RPN develops in a variety of diseases including cultures were negative on two separate occadiabetes mellitus, pyelonephritis, obstructive uropathy, sions. Abdominal X-rays were within normal limits. analgesic abuse, sickle cell haemoglobinopathy, renal Intravenous pyelogram revealed only filling defects in transplant rejection, cirrhosis of the liver, and dehydrathe bladder and renal pelvis with no classical finding tion [3]. We report development of an acute exsanguinof RPN. ating form of RPN in an otherwise healthy patient in Serum immunopathology investigations were perassociation with histologic changes suggestive of granuformed. Anti-nuclear antibody (ANA) and antilomatous interstitial nephritis. Our literature review deoxyribonucleic acid (anti-DNA) were negative. Antiover the previous 30 years failed to identify idiopathic extractable nuclear antigens (anti-ENA) SM, RNP, RPN specifically in conjunction with the above pathoand LA were negative but anti-Ro was marginally logical changes. Earlier reports of idiopathic RPN were positive at 29 EU/ml (<25 EU/ml ). Anticardiolipin before discovery of association of RPN with analgesic antibody was negative. Complements C3 and C4 were abuse. normal. Quantitative immunoglobulins IgA and IgM