Carlo Catalano

Acute Interstitial Nephritis Associated With Uveitis and Primary Hypoparathyroidism

In a study of a patient with acute renal failure and uveitis, renal biopsy showed acute interstitial nephritis. Serum calcium and parathyroid hormone concentrations were persistently low during the acute phase and after the resolution of renal failure. Clinical history was negative for intake of drugs capable of inducing acute interstitial nephritis.

Influence of Long-Term Diabetes on Renal Glycogen Metabolism in the Rat

Background/Aims: The effects of acute insulin deficiency on the kidney have been investigated in animal models of experimental diabetes; however, the impact of long-term diabetes has not been determined. Methods: We measured renal glycogen contents in streptozotocin (STZ)-diabetic rats 3 weeks (n = 12) or 9 months (n = 12) after the induction of diabetes, and in 2 groups of control rats of similar age (n = 16 and n = 12, respectively), in the fed state and after a 24-hour fast. Results: Diabetic rats had high glucose levels, low insulin but normal glucagon concentrations in portal blood. In the fasting state, kidney glycogen content was very low in both young control and young diabetic rats (54 ± 15 and 189 ± 26 µg/g, respectively, mean ± SD); in contrast, glycogen levels were markedly elevated in rats with long-standing diabetes as compared to old nondiabetic animals (2,628 ± 1,023 ± and 1,968 ± 989 µg/g of diabetic rat, fasting and fed, respectively, p < 0.001 vs. 0 ± 0 and 4 ± 6 µg/g of control rats). On electron microscopy, large glycogen clusters were localized to the renal tubules. Kidney phosphorylase activity was higher, and synthase activity lower in diabetic than control rats (p < 0.05 for both), whereas kidney glycogen was strongly related to plasma glucose levels, suggesting that the enzyme changes were secondary to glycogen accumulation itself. Renal hexosephosphates and fructose-2,6-bisphosphate contents were both increased in long-term diabetic rats (p < 0.05), implying enhanced fluxes through both glycolysis and gluconeogenesis. Conclusion: In chronic, untreated diabetes glycogen accumulates in the renal tubules; prolonged hyperglycemia is the sole driving force for this phenomenon.

Esophagogastroduodenoscopy in chronic hemodialysis patients: 2-year clinical experience in a renal unit.

INTRODUCTION Upper gastrointestinal (UGI) disorders are frequent in uremic patients and esophagogastroduodenoscopy (OGD) is an important investigation for their management. SUBJECTS AND METHODS From January 1, 1997 to December 31, 1998, 57 endoscopies were performed in 96 hemodialysis patients (aged 65+/-12 years, 68 M, 28 F, dialysis duration 51+/-58 months) chronically treated in our unit in that period. The reasons for prescribing OGD were: anemia, after exclusion of poor response to EPO, in 26 patients (mean decrease in hemoglobin (Hb) levels 2.6+/-1.3 g/dl: the reference Hb level was the mean value measured before Hb decrease), dyspepsia in 11 and in preparation for renal transplantation in 20 patients. Twelve patients were diabetics, 24 smokers, 41 alcohol drinkers, 13 had hepatitis B or C, 6 were non-steroidal anti-inflammatory drugs (NSAIDs) abusers for bone pain and 21 were taking H2 receptor antagonists or proton-pump inhibitors chronically. Multiple biopsies of gastric mucosa were performed in 38 patients. RESULTS Endoscopy revealed normal mucosa in 17.5% of cases, whilst chronic gastritis was diagnosed in 30%. Chronic gastritis was also the commonest microscopic abnormality diagnosed in 71.5% of biopsies. Anemic and non-anemic patients were matched and the 2 groups did not show significant differences in endoscopic findings and histological appearance. Thirteen patients had Helicobacter pylori (HP) infection demonstrated by biopsy specimen examination and were treated by metronidazole, clarithromycin and omeprazole. A logistic regression analysis was carried out in all subjects, considering the decrement in Hb as a dependent variable and demographic and clinical characteristics as independent variables. The analysis demonstrates that age (odds ratio 1.05; p < 0.05), NSAIDs abuse (odds ratio 15.6; p < 0.05) and HP infection (odds ratio 16.7; p < 0.01) were independently related to Hb decrease. CONCLUSIONS In our experience, non-EPO-related anemia and dyspepsia are frequent features in hemodialysis patients. OGD is frequently requested (30% of patients/year) and 83% of patients investigated had abnormal UGI mucosa. Underlying mucosal inflammation might promote UGI bleeding but is not likely to be the cause, making it a necessary superimposed factor such as NSAIDs or HP infection.

Reflex Anuria from Unilateral Ureteral Obstruction

Renal function is usually normal or only marginally affected in patients with unilateral ureteral obstruction due to the vicarious function of the contralateral kidney. Few reports exist in which unilateral renal obstruction is associated with anuria (reflex anuria, RA) and acute renal failure. We report the clinical case of a female patient who was referred to the emergency department due to anuria of 72 h duration and acute renal failure (serum creatinine 9 mg/dl) associated with several episodes of violent right flank pain with hematuria following extracorporeal shock wave lithotripsy (ESWL). A few weeks before ESWL, urography showed a 2-cm stone located in the right pelvis whilst the left kidney was functionally normal. On admission, renal ultrasound documented a normal left kidney, whilst the right pelvis was hydronephrotic and there were two indwelling stones at the right pyeloureteral junction. After the patient passed a urinary stone, diuresis restarted and acute renal failure was resolved. Thereafter, urography confirmed that the left kidney, the left ureter and bladder were functionally and morphologically normal. RA with acute renal failure has been so scarcely documented that it is considered to be legend by many clinicians. Major textbooks do not discuss RA with acute renal failure. Vascular or ureteral spasm related in part to a peculiar hyperexcitability of the autonomic nervous system may explain RA. We suggest that nephrologists should always consider RA when evaluating acute renal failure. On the other hand, RA might be relatively common and we cannot rule out that only the most severe and/or better-documented cases have been reported in the medical literature.

Erythropoietin Is Beneficial in Mitomycin-Induced Hemolytic-Uremic Syndrome

Mitomycin C is a powerful antineoplastic agent. If used at high dosage, it may cause a secondary form of adult hemolytic-uremic syndrome (HUS). Blood transfusions worsen the evolution of this peculiar form of HUS. We describe a patient who developed HUS after treatment with mitomycin C (total dose 144 mg/m2) due to a carcinoma of the ascending colon. Repeated blood transfusions were associated with rapidly evolving renal failure coupled with anemia and thrombocytopenia. Haptoglobin was undetectable. Soon after starting subcutaneous erythropoietin, the velocity of progression of renal failure slowed whilst no more blood transfusions were required and haptoglobin levels returned to normal. Thereafter, the patient’s renal function slowly worsened and she started chronic hemodialysis 5 years later. Up to now, all investigations have failed to show a relapse of her adenocarcinoma. A possible explanation of these data is that erythropoietin permitted the termination of blood transfusions which both triggered and perpetuated the syndrome. However, we cannot exclude a primitive effect of erythropoietin on the endothelium or on the platelets.

Diabetes and renal failure: A southern Italian perspective

The authors carried out a retrospective survey assessing the total proportion of diabetic patients and relative proportion of patients with Type I and Type II diabetes among patients receiving renal replacement therapy and those evaluated for chronic renal failure in a southern Italian renal unit during the period 1972-1986. The proportion of diabetics among patients accepted for renal replacement therapy was 10% (34/336); of the 34 diabetic patients, only one was clearly affected by Type I diabetes, 26 had Type II diabetes, and the classification was uncertain in four patients. Similar relative proportions of Types I and II diabetes were observed among patients referred during the same period for evaluation of chronic renal failure.

Acute Renal Failure due to a Calculus Obstructing a Transplanted Kidney

Nephrolithiasis is a rare finding in kidney transplantation and anuria could be the only clinical sign. We report the case of a 52-year-old Caucasian male renal transplant recipient admitted due to acute renal failure (ARF) and anuria. He reported no symptoms and a palpable bulge in the right iliac fossa corresponding to the graft was present. Ultrasonography showed hydronephrosis of the graft. A double-J ureteral stent was inserted with resolution of ARF. ARF with anuria and the presence of a palpable non-tender, elastic mass over the graft could be the clinical picture of obstructive ARF in a transplanted kidney.

Stomach Phytobezoars in Two Uremic Anorexic Patients

Conglomerates of food and mucus or phytobezoars composed of vegetable matter are sometimes found in the stomach in the general population. Reports of phytobezoars in uremic patients are, however, scarce. Here we describe 2 uremic patients in which esophagogastroduodenoscopy was performed due to dyspepsia associated with weight loss and in which stomach phytobezoars were discovered. Theoretically, uremic patients should be at risk for producing bezoars. In fact, these patients frequently present predisposing conditions such as autonomic neuropathy, diabetes mellitus and delayed gastric emptying. Gastric bezoars cause anorexia. Anorexia is a frequent symptom in dialysis patients and is associated with malnutrition. In these patients, malnutrition is strongly associated with mortality and is quite difficult to reverse. Similarly, phytobezoars cause chronic anorexia. We suggest that clinicians working in dialysis units should consider the possibility of a gastric bezoar when evaluating anorexic uremic patients.