Megalocytic Interstitial Nephritis Following Acute Pyelonephritis with Escherichia coli Bacteremia: A Case Report

Abstract

Megalocytic interstitial nephritis is a rare form of kidney disease caused by chronic inflammation. We report a case of megalocytic interstitial nephritis occurring in a 45-yrold woman who presented with oliguric acute kidney injury and acute pyelonephritis accompanied by Escherichia coli bacteremia. Her renal function was not recovered despite adequate duration of susceptible antibiotic treatment, accompanied by negative conversion of bacteremia and bacteriuria. Kidney biopsy revealed an infiltration of numerous histiocytes without Michaelis-Gutmann bodies. The patient's renal function was markedly improved after short-term treatment with high-dose steroid.Graphical Abstract

Persistent Aseptic Pyelonephritis After Acute Bacterial Pyelonephritis: Possible Role of Corticosteroids

“…Some rare cases were reported in the literature. [1][2][3] but this is the first case series describing the biological, histologic, and clinical presentation and evolution since Richet and Mayaud's 5 description in 1978. In this study, most cases were attributed to drug allergy or toxicities but may have been misclassified because of the absence of preexisting data.…”

“… 1 In some of these latter, renal dysfunction persists despite appropriate antiinfectious treatment and urine sterilization. 2 , 3 , 4 Some authors suggest the use of corticosteroids to treat inflammatory tubulointerstitial nephritis (TIN) triggered by the infection. 2 , 3 , 4 Nevertheless, this approach is not validated by any evidence-based study and therefore not mentioned in any guideline.…”