ASN's Mission

To create a world without kidney diseases, the ASN Alliance for Kidney Health elevates care by educating and informing, driving breakthroughs and innovation, and advocating for policies that create transformative changes in kidney medicine throughout the world.

learn more

Contact ASN

1401 H St, NW, Ste 900, Washington, DC 20005

email@asn-online.org

202-640-4660

The Latest on Twitter

Kidney Week

Abstract: TH-PO584

Renal Biopsy in Systemic Infections: Expect the Unexpected

Session Information

  • Pathology and Lab Medicine
    November 03, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
    Abstract Time: 10:00 AM - 12:00 PM

Category: Pathology and Lab Medicine

  • 1700 Pathology and Lab Medicine

Authors

  • Wang, Bangchen, Duke University Health System, Durham, North Carolina, United States
  • Grand, Alexandra, Duke University Health System, Durham, North Carolina, United States
  • Schub, Micah, Duke University Health System, Durham, North Carolina, United States
  • Singh, Harpreet K., Duke University Health System, Durham, North Carolina, United States
  • Ortiz Melo, David I., Duke University Health System, Durham, North Carolina, United States
  • Howell, David Noble, Duke University Health System, Durham, North Carolina, United States
Introduction

Infection-related glomerulonephritis is well recognized and often included in the differential diagnosis in patients with ongoing infections. It can be missed, however, if the infection is unusual or undetected. We present three cases where the renal biopsy findings prompted the identification or treatment of systemic infections.

Case Description

Case 1: A 84-year-old male presented with acute kidney injury (AKI) and a new purpuric rash. Clinically, IgA nephropathy was suspected. A renal biopsy showed active glomerulonephritis with abundant neutrophils, focal segmental tuft necrosis, and one cellular crescent. Predominantly mesangial immune complex deposits containing IgA and IgG were seen. The findings suggested IgA-rich infection-associated glomerulonephritis. Infectious workup was positive for COVID-19, suggesting exacerbation of IgA nephropathy by recent COVID-19 infection.

Case 2: A 31-year-old female status post kidney transplant for granulomatosis with polyangiitis (GPA) had recent pregnancy with preterm delivery, disseminated herpes simplex virus (HSV) infection with HSV hepatitis, and AKI. Urine culture was positive for E. coli. The differential diagnosis included HSV nephritis, drug reaction, rejection, recurrent GPA, thrombotic microangiopathy (TMA), and pyelonephritis. A renal biopsy showed proliferative glomerulonephritis with subendothelial and mesangial immune complex deposits containing IgG and C3. The findings were most consistent with infection-related immune complex glomerulonephritis, most likely related to the HSV infection.

Case 3: A 78-year-old female presented with AKI, proteinuria, hematuria, and positive p-ANCA. Clinically, ANCA vasculitis was suspected, and the renal biopsy did show focal, segmental, necrotizing glomerulonephritis. However, immunofluorescence and electron microscopy showed IgM-rich immune complex deposits in the mesangium. The unusual presentation of ANCA glomerulonephritis was suggestive of an underlying infection. Bartonella antibody panel showed very high titers; the patient was treated with antibiotics for Bartonella endocarditis.

Discussion

Infection-related glomerulonephritis has a wide variety of presentations histologically and clinically. The three cases we present here emphasize the importance of recognizing these entities to help guide treatment and improve patient care.