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 X

Kidney Week

Abstract: TH-PO0808

The Great Masquerader: Phospholipase A2 Receptor-Negative Membranous Nephropathy Secondary to Sarcoidosis

Session Information

Category: Glomerular Diseases

  • 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics

Authors

  • Killen, John P., Macquarie University, Sydney, New South Wales, Australia
  • Wang, Rosy, Northern Beaches Hospital, Frenchs Forest, New South Wales, Australia
  • Teh, Tobias T K, Macquarie University, Sydney, New South Wales, Australia
  • Yun, James, Northern Beaches Hospital, Frenchs Forest, New South Wales, Australia
Introduction

Sarcoidosis is a multisystem granulomatous disease that causes renal impairment in under 10% of cases. While this typically manifests as tubulointerstitial disease, membranous nephropathy (MN) is the predominant glomerular form.

Case Description

A 62-year-old female with hypercholesterolaemia and Crohn’s disease in remission, presented with subacute myalgia and generalised oedema. She was normotensive with preserved renal function, raised creatine kinase (CK) 9000 U/L and features of nephrotic syndrome: serum albumin 23 g/L, urine albumin/creatinine ratio (UACR) 369 mg/mmol. Glomerulonephritis screen was unremarkable including negative phospholipid A2 receptor (PLA2R) antibody. Kidney biopsy confirmed MN. Muscle biopsy demonstrated non-caseating granulomas and resolving statin-induced rhabdomyolysis. A subsequent positron emission tomography scan revealed mediastinal lymphadenopathy, with polyclonal lymphoid cells on fine needle aspirate. Acid-fast bacilli cultures were negative on both muscle and lymph node tissue. Following these extensive investigations, the patient was diagnosed with sarcoidosis.
In the absence of high-risk features for disease progression, the patient received optimal supportive care with diuretics, valsartan, dapagliflozin and therapeutic apixaban. CK resolved with statin cessation. Six-month follow-up chest imaging showed resolution of mediastinal lymphadenopathy without parenchymal fibrosis. One year after initial diagnosis, the patient remains stable on conservative management with UACR 354 mg/mmol, serum albumin 33 g/L and normal renal function (creatinine 50 umol/L, eGFR > 90 mL/min/1.73m2).

Discussion

Membranous nephropathy is an exceedingly rare manifestation of sarcoidosis, and we highlight a unique presentation of nephrotic syndrome synchronously with statin-induced myopathy. While hypoalbuminaemia may have potentiated free drug levels and statin toxicity, non-caseating granulomas on muscle biopsy point towards sarcoidosis as the unifying diagnosis. The antigen profile in sarcoidosis-associated MN mimics that of primary MN with PLA2R and neural epidermal growth factor-like 1 being the most common. The causative antigen in our patient remains unknown, although we will send any future kidney biopsy tissue for mass spectrometry to characterise the culprit antigen.

Digital Object Identifier (DOI)