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Abstract: FR-PO053

Importance of Renal Biopsy in the Current COVID-19 Era: Acute Phosphate Nephropathy in a Patient With COVID-19 and New Systemic Lupus Diagnosis

Session Information

Category: Coronavirus (COVID-19)

  • 000 Coronavirus (COVID-19)

Author

  • Babu, Mathura, Ascension St John Hospital, Detroit, Michigan, United States
Introduction

Lupus nephritis is a common manifestation of systemic lupus erythematosus. About 40-60% of patients with systemic lupus erythematosus will have renal involvement. We present a case of a young lady with SARS-CoV-2 pneumonia who additionally presented with alopecia, arthritis and acute renal injury. Initially, the consulting team presumed the diagnosis to be due to lupus nephritis. The patient was treated with IV methylprednisolone and oral prednisone. The renal biopsy revealed widespread calcium phosphate crystals within the tubular lumens, suggestive of acute phosphate nephropathy. Electron microscopy showed diffuse foot process effacement consistent with minimal change disease.

Case Description

A 20-year-old lady with no past medical history presented with right-sided chest pain, myalgias, fever, and vomiting for 5-6 days. She had proteinuria and serum creatinine of 5 mg/dl. She was SARS-CoV-2 positive. She also had frontal alopecia and photosensitivity over the past five months, along with swelling/tenderness in her wrists and MCPs over the past year. The patient’s mother had a diagnosis of lupus which was well controlled on Hydroxychloroquine. Further lab work revealed lymphopenia, positive for smith, coombs, cryoglobulins, RF, RNP, and SSA. Other pertinent work-up was negative. The patient was started on induction therapy for possible lupus nephritis of 1 g IV solumedrol daily for three days. The patient progressively became anuric, and creatinine peaked to 8 mg/dl. Dialysis was initiated. Her urine output improved after the third dialysis session, and dialysis was stopped. Her creatinine improved to 2.4 mg/dl. After the biopsy confirmed phosphate nephropathy, a focused history failed to reveal a cause. She denied sodium phosphate bowel preparations, consuming star fruit or ethylene glycol exposure.

Discussion

This case shows the importance of biopsy even in a well-known condition such as lupus nephritis. The etiology of renal failure in SARS-CoV-2 is primarily acute tubular necrosis, with collapsing focal segmental glomerulosclerosis also reported. Calcium phosphate deposition is not a reported complication of COVID-19 or lupus nephritis. The tubuloreticular inclusions can be found with lupus nephritis and viral infection. The etiology of phosphate-induced nephropathy remains unclear.