Sustained Response to Eculizumab in a Patient With COVID-19–Associated Acute Thrombotic Microangiopathy of the Allograft Kidney: A Case Report

Acute thrombotic microangiopathy (TMA) developing in association with SARS-CoV-2 infection is a rare but recognized phenomenon in native kidneys. In the allograft kidney, a diagnosis of TMA has a broad etiologic differential, including antibody-mediated rejection and recurrent and de novo causes of TMA that affect the native kidney. Prior case reports have described plasma exchange or eculizumab use in patients with COVID-19–associated TMA. Herein, we describe the course of a kidney transplant patient with COVID-19–associated TMA with response to eculizumab that was sustained after medication withdrawal and review the literature on COVID-19–associated TMA of the allograft kidney.

Sustained Response to Eculizumab in a Patient With COVID-19-Associated Acute Thrombotic Microangiopathy of the Allograft Kidney: A Case Report.

Acute thrombotic microangiopathy (TMA) developing in association with SARS-CoV-2 infection is a rare but recognized phenomenon in native kidneys. In the allograft kidney, a diagnosis of TMA has a broad etiologic differential, including antibody-mediated rejection and recurrent and de novo causes of TMA that affect the native kidney. Prior case reports have described plasma exchange or eculizumab use in patients with COVID-19-associated TMA. Herein, we describe the course of a kidney transplant patient with COVID-19-associated TMA with response to eculizumab that was sustained after medication withdrawal and review the literature on COVID-19-associated TMA of the allograft kidney.

Increased Rates of Supplement-Associated Oxalate Nephropathy During COVID-19 Pandemic.

Introduction: Causes of secondary oxalate nephropathy include enteric dysfunction and excessive intake of oxalate or oxalate precursors. During the COVID-19 pandemic, there has been a dramatic rise in sales of supplements and vitamin C, during which time we observed an apparent increase in the proportion of ingestion-associated oxalate nephropathy. Methods: We retrospectively reviewed secondary oxalate nephropathy and compared pre-pandemic (2018-2019) and pandemic (2020-early 2022) time periods. Results: We identified 35 patients with kidney biopsy proven (30 native, 5 allograft) oxalate nephropathy at a single academic institution. Supplement-associated oxalate nephropathy comprised a significantly higher proportion of cases during COVID-19 pandemic compared with the preceding 2 years (44% vs. 0%, P = 0.002), and was associated with use of vitamin C, dietary changes, and supplements. Oxalate nephropathy in the kidney allograft, in contrast, remained associated with enteric hyperoxaluria, antibiotic use, and dehydration. Many patients had diabetes mellitus (57%), hypertension (40%) and/or pre-existing chronic kidney disease (CKD, 49%). Of 9 patients in which the potentially causative ingestion was identified and removed, 8 experienced improvement in kidney function. Conclusion: There was a shift toward supplements rather than enteric hyperoxaluria as a leading cause of secondary oxalate nephropathy during the COVID-19 pandemic. Kidney outcomes are better than those observed for enteric hyperoxaluria, if the offending agent is identified and removed.

Increased rates of supplement-associated oxalate nephropathy during COVID-19 pandemic

Introduction Causes of secondary oxalate nephropathy include enteric dysfunction and excessive intake of oxalate or oxalate precursors. During the COVID-19 pandemic, there has been a dramatic rise in sales of supplements and vitamin C, during which time we observed an apparent increase in the proportion of ingestion-associated oxalate nephropathy. Methods We retrospectively reviewed secondary oxalate nephropathy and compared pre-pandemic (2018 - 2019) and pandemic (2020 - early 2022) eras. Results We identified 35 patients with kidney biopsy proven (30 native, 5 allograft) oxalate nephropathy at a single academic institution. Supplement-associated oxalate nephropathy comprised a significantly higher proportion of cases during COVID-19 pandemic compared with the preceding 2 years (44% vs. 0%, p=0.002), and was associated with use of vitamin C, dietary changes, and supplements. Oxalate nephropathy in the kidney allograft, in contrast, remained associated with enteric hyperoxaluria, antibiotic use, and dehydration. Many patients had diabetes mellitus (57%), hypertension (40%) and/or pre-existing chronic kidney disease (49%). Of 9 patients in which the potentially causative ingestion was identified and removed, 8 experienced improvement in kidney function. Conclusion There was a shift toward supplements rather than enteric hyperoxaluria as a leading cause of secondary oxalate nephropathy during the COVID-19 pandemic. Kidney outcomes are better than those observed for enteric hyperoxaluria, if the offending agent is identified and removed.