COVID-19-Related Collapsing Glomerulopathy in a Kidney Transplant Recipient

Abstract

We report a case of a kidney transplant recipient who presented with acute kidney injury and nephrotic-range proteinuria in a context of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Kidney biopsy revealed collapsing glomerulopathy. Droplet-based digital polymerase chain reaction did not detect the presence of SARS-CoV-2 RNA in the biopsy fragment, and the virus was barely detectable in plasma at the time of the biopsy. SARS-CoV-2 RNAemia peaked several days later, followed by a seroconversion despite the absence of circulating CD19-positive lymphocytes at admission due to rituximab-based treatment of antibody-mediated rejection 3 months earlier. Genotyping for the 2 risk alleles of the apolipoprotein L1 (APOL1) gene revealed that the donor carried the low-risk G0/G2 genotype. This case illustrates that coronavirus disease 2019 infection may promote a collapsing glomerulopathy in kidney allografts with a low-risk APOL1 genotype in the absence of detectable SARS-CoV-2 RNA in the kidney and that podocyte injury may precede SARS-CoV-2 RNAemia.

Keywords: Kidney transplantation; acute kidney injury (AKI); allograft biopsy; case report; collapsing glomerulopathy; coronavirus 2019 (COVID-19); severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Figure 1

Kidney allograft pathology findings. (A-C) Kidney histology of the first kidney allograft biopsy with (A) Masson trichrome staining showing patterns of acute antibody-mediated rejection with glomerulitis (arrow) and peritubular capillaritis (∗), (B) periodic acid–Schiff staining showing glomerulitis (arrow), and (C) immunohistochemistry displaying positive staining for C4d on peritubular capillaries (∗) (brown). (D-G) Kidney histology of the second graft biopsy with (D) Masson trichrome staining showing collapsing glomerulopathy with podocyte hypertrophy and hyperplasia and collapse of the glomerular tuft (arrow), (E, F) Jones methenamine silver staining showing (E) collapsing glomerulopathy with podocyte hypertrophy and hyperplasia and collapse of the glomerular tuft and (F) tubular necrosis, and (G) immunohistochemistry displaying negative staining for C4d on peritubular capillaries (∗).

Figure 2

Evolution of biological parameters during follow-up. Serum creatinine (SCr), urinary albumin-creatinine ratio (ACR), and SARS-CoV-2 RNA in plasma were sequentially measured. Kidney biopsies are indicated, as well as serologic test and B-cell counts. Conversion factor for SCr in μmol/L to mg/dL, ×0.0113. N IgG are immunoglobulin G antibodies against SARS-CoV-2 nucleocapsid. Abbreviation: ABMR, antibody-mediated rejection.