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1.
Dis Model Mech ; 14(8)2021 08 01.
Article in English | MEDLINE | ID: covidwho-1910409

ABSTRACT

People of recent sub-Saharan African ancestry develop kidney failure much more frequently than other groups. A large fraction of this disparity is due to two coding sequence variants in the APOL1 gene. Inheriting two copies of these APOL1 risk variants, known as G1 and G2, causes high rates of focal segmental glomerulosclerosis (FSGS), HIV-associated nephropathy and hypertension-associated end-stage kidney disease. Disease risk follows a recessive mode of inheritance, which is puzzling given the considerable data that G1 and G2 are toxic gain-of-function variants. We developed coisogenic bacterial artificial chromosome (BAC) transgenic mice harboring either the wild-type (G0), G1 or G2 forms of human APOL1. Expression of interferon gamma (IFN-γ) via plasmid tail vein injection results in upregulation of APOL1 protein levels together with robust induction of heavy proteinuria and glomerulosclerosis in G1/G1 and G2/G2 but not G0/G0 mice. The disease phenotype was greater in G2/G2 mice. Neither heterozygous (G1/G0 or G2/G0) risk variant mice nor hemizygous (G1/-, G2/-) mice had significant kidney injury in response to IFN-γ, although the heterozygous mice had a greater proteinuric response than the hemizygous mice, suggesting that the lack of significant disease in humans heterozygous for G1 or G2 is not due to G0 rescue of G1 or G2 toxicity. Studies using additional mice (multicopy G2 and a non-isogenic G0 mouse) supported the notion that disease is largely a function of the level of risk variant APOL1 expression. Together, these findings shed light on the recessive nature of APOL1-nephropathy and present an important model for future studies.


Subject(s)
AIDS-Associated Nephropathy , Apolipoprotein L1 , Animals , Apolipoprotein L1/genetics , Apolipoprotein L1/metabolism , Chromosomes, Artificial, Bacterial/metabolism , Gain of Function Mutation , Genetic Predisposition to Disease , Humans , Mice , Mice, Transgenic
2.
JCI Insight ; 7(11)2022 06 08.
Article in English | MEDLINE | ID: covidwho-1807764

ABSTRACT

COVID-19 infection causes collapse of glomerular capillaries and loss of podocytes, culminating in a severe kidney disease called COVID-19-associated nephropathy (COVAN). The underlying mechanism of COVAN is unknown. We hypothesized that cytokines induced by COVID-19 trigger expression of pathogenic APOL1 via JAK/STAT signaling, resulting in podocyte loss and COVAN phenotype. Here, based on 9 biopsy-proven COVAN cases, we demonstrated for the first time, to the best of our knowledge, that APOL1 protein was abundantly expressed in podocytes and glomerular endothelial cells (GECs) of COVAN kidneys but not in controls. Moreover, a majority of patients with COVAN carried 2 APOL1 risk alleles. We show that recombinant cytokines induced by SARS-CoV-2 acted synergistically to drive APOL1 expression through the JAK/STAT pathway in primary human podocytes, GECs, and kidney micro-organoids derived from a carrier of 2 APOL1 risk alleles, but expression was blocked by a JAK1/2 inhibitor, baricitinib. We demonstrate that cytokine-induced JAK/STAT/APOL1 signaling reduced the viability of kidney organoid podocytes but was rescued by baricitinib. Together, our results support the conclusion that COVID-19-induced cytokines are sufficient to drive COVAN-associated podocytopathy via JAK/STAT/APOL1 signaling and that JAK inhibitors could block this pathogenic process. These findings suggest JAK inhibitors may have therapeutic benefits for managing cytokine-induced, APOL1-mediated podocytopathy.


Subject(s)
COVID-19 , Cytokines , Janus Kinase Inhibitors , Kidney Diseases , Apolipoprotein L1/genetics , Azetidines/pharmacology , COVID-19/drug therapy , COVID-19/metabolism , Cytokines/metabolism , Endothelial Cells/metabolism , Humans , Janus Kinase Inhibitors/pharmacology , Janus Kinases/metabolism , Kidney Diseases/drug therapy , Kidney Diseases/metabolism , Kidney Diseases/virology , Organoids/metabolism , Purines/pharmacology , Pyrazoles/pharmacology , SARS-CoV-2/isolation & purification , STAT Transcription Factors/metabolism , Signal Transduction/drug effects , Sulfonamides/pharmacology
3.
Kidney Int ; 101(6): 1216-1231, 2022 06.
Article in English | MEDLINE | ID: covidwho-1665244

ABSTRACT

Risk variants of the apolipoprotein-L1 (APOL1) gene are associated with severe kidney disease, putting homozygous carriers at risk. Since APOL1 lacks orthologs in all major model organisms, a wide range of mechanisms frequently in conflict have been described for APOL1-associated nephropathies. The genetic toolkit in Drosophila allows unique in vivo insights into disrupted cellular homeostasis. To perform a mechanistic analysis, we expressed human APOL1 control and gain-of-function kidney risk variants in the podocyte-like garland cells of Drosophila nephrocytes and a wing precursor tissue. Expression of APOL1 risk variants was found to elevate endocytic function of garland cell nephrocytes that simultaneously showed early signs of cell death. Wild-type APOL1 had a significantly milder effect, while a control transgene with deletion of the short BH3 domain showed no overt phenotype. Nephrocyte endo-lysosomal function and slit diaphragm architecture remained unaffected by APOL1 risk variants, but endoplasmic reticulum (ER) swelling, chaperone induction, and expression of the reporter Xbp1-EGFP suggested an ER stress response. Pharmacological inhibition of ER stress diminished APOL1-mediated cell death and direct ER stress induction enhanced nephrocyte endocytic function similar to expression of APOL1 risk variants. We confirmed APOL1-dependent ER stress in the Drosophila wing precursor where silencing the IRE1-dependent branch of ER stress signaling by inhibition with Xbp1-RNAi abrogated cell death, representing the first rescue of APOL1-associated cytotoxicity in vivo. Thus, we uncovered ER stress as an essential consequence of APOL1 risk variant expression in vivo in Drosophila, suggesting a central role of this pathway in the pathogenesis of APOL1-associated nephropathies.


Subject(s)
Kidney Diseases , Podocytes , Animals , Apolipoprotein L1/genetics , Drosophila/genetics , Endoplasmic Reticulum Stress/genetics , Humans , Kidney Diseases/pathology , Podocytes/pathology
4.
JAMA Intern Med ; 182(4): 386-395, 2022 04 01.
Article in English | MEDLINE | ID: covidwho-1653126

ABSTRACT

IMPORTANCE: Coronavirus disease 2019 (COVID-19) confers significant risk of acute kidney injury (AKI). Patients with COVID-19 with AKI have high mortality rates. OBJECTIVE: Individuals with African ancestry with 2 copies of apolipoprotein L1 (APOL1) variants G1 or G2 (high-risk group) have significantly increased rates of kidney disease. We tested the hypothesis that the APOL1 high-risk group is associated with a higher-risk of COVID-19-associated AKI and death. DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study included 990 participants with African ancestry enrolled in the Million Veteran Program who were hospitalized with COVID-19 between March 2020 and January 2021 with available genetic information. EXPOSURES: The primary exposure was having 2 APOL1 risk variants (RV) (APOL1 high-risk group), compared with having 1 or 0 risk variants (APOL1 low-risk group). MAIN OUTCOMES AND MEASURES: The primary outcome was AKI. The secondary outcomes were stages of AKI severity and death. Multivariable logistic regression analyses adjusted for preexisting comorbidities, medications, and inpatient AKI risk factors; 10 principal components of ancestry were performed to study these associations. We performed a subgroup analysis in individuals with normal kidney function prior to hospitalization (estimated glomerular filtration rate ≥60 mL/min/1.73 m2). RESULTS: Of the 990 participants with African ancestry, 905 (91.4%) were male with a median (IQR) age of 68 (60-73) years. Overall, 392 (39.6%) patients developed AKI, 141 (14%) developed stages 2 or 3 AKI, 28 (3%) required dialysis, and 122 (12.3%) died. One hundred twenty-five (12.6%) of the participants were in the APOL1 high-risk group. Patients categorized as APOL1 high-risk group had significantly higher odds of AKI (adjusted odds ratio [OR], 1.95; 95% CI, 1.27-3.02; P = .002), higher AKI severity stages (OR, 2.03; 95% CI, 1.37-2.99; P < .001), and death (OR, 2.15; 95% CI, 1.22-3.72; P = .007). The association with AKI persisted in the subgroup with normal kidney function (OR, 1.93; 95% CI, 1.15-3.26; P = .01). Data analysis was conducted between February 2021 and April 2021. CONCLUSIONS AND RELEVANCE: In this cohort study of veterans with African ancestry hospitalized with COVID-19 infection, APOL1 kidney risk variants were associated with higher odds of AKI, AKI severity, and death, even among individuals with prior normal kidney function.


Subject(s)
Acute Kidney Injury , COVID-19 , Veterans , Acute Kidney Injury/genetics , African Americans/genetics , Aged , Apolipoprotein L1/genetics , Cohort Studies , Female , Hospitalization , Humans , Male , Middle Aged , Retrospective Studies , Risk Factors
5.
Immunity ; 54(11): 2632-2649.e6, 2021 11 09.
Article in English | MEDLINE | ID: covidwho-1549842

ABSTRACT

The incidence and severity of sepsis is higher among individuals of African versus European ancestry. We found that genetic risk variants (RVs) in the trypanolytic factor apolipoprotein L1 (APOL1), present only in individuals of African ancestry, were associated with increased sepsis incidence and severity. Serum APOL1 levels correlated with sepsis and COVID-19 severity, and single-cell sequencing in human kidneys revealed high expression of APOL1 in endothelial cells. Analysis of mice with endothelial-specific expression of RV APOL1 and in vitro studies demonstrated that RV APOL1 interfered with mitophagy, leading to cytosolic release of mitochondrial DNA and activation of the inflammasome (NLRP3) and the cytosolic nucleotide sensing pathways (STING). Genetic deletion or pharmacological inhibition of NLRP3 and STING protected mice from RV APOL1-induced permeability defects and proinflammatory endothelial changes in sepsis. Our studies identify the inflammasome and STING pathways as potential targets to reduce APOL1-associated health disparities in sepsis and COVID-19.


Subject(s)
Apolipoprotein L1/genetics , COVID-19/genetics , Genetic Predisposition to Disease/genetics , Sepsis/genetics , Animals , Apolipoprotein L1/blood , COVID-19/pathology , DNA, Mitochondrial/metabolism , Endothelial Cells/metabolism , Humans , Inflammation/genetics , Inflammation/pathology , Membrane Proteins/antagonists & inhibitors , Membrane Proteins/genetics , Membrane Proteins/metabolism , Mice , Mice, Knockout , Mitophagy/genetics , NLR Family, Pyrin Domain-Containing 3 Protein/antagonists & inhibitors , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Risk Factors , Sepsis/pathology , Severity of Illness Index , /statistics & numerical data
6.
Am J Case Rep ; 22: e933462, 2021 Nov 02.
Article in English | MEDLINE | ID: covidwho-1497918

ABSTRACT

BACKGROUND COVID-19 can be complicated by kidney disease, including focal segmental glomerulosclerosis (FSGS), interstitial nephritis, and acute kidney injury (AKI). Almost all known cases of COVID-19-associated glomerulonephritis have been in patients of African descent, with G1 or G2 apolipoprotein L1 (APOL1) risk alleles, and they presented collapsing type of FSGS. CASE REPORT We report a case of biopsy-confirmed non-collapsing FSGS with secondary acute interstitial nephritis and AKI in a young White man with APOL1 low-risk genotype, who had COVID-19 pneumonia. His past history included arterial hypertension, anabolic steroids, and high-protein diet. He fully recovered from type 1 respiratory failure and AKI after transfusion of COVID-19 convalescent plasma and intravenous treatment with dexamethasone administered for 16 days in a dose reduced from 16 to 2 mg/day. Due to progressing severe nephrotic proteinuria (22.6 g/24 h), intravenous methylprednisolone was administered (1500 mg divided in 3 pulses over 3 days) immediately followed by oral prednisone (0.6 mg/kg body weight), with dose reduced 19 weeks later and switched to cyclosporine A (4 mg/kg body weight). Kidney re-biopsy, at that time, showed a decrease in proportion of glomeruli affected with podocytopathy, but progression of interstitial lesions. After 23 weeks of therapy, partial remission of FSGS was attained and proteinuria dropped to 3.6 g/24 h. After 43 weeks, proteinuria decreased to 0.4 g/24 h and the serum creatinine concentration remained steady. CONCLUSIONS High-dose glucocorticoid therapy was effective in the initial treatment of COVID-19-related non-collapsing FSGS, but had no effect on interstitial changes. Introduction of cyclosporine A to the therapy contributed to remission of disease.


Subject(s)
Acute Kidney Injury , COVID-19 , Glomerulosclerosis, Focal Segmental , Nephritis, Interstitial , Acute Kidney Injury/etiology , Apolipoprotein L1/genetics , COVID-19/therapy , Genotype , Glomerulosclerosis, Focal Segmental/drug therapy , Glucocorticoids/therapeutic use , Humans , Immunization, Passive , Male , SARS-CoV-2
7.
Nat Rev Immunol ; 21(12): 759, 2021 12.
Article in English | MEDLINE | ID: covidwho-1493127
9.
Kidney Int ; 100(6): 1303-1315, 2021 12.
Article in English | MEDLINE | ID: covidwho-1336699

ABSTRACT

Kidney failure is common in patients with Coronavirus Disease-19 (COVID-19), resulting in increased morbidity and mortality. In an international collaboration, 284 kidney biopsies were evaluated to improve understanding of kidney disease in COVID-19. Diagnoses were compared to five years of 63,575 native biopsies prior to the pandemic and 13,955 allograft biopsies to identify diseases that have increased in patients with COVID-19. Genotyping for APOL1 G1 and G2 alleles was performed in 107 African American and Hispanic patients. Immunohistochemistry for SARS-CoV-2 was utilized to assess direct viral infection in 273 cases along with clinical information at the time of biopsy. The leading indication for native biopsy was acute kidney injury (45.4%), followed by proteinuria with or without concurrent acute kidney injury (42.6%). There were more African American patients (44.6%) than patients of other ethnicities. The most common diagnosis in native biopsies was collapsing glomerulopathy (25.8%), which was associated with high-risk APOL1 genotypes in 91.7% of cases. Compared to the five-year biopsy database, the frequency of myoglobin cast nephropathy and proliferative glomerulonephritis with monoclonal IgG deposits was also increased in patients with COVID-19 (3.3% and 1.7%, respectively), while there was a reduced frequency of chronic conditions (including diabetes mellitus, IgA nephropathy, and arterionephrosclerosis) as the primary diagnosis. In transplants, the leading indication was acute kidney injury (86.4%), for which rejection was the predominant diagnosis (61.4%). Direct SARS-CoV-2 viral infection was not identified. Thus, our multi-center large case series identified kidney diseases that disproportionately affect patients with COVID-19 and demonstrated a high frequency of APOL1 high-risk genotypes within this group, with no evidence of direct viral infection within the kidney.


Subject(s)
Acute Kidney Injury , COVID-19 , Apolipoprotein L1/genetics , Humans , Kidney , Retrospective Studies , SARS-CoV-2
10.
Mamm Genome ; 32(5): 389-400, 2021 10.
Article in English | MEDLINE | ID: covidwho-1258196

ABSTRACT

Acute Kidney Injury (AKI) is a common manifestation of COVID-19 and several cases have been reported in the setting of the high-risk APOL1 genotype (common genetic variants). This increases the likelihood that African American people with the high-risk genotype APOL1 are at increased risk for kidney disease in the COVID-19 environment. Single-nucleotide polymorphisms (SNPs) are found in various microRNAs (miRNAs) and target genes change the miRNA activity that leads to different diseases. Evidence has shown that SNPs increase/decrease the effectiveness of the interaction between miRNAs and disease-related target genes. The aim of this study is not only to identify miRSNPs on the APOL1 gene and SNPs in miRNA genes targeting 3'UTR but also to evaluate the effect of these gene variations in kidney patients and their association with SARS-COV-2 infection. In 3'UTR of the APOL1 gene, we detected 96 miRNA binding sites and 35 different SNPs with 10 different online software in the binding sites of the miRNA (in silico). Also we studied gene expression of patients and control samples by using qRT-PCR (in vitro). In silico study, the binding site of miR-6741-3p on APOL1 has two SNPs (rs1288875001, G > C; rs1452517383, A > C) on APOL1 3'UTR, and its genomic sequence is the same nucleotide as rs1288875001. Similarly, two other SNPs (rs1142591, T > A; rs376326225, G > A) were identified in the binding sites of miR-6741-3p at the first position. Here, the miRSNP (rs1288875001) in APOL1 3'UTR and SNP (rs376326225) in the miR-6741-3p genomic sequence are cross-matched in the same binding region. In vitro study, the relative expression levels were calculated by the 2-ΔΔCt method & Mann-Whitney U test. The expression of APOL1 gene was different in chronic kidney patients along with COVID-19. By these results, APOL1 expression was found lower in patients than healthy (p < 0.05) in kidney patients along with COVID-19. In addition, miR-6741-3p targets many APOL1-related genes (TLR7, SLC6A19, IL-6,10,18, chemokine (C-C motif) ligand 5, SWT1, NFYB, BRF1, HES2, NFYB, MED12L, MAFG, GTF2H5, TRAF3, angiotensin II receptor-associated protein, PRSS23) by evaluating online software in the binding sites of the miR-6741-3p. miR-6741-3p has not previously shown any association with kidney diseases and SARS-COV-2 infection. It assures that APOL1 can have a significant consequence in kidney-associated diseases by different pathways. Henceforth, this study represents and demonstrates an effective association between miR-6741-3p and kidney diseases, i.e., collapsing glomerulopathy, chronic kidney disease (CKD), acute kidney injury (AKI), and tubulointerstitial lesions susceptibility to SARS-COV-2 infection via in silico and in vitro exploration and recommended to have better insight.


Subject(s)
3' Untranslated Regions/genetics , Apolipoprotein L1/genetics , COVID-19/genetics , Kidney Diseases/genetics , MicroRNAs/genetics , Polymorphism, Single Nucleotide/genetics , Binding Sites/genetics , Case-Control Studies , Genotype , Humans , Kidney/pathology , SARS-CoV-2/pathogenicity
11.
Transplantation ; 105(1): 206-211, 2021 01 01.
Article in English | MEDLINE | ID: covidwho-1226601

ABSTRACT

BACKGROUND: There is compelling evidence that renal complications in a native kidney are a major concern in patients infected with severe acute respiratory syndrome coronavirus 2, the causal agent of coronavirus disease 2019 (COVID-19). The spectrum of renal lesions observed on renal grafts in this context remains to be determined. METHODS: We report the case of a renal transplant recipient with non-severe COVID-19, who subsequently developed nephrotic syndrome associated with acute renal injury. RESULTS: Renal biopsy demonstrated focal and segmental glomerulosclerosis lesions classified as not otherwise specified histological variant. Genotyping for 2 risk alleles of the apolipoprotein L1 gene demonstrated that the donor was homozygous for the G2/G2 genotype. CONCLUSIONS: In renal transplant patients receiving kidneys from donors with high-risk apolipoprotein L1 variants, COVID-19 may promote acute glomerular injury in the form of focal and segmental glomerulosclerosis.


Subject(s)
Apolipoprotein L1/genetics , COVID-19/complications , Glomerulosclerosis, Focal Segmental/etiology , Kidney Transplantation/adverse effects , SARS-CoV-2 , Tissue Donors , Humans , Kidney/pathology , Male , Middle Aged
12.
Arch Virol ; 166(8): 2089-2108, 2021 Aug.
Article in English | MEDLINE | ID: covidwho-1209235

ABSTRACT

The SARS-CoV-2 pandemic has become one of the most serious health concerns globally. Although multiple vaccines have recently been approved for the prevention of coronavirus disease 2019 (COVID-19), an effective treatment is still lacking. Our knowledge of the pathogenicity of this virus is still incomplete. Studies have revealed that viral factors such as the viral load, duration of exposure to the virus, and viral mutations are important variables in COVID-19 outcome. Furthermore, host factors, including age, health condition, co-morbidities, and genetic background, might also be involved in clinical manifestations and infection outcome. This review focuses on the importance of variations in the host genetic background and pathogenesis of SARS-CoV-2. We will discuss the significance of polymorphisms in the ACE-2, TMPRSS2, vitamin D receptor, vitamin D binding protein, CD147, glucose-regulated protein 78 kDa, dipeptidyl peptidase-4 (DPP4), neuropilin-1, heme oxygenase, apolipoprotein L1, vitamin K epoxide reductase complex 1 (VKORC1), and immune system genes for the clinical outcome of COVID-19.


Subject(s)
COVID-19/genetics , ABO Blood-Group System/genetics , Angiotensin-Converting Enzyme 2/genetics , Apolipoprotein L1/genetics , Basigin/genetics , COVID-19/epidemiology , COVID-19/therapy , Dipeptidyl Peptidase 4/genetics , Heat-Shock Proteins/genetics , Heme Oxygenase-1/genetics , Humans , Immunity/genetics , Neuropilin-1/genetics , Patient Outcome Assessment , Polymorphism, Genetic , Receptors, Calcitriol/genetics , SARS-CoV-2 , Serine Endopeptidases/genetics , Vitamin D-Binding Protein/genetics , Vitamin K Epoxide Reductases/genetics
14.
Adv Chronic Kidney Dis ; 27(5): 365-376, 2020 09.
Article in English | MEDLINE | ID: covidwho-975047

ABSTRACT

Acute kidney injury (AKI) is common among hospitalized patients with Coronavirus Infectious Disease 2019 (COVID-19), with the occurrence of AKI ranging from 0.5% to 80%. The variability in the occurrence of AKI has been attributed to the difference in geographic locations, race/ethnicity, and severity of illness. AKI among hospitalized patients is associated with increased length of stay and in-hospital deaths. Even patients with AKI who survive to hospital discharge are at risk of developing chronic kidney disease or end-stage kidney disease. An improved knowledge of the pathophysiology of AKI in COVID-19 is crucial to mitigate and manage AKI and to improve the survival of patients who developed AKI during COVID-19. The goal of this article is to provide our current understanding of the etiology and the pathophysiology of AKI in the setting of COVID-19.


Subject(s)
Acute Kidney Injury/metabolism , COVID-19/metabolism , Cytokines/metabolism , Glomerulonephritis/metabolism , Thrombotic Microangiopathies/metabolism , Acute Kidney Injury/etiology , Acute Kidney Injury/pathology , Acute Kidney Injury/physiopathology , Anti-Bacterial Agents/adverse effects , Antiviral Agents/adverse effects , Apolipoprotein L1/genetics , Ascorbic Acid/adverse effects , Azotemia/metabolism , Azotemia/pathology , Azotemia/physiopathology , COVID-19/drug therapy , COVID-19/pathology , COVID-19/physiopathology , Disease Progression , Glomerulonephritis/pathology , Glomerulonephritis/physiopathology , Glomerulonephritis, Membranous/metabolism , Glomerulonephritis, Membranous/pathology , Glomerulonephritis, Membranous/physiopathology , Hospital Mortality , Humans , Kidney Tubules, Proximal/injuries , Length of Stay , Myoglobin/metabolism , Nephritis, Interstitial/metabolism , Nephritis, Interstitial/pathology , Nephritis, Interstitial/physiopathology , Nephrosis, Lipoid/metabolism , Nephrosis, Lipoid/pathology , Nephrosis, Lipoid/physiopathology , Renal Insufficiency, Chronic , Rhabdomyolysis/metabolism , SARS-CoV-2 , Severity of Illness Index , Thrombotic Microangiopathies/pathology , Thrombotic Microangiopathies/physiopathology , Vitamins/adverse effects
15.
16.
J Am Soc Nephrol ; 32(1): 33-40, 2021 01.
Article in English | MEDLINE | ID: covidwho-937294

ABSTRACT

BACKGROUND: Studies have documented AKI with high-grade proteinuria in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In some patients, biopsies have revealed collapsing glomerulopathy, a distinct form of glomerular injury that has been associated with other viruses, including HIV. Previous patient reports have described patients of African ancestry who developed nephrotic-range proteinuria and AKI early in the course of disease. METHODS: In this patient series, we identified six patients with coronavirus disease 2019 (COVID-19), AKI, and nephrotic-range proteinuria. COVID-19 was diagnosed by a positive nasopharyngeal swab RT-PCR for SARS-CoV-2 infection. We examined biopsy specimens from one transplanted kidney and five native kidneys. Three of the six patients underwent genetic analysis of APOL1, the gene encoding the APOL1 protein, from DNA extracted from peripheral blood. In addition, we purified genomic DNA from paraffin-embedded tissue and performed APOL1 genotype analysis of one of the native biopsies and the donor kidney graft. RESULTS: All six patients were of recent African ancestry. They developed COVID-19-associated AKI with podocytopathy, collapsing glomerulopathy, or both. Patients exhibited generally mild respiratory symptoms, and no patient required ventilator support. Genetic testing performed in three patients confirmed high-risk APOL1 genotypes. One APOL1 high-risk patient developed collapsing glomerulopathy in the engrafted kidney, which was transplanted from a donor who carried a low-risk APOL1 genotype; this contradicts current models of APOL1-mediated kidney injury, and suggests that intrinsic renal expression of APOL1 may not be the driver of nephrotoxicity and specifically, of podocyte injury. CONCLUSIONS: Glomerular disease presenting as proteinuria with or without AKI is an important presentation of COVID-19 infection and may be associated with a high-risk APOL1 genotype.


Subject(s)
Acute Kidney Injury/etiology , African Americans , Apolipoprotein L1/genetics , COVID-19/complications , Kidney Glomerulus/physiopathology , SARS-CoV-2 , Acute Kidney Injury/ethnology , Acute Kidney Injury/genetics , Acute Kidney Injury/physiopathology , African Americans/genetics , Apolipoprotein L1/physiology , Biopsy , Diabetic Nephropathies/complications , Female , Genetic Predisposition to Disease , Genotype , Hematuria/etiology , Humans , Hypertension/complications , Kidney Glomerulus/pathology , Kidney Transplantation , Male , Middle Aged , Models, Biological , Podocytes/pathology , Podocytes/virology , Proteinuria/etiology , Risk , SARS-CoV-2/pathogenicity , Viral Tropism
17.
Transplant Proc ; 52(9): 2693-2697, 2020 Nov.
Article in English | MEDLINE | ID: covidwho-797224

ABSTRACT

Kidney injury is a well-known complication in people with coronavirus disease 2019 (COVID-19). In kidney transplant recipients with COVID-19, presentation with nephrotic syndrome has not been well described. We report on a 49-year-old black female kidney transplant recipient who presented 25 years after transplant with clinical features of nephrotic syndrome following a diagnosis of COVID-19. Histologic examination showed acute tubular injury with unremarkable glomeruli on light microscopy and diffuse foot process effacement of podocytes on electron microscopy, consistent with minimal change-like podocyte injury. Apolipoprotein L1 (APOL1) genetic testing confirmed 2 high-risk APOL1 alleles in the kidney donor. We speculate that COVID-19-induced systemic or local cytokine release could serve as a second hit in the presence of APOL1 risk alleles and mediate a podocytopathy manifesting as nephrotic syndrome. The presented case with minimal change-like disease, occurring in the context of the donor high-risk APOL1 genotype, extends the spectrum of clinical manifestations in COVID-19-associated nephropathy.


Subject(s)
Apolipoprotein L1/genetics , Coronavirus Infections/immunology , Immunocompromised Host , Nephrosis, Lipoid/genetics , Nephrosis, Lipoid/virology , Pneumonia, Viral/immunology , Betacoronavirus , COVID-19 , Female , Humans , Kidney Transplantation , Middle Aged , Pandemics , SARS-CoV-2
19.
J Am Soc Nephrol ; 31(8): 1688-1695, 2020 Aug.
Article in English | MEDLINE | ID: covidwho-633952

ABSTRACT

BACKGROUND: Kidney involvement is a feature of COVID-19 and it can be severe in Black patients. Previous research linked increased susceptibility to collapsing glomerulopathy, including in patients with HIV-associated nephropathy, to apo L1 (APOL1) variants that are more common in those of African descent. METHODS: To investigate genetic, histopathologic, and molecular features in six Black patients with COVID-19 presenting with AKI and de novo nephrotic-range proteinuria, we obtained biopsied kidney tissue, which was examined by in situ hybridization for viral detection and by NanoString for COVID-19 and acute tubular injury-associated genes. We also collected peripheral blood for APOL1 genotyping. RESULTS: This case series included six Black patients with COVID-19 (four men, two women), mean age 55 years. At biopsy day, mean serum creatinine was 6.5 mg/dl and mean urine protein-creatinine ratio was 11.5 g. Kidney biopsy specimens showed collapsing glomerulopathy, extensive foot process effacement, and focal/diffuse acute tubular injury. Three patients had endothelial reticular aggregates. We found no evidence of viral particles or SARS-CoV-2 RNA. NanoString showed elevated chemokine gene expression and changes in expression of genes associated with acute tubular injury compared with controls. All six patients had an APOL1 high-risk genotype. Five patients needed dialysis (two of whom died); one partially recovered without dialysis. CONCLUSIONS: Collapsing glomerulopathy in Black patients with COVID-19 was associated with high-risk APOL1 variants. We found no direct viral infection in the kidneys, suggesting a possible alternative mechanism: a "two-hit" combination of genetic predisposition and cytokine-mediated host response to SARS-CoV-2 infection. Given this entity's resemblance with HIV-associated nephropathy, we propose the term COVID-19-associated nephropathy to describe it.


Subject(s)
Acute Kidney Injury/genetics , Apolipoprotein L1/genetics , Coronavirus Infections/genetics , Kidney Glomerulus/virology , Pneumonia, Viral/genetics , Acute Kidney Injury/complications , Adult , Aged , Alleles , Biopsy , COVID-19 , Coronavirus Infections/complications , Creatinine/blood , Female , Genotype , Humans , Kidney/pathology , Kidney Glomerulus/physiopathology , Kidney Tubules/pathology , Male , Middle Aged , Pandemics , Pneumonia, Viral/complications , Risk
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