Histopathologic findings on indication renal allograft biopsies after recovery from acute COVID-19

The Effects of COVID-19 in Kidney Transplantation: Evidence From Tissue Pathology

BACKGROUND

The biological effects of SARS-CoV-2 infection in transplanted kidneys are uncertain with little pathological information.

METHODS

This single-center, prospective observational study evaluated kidney transplant biopsies from recipients of deceased donors with COVID-19, current recipients contracting SARS-CoV-2 Omicron variant in 2022, against prior BK virus (BKV) infection and uninfected (without SARS-CoV-2 or BKV) samples, as respective positive and negative comparators (n = 503 samples).

RESULTS

We demonstrated nonvirus tubular injury in implanted tissue from infected donors and prevalent recipients with mild acute COVID-19 and acute kidney injury, excluding direct viral infection as a cause of kidney damage. COVID particles were absent in 4116 ultrastructural images of 295 renal tubules from 4 patients with acute COVID-19. No viral cytopathic effect, viral allograft nephropathy, or SARS-CoV-2 RNA was detected in acute tissues, nor in 128 sequential samples from infected donors or recipients with COVID-19. Following recipient COVID-19 (mean 16.8 ± 12.0 wk post-infection), the biopsy-prevalence of rejection was 33.0% (n = 100 biopsies) versus 13.4% for contemporaneous uninfected controls (n = 337; P < 0.001). Prior COVID-19 was an independent risk factor for incident rejection using multivariable generalized estimating equation adjusted for competing risks (odds ratio, 2.195; 95% confidence interval, 1.189-4.052; P = 0.012). Landmark and matched-pair analyses confirmed an association of SARS-CoV-2 with subsequent transplant rejection, with a similar pattern following BKV infection.

CONCLUSIONS

Transplantation from COVID-19+ deceased donors yielded good recipient outcomes without evidence of viral tissue transmission. Acute kidney injury during COVID-19 was mediated by archetypical tubular injury and infection correlated with an increased risk of subsequent rejection.

FSGS and COVID-19 in Non-African American Patients

Collapsing Focal Segmental Glomerulosclerosis (FSGS) has been reported relatively frequently in African American (AA) patients with coronavirus disease 2019 (COVID-19), and it is associated almost always with Apolipoprotein L gen 1 (APOL1) high-risk variants. We reviewed the published literature from April 2020 to November 2022 searching for non-African American (non-AA) patients with FSGS associated with COVID-19 (eight White patients, six Hispanic patients, three Asian patients, one Indian patient, and one Asian Indian patient). The following histologic patterns were found: collapsing (n=11), not otherwise specified (n=5), tip (n=2), and perihilar (n=1). Fifteen of the 19 patients had AKI. The APOL1 genotype was reported in only six of the 19 non-AA patients. Three of them (two Hispanic patients and one White patient) with collapsing FSGS had high-risk APOL1 variants. The other three patients (two White patients and one Hispanic patient with the collapsing variant, tip variant, and not otherwise specified) had low-risk APOL1 variants. Among 53 African American patients with collapsing FSGS associated with COVID-19, 48 had high-risk APOL1 variants and five had low-risk APOL1 variants. We conclude that in non-AA patients, FSGS is a rare complication of COVID-19. FSGS associated with COVID-19 can occur rarely with low-risk APOL1 variants in non-AA and AA patients. Non-AA patients reported to be associated with high-risk APOL1 variants possibly reflect inaccuracy of self-reported race with AA admixture because of unknown ancestry. Given the importance of APOL1 in the pathogenesis of FSGS associated with viral infection and to avoid racial bias, it seems appropriate that APOL1 testing be considered in patients with FSGS associated with COVID-19, regardless of self-reported race.

A Case of Acute Kidney Injury Caused by Myoglobin Cast Nephropathy With Sars-Cov-2 Infection in a Living-Donor Kidney Transplant Recipient

When COVID-19 affects patients with risk factors such as chronic kidney disease or on immunosuppressive drugs, they often rapidly become seriously ill. We describe a 50-year-old man who was affected with SARS-CoV-2 and had undergone an ABO-compatible living-donor kidney transplantation from his father 14 years ago because of end-stage renal failure due to hypertensive nephrosclerosis. He had continued on immunosuppressive drugs and completed vaccination twice (9 months ago and 6 months ago) with messenger RNA (mRNA) vaccines against SARS-CoV-2. However, he was temporarily on a mechanical ventilator due to respiratory failure and hemodialysis due to acute kidney injury (AKI). He was finally weaned from the ventilator and hemodialysis by taking steroid and antiviral drugs. Echo-guided renal biopsy revealed myoglobin cast nephropathy. We experienced 14 outpatients after living-donor kidney transplantation infected with SARS-CoV-2, but only this case developed AKI.

Modified Banff Criteria in Assessing SARS-CoV-2-Associated Renal Pathology: An Autopsy Study

Introduction SARS-CoV-2 is an epitheliotropic viral agent with epithelial tropism. Although the clinical significance and severity of affection is the most pronounced in the respiratory system, other organs and systems are also infected and, hence affected, such as the central nervous system, gastrointestinal tract, cardiovascular, and urinary systems. Herein, we set out to evaluate the presence and degree of morphological changes within the renal parenchyma and its relation to disease outcome. Materials and methods A retrospective non-clinical approach was utilized for the means of the study. All patients with real-time reverse transcriptase-polymerase chain reaction proven infection, subject to an autopsy performed in a period of two calendar years, were included in the study. Kidney tissue histopathology samples were analyzed using a modified Banff criteria system for acute onset and chronic changes. The results were compared for statistical significance with overall patient survival from symptom onset to death. Furthermore, SARS-CoV-2 viral presence was evaluated in renal structures by means of immunohistochemistry. Results A total of 40 patients were included in the study. Immunohistochemistry showed viral presence within a myriad of renal structured - endothelial cells, tubular cells, and podocytes. Modified Banff criteria showed significant acute changes within the parenchyma, including endotheliitis, glomerulitis, mesangial matrix expansion, tubulitis, capillaritis, arteritis, thrombosis (including thrombotic microangiopathy in four patients), and hemorrhages. Individual cases also presented with signs of rhabdomyolysis - myoglobulin casts. Signs of chronic injury were also present in most patients. However, when calculated as scores, neither acute nor chronic changes showed a correlation with time from symptom onset to death. Conclusion The results of the present study show both viral presence and a myriad of induced changes in the contents of SARS-CoV-2 infection within the renal parenchyma. The lack of correlation with the degree of changes, when compared to survival, is an encouraging fact that the changes are unlikely to play a role in direct tanatogenesis while having the potential to manifest as chronic kidney disease in the future.

Collapsing focal segmental glomerulosclerosis secondary to COVID-19: A systematic review and meta-analysis

The renal system manifestations of coronavirus disease-2019 have been documented extensively; however, scientific literature remains scarce regarding collapsing glomerulopathy hence the need for this investigation.

Methods

A comprehensive review was conducted covering a timeline from 1 January 2020 to 5 February 2022 without any restrictions. The data extraction was conducted independently, and articles were assessed for the risk of bias. Data analysis was conducted using Comprehensive Meta-Analysis version 3.3.070 and RevMan version 5.4 for pooled proportions and risk ratio (RR) between dialysis-dependent and independent treatment groups with a P-value less than 0.05 considered significant.

Results

A total of 38 studies were included in this review, including 74 (65.9%) males. The mean age was 54.2 years old. The most common symptoms reported were related to the respiratory system (59.6%, 95% CI: 50.4-68.2%) and hematuria (34.2%, 95% CI: 26.1-43.4). Antibiotics (25.9%, 95% CI: 12.9-45.3%) was the commonest management used. Proteinuria was the most reported laboratory finding at 89.5% (95% CI: 82.4-93.9%), while the commonest microscopic finding was acute tubular injury (77.2%, 95% CI: 68.6-84.0%). An increased risk of the presence of symptoms (P=0.005) and microscopic findings (P=0.0003) related to collapsing glomerulopathy in dialysis-dependent group was noted with increased management (P=0.01) used in this group for coronavirus disease-2019 infection.

Conclusion

The findings of this study portray the prognostic value of the variables (symptoms and microscopic findings, etc.) reported in the analysis. Hence this study serves as a foundation for future investigations that minimize the study's limitations to provide a more robust conclusion.

Two-Hit Kidney Allograft Injury by SARS-CoV-2

Coronavirus disease 2019 (COVID-19) has been associated with acute kidney injury in kidney transplant recipients by several mechanisms. The authors report a case of acute kidney allograft dysfunction in a 48-year-old patient who presented in the emergency room with anasarca and nephrotic syndrome close after mild COVID-19 and no other clinical condition. Histopathology of the allograft biopsy revealed two distinct and simultaneous kidney lesions, collapsing glomerulopathy and thrombotic microangiopathy. Renal function persistently deteriorated, and definitive dialysis was initiated. After excluding other plausible causes for the findings, this case strengthens the hypothesis that the kidney allograft is also a target of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Kidney Disease and Viral Infection in COVID-19: Why Are Kidney Organoid and Biopsy Studies Not in Agreement?

CONTEXT

The clinical course of coronavirus disease-19 (COVID-19) can be complicated by acute kidney injury and proteinuria. Kidney cells express receptors for SARS-CoV-2, the virus responsible for COVID-19. Direct infection of the kidney parenchyma by SARS-CoV-2 has been proposed as the cause of renal dysfunction in COVID-19. Subject of Review: Kidney organoids derived from human embryonic stem cells or induced pluripotent cells can be reproducibly infected by SARS-CoV-2 in vitro and used to study therapeutics. However, kidney biopsy studies of COVID-19 patients with renal dysfunction have shown no evidence of viral infection. Second Opinion: Kidney organoids are susceptible to SARS-CoV-2 infection, which is probably facilitated by their limited architectural complexity and maturation compared to the intact organ and by the in vitro culture conditions. Conversely, kidneys in COVID-19 patients appear resistant to infection and may be injured through indirect mechanisms mediated by the host response to the respiratory viral infection, genetic susceptibility to the immune response, physiological disturbances, and therapies. More studies are needed to better understand why kidney organoids are more susceptible than mature kidneys to SARS-CoV-2 infection and further characterize the mechanisms of kidney injury in COVID-19.

Solid Organ Rejection following SARS-CoV-2 Vaccination or COVID-19 Infection: A Systematic Review and Meta-Analysis

Background: Solid organ rejection post-SARS-CoV-2 vaccination or COVID-19 infection is extremely rare but can occur. T-cell recognition of antigen is the primary and central event that leads to the cascade of events that result in rejection of a transplanted organ. Objectives: To describe the results of a systematic review for solid organ rejections following SARS-CoV-2 vaccination or COVID-19 infection. Methods: For this systematic review and meta-analysis, we searched Proquest, Medline, Embase, Pubmed, CINAHL, Wiley online library, Scopus and Nature through the Preferred Reporting Items for Systematic Reviews and Meta Analyses (PRISMA) guidelines for studies on the incidence of solid organ rejection post-SARS-CoV-2 vaccination or COVID-19 infection, published from 1 December 2019 to 31 May 2022, with English language restriction. Results: One hundred thirty-six cases from fifty-two articles were included in the qualitative synthesis of this systematic review (56 solid organs rejected post-SARS-CoV-2 vaccination and 40 solid organs rejected following COVID-19 infection). Cornea rejection (44 cases) was the most frequent organ observed post-SARS-CoV-2 vaccination and following COVID-19 infection, followed by kidney rejection (36 cases), liver rejection (12 cases), lung rejection (2 cases), heart rejection (1 case) and pancreas rejection (1 case). The median or mean patient age ranged from 23 to 94 years across the studies. The majority of the patients were male (n = 51, 53.1%) and were of White (Caucasian) (n = 51, 53.7%) and Hispanic (n = 15, 15.8%) ethnicity. A total of fifty-six solid organ rejections were reported post-SARS-CoV-2 vaccination [Pfizer-BioNTech (n = 31), Moderna (n = 14), Oxford Uni-AstraZeneca (n = 10) and Sinovac-CoronaVac (n = 1)]. The median time from SARS-CoV-2 vaccination to organ rejection was 13.5 h (IQR, 3.2–17.2), while the median time from COVID-19 infection to organ rejection was 14 h (IQR, 5–21). Most patients were easily treated without any serious complications, recovered and did not require long-term allograft rejection therapy [graft success (n = 70, 85.4%), graft failure (n = 12, 14.6%), survived (n = 90, 95.7%) and died (n = 4, 4.3%)]. Conclusion: The reported evidence of solid organ rejections post-SARS-CoV-2 vaccination or COIVD-19 infection should not discourage vaccination against this worldwide pandemic. The number of reported cases is relatively small in relation to the hundreds of millions of vaccinations that have occurred, and the protective benefits offered by SARS-CoV-2 vaccination far outweigh the risks.

Spectrum of Kidney Injury Following COVID-19 Disease: Renal Biopsy Findings in a Single Italian Pathology Service

The onset of coronavirus disease (COVID-19) as a pandemic infection, has led to increasing insights on its pathophysiology and clinical features being revealed, such as a noticeable kidney involvement. In this study, we describe the histopathological, immunofluorescence, and ultrastructural features of biopsy-proven kidney injury observed in a series of SARS-CoV-2 positive cases in our institution from April 2020 to November 2021. We retrieved and retrospectively reviewed nine cases (two pediatric and seven adults) that experienced nephrotic syndrome (six cases), acute kidney injury (two cases), and a clinically silent microhematuria and leukocyturia. Kidney biopsies were investigated by means of light microscopy, direct immunofluorescence, and electron microscopy. The primary diagnoses were minimal change disease (four cases), acute tubular necrosis (two cases), collapsing glomerulopathy (two cases), and C3 glomerulopathy (one case). None of the cases showed viral or viral-like particles on ultrastructural analysis. Novel and specific histologic features on kidney biopsy related to SARS-CoV-2 infection have been gradually disclosed and reported, harboring relevant clinical and therapeutic implications. Recognizing and properly diagnosing renal involvement in patients experiencing COVID-19 could be challenging (due to the lack of direct proof of viral infection, e.g., viral particles) and requires a proper integration of clinical and pathological data.