A Population-Based Analysis of the Risk of Glomerular Disease Relapse after COVID-19 Vaccination

Proliferative glomerulonephritis with monoclonal immunoglobulin deposits and atypical pathological findings treated with corticosteroid and rituximab

A 16-year-old girl with fever that appeared after taking the second COVID-19 vaccine presented to the clinic with a serum creatinine of 0.89 mg/dL and C-reactive protein of 6.9 mg/dL. She had proteinuria and microscopic hematuria, with slowly worsening kidney function. Her kidney biopsy showed fibrocellular crescents in seven of nine glomeruli that were observed under light microscopy. Another glomerulus showed endocapillary hypercellularity and mesangial cell proliferation. Electron-dense deposits were significant in the mesangial area, with monoclonal IgG1-κ and C3 deposition by immunofluorescence. The patient was diagnosed with proliferative glomerulonephritis with monoclonal immunoglobulin deposits (PGNMID) and atypical pathological finding of diffuse crescent formation. The treatment regimen for PGNMID has not yet been established, and the appropriate duration of treatment is unknown. In our case, considering that rituximab acts by binding to CD20 on the surface of B cells through its crystallizable fragment, it was administered in addition to prednisolone, which successfully decreased the proteinuria over time.

Glomerulonephritis following COVID-19 infection or vaccination: a multicenter study in South Korea

BACKGROUND

Despite the widespread impact of the severe acute respiratory syndrome coronavirus 2 (coronavirus disease 2019, COVID-19) and vaccination in South Korea, our understanding of kidney diseases following these events remains limited. We aimed to address this gap by investigating the characteristics of glomerular diseases following the COVID-19 infection and vaccination in South Korea.

METHODS

Data from multiple centers were used to identify de novo glomerulonephritis (GN) cases with suspected onset following COVID-19 infection or vaccination. Retrospective surveys were used to determine the COVID-19-related histories of patients who were initially not implicated. Bayesian structural time series and autoregressive integrated moving average models were used to determine causality.

RESULTS

Glomerular diseases occurred shortly after the infection or vaccination. The most prevalent postinfection GN was podocytopathy (42.9%), comprising primary focal segmental glomerulosclerosis and minimal change disease, whereas postvaccination GN mainly included immunoglobulin A nephropathy (IgAN; 57.9%) and Henoch-Schönlein purpura nephritis (HSP; 15.8%). No patient progressed to end-stage kidney disease. Among the patients who were initially not implicated, nine patients with IgAN/HSP were recently vaccinated against COVID-19. The proportion of glomerular diseases changed during the pandemic in South Korea, with an increase in acute interstitial nephritis and a decrease in pauci-immune crescentic GN.

CONCLUSION

This study showed the characteristics of GNs following COVID-19 infection or vaccination in South Korea. Understanding these associations is crucial for developing effective patient management and vaccination strategies. Further investigation is required to fully comprehend COVID-19's impact on GN.

Association of COVID-19 Versus COVID-19 Vaccination With Kidney Function and Disease Activity in Primary Glomerular Disease: A Report of the Cure Glomerulonephropathy Study

RATIONALE & OBJECTIVE

Patients with glomerular disease (GN) may be at increased risk of severe COVID-19, yet concerns over vaccines causing disease relapse may lead to vaccine hesitancy. We examined the associations of COVID-19 with longitudinal kidney function and proteinuria and compared these with similar associations with COVID-19 vaccination.

STUDY DESIGN

Observational cohort study from July 1, 2021, to January 1, 2023.

SETTING & PARTICIPANTS

A prospective observational study network of 71 centers from North America and Europe (CureGN) with children and adults with primary minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy, or IgA nephropathy.

EXPOSURE

COVID-19 and COVID-19 vaccination.

OUTCOME

Repeated measure of estimated glomerular filtration rate (eGFR); recurrent time-to-event outcome of GN disease worsening as defined by doubling of the urinary protein-creatinine ratio (UPCR) to at least 1.5g/g or increase in dipstick urine protein by 2 ordinal levels to 3+(300mg/dL) or above.

ANALYTICAL APPROACH

Interrupted time series analysis for eGFR. Prognostic matched sequential stratification recurrent event analysis for GN disease worsening.

RESULTS

Among 2,055 participants, 722 (35%) reported COVID-19 infection; of these, 92 (13%) were hospitalized, and 3 died (<1%). The eGFR slope before COVID-19 infection was-1.40mL/min/1.73m2 (± 0.29 SD); within 6 months after COVID-19 infection, the eGFR slope was-4.26mL/min/1.73m2 (± 3.02 SD), which was not significantly different (P=0.34). COVID-19 was associated with increased risk of worsening GN disease activity (HR, 1.35 [95% CI, 1.01-1.80]). Vaccination was not associated with a change in eGFR (-1.34mL/min/1.73m2±0.15 SD vs-2.16mL/min/1.73m2±1.74 SD; P=0.6) or subsequent GN disease worsening (HR 1.02 [95% CI, 0.79-1.33]) in this cohort.

LIMITATIONS

Infrequent or short follow-up.

CONCLUSIONS

Among patients with primary GN, COVID-19 infection was severe for 1 in 8 cases and was associated with subsequent worsening of GN disease activity, as defined by proteinuria. By contrast, vaccination against COVID-19 was not associated with change in disease activity or kidney function decline. These results support COVID-19 vaccination for patients with GN.

PLAIN-LANGUAGE SUMMARY

In this cohort study of 2,055 patients with minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy, or IgA nephropathy, COVID-19 resulted in hospitalization or death for 1 in 8 cases and was associated with a 35% increase in risk for worsening proteinuria. By contrast, vaccination did not appear to adversely affect kidney function or proteinuria. Our data support vaccination for COVID-19 in patients with glomerular disease.

Adverse events of acute nephrotoxicity reported to EudraVigilance and VAERS after COVID-19 vaccination

OBJECTIVES

The present study aimed to estimate the reporting rates (RRs) of acute kidney injury (AKI) and renal failure (RF) after COVID-19 vaccination in the European Economic Area (EEA) and the United States.

METHODS

We retrieved and analyzed pharmacovigilance data on suspected AKI and RF cases and fatalities post COVID-19 vaccination with licensed vaccines reported to EudraVigilance and VAERS between week 52/2020 and week 52/2022 or week 1/2023, respectively. Reporting rates with 95% confidence intervals were estimated per million administered vaccine doses.

RESULTS

In total, 4,244 AKI and 1,557 RF suspected cases were notified to EudraVigilance (1,692 AKI/971 RF) and VAERS (2,552 AKI/586 RF) during the study period following the administration of >1.6 billion COVID-19 vaccine doses (EEA: 970,934,453/US: 666,511,603). The overall RRs were 3.03 (95 % CI: 2.94-3.12) for AKI and 1.11 (95 % CI: 1.06-1.17) for RF per million administered vaccine doses. Indices for statistically significant increased risks were found in subjects, especially males, ≥65 years compared to 18-64 years old (AKI: OR = 7.23, 95 % CI: 6.63-7.88, p = 0.000, and RF: OR = 4.74, 95 % CI: 3.99-5.63, p < 0.001). AKI reporting rates were higher in the US, while RF reporting rates were higher in Europe. Both potential side effects were elevated following vectored rather than mRNA vaccines, with the highest reporting rates post AD26.COV2.S vaccination in the US (AKI: RR = 12.24, 95 % CI: 10.66-13.81; RF: RR = 3.17, 95 % CI: 2.36-3.97). There were 1,312 deaths possibly associated with AKI (RR = 0.94, 95 % CI: 0.89-0.99) and 460 deaths possibly associated with RF (RR = 0.33, 95 % CI: 0.30-0.36) per million vaccine doses. Fatalities were lower in Europe than in the US (AKI: OR = 0.25, 95 % CI: 0.22-0.28, p < 0.001; RF: OR = 0.82, 95 % CI: 0.69-0.99, p = 0.036).

CONCLUSIONS

AKI and RF may be observed rarely following vaccination against COVID-19. Further studies are warranted to confirm these findings and uncover the underlying pathophysiological mechanism.

Acute exacerbation of immunoglobulin A nephropathy complicated by alveolar hemorrhage after coronavirus disease 2019 vaccination: A case report

RATIONALE

Reports have suggested a relationship between coronavirus disease 2019 (COVID-19) vaccination and new-onset or recurring renal diseases, of which immunoglobulin A (IgA) nephropathy is a representative disease. Alveolar hemorrhage in patients with IgA nephropathy is rare but reportedly has a high mortality and morbidity. To our knowledge, there have been no reports regarding the development of IgA nephropathy with alveolar hemorrhage following COVID-19 vaccination.

PATIENTS CONCERN

A 23-year-old Japanese man presented with hemoptysis and peripheral edema a few days after receiving a second dose of a COVID-19 mRNA vaccine. Severe renal failure and alveolar hemorrhage were noted thereafter, and renal biopsy showed crescentic glomerulonephritis with mesangial proliferation accompanied by mesangial electron-dense deposits containing IgA. Renal biopsy tissue also showed chronic histological changes suggestive of acute exacerbation of preexisting IgA nephropathy.

DIAGNOSIS

The diagnosis of IgA nephropathy complicated by alveolar hemorrhage was made.

INTERVENTIONS AND OUTCOMES

Renal function did not recover despite treatment with high-dose steroids; the patient was maintained on hemodialysis and eventually underwent successful renal transplantation.

LESSONS

The present case suggested that although extremely rare, severe renal failure requiring renal replacement therapy could occur in patients with IgA nephropathy after COVID-19 vaccination. Future accumulation of similar cases is needed to predict the risk of renal injury following vaccination.

Exacerbation of Minimal Change Disease Following mRNA COVID-19 Vaccination

BACKGROUND Minimal change disease is a common cause of nephrotic syndrome in adults. There are few reported cases of vaccine-related podocytopathy with nephrotic-range proteinuria in the setting of a minimal change disease history. There have been rare reports of acute renal damage following vaccination to prevent COVID-19 and some cases of exacerbation of ongoing nephropathy. This report is a 33-year-old man with a 22-year history of nephrotic syndrome due to minimal change disease which exacerbated following a third dose of an mRNA SARS-CoV-2 vaccine for COVID-19. CASE REPORT We report a case of nephrotic syndrome after the third dose of the BNT162b2 mRNA COVID-19 vaccine. The patient presented with mild edema in the bilateral lower extremities and sacrum. Laboratory investigations confirmed nephrotic-range proteinuria and hypoalbuminemia. A kidney sonogram demonstrated mild renal parenchymal disease and a small non-obstructing right renal calculus. Renal biopsy revealed diffuse podocyte foot process effacement, punctuate IgG podocyte cytoplasmic staining, and minimal global glomerulosclerosis, consistent with a diagnosis of a diffuse podocytopathy with a minimal change disease phenotype. The patient was started on oral prednisone treatment, which led to remission of his symptoms and normalization of lab test results with normal BUN and Cr and resolution of proteinuria. Treatment was tapered off over the course of 28 weeks. CONCLUSIONS We presents a case of longstanding minimal change disease that showed exacerbation following a third dose of an mRNA vaccine for SARS-CoV-2. Although this may be a rare association, this case supports that patients with chronic glomerulonephritis need to be monitored.

Safety and effectiveness of COVID-19 vaccines in patients with IgA nephropathy: a retrospective cohort study from the TriNetX global collaborative networks

Background

This study aimed to evaluate the renal safety and effectiveness of COVID-19 vaccination in patients with immunoglobulin A nephropathy (IgAN).

Methods

We conducted a global and retrospective collaborative network analysis using TriNetX data from September 11, 2018 to September 11, 2023, to address this question. The study recorded diagnoses of IgAN, COVID-19 vaccinations, and outcomes of effectiveness using International Classification of Diseases, Tenth Revision, Clinical Modification codes and procedure codes. Propensity score matching (PSM) created matched groups (1:1). Hazard ratios (HR) with 95% confidence intervals (95% CI) were calculated for outcomes of effectiveness, and Kaplan-Meier method assessed survival probability. Safety outcomes regarding renal function were compared with estimated glomerular filtration rate (eGFR), proteinuria, and hematuria. Subgroup analyses were based on sex and age group. Sensitivity analysis was done before the outbreak of Omicron (from September 11, 2018 to October 31, 2021).

Findings

The study involved 1010 vaccinated and 2776 unvaccinated patients with IgAN without COVID-19 infection at baseline. After PSM (1:1) with 25 variables, both groups consisted of well-matched 979 patients who were relatively young (around 55 years old) and in good health (eGFR: 78-80 ml/min/1.732 m2). Compared to the non-vaccinated group, vaccinated patients had significantly lower risks of COVID-19 infection and complications, including COVID-19 infection (HR: 0.050, 95% CI: 0.026, 0.093), COVID-19 pneumonia (HR: 0), severe lung complication (0.647, 95% CI: 0.421, 0.994), acute respiratory failure (0.625, 95% CI: 0.400, 0.978), sepsis (0.545, 95% CI: 0.334, 0.890), emergency department visits (0.716, 95% CI: 0.615, 0.833), all hospitalizations (0.573, 95% CI: 0.459, 0.715), and mortality (0.595, 95% CI: 0.366, 0.969). However, one month after the follow-up, the vaccinated group exhibited a slightly, but statistically significantly, lower eGFR compared to the non-vaccinated group (73.58 vs. 83.05 ml/min/1.732 m2, p = 0.047). Nine months after the follow-up, the difference in eGFR between the two groups disappeared. The lower risk of COVID-19 infection was observed across genders (male and female) and age groups (young and old). For the period before Omicron outbreak, results were also similar.

Interpretation

In the largest TriNetX matched cohort study of IgAN, COVID-19 vaccination was associated with a reduced risk of COVID-19 infection and associated complications. However, careful monitoring of renal function, especially GFR, is advisable.

Funding

This study was supported by grant TCVGH-1103602C, TCVGH-1103601D, and TCVGH-1113602D from Taichung Veterans General Hospital.

[Diagnosis and treatment of Minimal Change Disease in adults-2023]

Minimal change disease is a glomerulopathy that clinically manifests as acute onset nephrotic syndrome. A diagnosis is made by renal biopsy, implying the absence of glomerular lesions on light microscopy but detection of extensive podocyte foot process effacement on electron miscroscopy. Considering the typically excellent response to immunosuppressive measures (especially to glucocorticoids), an autoimmune pathogenesis is assumed. Although general prognosis is overall beneficial, steroid-dependent, steroid-resistant and frequently-relapsing disease courses may complicate the management of these patients and necessitate the use of alternative immunosuppressive treatment strategies. Here, the Austrian Society of Nephrology (ÖGN) provides a consensus on how to best diagnose and manage adult patients with minimal change disease.

Predictors of Gross Hematuria After SARS-CoV-2 mRNA Vaccination in Patients with IgA Nephropathy

Key Points

Little is known about the clinical characteristics of patients with immunoglobulin A nephropathy (IgAN) who present with gross hematuria in relation to SARS-CoV-2 mRNA vaccination. The relationship between the clinical features in patients with IgAN at the time of SARS-CoV-2 mRNA vaccination and the subsequent appearance of gross hematuria was investigated. This study demonstrates the clinical significance of microscopic hematuria in patients with IgAN as a predictor of gross hematuria after SARS-CoV-2 mRNA vaccination.

Background

There have been several reports of immunoglobulin A nephropathy (IgAN) patients with gross hematuria and acute deterioration of urinary findings and kidney function after severe acute respiratory syndrome coronavirus 2 mRNA vaccination. Recent case series studies have indicated a possible link between the status of urinary findings at the time of vaccination and the subsequent appearance of gross hematuria. In this study, we aimed to determine whether the status of prevaccination urinary findings was associated with postvaccination gross hematuria in patients already diagnosed with IgAN.

Methods

Outpatients with IgAN who had been followed up before vaccination were included. We analyzed the association between the remission of prevaccination microscopic hematuria (urine sediment <5 red blood cells/high-power field) or proteinuria (<0.3 g/gCr) and postvaccination gross hematuria.

Results

A total of 417 Japanese patients with IgAN (median age, 51 years; 56% female; eGFR, 58 ml/min per 1.73 m2) were included. The frequency of gross hematuria after vaccination was higher in 20 of 123 patients (16.3%) with microscopic hematuria than in 5 of 294 patients (1.7%) without microscopic hematuria before vaccination (P < 0.001). There was no association between prevaccination proteinuria and postvaccination gross hematuria. After adjusting for potential confounders, such as sex (female), age (younger than 50 years), eGFR (≥60 ml/min per 1.73 m2), and histories of tonsillectomy and corticosteroid therapy, prevaccination microscopic hematuria was still associated with postvaccination gross hematuria (odds ratio, 8.98; P < 0.001). As the severity of prevaccination microscopic hematuria increased, the incidence of postvaccination gross hematuria increased (P < 0.001).

Conclusions

Prevaccination microscopic hematuria in patients with IgAN is a major predictor of postvaccination gross hematuria, regardless of potential confounders, including previous treatments of IgAN.

Subsequent COVID-19 Prophylaxis in COVID-19 Associated Glomerulopathies

Successful vaccination has been the decisive factor in the overall decline of SARS-CoV2 infection related morbidity and mortality. However, global effects of the COVID-19 pandemic are ongoing, with reports of glomerular disease occurring in relation to both infection and vaccination. A particular rise in anti-GBM disease has been identified. Information is still emerging regarding the optimal management of such cases. We reviewed anti-GBM antibody detection rates at our test center over the past 5 years. We followed three patients with biopsy confirmed glomerular disease temporally related to COVID-19 vaccination. Each patient proceeded to receive subsequent COVID-19 vaccination as per immunologist recommendations. Further assessment included COVID-19 antibody testing in each case. A three-fold increase in significant anti-GBM antibody results noted at our center was associated with COVID infection in 10% of cases, and COVID vaccination in 25% of cases. We demonstrated that subsequent vaccination did not appear to lead to adverse effects including relapse in our three cases of COVID-19 vaccine-associated GN. We also identified positive COVID-19 antibody levels in two out of three cases, despite immunosuppression. We report a rise in anti-GBM antibody disease incidence. Our small study suggests that COVID-19 antibody testing can help determine COVID prophylaxis requirements, and subsequent vaccination with an alternative vaccine type appears safe.

SARS-CoV-2 infection: a possible trigger for the recurrence of IgA nephropathy after kidney transplantation?

Immunoglobulin A nephropathy, the most common primary glomerulonephritis worldwide, is a leading cause of chronic kidney disease and end-stage kidney failure. Several cases of immunoglobulin A nephropathy relapse in native kidneys have been described after COVID-19 vaccination or SARS-CoV-2 infection. Here, we report the case of a 52-year-old kidney transplant recipient who had a stable transplant function for more than 14 years, with a glomerular filtration rate above 30 ml/min/1.73 m². The patient had been vaccinated against COVID-19 four times with the Pfizer-BioNTech vaccine, most recently in March 2022. Eight weeks after a symptomatic SARS-CoV-2 infection in June 2022, his glomerular filtration rate had decreased by more than 50%, and his proteinuria increased to 17.5 g per day. A renal biopsy indicated highly active immunoglobulin A nephritis. Despite steroid therapy, the function of the transplanted kidney deteriorated, and long-term dialysis became necessary because of recurrence of his underlying renal disease. This case report provides what is, to our knowledge, the first description of recurrent immunoglobulin A nephropathy in a kidney transplant recipient after SARS-CoV-2 infection leading to severe transplant failure and finally graft loss.

Protective Effect of Vaccine Doses and Antibody Titers Against SARS-CoV-2 Infection in Kidney Transplant Recipients

Patients undergoing kidney transplantation have a poor response to vaccination and a higher risk of disease progression of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The effectiveness of vaccine doses and antibody titer tests against the mutant variant in these patients remains unclear. We retrospectively analyzed the risk of SARS-CoV-2 infection in a single medical center according to vaccine doses and immune responses before the outbreak. Among 622 kidney transplant patients, there were 77 patients without vaccination, 26 with one dose, 74 with two doses, 357 with three, and 88 with four doses. The vaccination status and infection rate proportion were similar to the general population. Patients undergoing more than three vaccinations had a lower risk of infection (odds ratio = 0.6527, 95% CI = 0.4324-0.9937) and hospitalization (odds ratio = 0.3161, 95% CI = 0.1311-0.7464). Antibody and cellular responses were measured in 181 patients after vaccination. Anti-spike protein antibody titer of more than 1,689.3 BAU/mL is protective against SARS-CoV-2 infection (odds ratio = 0.4136, 95% CI = 0.1800-0.9043). A cellular response by interferon-γ release assay was not correlated with the disease (odds ratio = 1.001, 95% CI = 0.9995-1.002). In conclusion, despite mutant strain, more than three doses of the first-generation vaccine and high antibody titers provided better protection against the omicron variant for a kidney transplant recipient.

Acute kidney disease following COVID-19 vaccination: a single-center retrospective study

Background

Rare cases of de novo or relapsed kidney diseases associated with vaccination against coronavirus disease 2019 (COVID-19) have been increasingly reported. The aim of this study was to report the incidence, etiologies, and outcomes of acute kidney disease (AKD) following COVID-19 vaccination.

Methods

This retrospective study extracted cases from renal registry of a single medical center from 1 March 2021 to 30 April 2022, prior to the significant surge in cases of the Omicron variant of COVID-19 infection in Taiwan. Adult patients who developed AKD after COVID-19 vaccination were included. We utilized the Naranjo score as a causality assessment tool for adverse vaccination reactions and charts review by peer nephrologists to exclude other causes. The etiologies, characteristics, and outcomes of AKD were examined.

Results

Twenty-seven patients (aged 23 to 80 years) with AKD were identified from 1,897 vaccines (estimated rate of 13.6 per 1000 patient-years within the renal registry). A majority (77.8%) of vaccine received messenger RNA-based regimens. Their median (IQR) Naranjo score was 8 (6-9) points, while 14 of them (51.9%) had a definite probability (Naranjo score ≥ 9). The etiologies of AKD included glomerular disease (n = 16) consisting of seven IgA nephropathy, four anti-neutrophil cytoplasmic antibodies-associated glomerulonephritis (AAN), three membranous glomerulonephritis, two minimal change diseases, and chronic kidney disease (CKD) with acute deterioration (n = 11). Extra-renal manifestations were found in four patients. Over a median (IQR) follow-up period of 42 (36.5-49.5) weeks, six patients progressed to end-stage kidney disease (ESKD).

Conclusion

Besides glomerulonephritis (GN), the occurrence of AKD following COVID-19 vaccination may be more concerning in high-risk CKD patients receiving multiple doses. Patients with the development of de novo AAN, concurrent extra-renal manifestations, or pre-existing moderate to severe CKD may exhibit poorer kidney prognosis.

Rapidly progressive IgA nephropathy with membranoproliferative glomerulonephritis-like lesions in an elderly man following the third dose of an mRNA COVID-19 vaccine: a case report

BACKGROUND

As messenger RNA (mRNA)-based vaccines for coronavirus disease 2019 (COVID-19) have been administered to millions of individuals worldwide, cases of de novo and relapsing glomerulonephritis after mRNA COVID-19 vaccination are increasing in the literature. While most previous publications reported glomerulonephritis after the first or second dose of an mRNA vaccine, few reports of glomerulonephritis occurring after the third dose of an mRNA vaccine currently exist.

CASE PRESENTATION

We report a case of rapidly progressive glomerulonephritis in a patient following the third dose of an mRNA COVID-19 vaccine. A 77-year-old Japanese man with a history of hypertension and atrial fibrillation was referred to our hospital for evaluation of anorexia, pruritus, and lower extremity edema. One year before referral, he received two mRNA vaccines (BNT162b2) for COVID-19. Three months before the visit, he received a third mRNA vaccine (mRNA-1273) for COVID-19. On admission, the patient presented severe renal failure with a serum creatinine level of 16.29 mg/dL, which had increased from 1.67 mg/dL one month earlier, prompting us to initiate hemodialysis. Urinalysis showed nephrotic-range proteinuria and hematuria. Renal biopsy revealed mild mesangial proliferation and expansion, a lobular appearance, and double contours of the glomerular basement membrane. Renal tubules had severe atrophy. Immunofluorescence microscopy showed strong mesangial staining for IgA, IgM, and C3c. Electron microscopy exhibited mesangial and subendothelial electron-dense deposits, leading to a diagnosis of IgA nephropathy with membranoproliferative glomerulonephritis-like changes. The kidney function remained unchanged after steroid therapy.

CONCLUSIONS

Although the link between renal lesions and mRNA vaccines remains unclear, a robust immune response induced by mRNA vaccines may play a role in the pathogenesis of glomerulonephritis. Further studies of the immunological effects of mRNA vaccines on the kidney are warranted.

COVID-19 and glomerular diseases

COVID (Coronavirus disease)-19 is a systemic disease and the kidney is one of the target organs of infection. Kidney injury is common and can occur in up to 40% of patients. Several glomerular diseases have been reported in association with COVID-19. Some are likely related to COVID-19 whereas many are likely coincidental. Glomerular diseases that are frequently reported in COVID-19 and have a plausible mechanistic explanation, are likely to be related to COVID-19. On the other hand, glomerular diseases that are seldom reported and have no known plausible mechanism, are likely to be unrelated. Collapsing glomerulopathy (CG) is by far the most prevalent. Its association with COVID-19, resembling human immunodeficiency virus (HIV) and CG, led to the newly proposed term “COVID-19 associated nephropathy” or “COVAN”. High-risk APOL1 genotypes are the major risk factor in COVAN patients. Podocytopathy, membranous nephropathy, pauci-immune crescentic glomerulonephritis, and thrombotic microangiopathy are also reported. In kidney allografts, CG remains the most common glomerular pathology. Patients typically present with acute kidney injury (AKI) or abnormal urinary findings at the time of or shortly after COVID-19 diagnosis. Treatment of glomerular disease in COVID-19 patients is challenging. Providers should cautiously consider balancing risks and benefit of immunosuppression, particularly in patients with active diseases. Short-term outcomes vary but generally remain poor with high morbidity and mortality. Future study of long-term outcomes is needed to improve our understanding of glomerular disease associated with COVID-19.

Importance of ACE2 for SARS-CoV-2 Infection of Kidney Cells

In late 2019, the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as the causative agent of coronavirus disease 2019 (COVID-19) emerged in China and spread rapidly around the world, causing an ongoing pandemic of global concern. COVID-19 proceeds with moderate symptoms in most patients, whereas others experience serious respiratory illness that requires intensive care treatment and may end in death. The severity of COVID-19 is linked to several risk factors including male sex, comorbidities, and advanced age. Apart from respiratory complications, further impairments by COVID-19 affecting other tissues of the human body are observed. In this respect, the human kidney is one of the most frequently affected extrapulmonary organs and acute kidney injury (AKI) is known as a direct or indirect complication of SARS-CoV-2 infection. The aim of this work was to investigate the importance of the protein angiotensin-converting enzyme 2 (ACE2) for a possible cell entry of SARS-CoV-2 into human kidney cells. First, the expression of the cellular receptor ACE2 was demonstrated to be decisive for viral SARS-CoV-2 cell entry in human AB8 podocytes, whereas the presence of the transmembrane protease serine 2 (TMPRSS2) was dispensable. Moreover, the ACE2 protein amount was well detectable by mass spectrometry analysis in human kidneys, while TMPRSS2 could be detected only in a few samples. Additionally, a negative correlation of the ACE2 protein abundance to male sex and elderly aged females in human kidney tissues was demonstrated in this work. Last, the possibility of a direct infection of kidney tubular renal structures by SARS-CoV-2 was demonstrated.

Double-Positive Anti-Glomerular Basement Membrane Antibody and Myeloperoxidase Antineutrophil Cytoplasmic Autoantibody-Associated Glomerulonephritis Post COVID-19 mRNA vaccine: A Case Series of 4 Patients

Rationale

Vaccines remain central to the management of COVID-19 pandemic, including the need for repeat doses of vaccines to boost immunity. There has been an accumulating case count of glomerulopathies temporally associated with COVID-19 vaccination. This case series presents 4 patients who developed double-positive anti-glomerular basement membrane antibody (anti-GBM) and myeloperoxidase (MPO) antineutrophil cytoplasmic autoantibody (ANCA)-associated glomerulonephritis after COVID-19 mRNA vaccination. This report contributes to our collective knowledge about the pathophysiology and clinical outcomes associated with this rare complication.

Presenting Concerns of the Patient

Four patients developed nephritic syndrome within 1 to 6 weeks after receiving a COVID-19 mRNA vaccine (3 post Pfizer-BioNTech and 1 post Moderna vaccination). Three of the 4 patients also had hemoptysis.

Diagnosis

Three of the 4 patients had double-positive serology, whereas the fourth patient had renal biopsy findings consistent with double-positive disease, although anti-GBM serology was negative. All patients had renal biopsy findings consistent with double-positive anti-GBM and ANCA-associated glomerulonephritis.

Interventions

All 4 patients were treated with pulse steroids, cyclophosphamide, and plasmapheresis.

Outcomes

Of the 4 patients, 1 demonstrated complete remission, 2 remained dialysis-dependent, and the fourth is deceased. Of the 2 patients who received repeat vaccination with COVID-19 mRNA vaccine, 1 patient had second serologic flare of anti-GBM in response to the vaccine.

Novel Findings

This case series reinforces growing evidence that COVID-19 mRNA vaccine-induced glomerulonephritis is a rare but real phenomenon. Dual ANCA and anti-GBM nephritis can present after the first dose of COVID-19 mRNA vaccine or after several administrations of the vaccine. We are the first to report cases of double-positive MPO ANCA and anti-GBM nephritis after Pfizer-BioNTech vaccination. To our knowledge, we are also the first to report outcomes of repeat COVID-19 vaccination in patients with de novo flare of ANCA and anti-GBM nephritis temporally associated with COVID-19 vaccination.

Acute Kidney Injury with SARS-CoV-2 Infection in Pediatric Patients Receiving High-Dose Methotrexate Chemotherapy: A Report of Three Cases

BACKGROUND

Methotrexate is renally excreted. HDMTX (high dose-methotrexate)-induced acute kidney injury (AKI) is a non-oliguric decrease in glomerular filtration rate (GFR) heralded by an acute rise in serum creatinine. Moreover, AKI is also a frequent complication of COVID-19. Among our patients treated with HDMTX, some of these developed AKI during SARS-CoV-2 infection. Therefore, we wondered whether our patients' kidney failure might have been triggered by their underlying SARS-CoV-2 positivity.

METHODS

Data were collected from the database at the Pediatric Oncology Unit of the Istituto Nazionale dei Tumori in Milan (Italy) regarding patients who matched the following selective criteria: (a) treatment with HDMTX during the pandemic period; (b) SARS-CoV-2 infection during the treatment; (c) development of AKI during HDMTX treatment and SARS-CoV-2 infection.

RESULTS

From March 2020 to March 2022, a total of 23 patients were treated with HDMTX; 3 patients were treated with HDMTX during SARS-CoV-2 infection and all 3 developed AKI.

CONCLUSIONS

Clinical manifestations associated with this virus are many, so we are not yet able to lower our guard and rule out this infection as a cause of clinical manifestations with any certainty.

Safety of COVID-19 Vaccines in Patients with Autoimmune Diseases, in Patients with Cardiac Issues, and in the Healthy Population

The coronavirus disease 2019 (COVID-19) has been a challenge for the whole world since the beginning of 2020, and COVID-19 vaccines were considered crucial for disease eradication. Instead of producing classic vaccines, some companies pointed to develop products that mainly function by inducing, into the host, the production of the antigenic protein of SARS-CoV-2 called Spike, injecting an instruction based on RNA or a DNA sequence. Here, we aim to give an overview of the safety profile and the actual known adverse effects of these products in relationship with their mechanism of action. We discuss the use and safety of these products in at-risk people, especially those with autoimmune diseases or with previously reported myocarditis, but also in the general population. We debate the real necessity of administering these products with unclear long-term effects to at-risk people with autoimmune conditions, as well as to healthy people, at the time of omicron variants. This, considering the existence of therapeutic interventions, much more clearly assessed at present compared to the past, and the relatively lower aggressive nature of the new viral variants.

COVID-19 vaccination and Atypical hemolytic uremic syndrome

Introduction

COVID-19 vaccination has been associated with rare but severe complications characterized by thrombosis and thrombocytopenia.

Methods and Results

Here we present three patients who developed de novo or relapse atypical hemolytic uremic syndrome (aHUS) in native kidneys, a median of 3 days (range 2-15) after mRNA-based (Pfizer/BioNTech's, BNT162b2) or adenoviral (AstraZeneca, ChAdOx1 nCoV-19) COVID-19 vaccination. All three patients presented with evident hematological signs of TMA and AKI, and other aHUS triggering or explanatory events were absent. After eculizumab treatment, kidney function fully recovered in 2/3 patients. In addition, we describe two patients with dubious aHUS relapse after COVID-19 vaccination. To assess the risks of vaccination, we retrospectively evaluated 29 aHUS patients (n=8 with native kidneys) without complement-inhibitory treatment, who received a total of 73 COVID-19 vaccinations. None developed aHUS relapse after vaccination.

Conclusion

In conclusion, aHUS should be included in the differential diagnosis of patients with vaccine-induced thrombocytopenia, especially if co-occuring with mechanical hemolytic anemia (MAHA) and acute kidney injury (AKI). Still, the overall risk is limited and we clearly advise continuation of COVID-19 vaccination in patients with a previous episode of aHUS, yet conditional upon clear patient instruction on how to recognize symptoms of recurrence. At last, we suggest monitoring serum creatinine (sCr), proteinuria, MAHA parameters, and blood pressure days after vaccination.

Subclinical Acute Kidney Injury in COVID-19: Possible Mechanisms and Future Perspectives

Since the outbreak of COVID-19 disease, a bidirectional interaction between kidney disease and the progression of COVID-19 has been demonstrated. Kidney disease is an independent risk factor for mortality of patients with COVID-19 as well as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection leading to the development of acute kidney injury (AKI) and chronic kidney disease (CKD) in patients with COVID-19. However, the detection of kidney damage in patients with COVID-19 may not occur until an advanced stage based on the current clinical blood and urinary examinations. Some studies have pointed out the development of subclinical acute kidney injury (subAKI) syndrome with COVID-19. This syndrome is characterized by significant tubule interstitial injury without changes in the estimated glomerular filtration rate. Despite the complexity of the mechanism(s) underlying the development of subAKI, the involvement of changes in the protein endocytosis machinery in proximal tubule (PT) epithelial cells (PTECs) has been proposed. This paper focuses on the data relating to subAKI and COVID-19 and the role of PTECs and their protein endocytosis machinery in its pathogenesis.