Collapsing glomerulopathy in a COVID-19 patient

Pathogenesis and virulence of coronavirus disease: Comparative pathology of animal models for COVID-19

Animal models that can replicate clinical and pathologic features of severe human coronavirus infections have been instrumental in the development of novel vaccines and therapeutics. The goal of this review is to summarize our current understanding of the pathogenesis of coronavirus disease 2019 (COVID-19) and the pathologic features that can be observed in several currently available animal models. Knowledge gained from studying these animal models of SARS-CoV-2 infection can help inform appropriate model selection for disease modelling as well as for vaccine and therapeutic developments.

A study of hospitalized COVID-19 patients with AKI in a setting of multiracial developing country

BACKGROUND

The commonest indication for hospitalization in COVID-19 patients is hypoxemia or severe respiratory symptoms. However, COVID-19 disease may result in extrapulmonary complications including kidney-related pathology. The reported incidence of renal involvement related to COVID infection varies based on geographical location.

OBJECTIVE

This study aimed to assess the incidence rate of AKI in hospitalized COVID-19 patients and identify risk factors and prognostic predictors.

METHOD

In this retrospective study, we recruited hospitalized COVID-19 patients from January 2021 until June 2021 at the University Malaya Medical Center. The inclusion criteria were hospitalized for ≥ 48 h with confirmed COVID-19 infection and at least 18 years old. Patient demographic and clinical data were collected from electronic medical records. The staging of AKI was based on criteria as per KDIGO guidelines.

RESULTS

One thousand five hundred twenty-nine COVID patients fulfilled the inclusion criteria with a male-to-female ratio of 759 (49.6%) to 770 (50.3%). The median age was 55 (IQR: 36-66). 500 patients (32.7%) had diabetes, 621 (40.6%) had hypertension, and 5.6% (n = 85) had pre-existing chronic kidney disease (CKD). The incidence rate of AKI was 21.1% (n = 323). The percentage of COVID patients in different AKI stages of 1,2 and 3 were 16.3%, 2.1%, and 2.7%, respectively. Fifteen hospitalized patients (0.98%) required renal replacement therapy. 58.8% (n = 190) of AKI group had complete recovery of kidney function. Demographic factors included age (p < 0.001), diabetes (p < 0.001), hypertension (p < 0.012), CKD (p < 0.001), and vaccination status (p = 0.042) were associated with an increased risk of developing AKI. We found that the AKI cohort had statistically significant lower platelet counts and higher ferritin levels than the non-AKI cohort. AKI is a risk predictor of prolonged hospitalization (p < 0.001) and higher mortality rates (P < 0.001).

CONCLUSION

AKI is a common clinical complication among hospitalized COVID-19 patients. The etiology of AKI is multifactorial and may have an adverse impact on patient morbidity and mortality.

A narrative review on adverse drug reactions of COVID-19 treatments on the kidney

Studies showed that the respiratory is not the only system affected by coronavirus 2, while cardiovascular, digestive, and nervous systems, as well as essential organs such as the kidneys, can be affected by this virus. In this review, we have studied the epidemiology, clinical, and laboratory findings on COVID-19 infection renal involvement, mortality, physiopathology, remaining renal sequels after recovery, underlying renal disease, and renal injury due to its treatment. Also, protective measures for kidney injury are explained in three levels. Evidence of viral particles and genome in the urine and renal tubular cells and signs of damage such as microangiopathy, hypercoagulopathy, and fibrosis are found in COVID-19 patients. The result of this study showed, in hospitalized COVID-19 patients, that the rate of acute kidney injury (AKI) was up to 46%, with a mortality ranging from 11 to 96%. A considerable proportion of patients with AKI would remain on renal replacement therapy. Proteinuria and hematuria are observed in 87 and 75% patients, and increased Cr and glomerular filtration rate (GFR) <60 ml/min per 1.73 m2 are observed in 29.6 and 35.3% of the patients, respectively. Remedsivir is considered to have adverse effects on GFR. COVID-19 patients need special attention to prevent AKI. Those with underlying chronic kidney disease or AKI need proper and explicit evaluation and treatment to improve their prognosis and decrease mortality, which should not be limited to the hospitalization period.

Potential Alternative Receptors for SARS-CoV-2-Induced Kidney Damage: TLR-4, KIM-1/TIM-1, and CD147

Kidney damage in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can occur even in patients with no underlying kidney disease. Signs of kidney problems can progress to a state that demands dialysis and hampering recovery. Although not without controversy, emerging evidence implicates direct infectivity of SARS-CoV-2 in the kidney. At the early stage of the pandemic, consideration was mainly on the well-recognized angiotensin-converting enzyme 2 (ACE2) receptor as being the site for viral interaction and subsequent cellular internalization. Despite the abundance of ACE2 receptors in the kidneys, researchers have expanded beyond ACE2 and identified novel viral entry pathways that could be advantageously explored as therapeutic targets. This review presents the potential involvement of toll-like receptor 4 (TLR-4), kidney injury molecule-1/T cell immunoglobulin mucin domain 1 (KIM-1/TIM-1), and cluster of differentiation 147 (CD147) in SARS-CoV-2-associated renal damage. In this context, we address the unresolved issues surrounding SARS-CoV-2 renal infectivity.

Acute Kidney Injury Among COVID-19-Positive Patients Is Associated With Higher Mortality: A Single-Center Experience

OBJECTIVES

Renal complications of COVID-19 are not yet well studied. We aimed to evaluate acute kidney injury prevalence among hospitalized patients with COVID-19 infection and explore its effect on patient outcomes.

MATERIALS AND METHODS

We retrospectively evaluated 586 hospitalized patients with COVID-19. Of these patients, 267 (45.5%) developed acute kidney injury, as classified according to the Kidney Disease Improving Global Outcomes guidelines. We compared this group with 319 patients (54.5%) without acute kidney injury.

RESULTS

Most patients in both study groups were men; mean age was 60.8 ± 14 versus 51.7 ± 16 years. Comorbid conditions that were substantially predominant among patients with acute kidney injury were diabetes mellitus (64% vs 42.9%), hypertension (72.6% vs 43.5%), and ischemic heart disease (25% vs 14.7%). Fever, cough, shortness of breath, and dehydration were the main presentations among patients with acute kidney injury, and patients in this group had greater prevalence of radiological findings concordant with COVID-19 (86.8% vs 59.8%). Sepsis, volume depletion, shock, arrhythmias, and acute respiratory distress syndrome were higher in patients with acute kidney injury. Anticoagulation (85% vs 59.2%), vasopressors, plasma infusions, antimicrobials, and steroids were more frequently used in patients with acute kidney injury. More patients with acute kidney injury had acute respiratory failure requiring mechanical ventilation (62.3% vs 32.9%), with higher overall mortality rate (63.2% vs 31.1%).

CONCLUSIONS

We found more frequent prevalence of acute kidney injury associated with severe COVID-19 than shown in reports from Chinese, European, and North American cohorts. Patients with COVID-19 who developed acute kidney injury had risk factors such as hypertension and diabetes, greater need for mechanical ventilation, were males, and were older age. Mortality was high in this population, especially among older patients and those who developed Kidney Disease Improving Global Outcomes stage 3 disease.

Post COVID-19 AA amyloidosis of the kidneys with rapidly progressive renal failure

Coronavirus disease 2019 (COVID-19) pandemic has taken the world by a storm, posing a gruelling challenge to the medical fraternity globally. Besides its very high infectivityinfectivity, significant organ dysfunction occurs in critically ill COVID-19 patients, leading to severe morbidity and mortality. Pulmonary involvement is the leading cause of death in these patients to be followed by the cardiovascular involvement. Kidney involvement due to COVID-19 is becoming more discernible with AKI adversely affecting the outcome. Besides AKI, a few cases of collapsing FSGS in genetically vulnerable patients and thrombotic microangiopathies have been reported as well. We report a case of AA amyloidosis of the kidney with a rapidly progressive renal failure and congestive heart failure with preserved left ventricular functions, which complicated a moderate COVID-19 pneumonia providing some clues to a possible association of this novel virus disease with this complication, which needs to be confirmed in future studies.

Podocytopathies related to either COVID-19 infection or its vaccination, our experience and literature review

Coronavirus disease 2019 (COVID-19) affects several organs including the kidney resulting in acute kidney injury (AKI) and variants of podocytopathies. From the beginning to the middle period of the COVID-19 pandemic, we have collected eight renal biopsies with various renal diseases including 4 podocytopathies. In addition, from the middle period to the near end of the COVID-19 pandemic, we have seen two of the patients who developed nephrotic syndrome following COVID-19 vaccination. Three of 4 podocytopathies were collapsing glomerulopathy (also called collapsing focal segmental glomerulosclerosis) and the fourth was a minimal change disease (MCD). Two of three collapsing glomerulopathy were found in African American patients, one of who was tested positive for having the high-risk allele APOL-1 G1. In addition, the two renal biopsies showed either MCD or replaced MCD following COVID-19 vaccination. MCD can be a rare complication following COVID-19 infection and COVID-19 vaccination, raising the question if there are similar antigens induced by the infection or by the vaccination that trigger the MCD. This article reports our experience of diagnosing podocytopathies related to either COVID-19 infection or its vaccination and provides a literature review regarding the incidence and potential pathophysiology in the field.

Our Experience with SARS-CoV-2 Infection and Acute Kidney Injury: Results from a Single-Center Retrospective Observational Study

BACKGROUND

Renal failure in COVID-19 patients is reportedly related to multiple factors such as a direct SARS-CoV-2 cytopathic effect, cytokine storm, the association of pulmonary and/or cardiovascular lesions, the presence of thrombotic microangiopathy, endothelial damage, or the use of potentially nephrotoxic medications.

METHODS

We retrospectively analyzed 466 cases of SARS-CoV-2 infection, comparing 233 patients with acute kidney injury (AKI) with 233 patients without AKI in terms of their demographic characteristics, comorbidities, clinical background, laboratory investigations, time of AKI onset, therapy, and outcomes after using univariate analysis and a CART decision-tree approach. The latter was constructed in a reverse manner, starting from the top with the root and branching out until the splitting ceased, interconnecting all the predictors to predict the overall outcome (AKI vs. non-AKI).

RESULTS

There was a statistically significant difference between the clinical form distribution in the two groups, with fewer mild (2 vs. 5) and moderate (54 vs. 133) cases in the AKI group than in the non-AKI group and more severe and critical patients in the AKI cohort (116 vs. 92 and 60 vs. 3). There were four deaths (1.71%) in the non-AKI group and 120 deaths in the AKI group (51.5%) (p-value < 0.001). We noted statistically significant differences between the two study groups in relation to different tissue lesions (LDH), particularly at the pulmonary (CT severity score), hepatic (AST, ALT), and muscular levels (Creatine kinase). In addition, an exacerbated procoagulant and inflammatory profile in the study group was observed. The CART algorithm approach yielded decision paths that helped sort the risk of AKI progression into three categories: the low-risk category (0-40%), the medium-risk category (40-80%), and the high-risk category (>80%). It recognized specific inflammatory and renal biomarker profiles with particular cut-off points for procalcitonin, ferritin, LDH, creatinine, initial urea, and creatinine levels as important predictive factors of AKI outcomes (93.3% overall performance).

CONCLUSIONS

Our study revealed the association between particular risk factors and AKI progression in COVID-19 patients. Diabetes, dyspnea on admission, the need for supplemental oxygen, and admission to the intensive care unit all had a crucial role in producing unfavorable outcomes, with a death rate of more than 50%. Necessary imaging studies (CT scan severity score) and changes in specific biomarker levels (ferritin and C-reactive protein levels) were also noted. These factors should be further investigated in conjunction with the pathophysiological mechanisms of AKI progression in COVID-19 patients.

Implementation and Feasibility of Clinical Genome Sequencing Embedded Into the Outpatient Nephrology Care for Patients With Proteinuric Kidney Disease

Introduction

The diagnosis and management of proteinuric kidney diseases such as focal segmental glomerulosclerosis (FSGS) are challenging. Genetics holds the promise to improve clinical decision making for these diseases; however, it is often performed too late to enable timely clinical action and it is not implemented within routine outpatient nephrology visits.

Methods

We sought to test the implementation and feasibility of clinical rapid genome sequencing (GS) in guiding decision making in patients with proteinuric kidney disease in real-time and embedded in the outpatient nephrology setting.

Results

We enrolled 10 children or young adults with biopsy-proven FSGS (9 cases) or minimal change disease (1 case). The mean age at enrollment was 16.2 years (range 2-30). The workflow did not require referral to external genetics clinics but was conducted entirely during the nephrology standard-of-care appointments. The total turn-around-time from enrollment to return-of-results and clinical decision averaged 21.8 days (12.4 for GS), which is well within a time frame that allows clinically relevant treatment decisions. A monogenic or APOL1-related form of kidney disease was diagnosed in 5 of 10 patients. The genetic findings resulted in a rectified diagnosis in 6 patients. Both positive and negative GS findings determined a change in pharmacological treatment. In 3 patients, the results were instrumental for transplant evaluation, donor selection, and the immunosuppressive treatment. All patients and families received genetic counseling.

Conclusion

Clinical GS is feasible and can be implemented in real-time in the outpatient care to help guiding clinical management. Additional studies are needed to confirm the cost-effectiveness and broader utility of clinical GS across the phenotypic and demographic spectrum of kidney diseases.

Acute and chronic histopathological findings in renal biopsies in COVID-19

The dominant ICU admission diagnosis of COVID-19 patients is respiratory insufficiency, but 32-57% of hospitalized COVID-19 patients develop acute kidney injury (COVID-AKI). The renal histopathological changes accompanying COVID-AKI are not yet fully described. To obtain a detailed insight into renal histopathological features of COVID-19, we conducted a review including all studies reporting histopathological findings of diagnostic and postmortem kidney biopsies from patients with COVID-19 published between January 1, 2020, and January 31, 2021. A total of 89 diagnostic and 194 postmortem renal biopsies from individual patients in 39 published studies were investigated and were included in the analysis. In the diagnostic biopsy group, mean age was 56 years and AKI incidence was 96%. In the postmortem biopsy group, mean age was 69 years and AKI incidence was 80%. In the diagnostic biopsy group, the prevalence of acute glomerular diseases was 74%. The most common glomerular lesions were collapsing focal segmental glomerulosclerosis (c-FSGS) in 54% and thrombotic microangiopathy (TMA) in 9% of patients. TMA was also found in 10% of patients in the postmortem biopsy group. The most common acute tubular lesions was acute tubular necrosis (ATN) which was present in 87% of patients in the diagnostic and in 77% of patients in the postmortem biopsy group. Additionally, we observed a high prevalence of preexisting chronic lesions in both groups such as atherosclerosis and glomerulosclerosis. Histopathological changes in renal biopsies of COVID-19 patients show a heterogeneous picture with acute glomerular lesions, predominantly c-FSGS and TMA, and acute tubular lesions, predominantly ATN. In many patients, these lesions were present on a background of chronic renal injury.

Kidney Injury in Critically Ill Patients with COVID-19 - From Pathophysiological Mechanisms to a Personalized Therapeutic Model

Acute kidney injury is a common complication of COVID-19, frequently fuelled by a complex interplay of factors. These include tubular injury and three primary drivers of cardiocirculatory instability: heart-lung interaction abnormalities, myocardial damage, and disturbances in fluid balance. Further complicating this dynamic, renal vulnerability to a "second-hit" injury, like a SARS-CoV-2 infection, is heightened by advanced age, chronic kidney disease, cardiovascular diseases, and diabetes mellitus. Moreover, the influence of chronic treatment protocols, which may constrain the compensatory intrarenal hemodynamic mechanisms, warrants equal consideration. COVID-19-associated acute kidney injury not only escalates mortality rates but also significantly affects long-term kidney function recovery, particularly in severe instances. Thus, the imperative lies in developing and applying therapeutic strategies capable of warding off acute kidney injury and decelerating the transition into chronic kidney disease after an acute event. This narrative review aims to proffer a flexible diagnostic and therapeutic strategy that recognizes the multi-faceted nature of COVID-19-associated acute kidney injury in critically ill patients and underlines the crucial role of a tailored, overarching hemodynamic and respiratory framework in managing this complex clinical condition.

Spotlight on contributory role of host immunogenetic profiling in SARS-CoV-2 infection: Susceptibility, severity, mortality, and vaccine effectiveness

BACKGROUND

The SARS-CoV-2 virus has spread continuously worldwide, characterized by various clinical symptoms. The immune system responds to SARS-CoV-2 infection by producing Abs and secreting cytokines. Recently, numerous studies have highlighted that immunogenetic factors perform a putative role in COVID-19 pathogenesis and implicate vaccination effectiveness.

AIM

This review summarizes the relevant articles and evaluates the significance of mutation and polymorphism in immune-related genes regarding susceptibility, severity, mortality, and vaccination effectiveness of COVID-19. Furthermore, the correlation between host immunogenetic and SARS-CoV-2 reinfection is discussed.

METHOD

A comprehensive search was conducted to identify relevant articles using five databases until January 2023, which resulted in 105 total articles.

KEY FINDINGS

Taken to gather this review summarized that: (a) there is a plausible correlation between immune-related genes and COVID-19 outcomes, (b) the HLAs, cytokines, chemokines, and other immune-related genes expression profiles can be a prognostic factor in COVID-19-infected patients, and (c) polymorphisms in immune-related genes have been associated with the effectiveness of vaccination.

SIGNIFICANCE

Regarding the importance of mutation and polymorphisms in immune-related genes in COVID-19 outcomes, modulating candidate genes is expected to help clinical decisions, patient outcomes management, and innovative therapeutic approach development. In addition, the manipulation of host immunogenetics is hypothesized to induce more robust cellular and humoral immune responses, effectively increase the efficacy of vaccines, and subsequently reduce the incidence rates of reinfection-associated COVID-19.

The metabolic effects of APOL1 in humans

Harboring apolipoprotein L1 (APOL1) variants coded by the G1 or G2 alleles of the APOL1 gene increases the risk for collapsing glomerulopathy, focal segmental glomerulosclerosis, albuminuria, chronic kidney disease, and accelerated kidney function decline towards end-stage kidney disease. However, most subjects carrying APOL1 variants do not develop the kidney phenotype unless a second clinical condition adds to the genotype, indicating that modifying factors modulate the genotype-phenotype correlation. Subjects with an APOL1 high-risk genotype are more likely to develop essential hypertension or obesity, suggesting that carriers of APOL1 risk variants experience more pronounced insulin resistance compared to noncarriers. Likewise, arterionephrosclerosis (the pathological correlate of hypertension-associated nephropathy) and glomerulomegaly take place among carriers of APOL1 risk variants, and these pathological changes are also present in conditions associated with insulin resistance, such as essential hypertension, aging, and diabetes. Insulin resistance may contribute to the clinical features associated with the APOL1 high-risk genotype. Unlike carriers of wild-type APOL1, bearers of APOL1 variants show impaired formation of lipid droplets, which may contribute to inducing insulin resistance. Nascent lipid droplets normally detach from the endoplasmic reticulum into the cytoplasm, although the proteins that enable this process remain to be fully defined. Wild-type APOL1 is located in the lipid droplet, whereas mutated APOL1 remains sited at the endoplasmic reticulum, suggesting that normal APOL1 may participate in lipid droplet biogenesis. The defective formation of lipid droplets is associated with insulin resistance, which in turn may modulate the clinical phenotype present in carriers of APOL1 risk variants.

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.

Coronavirus disease 2019-associated nephropathy in an African American patient: a case report and review of the literature

BACKGROUND

Acute kidney injury is now recognized as a common complication of coronavirus disease 2019, affecting up to 46% of patients, with acute tubular injury as the most common etiology. Recently, we have seen an increase in cases of collapsing glomerulonephritis in patients with coronavirus disease 2019, also known as coronavirus disease 2019-associated nephropathy. It has been noted to be seen with a higher incidence in African American patients who are carriers of the APOL1 variant allele.

CASE PRESENTATION

A 47-year-old African American male with a past medical history of asthma presented to the emergency department with complaints of intermittent chest pain, shortness of breath, and worsening confusion. On admission, he was found to be hemodynamically stable, but labs were significant for elevated creatinine and blood urea nitrogen, signifying acute kidney injury. He was admitted and taken for emergent dialysis. During his hospitalization, he was found to be positive for coronavirus disease 2019. Renal biopsy was done, which showed collapsing glomerulopathy, and the patient continues to require outpatient dialysis after discharge.

CONCLUSION

Collapsing glomerulonephritis has emerged as a complication in patients with coronavirus disease 2019. This condition should be particularly suspected in African American patients who present with acute kidney injury, nephrotic-range proteinuria, and who are positive for coronavirus disease 2019. Current treatment options are limited to supportive treatment and renal replacement therapy. More clinical cases and trials are needed to better understand and improve therapeutic outcomes in these patients.

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.

A specific molecular signature in SARS-CoV-2-infected kidney biopsies

Acute kidney injury is one of the most important complications in patients with COVID-19 and is considered a negative prognostic factor with respect to patient survival. The occurrence of direct infection of the kidney by SARS-CoV-2, and its contribution to the renal deterioration process, remain controversial issues. By studying 32 renal biopsies from patients with COVID-19, we verified that the major pathological feature of COVID-19 is acute tubular injury (ATI). Using single-molecule fluorescence in situ hybridization, we showed that SARS-CoV-2 infected living renal cells and that infection, which paralleled renal angiotensin-converting enzyme 2 expression levels, was associated with increased death. Mechanistically, a transcriptomic analysis uncovered specific molecular signatures in SARS-CoV-2-infected kidneys as compared with healthy kidneys and non-COVID-19 ATI kidneys. On the other hand, we demonstrated that SARS-CoV-2 and hantavirus, 2 RNA viruses, activated different genetic networks despite triggering the same pathological lesions. Finally, we identified X-linked inhibitor of apoptosis-associated factor 1 as a critical target of SARS-CoV-2 infection. In conclusion, this study demonstrated that SARS-CoV-2 can directly infect living renal cells and identified specific druggable molecular targets that can potentially aid in the design of novel therapeutic strategies to preserve renal function in patients with COVID-19.

Potential Role of High-Dose Steroids in the Treatment of COVID-19-Associated Nephropathy

With the increasing number of COVID-19-associated nephropathy (COVAN), biopsy-proven cases of collapsing variety of focal segmental glomerulosclerosis (FSGS) are emerging. Though the recommendations on treatment for COVID-19-associated respiratory symptoms are evolving, there is still no definitive treatment for the collapsing FSGS secondary to COVAN. We report a case of a 47-year-old male admitted with acute kidney injury from COVID-19 infection and found to have collapsing FSGS on renal biopsy. Almost all the patients who were found to have similar conditions were treated with a relatively smaller dose of steroids and ultimately required dialysis. Our patient showed improvement with the trial of higher doses of steroids and never required dialysis. Hence, our case report emphasizes the need for a randomized controlled trial (RCT) with regard to the use of high-dose steroids in COVAN.

Collapsing Focal Segmental Glomerulosclerosis After Kidney Transplantation: Is It a Consequence of Viral Infections?

BACKGROUND

The aim of this case study was to explore the possible link between viral infections and collapsing focal segmental glomerulosclerosis (cFSGS) in patients who underwent kidney transplantation.

METHODS

This case study included 3 case reports of patients who underwent kidney transplantation. The case reports were presented clinically and pathohistologically with cFsGS as a possible consequence of viral infections.

RESULTS

The first patient developed cFSGS after polymerase chain reaction for SARS-CoV2 was positive twice. He gradually developed terminal stage chronic kidney disease. The second patient developed cFSGS with high range proteinuria after cytomegalovirus infection, which has been treated with 3 lines of antiviral medicaments. The third patient developed cFSGS as a possible consequence of hepatitis B virus infection.

CONCLUSIONS

This case study highlighted the importance of viral etiology in the pathway of cFSGS. Pathogenic links between viral infections and concomitant glomerulopathies are challenging, especially in immunocompromised transplanted patients.

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.

Pathogenesis and histological changes of nephropathy associated with COVID-19

Coronavirus disease 2019 (COVID-19) can cause damage to multiple organ, not only to the lungs, but also to the kidneys. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can cause acute and chronic kidney disease through direct viral infection, indirect injury, and vaccination-related injury. Like lung injury, kidney injury is also an important aspect affecting the severity and prognosis of SARS-CoV-2. This article summarizes the pathogenesis, pathological manifestations, and clinical features of SARS-CoV-2 direct or indirect renal injury. Including direct injury, indirect injury, special comorbidities (receiving kidney transplantation and chronic kidney disease), and vaccine-related renal injury, and exploring the possible therapeutic effect of anti-SARS-CoV-2 therapy on renal injury. The purpose is to provide reference for understanding COVID-19-related renal injury, guiding clinical and pathological diagnosis and treatment, and evaluating prognosis.

Kidney injury associated with COVID-19 infection and vaccine: A narrative review

The respiratory tract is the main infection site for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), resulting in many admissions to intensive care centers in several countries. However, in addition to lung involvement, kidney injury caused by the novel coronavirus has proven to be a significant factor related to high morbidity and mortality, alarming experts worldwide. The number of deaths has drastically reduced with the advent of large-scale immunization, highlighting the importance of vaccination as the best way to combat the pandemic. Despite the undeniable efficacy of the vaccine, the renal side effects associated with its use deserve to be highlighted, especially the emergence or reactivation of glomerulopathies mentioned in some case reports. This study aimed to identify the main renal morphological findings correlated with COVID-19 infection and its vaccination, seeking to understand the pathophysiological mechanisms, main clinical features, and outcomes.

Ultrastructural Changes in Autopsy Tissues of COVID-19 Patients

INTRODUCTION

The COVID-19 pandemic resulted in substantial morbidity and mortality across the world. The prognosis was found to be poor in patients with co-morbidities such as diabetes, hypertension, interstitial lung disease, etc. Although biochemical studies were done in patient samples, no study has been reported from the Indian subcontinent about ultrastructural changes in the vital organs of COVID-19 patients. The present study was, therefore, conducted to understand the ultrastructural changes in the lung, liver, and brain of the deceased patients.

METHODS

The present study was conducted on samples obtained from reverse transcription-polymerase chain reaction (RT-PCR)-positive patients who were admitted to a tertiary care hospital in Western India. Core needle biopsies were done in eight fatal cases of COVID-19. The samples were taken from the lungs, liver, and brain and subjected to light microscopy, immunohistochemistry (IHC), and transmission electron microscopy (TEM). Clinical details and biochemical findings were also collected.  Results: The study participants included seven males and one female. The presenting complaints included fever, breathlessness, and cough. Light microscopy revealed diffuse alveolar damage in the lungs. Further, a positive expression of SARS-CoV-2 nucleocapsid protein was observed in the pulmonary parenchyma of five patients. Also, the TEM microphotograph showed viral particles of size up to 80nm localized in alveolar epithelial cells. However, no viral particles were found in liver or brain samples. In the liver, macrovesicular steatosis and centrizonal congestion with loss of hepatocytes were observed in light microscopy.

CONCLUSION

 This is the first study in the Indian population showing the in-situ presence of viral particles in core biopsies from fatal cases of COVID-19. As evident from the results, histology and ultrastructural changes in the lung correlated with the presence of viral particles. The study revealed a positive correlation between the damage in the lungs and the presence of viral particles.

Acute Kidney Injury in Non-Intensive Care Unit (ICU) Hospitalizations for Coronavirus Disease (COVID-19)

Background: Acute kidney injury (AKI) is a common complication among SARS-CoV-2-positive patients who undergo hospitalization. Abundant evidence exists concerning the epidemiology of AKI in patients hospitalized in the ICU for COVID-19 but limited data are available about the occurrence of AKI in SARS-CoV-2-positive patients being hospitalized in a non-ICU setting. Aim and Methods: We have carried out a retrospective study to evaluate frequency and risk factors for AKI among patients consecutively admitted at a third-level university hospital starting from February 2020 (the beginning of the first wave of the SARS-CoV-2 pandemic); all patients were hospitalized outside the ICU. Results: A total of 387 SARS-CoV-2-positive patients were included in the current study; 372 (96.1%) had SARS-CoV-2-related pneumonia. In-hospital AKI onset was recorded in 119 (30.7%) patients, mainly with AKI stage 1 (n = 74, 62.2%); eighteen (4.6%) patients reported AKI stage 3 and six (1.5%) patients had HD-dependent AKI. There were 235 (60.7%) patients with severe COVID-19, and this was more common in patients developing AKI, 94.5% (86/119) vs. 86.1% (149/268), p = 0.02. Multivariate regression model (n = 144 patients) reported an independent and significant relationship between AKI occurrence and greater levels of ferritin (p = 0.036), IL-6 (p = 0.032), and azotemia at admission (p = 0.0001). A total of 69 (17.8%) SARS-CoV-2-positive patients died and strong predictors of in-hospital death resulted from age (p < 0.0001), serum ferritin (p < 0.0001) and white blood cells (p < 0.001). According to multivariable analysis (n = 163 patients), there was a consistent link between in-hospital death and AKI stage (1) (p = 0.021) and -stage (2) (p = 0.009). Our results support the notion that AKI occurs frequently among hospitalized COVID-19 patients even in a non-ICU setting and plays a pivotal role in the mortality of this population. Further studies are ongoing in order to clearly establish the frequency of AKI in patients with COVID-19; the mechanisms underlying kidney injury in this population are an area of active investigation. These data provide solid evidence to support close monitoring of COVID-19 patients for the development of AKI and measures taken to prevent this.

Virus-Associated Nephropathies: A Narrative Review

While most viral infections cause mild symptoms and a spontaneous favorable resolution, some can lead to severe or protracted manifestations, specifically in immunocompromised hosts. Kidney injuries related to viral infections may have multiple causes related to the infection severity, drug toxicity or direct or indirect viral-associated nephropathy. We review here the described virus-associated nephropathies in order to guide diagnosis strategies and treatments in cases of acute kidney injury (AKI) occurring concomitantly with a viral infection. The occurrence of virus-associated nephropathy depends on multiple factors: the local epidemiology of the virus, its ability to infect renal cells and the patient's underlying immune response, which varies with the state of immunosuppression. Clear comprehension of pathophysiological mechanisms associated with a summary of described direct and indirect injuries should help physicians to diagnose and treat viral associated nephropathies.

Enhanced metanephric specification to functional proximal tubule enables toxicity screening and infectious disease modelling in kidney organoids

While pluripotent stem cell-derived kidney organoids are now being used to model renal disease, the proximal nephron remains immature with limited evidence for key functional solute channels. This may reflect early mispatterning of the nephrogenic mesenchyme and/or insufficient maturation. Here we show that enhanced specification to metanephric nephron progenitors results in elongated and radially aligned proximalised nephrons with distinct S1 - S3 proximal tubule cell types. Such PT-enhanced organoids possess improved albumin and organic cation uptake, appropriate KIM-1 upregulation in response to cisplatin, and improved expression of SARS-CoV-2 entry factors resulting in increased viral replication. The striking proximo-distal orientation of nephrons resulted from localized WNT antagonism originating from the organoid stromal core. PT-enhanced organoids represent an improved model to study inherited and acquired proximal tubular disease as well as drug and viral responses.

HIV at 40: kidney disease in HIV treatment, prevention, and cure

Four decades after the first cases of HIV were reported, kidney disease remains an important comorbidity in people with HIV (PWH). Both HIV-associated nephropathy and immune complex kidney disease were recognized as complications of HIV infection in the early years before treatment was available. Although the introduction of effective antiretroviral therapy in the late 1990s resulted in dramatic improvements in survival and health in PWH, several commonly used antiretroviral agents have been associated with kidney injury. HIV infection and treatment may also promote the progression of comorbid chronic kidney disease due to traditional risk factors such as diabetes, and HIV is one of the strongest "second hits" for the high-risk APOL1 genotype. Unique considerations in the management of chronic kidney disease in PWH are largely related to the need for lifelong antiretroviral therapy, with potential for toxicity, drug-drug interactions, and polypharmacy. PWH who develop progressive chronic kidney disease are candidates for all modalities of kidney replacement therapy, including kidney transplantation, and at some centers, PWH may be candidates to serve as donors for recipients with HIV. Transplantation of kidney allografts from donors with HIV also offers a unique opportunity to study viral dynamics in the kidney, with implications for kidney health and for research toward HIV cure. In addition, HIV-transgenic animal models have provided important insights into kidney disease pathogenesis beyond HIV, and experience with HIV and HIV-related kidney disease has provided important lessons for future pandemics.

The Effects of Race on Acute Kidney Injury

Racial disparities in incidence and outcomes of acute kidney injury (AKI) are pervasive and are driven in part by social inequities and other factors. It is well-documented that Black patients face higher risk of AKI and seemingly have a survival advantage compared to White counterparts. Various explanations have been advanced and suggested to account for this, including differences in susceptibility to kidney injury, severity of illness, and socioeconomic factors. In this review, we try to understand and further explore the link between race and AKI using the incidence, diagnosis, and management of AKI to illustrate how race is directly related to AKI outcomes, with a focus on Black and White individuals with AKI. In particular, we explore the effect of race-adjusted estimated glomerular filtration rate (eGFR) equation on AKI prediction and discuss racial disparities in the management of AKI and how this might contribute to racial differences in AKI-related mortality among Blacks with AKI. We also identify some opportunities for future research and advocacy.

The Perspective of Vitamin D on suPAR-Related AKI in COVID-19

The coronavirus disease 2019 (COVID-19) pandemic has claimed the lives of millions of people around the world. Severe vitamin D deficiency can increase the risk of death in people with COVID-19. There is growing evidence that acute kidney injury (AKI) is common in COVID-19 patients and is associated with poorer clinical outcomes. The kidney effects of SARS-CoV-2 are directly mediated by angiotensin 2-converting enzyme (ACE2) receptors. AKI is also caused by indirect causes such as the hypercoagulable state and microvascular thrombosis. The increased release of soluble urokinase-type plasminogen activator receptor (suPAR) from immature myeloid cells reduces plasminogen activation by the competitive inhibition of urokinase-type plasminogen activator, which results in low plasmin levels and a fibrinolytic state in COVID-19. Frequent hypercoagulability in critically ill patients with COVID-19 may exacerbate the severity of thrombosis. Versican expression in proximal tubular cells leads to the proliferation of interstitial fibroblasts through the C3a and suPAR pathways. Vitamin D attenuates the local expression of podocyte uPAR and decreases elevated circulating suPAR levels caused by systemic inflammation. This decrease preserves the function and structure of the glomerular barrier, thereby maintaining renal function. The attenuated hyperinflammatory state reduces complement activation, resulting in lower serum C3a levels. Vitamin D can also protect against COVID-19 by modulating innate and adaptive immunity, increasing ACE2 expression, and inhibiting the renin–angiotensin–aldosterone system. We hypothesized that by reducing suPAR levels, appropriate vitamin D supplementation could prevent the progression and reduce the severity of AKI in COVID-19 patients, although the data available require further elucidation.

COVID-19 and Kidney Disease: Progress in Health Inequity From Low-Income Settings

The acute coronavirus disease-2019 (COVID-19) pandemic has had a significant impact on the incidence and prevalence of acute kidney injury and chronic kidney disease globally and in low-income settings. Chronic kidney disease increases the risk of developing COVID-19 and COVID-19 causes acute kidney injury directly or indirectly and is associated with high mortality in severe cases. Outcomes of COVID-19-associated kidney disease were not equitable globally owing to a lack of health infrastructure, challenges in diagnostic testing, and management of COVID-19 in low-income settings. COVID-19 also significantly impacted kidney transplant rates and mortality among kidney transplant recipients. Vaccine availability and uptake remains a significant challenge in low- and lower-middle-income countries compared with high-income countries. In this review, we explore the inequities in low- and lower-middle-income countries and highlight the progress made in the prevention, diagnosis, and management of patients with COVID-19 and kidney disease. We recommend further studies into the challenges, lessons learned, and progress made in the diagnosis, management, and treatment of patients with COVID-19-related kidney diseases and suggest ways to improve the care and management of patients with COVID-19 and kidney disease.

Renin-Angiotensin System Inhibitors in Patients With COVID-19: A Meta-Analysis of Randomized Controlled Trials Led by the International Society of Hypertension

Background

Published randomized controlled trials are underpowered for binary clinical end points to assess the safety and efficacy of renin‐angiotensin system inhibitors (RASi) in adults with COVID‐19. We therefore performed a meta‐analysis to assess the safety and efficacy of RASi in adults with COVID‐19.

Methods and Results

MEDLINE, EMBASE, ClinicalTrials.gov, and the Cochrane Controlled Trial Register were searched for randomized controlled trials that randomly assigned patients with COVID‐19 to RASi continuation/commencement versus no RASi therapy. The primary outcome was all‐cause mortality at ≤30 days. A total of 14 randomized controlled trials met the inclusion criteria and enrolled 1838 participants (aged 59 years, 58% men, mean follow‐up 26 days). Of the trials, 11 contributed data. We found no effect of RASi versus control on all‐cause mortality (7.2% versus 7.5%; relative risk [RR], 0.95; [95% CI, 0.69–1.30]) either overall or in subgroups defined by COVID‐19 severity or trial type. Network meta‐analysis identified no difference between angiotensin‐converting enzyme inhibitors versus angiotensin II receptor blockers. RASi users had a nonsignificant reduction in acute myocardial infarction (2.1% versus 3.6%; RR, 0.59; [95% CI, 0.33–1.06]), but increased risk of acute kidney injury (7.0% versus 3.6%; RR, 1.82; [95% CI, 1.05–3.16]), in trials that initiated and continued RASi. There was no increase in need for dialysis or differences in congestive cardiac failure, cerebrovascular events, venous thromboembolism, hospitalization, intensive care admission, inotropes, or mechanical ventilation.

Conclusions

This meta‐analysis of randomized controlled trials evaluating angiotensin‐converting enzyme inhibitors/angiotensin II receptor blockers versus control in patients with COVID‐19 found no difference in all‐cause mortality, a borderline decrease in myocardial infarction, and an increased risk of acute kidney injury with RASi. Our findings provide strong evidence that RASi can be used safely in patients with COVID‐19.

COVID-19 Infection in Renal Transplant Recipients at Dubai Hospital: Incidence, Clinical Profile, and Outcome

<b><i>Background:</i></b> Renal transplant recipients are at risk to acquire COVID-19 infection quite frequently, owing to their immunocompromized state. Nevertheless, data on the effects of this infection on patients and graft function are sparse from the Arab world. <b><i>Methods:</i></b> This retrospective cohort study was conducted in Dubai Hospital from April 1, 2020, to August 1, 2021. We analyzed 42 COVID-19-positive renal transplant recipients’ data. Information concerning demographics, comorbidities, medications, clinical and laboratory data, and outcomes was collected from the electronic medical records. Univariate analyses were performed to determine the association of acute kidney injury (AKI) with in-hospital mortality. <b><i>Results:</i></b> Median age was 47.46 (17–66) years; about 59% of patients were male. Eleven (26.19%) patients developed AKI during hospitalization. On admission high ferritin, C-reactive protein, creatinine, and low absolute lymphocyte count are identified risk factors for in-hospital AKI. Seven (21.87%) patients had their calcineurin inhibitor levels touch a toxic peak possibly due to an interaction with antivirals. Mortality was 14.28%, and the same number of patients required mechanical ventilation during treatment. <b><i>Conclusion:</i></b> A significant number of renal transplant recipients suffered from AKI during COVID-19 infection, and the mortality rate in this study population was less than in studies from other countries in the region. More insights are required to manage this infection in renal transplant recipients.

Enhanced metanephric specification to functional proximal tubule enables toxicity screening and infectious disease modelling in kidney organoids

While pluripotent stem cell-derived kidney organoids are now being used to model renal disease, the proximal nephron remains immature with limited evidence for key functional solute channels. This may reflect early mispatterning of the nephrogenic mesenchyme and/or insufficient maturation. Here we show that enhanced specification to metanephric nephron progenitors results in elongated and radially aligned proximalised nephrons with distinct S1 - S3 proximal tubule cell types. Such PT-enhanced organoids possess improved albumin and organic cation uptake, appropriate KIM-1 upregulation in response to cisplatin, and improved expression of SARS-CoV-2 entry factors resulting in increased viral replication. The striking proximo-distal orientation of nephrons resulted from localized WNT antagonism originating from the organoid stromal core. PT-enhanced organoids represent an improved model to study inherited and acquired proximal tubular disease as well as drug and viral responses.

Plasma Levels and Renal Handling of Amino Acids Contribute to Determination of Risk of Mortality or Feed of Ventilation in Patients with COVID-19

COVID-19 infection may lead to serious complications, e.g., need for mechanical ventilation or death in some cases. A retrospective analysis of patients referred to our COVID Emergency Department, indiscriminately, was performed. A routine lab analysis measured amino acids in plasma and urine of patients. Data of surviving and deceased patients and those requiring or not requiring mechanical ventilation were compared, and logistic regression analyses have been performed. Deceased patients were older, had higher blood glucose, potassium, AST, LDH, troponin, d-dimer, hsCRP, procalcitonin, interleukin-6 levels (p < 0.05 for all). They had lower plasma serine, glycine, threonine, tryptophan levels (p < 0.01), higher tyrosine and phenylalanine levels (p < 0.05), and higher fractional excretion of arginine, methionine, and proline (p < 0.05) than survivors. In a regression model, age, severity score of COVID-pneumonia, plasma levels of threonine and phenylalanine were predictors of in-hospital mortality. There was a difference in ventilated vs. non-ventilated patients in CT-scores, glucose, and renal function (p < 0.001). Using logistic regression, CT-score, troponin, plasma level, and fractional excretion of glycine were predictors of ventilation. Plasma levels and renal excretion of certain amino acids are associated with the outcome of COVID-19 infection beside other parameters such as the CT-score or age.

Avaliação da Disfunção Endotelial em Casos de COVID-19 com Dilatação Fluxo-Mediada

Fundamento:

Sabe-se que a inflamação desempenha um papel crucial em muitas doenças, incluindo a COVID-19.

Objetivo:

Utilizando a dilatação fluxo-mediada (DFM), objetivou-se avaliar os efeitos da inflamação na função endotelial de pacientes com COVID-19.

Métodos:

Este estudo foi realizado com um total de 161 indivíduos, dos quais 80 foram diagnosticados com COVID-19 nos últimos seis meses (48 mulheres e 32 homens com idade média de 32,10±5,87 anos) e 81 eram controles saudáveis (45 mulheres e 36 homens com idade média de 30,51±7,33 anos). Os achados do ecocardiograma transtorácico e da DFM foram analisados em todos os indivíduos. Resultados com p<0,05 foram considerados estatisticamente significantes.

Resultados:

O ecocardiograma e a DFM do grupo COVID-19 foram realizados 35 dias (intervalo: 25–178) após o diagnóstico. Não houve diferença estatisticamente significativa nos parâmetros ecocardiográficos. Em contraste, a DFM (%) foi significativamente maior no grupo controle (9,52±5,98 versus 12,01±6,18; p=0,01). Na análise multivariada com o modelo stepwise progressivo, a DFM foi significativamente diferente no grupo controle em relação ao grupo COVID-19 (1,086 (1,026–1,149), p=0,04). O teste de correlação de Spearman indicou que a DFM (r=0,27; p=0,006) apresentou correlação positiva fraca com a presença de COVID-19.

Conclusão:

Os achados deste estudo apontam para disfunção endotelial induzida por COVID-19, avaliada por DFM, na fase inicial de recuperação.

Emerging Viral Infections and the Potential Impact on Hypertension, Cardiovascular Disease, and Kidney Disease

Viruses are ubiquitous in the environment and continue to have a profound impact on human health and disease. The COVID-19 pandemic has highlighted this with impressive morbidity and mortality affecting the world's population. Importantly, the link between viruses and hypertension, cardiovascular disease, and kidney disease has resulted in a renewed focus and attention on this potential relationship. The virus responsible for COVID-19, SARS-CoV-2, has a direct link to one of the major enzymatic regulatory systems connected to blood pressure control and hypertension pathogenesis, the renin-angiotensin system. This is because the entry point for SARS-CoV-2 is the ACE2 (angiotensin-converting enzyme 2) protein. ACE2 is one of the main enzymes responsible for dampening the primary effector peptide Ang II (angiotensin II), metabolizing it to Ang-(1-7). A myriad of clinical questions has since emerged and are covered in this review. Several other viruses have been linked to hypertension, cardiovascular disease, and kidney health. Importantly, patients with high-risk apolipoprotein L1 (APOL1) alleles are at risk for developing the kidney lesion of collapsing glomerulopathy after viral infection. This review will highlight several emerging viruses and their potential unique tropisms for the kidney and cardiovascular system. We focus on SARS-CoV-2 as this body of literature in regards to cardiovascular disease has advanced significantly since the COVID-19 pandemic.

COVID-19 associated collapsing glomerulopathy presenting as acute kidney injury on chronic kidney disease: a case report and review of the literature

Traditionally collapsing glomerulopathy (CG) is associated with medications, autoimmune disease, viral infection and the APOL1 gene variant seen in blacks/African Americans. Most reported cases of acute kidney injury (AKI) in COVID-19 infected individuals have been in individuals without prior CKD. In this report, we present a 49-year-old African American female with a past medical history of chronic kidney disease (CKD) stage 4, hypertension, type 2 diabetes mellitus, recent COVID-19 infection, and a repeat positive blood test for COVID-19 more than 21 days after the initial result, who presented with an AKI on CKD. Renal biopsy revealed a collapsing glomerulopathy. She was started on hemodialysis and did not receive immunosuppressive therapy due to the advanced scaring seen on the renal biopsy. Concerning the pathophysiology of COVID-19-associated CG, researchers have postulated different mechanisms such as a direct cytopathic effect of the virus on podocytes, immune dysregulation, and fluid imbalance. This is one of a few cases of AKI on CKD due to CG related to COVID-19. The mechanism of CG was, however, unclear. Currently, there is no specific interventions to prevent the development of CG in patients with COVID-19 infection. Further studies should investigate measures to prevent the development of CG.

COVID-19 and the kidney: time to take a closer look

Although coronavirus disease (COVID-19) is primarily a respiratory disease, the kidney may be among the target organs of infection with severe acute respiratory syndrome coronavirus 2 (SARS-COV-2). Independently of baseline kidney function, acute kidney injury (AKI) is a common complication of COVID-19, associated with increased mortality and morbidity. Most frequently, COVID-19 causes acute tubular necrosis; however, in some cases, collapsing focal segmental glomerulosclerosis and direct viral tropism of the kidneys have also been documented. AKI secondary to COVID-19 has a multi-factorial origin. Even mild impairment of renal function is an independent risk factor for COVID-19 infection, hospitalisation and mortality. Dialysis patients also carry an increased risk of other severe COVID-related complications, including arrhythmias, shock, acute respiratory distress syndrome and acute heart failure. In such patients, COVID-19 may even present with atypical clinical symptoms, including gastrointestinal disorders and deterioration of mental status. More research is needed on the exact effects of SARS-CoV-2 on the kidneys. Finally, it remains to be proven whether the outcome of patients with kidney disease may be improved with anticipated vaccination programmes.

COVID-19 in patients with glomerular disease

PURPOSE OF REVIEW

Managing patients with glomerular disease during the COVID-19 pandemic has been challenging, as the infection risk associated with immunosuppression must be balanced against the need to control severe glomerular disease that can lead to kidney failure. This review provides an overview of COVID-19 and the effectiveness of SARS-CoV-2 vaccination in patients with glomerular disease.

RECENT FINDINGS

Registry data, although biased towards outcomes of hospitalized patients, suggest that the mortality from COVID-19 is higher in patients with glomerular disease than in the general population. Glucocorticoid use prior to SARS-CoV-2 infection is associated with adverse outcomes from COVID-19. Rituximab significantly attenuates serological responses to both natural infection and vaccination against SARS-CoV-2, although it is not clear whether this leads to adverse outcomes. Case reports of disease flares occurring after vaccination have been reported, but causality in any of these cases has yet to be proven and the absolute risk remains very small.

SUMMARY

Patients with glomerular disease represent an at-risk group for severe COVID-19 disease and vaccination is key to reducing this risk. As immunosuppressed patients demonstrate an attenuated response to vaccination, the efficacy of a third primary dose followed by a subsequent booster is being investigated.

COVID-19 Survival and its impact on chronic kidney disease

Up to 87% of patients hospitalized with coronavirus disease 2019 (COVID-19) experience chronic sequelae following infection. The long-term impact of COVID-19 infection on kidney function is largely unknown at this point in the COVID-19 pandemic. In this review, we highlight the current understanding of the pathophysiology of COVID-19-associated kidney injury and the impact COVID-19 may have on long-term kidney function. COVID-19-induced acute kidney injury may lead to tubular injury, endothelial injury, and glomerular injury. We highlight histopathologic correlates from large kidney biopsy and autopsy series. By conducting a comprehensive review of published literature to date, we summarize the rates of recovery from COVID-19-associated-AKI. Finally, we discuss how certain genetic differences, including APOL1 risk alleles (a risk factor for collapsing glomerulopathy), coupled with systemic healthcare disparities, may lead to a disproportionate burden of post-COVID-19-kidney function decline among racial and ethnic minority groups. We highlight the need for prospective studies to determine the true incidence of chronic kidney disease burden after COVID-19.

Potentials of post-mortem CT investigations during SARS-COV-2 pandemic: a narrative review

In December 2019, a new coronavirus, SARS-COV-2, caused a cluster of cases of pneumonia in China, and rapidly spread across the globe. It was declared a pandemic by the World Health Organization on March 11th, 2020. Virtual autopsy by post-mortem CT (PMCT) and its ancillary techniques are currently applied in post-mortem examinations as minimally or non-invasive techniques with promising results. In this narrative review, we speculate on the potentials of PMCT and its ancillary techniques, as a viable investigation technique for analysis of suspected or confirmed SARS-COV-2 deaths. An online literature search was performed by using three prefix search terms (postmortem, post-mortem, post mortem) individually combined with the suffix radiology, imaging, computed tomography, CT and with the search terms ‘SARS-CoV-2’ and ‘COVID-19’ to identify papers about PMCT and its ancillary techniques in SARS-COV-2 positive cadavers. PMCT findings suggestive for pulmonary COVID-19 in deceased positive SARS-COV-2 infection are reported in the literature. PMCT ancillary techniques were never applied in such cases. PMCT imaging of the lungs has been proposed as a pre-autopsy screening method for SARS-COV-2 infection. Further studies are needed to ascertain the value of PMCT in determining COVID-19 as the cause of death without autopsy histopathological confirmation. We advocate the application of PMCT techniques in the study of ascertained or suspected SARS-COV-2 infected deceased individuals as a screening technique and as a method of post-mortem investigation, to augment the numbers of case examined and significantly reducing infection risk for the operators.

Lipid and Nucleocapsid N-Protein Accumulation in COVID-19 Patient Lung and Infected Cells

The pandemic of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global outbreak and prompted an enormous research effort. Still, the subcellular localization of the coronavirus in lungs of COVID-19 patients is not well understood. Here, the localization of the SARS-CoV-2 proteins is studied in postmortem lung material of COVID-19 patients and in SARS-CoV-2-infected Vero cells, processed identically. Correlative light and electron microscopy on semithick cryo-sections demonstrated induction of electron-lucent, lipid-filled compartments after SARS-CoV-2 infection in both lung and cell cultures. In lung tissue, the nonstructural protein 4 and the stable nucleocapsid N-protein were detected on these novel lipid-filled compartments. The induction of such lipid-filled compartments and the localization of the viral proteins in lung of patients with fatal COVID-19 may explain the extensive inflammatory response and provide a new hallmark for SARS-CoV-2 infection at the final, fatal stage of infection. IMPORTANCE Visualization of the subcellular localization of SARS-CoV-2 proteins in lung patient material of COVID-19 patients is important for the understanding of this new virus. We detected viral proteins in the context of the ultrastructure of infected cells and tissues and discovered that some viral proteins accumulate in novel, lipid-filled compartments. These structures are induced in Vero cells but, more importantly, also in lung of patients with COVID-19. We have characterized these lipid-filled compartments and determined that this is a novel, virus-induced structure. Immunogold labeling demonstrated that cellular markers, such as CD63 and lipid droplet marker PLIN-2, are absent. Colocalization of lipid-filled compartments with the stable N-protein and nonstructural protein 4 in lung of the last stages of COVID-19 indicates that these compartments play a key role in the devastating immune response that SARS-CoV-2 infections provoke.

The mechanism underlying extrapulmonary complications of the coronavirus disease 2019 and its therapeutic implication

The coronavirus disease 2019 (COVID-19) is a highly transmissible disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that poses a major threat to global public health. Although COVID-19 primarily affects the respiratory system, causing severe pneumonia and acute respiratory distress syndrome in severe cases, it can also result in multiple extrapulmonary complications. The pathogenesis of extrapulmonary damage in patients with COVID-19 is probably multifactorial, involving both the direct effects of SARS-CoV-2 and the indirect mechanisms associated with the host inflammatory response. Recognition of features and pathogenesis of extrapulmonary complications has clinical implications for identifying disease progression and designing therapeutic strategies. This review provides an overview of the extrapulmonary complications of COVID-19 from immunological and pathophysiologic perspectives and focuses on the pathogenesis and potential therapeutic targets for the management of COVID-19.

A case of crescentic glomerulonephritis in a patient with COVID-19 infection: A case report and literature review

RATIONALE

Kidney involvement with COVID-19 infection is a well-known complication, and the majority of kidney involvement is related to ischemic injury/acute tubular injury. However, there are some cases of glomerulonephritis, the etiology of which is not yet known, but an immune process is likely to be the trigger.

PATIENT CONCERNS

A 27-year-old man presented to our hospital with facial puffiness and lower-limb swelling.

DIAGNOSIS

Laboratory assessment revealed features of impaired kidney function with proteinuria and hematuria; COVID-19 polymerase chain reaction was positive, which was consistent with pauci-immune crescentic focal segmental glomerulonephritis.

INTERVENTION

After renal biopsy, the patient was started on methylprednisolone and rituximab. Due to worsening kidney parameters, he underwent intermittent hemodialysis as needed.

OUTCOME

Kidney function tests partially improved; he was discharged on oral steroids with follow-up in the nephrology clinic to observe for the need for further hemodialysis.

LESSONS

We conducted a literature review of cases of glomerulonephritis associated with COVID-19 and described numerous types of glomerulonephritis. This report highlights the importance of recognizing emerging glomerulonephritis with COVID-19, the different pathological patterns of renal biopsies, and management interventions and responses.

Kidney Injury in COVID-19: Epidemiology, Molecular Mechanisms, and Potential Therapeutic Targets

As of December 2021, SARS-CoV-2 had caused over 250 million infections and 5 million deaths worldwide. Furthermore, despite the development of highly effective vaccines, novel variants of SARS-CoV-2 continue to sustain the pandemic, and the search for effective therapies for COVID-19 remains as urgent as ever. Though the primary manifestation of COVID-19 is pneumonia, the disease can affect multiple organs, including the kidneys, with acute kidney injury (AKI) being among the most common extrapulmonary manifestations of severe COVID-19. In this article, we start by reflecting on the epidemiology of kidney disease in COVID-19, which overwhelmingly demonstrates that AKI is common in COVID-19 and is strongly associated with poor outcomes. We also present emerging data showing that COVID-19 may result in long-term renal impairment and delve into the ongoing debate about whether AKI in COVID-19 is mediated by direct viral injury. Next, we focus on the molecular pathogenesis of SARS-CoV-2 infection by both reviewing previously published data and presenting some novel data on the mechanisms of cellular viral entry. Finally, we relate these molecular mechanisms to a series of therapies currently under investigation and propose additional novel therapeutic targets for COVID-19.

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.

Electron microscopy overview of SARS-COV2 and its clinical impact

Research centers around the world are competing to develop therapeutic and prophylactic agents to provide new intervention strategies that could halt or even help slow the progression of the COVID19 pandemic. This requires a deep understanding of the biology and cytopathology of the interaction of SARS-CoV-2 with the cell. This review highlights the importance of electron microscopy (EM) in better understanding the morphology, the subcellular morphogenesis, and pathogenesis of SARS-CoV-2, given its nanometric dimensions. The study also underscores the value of cryo-electron microscopy for analyzing the structure of viral protein complex at atomic resolution in its native state and the development of novel antibodies, vaccines, and therapies targeting the trimeric S spike proteins and the viral replication organelles. This review highlighted the emergence in a short period of time of several viral variants of concern with enhanced transmissibility and increased infectivity. This is due to the elevated affinity of the host receptor with acquired adaptive mutations in the spike protein gene of the virus.Subsequently, to the technical improvement of EM resolutions and the recent promising results with SARS-CoV2 variant structure determination, antibodies production, and vaccine development, it is necessary to maximize our investigations regarding the potential occurrence of immune pressure and viral adaptation secondary to repeated infection and vaccination.