COVID-19 and Acute Kidney Injury: A Systematic Review and Meta-Analysis

Are Kidneys Affected by SARS-CoV-2 Infection? An Updated Review on COVID-19-Associated AKI

BACKGROUND

Human kidneys are an important target of SARS-CoV-2 infection, and many renal abnormalities have been found in patients with SARS-CoV-2 infection, including proteinuria, hematuria, and acute kidney injury. Acute kidney injury is now considered a common complication of COVID-19, and the epidemiology of AKI in SARS-CoV-2-infected patients continues to be controversial.

AIM AND METHODS

We have carried out a narrative review to evaluate the frequency and risk factors for AKI among patients hospitalized due to COVID-19, and the latest surveys on this topic have been included. The mechanisms by which AKI occurs in COVID-19 patients have also been reviewed.

RESULTS

Multiple risk factors for the development of AKI in patients with SARS-CoV-2 infection have been identified; these have been classified in various groups (management and background factors, among others). SARS-CoV-2 targets the kidneys by indirect activity, but SARS-CoV-2 infects tubular epithelial cells and podocytes. We retrieved 24 reports (n = 502,593 unique patients with SARS-CoV-2 infection) and found an incidence of AKI of 31.8% (range, 0.5% to 56.9%). Only a minority (n = 2) of studies had a prospective design. We found that the AKI risk was greater in SARS-CoV-2 patients who underwent in-hospital deaths vs. those who survived; the summary estimate of the unadjusted RR of AKI was 2.63 (95% CI, 2.37; 2.93) (random-effects model). A stratified analysis showed that the incidence of AKI was greater in those reports where the frequency of COVID-19-positive patients having comorbidities (diabetes mellitus, arterial hypertension, and advanced age) was high. The unadjusted relative risk (aRR) of AKI was greater in SARS-CoV-2 patients who underwent ICU admission vs. those who did not; the pooled estimate of AKI risk was 2.64 (95% CI, 1.96; 3.56) according to the random-effects model.

CONCLUSIONS

AKI is a common complication of hospitalized SARS-CoV-2-infected patients, and some comorbidities are important risk factors for it. The direct activity of the virus on the kidneys has been mentioned in the pathogenesis of AKI in SARS-CoV-2 patients. Further studies are ongoing in order to identify the mechanisms underlying the kidney injury in this population. The role of AKI on survival in SARS-CoV-2-infected patients is another area of active investigation.

Correlation of pre-existing comorbidities with disease severity in individuals infected with SARS-COV-2 virus

Shortly after the first publication on the new disease called Coronavirus Disease 2019 (Covid-19), studies on the causal consequences of this disease began to emerge, initially focusing only on transmission methods, and later on its consequences analyzed in terms of gender, age, and the presence of comorbidities. The aim of our research is to determine which comorbidities have the greatest negative impact on the worsening of the disease, namely which comorbidities indicate a predisposition to severe Covid-19, and to understand the gender and age representation of participants and comorbidities. The results of our study show that the dominant gender is male at 54.4% and the age of 65 and older. The most common comorbidities are arterial hypertension, diabetes mellitus, and cardiovascular diseases. The dominant group is recovered participants aged 65 and older, with comorbidities most frequently present in this group. The highest correlation between patients with different severity of the disease was found with cardiovascular diseases, while the coefficient is slightly lower for the relationship between patients with different disease severity and urinary system diseases and hypertension. According to the regression analysis results, we showed that urinary system diseases have the greatest negative impact on the worsening of Covid-19, with the tested coefficient b being statistically significant as it is 0.030 < 0.05. An increase in cardiovascular diseases affects the worsening of Covid-19, with the tested coefficient b being statistically significant as it is 0.030 < 0.05. When it comes to arterial hypertension, it has a small impact on the worsening of Covid-19, but its tested coefficient b is not statistically significant as it is 0.169 > 0.05. The same applies to diabetes mellitus, which also has a small impact on the worsening of Covid-19, but its tested coefficient b is not statistically significant as it is 0.336 > 0.05. Our study has shown that comorbidities such as urinary system diseases and cardiovascular diseases tend to have a negative impact on Covid-19, leading to a poor outcome resulting in death, while diabetes mellitus and hypertension have an impact but without statistical significance.

Research progress of post-acute sequelae after SARS-CoV-2 infection

SARS-CoV-2 has spread rapidly worldwide and infected hundreds of millions of people worldwide. With the increasing number of COVID-19 patients discharged from hospitals, the emergence of its associated complications, sequelae, has become a new global health crisis secondary to acute infection. For the time being, such complications and sequelae are collectively called "Post-acute sequelae after SARS-CoV-2 infection (PASC)", also referred to as "long COVID" syndrome. Similar to the acute infection period of COVID-19, there is also heterogeneity in PASC. This article reviews the various long-term complications and sequelae observed in multiple organ systems caused by COVID-19, pathophysiological mechanisms, diagnosis, and treatment of PASC, aiming to raise awareness of PASC and optimize management strategies.

Burden and risk profile of acute kidney injury in severe COVID-19 pneumonia admissions: a Finding from Jimma University medical center, Ethiopia

BACKGROUND

Acute kidney injury (AKI) is a serious complication of the Corona Virus Disease of 2019 (COVID-19). However, data on its magnitude and risk factors among hospitalized patients in Ethiopia is limited. This study aimed to determine the magnitude of AKI and associated factors among patients admitted for severe COVID-19 pneumonia.

METHODS

An institution-based retrospective cross-sectional study was conducted among 224 patients admitted to Jimma University Medical Center in Ethiopia for severe COVID-19 pneumonia from May 2020 to December 2021. Systematic random sampling was used to select study participants. Medical records were reviewed to extract sociodemographic, clinical, laboratory, therapeutic, and comorbidity data. Bivariable and multivariable logistic regressions were performed to examine factors associated with AKI. The magnitude of the association between the explanatory variables and AKI was estimated using an adjusted odds ratio (AOR) with a 95% confidence interval (CI), and significance was declared at a p-value of 0.05.

RESULTS

The magnitude of AKI was 42% (95% CI: 35.3-48.2%) in the study area. Mechanical ventilation, vasopressors, and antibiotics were required in 32.6, 3.7, and 97.7% of the patients, respectively. After adjusting for possible confounders, male sex (AOR 2.79, 95% CI: 1.3-6.5), fever (AOR 6.5, 95% CI: 2.7-15.6), hypoxemia (AOR 5.1, 95% CI: 1.4-18.9), comorbidities (AOR 2.8, 95% CI: 1.1-7.0), and severe anemia (AOR 10, 95% CI: 1.7-65.7) remained significantly associated with higher odds of AKI.

CONCLUSION

The burden of AKI among patients with severe COVID-19 pneumonia is high in our setting. Male sex, abnormal vital signs, chronic conditions, and anemia can identify individuals at increased risk and require close monitoring and prevention efforts.

The role of thromboinflammation in acute kidney injury among patients with septic coagulopathy

Inflammation and coagulation are critical self-defense mechanisms for mitigating infection that can nonetheless induce tissue injury and organ dysfunction. In severe cases, like sepsis, a dysregulated thromboinflammatory response may result in multiorgan dysfunction. Sepsis-associated acute kidney injury (AKI) is a significant contributor to patient morbidity and mortality. The connection between AKI and thromboinflammation is largely due to unique aspects of the renal vasculature. Specifically, the interaction between blood cells with the endothelial, glomerular, and peritubular capillary systems during thromboinflammation reduces oxygen supply to tubular epithelial cells. Previous studies have focused on tubular epithelial cell damage due to hypoxia, oxidative stress, and nephrotoxins. Although these factors are pivotal in acute tubular injury or necrosis, recent studies have demonstrated that AKI in sepsis encompasses a mixture of tubular and glomerular damage subtypes. In cases of sepsis-induced coagulopathy, thromboinflammation within the glomerulus and peritubular capillaries is an important pathogenic mechanism for AKI. Unfortunately, and despite the use of renal replacement therapy, the development of AKI in sepsis continues to be associated with high morbidity, mortality, and clinical challenges requiring alternative approaches. This review introduces the important role of thromboinflammation in AKI pathogenesis and details innovative vascular-targeting therapeutic strategies.

A retrospective analysis of acute kidney injury in children with post-COVID-19 multisystem inflammatory syndrome: insights into promising outcomes

BACKGROUND

Acute kidney injury (AKI) in patients with multisystem inflammatory syndrome (MIS), COVID-19 related infection has been increasingly recognized with a paucity of data on AKI incidence, related mortality, and the requirement of renal replacement therapy in children with MIS (MIS-C).

METHODS

This is a retrospective study evaluating the prevalence, severity, management and outcomes of AKI in a cohort of Egyptian children with MIS-children (MIS-C) post-COVID infection. Patients were included if they met the criteria for MIS-C based on CDC guidelines. All patients were evaluated for AKI diagnosis and staging according to the Kidney Disease Improving Global Outcomes (KDIGO) criteria.

RESULTS

Between March 2021 and June 2023, a total of 655 confirmed COVID-19 cases were admitted and then followed up in our hospital, of whom 138 (21%) were diagnosed with MIS-C. Fifty-one patients developed AKI associated with MIS-C post-COVID infection, 42 of whom were included in the analysis. Thirty-one patients had AKI in a formerly healthy kidney, of whom 51% (16 patients) were classified as KDIGO stage 3, 5 patients needed hemodialysis and 13 needed mechanical ventilation. Higher WBCs count, and serum ferritin on admission were associated with more severe AKI (KDIGO stage 3) (p = 0.04), while multivariate analysis showed high serum ferritin to be independent predictor of more severe AKI (p = 0.02). Two patients (2/31) died during hospital admission, while no residual renal impairment was reported at the time of discharge of patients with previously normal kidney functions.

CONCLUSION

More than one-third of patients with MIS-C develop AKI. Avoidance of nephrotoxic drugs, early recognition, and prompt management of AKI, including well-timed commencement of dialysis in MIS-C cases, is associated with favorable outcomes.

Acute kidney injury in patients with COVID-19 compared to those with influenza: a systematic review and meta-analysis

Background

COVID-19 and influenza can both lead to acute kidney injury (AKI) as a common complication. However, no meta-analysis has been conducted to directly compare the incidence of AKI between hospitalized patients with COVID-19 and influenza. The objective of our study aims to investigate the incidence and outcomes of AKI among hospitalized patients between these two groups.

Materials and methods

A systematic search of PubMed, Embase, and Cochrane databases was conducted from December 2019 to August 2023 to identify studies examining AKI and clinical outcomes among hospitalized patients with COVID-19 and influenza. The primary outcome of interest was the incidence of AKI, while secondary outcomes included in-hospital mortality, recovery from AKI, hospital and ICU stay duration. The quality of evidence was evaluated using Cochrane and GRADE methods.

Results

Twelve retrospective cohort studies, involving 17,618 hospitalized patients with COVID-19 and influenza, were analyzed. COVID-19 patients showed higher AKI incidence (29.37% vs. 20.98%, OR: 1.67, 95% CI 1.56-1.80, p < 0.01, I2 = 92.42%), and in-hospital mortality (30.95% vs. 5.51%, OR: 8.16, 95% CI 6.17-10.80, p < 0.01, I2 = 84.92%) compared to influenza patients with AKI. Recovery from AKI was lower in COVID-19 patients (57.02% vs., 80.23%, OR: 0.33, 95% CI 0.27-0.40, p < 0.01, I2 = 85.17%). COVID-19 patients also had a longer hospital stay (SMD: 0.69, 95% CI 0.65-0.72, p < 0.01, I2 = 98.94%) and longer ICU stay (SMD: 0.61, 95% CI 0.50-0.73, p < 0.01, I2 = 94.80%) than influenza patients. In our study, evidence quality was high (NOS score 7-9), with low certainty for AKI incidence and moderate certainty for recovery form AKI by GRADE assessment.

Conclusion

COVID-19 patients had higher risk of developing AKI, experiencing in-hospital mortality, and enduring prolonged hospital/ICU stays in comparison to influenza patients. Additionally, the likelihood of AKI recovery was lower among COVID-19 patients.

[Mortality in patients with COVID-19 and acute kidney injury on hemodialysis]

Background

A high in-hospital mortality has been identified in patients with COVID-19 who develop acute kidney injury, particularly in those who received renal replacement therapy. In our country there are few studies up until now that report the proportion of deaths in this group of patients.

Objective

To identify the proportion of deaths in patients with COVID-19 who developed acute kidney injury and required hemodialysis.

Material and methods

an observational, descriptive, cross-sectional, retrospective study was carried out and the total population was studied. It included patients over 18 years of age who required dialysis, who received one or more sessions of conventional hemodialysis. The data were obtained from the electronic file and the registry of the hemodialysis unit. For the descriptive analysis, measures of central tendency were used and the proportion of deaths in patients with COVID-19 was calculated.

Results

The study population was made up of 40 patients; the proportion of deaths was 86.1%. The average number of days elapsed from admission to the development of acute kidney injury and dialysis requirement was 5.2 days and the average number of hemodialysis sessions received was 1.7 sessions.

Conclusions

In this study it was documented a high proportion of deaths in patients with COVID-19 who developed acute kidney injury and required renal replacement therapy, which coincides with similar studies reported internationally.

Association of Neutrophil/Lymphocyte Ratio and Neutrophil/Lymphocyte Platelet Ratio With Acute Kidney Injury in Severe COVID-19

Background Severe disease from COVID-19 was the leading cause of admission to the emergency room and hospitalization during the pandemic in Mexico. Acute kidney injury was one of the most prevalent complications in these patients. The neutrophil/lymphocyte (NL) index and the neutrophil/lymphocyte platelet (NLP) index have previously been described as possible markers associated with complications and mortality in this disease. Objective To determine the association of the NL ratio and the NLP ratio in patients with acute kidney injury secondary to severe COVID-19. Materials and methods This is a case-control study, unpaired, of patients diagnosed with severe COVID-19 who presented or did not present acute kidney injury. On admission to the hospital, the hematological ratios were calculated, and Mann-Whitney U tests and multivariate logistic regression were performed. Results A total of 160 patients were included, and a difference in the NLP ratio (4.2 vs. 3.1, p = 0.001) was observed between patients with and without acute kidney injury. Additionally, the NLP ratio was the main risk variable for acute kidney injury in severe COVID-19, with an odds ratio of 2.5 and a 95% confidence interval of 1.108-5.66. Conclusions The NLP ratio has a moderate association and is a risk factor associated with the presence of acute kidney injury in patients with severe COVID-19.

[Characterization of hospitalized patients with acute kidney injury associated with COVID-19 in Spain: Renal replacement therapy and mortality. FRA-COVID SEN Registry Data]

Background and objectives

Acute kidney injury (AKI) is common among hospitalized patients with COVID-19 and associated with worse prognosis. The Spanish Society of Nephrology created the AKI-COVID Registry to characterize the population admitted for COVID-19 that developed AKI in Spanish hospitals. The need of renal replacement therapy (RRT) therapeutic modalities, and mortality in these patients were assessed.

Material and method

In a retrospective study, we analyzed data from the AKI-COVID Registry, which included patients hospitalized in 30 Spanish hospitals from May 2020 to November 2021. Clinical and demographic variables, factors related to the severity of COVID-19 and AKI, and survival data were recorded. A multivariate regression analysis was performed to study factors related to RRT and mortality.

Results

Data from 730 patients were recorded. A total of 71.9% were men, with a mean age of 70 years (60-78), 70.1% were hypertensive, 32.9% diabetic, 33.3% with cardiovascular disease and 23.9% had some degree of chronic kidney disease (CKD). Pneumonia was diagnosed in 94.6%, requiring ventilatory support in 54.2% and admission to the ICU in 44.1% of cases.The median time from the onset of COVID-19 symptoms to the appearance of AKI (37.1% KDIGO I, 18.3% KDIGO II, 44.6% KDIGO III) was 6 days (4-10). A total of 235 (33.9%) patients required RRT: 155 patients with continuous renal replacement therapy, 89 alternate-day dialysis, 36 daily dialysis, 24 extended hemodialysis and 17 patients with hemodiafiltration. Smoking habit (OR 3.41), ventilatory support (OR 20.2), maximum creatinine value (OR 2.41) and time to AKI onset (OR 1.13) were predictors of the need for RRT; age was a protective factor (0.95). The group without RRT was characterized by older age, less severe AKI, shorter kidney injury onset and recovery time (p < 0.05). 38.6% of patients died during hospitalization; serious AKI and RRT were more frequent in the death group. In the multivariate analysis, age (OR 1.03), previous chronic kidney disease (OR 2.21), development of pneumonia (OR 2.89), ventilatory support (OR 3.34) and RRT (OR 2.28) were predictors of mortality while chronic treatment with ARBs was identified as a protective factor (OR 0.55).

Conclusions

Patients with AKI during hospitalization for COVID-19 had a high mean age, comorbidities and severe infection. We defined two different clinical patterns: an AKI of early onset, in older patients that resolves in a few days without the need for RRT; and another more severe pattern, with greater need for RRT, and late onset, which was related to greater severity of the infectious disease. The severity of the infection, age and the presence of CKD prior to admission were identified as risk factors for mortality in these patients. In addition chronic treatment with ARBs was identified as a protective factor for mortality.

Risk factors, clinical characteristics and prognostic value of acute kidney injury in COVID-19 compared with influenza virus and respiratory syncytial virus

BACKGROUND

Acute Kidney Injury (AKI) complicates a substantial part of patients with COVID-19. Direct viral penetration of renal cells through the Angiotensin Converting Enzyme 2 receptor, and indirect damage by the aberrant inflammatory response characteristic of COVID-19 are likely mechanisms. Nevertheless, other common respiratory viruses such as Influenza and Respiratory Syncytial Virus (RSV) are also associated with AKI.

METHODS

We retrospectively compared the incidence, risk factors and outcomes of AKI among patients who were admitted to a tertiary hospital because of infection with COVID-19, influenza (A + B) or RSV.

RESULTS

We collected data of 2593 patients hospitalized with COVID-19, 2041 patients with influenza and 429 with RSV. Patients affected by RSV were older, had more comorbidities and presented with higher rates of AKI at admission and within 7 days (11.7% vs. 13.3% vs. 18% for COVID-19, influenza and RSV, respectively p = 0.001). Nevertheless, patients hospitalized with COVID-19 had higher mortality (18% with COVID-19 vs. 8.6% and 13.5% for influenza and RSV, respectively P < 0.001) and higher need of mechanical ventilation (12.4% vs. 6.5% vs.8.2% for COVID-19, influenza and RSV, respectively, P = 0.002). High ferritin levels and low oxygen saturation were independent risk factors for severe AKI only in the COVID-19 group. AKI in the first 48 h of admission and in the first 7 days of hospitalization were strong independent risk factors for adverse outcome in all groups.

CONCLUSION

Despite many reports of direct kidney injury by SARS-COV-2, AKI was less in patients with COVID-19 compared to influenza and RSV patients. AKI was a prognostic marker for adverse outcome across all viruses.

Acute Kidney Injury Associated with Severe SARS-CoV-2 Infection: Risk Factors for Morbidity and Mortality and a Potential Benefit of Combined Therapy with Tocilizumab and Corticosteroids

Background: Acute kidney injury (AKI) is a common complication in patients with severe COVID-19. Methods: We retrospectively reviewed 249 patients admitted to an intensive care unit (ICU) during the first wave of the pandemic to determine risk factors for AKI. Demographics, comorbidities, and clinical and outcome variables were obtained from electronic medical records. Results: Univariate analysis revealed older age, higher admission serum creatinine, elevated Sequential Organ Failure Assessment (SOFA) score, elevated admission D-Dimer, elevated CRP on day 2, mechanical ventilation, vasopressor requirement, and azithromycin usage as significant risk factors for AKI. Multivariate analysis demonstrated that higher admission creatinine (p = 0.0001, OR = 2.41, 95% CI = 1.56–3.70), vasopressor requirement (p = 0.0001, OR = 3.20, 95% CI = 1.69–5.98), elevated admission D-Dimer (p = 0.008, OR = 1.0001, 95% CI = 1.000–1.001), and elevated C-reactive protein (CRP) on day 2 (p = 0.033, OR = 1.0001, 95% CI = 1.004–1.009) were independent risk factors. Conversely, the combined use of Tocilizumab and corticosteroids was independently associated with reduced AKI risk (p = 0.0009, OR = 0.437, 95% CI = 0.23–0.81). Conclusion: This study confirms the high rate of AKI and associated mortality among COVID-19 patients admitted to ICUs and suggests a role for inflammation and/or coagulopathy in AKI development. One should consider the possibility that early administration of anti-inflammatory agents, as is now routinely conducted in the management of COVID-19-associated acute respiratory distress syndrome, may improve clinical outcomes in patients with AKI.

Genitourinary tract symptoms in patients admitted with COVID-19: Exploring changes in frequency by determinants and pandemic waves

Background

Urothelial cells exhibit increased expression of angiotensin-converting enzyme-2 receptor, which is the binding site of severe acute respiratory syndrome coronavirus 2 to cells. The frequency and distribution of genitourinary tract symptoms in patients diagnosed with coronavirus disease 2019 (COVID-19) is unknown.

Objective

We explored trends in genitourinary tract symptoms by gender and each of six pandemic waves in patients admitted for COVID-19, and related them with severity, death and length of hospitalization.

Design Setting and Participants

A retrospective study took place in our institution of COVID-19 admitted patients. Only patients with RT-PCR or antigen test confirmed SARS-CoV-2 infection were included. Demographic, clinical, and genitourinary symptoms were explored.

Outcome Measurements and Statistical Analysis

COVID-19 patients with genitourinary tract symptoms were compared with those without. Statistical comparisons were conducted by parametric and nonparametric tests for quantitative variables, and χ 2 test for qualitative variables.

Results and limitations

Out of a total of 4,661 COVID-19 patients, genitourinary symptoms were found in 21,1%. These symptoms were more frequent in patients admitted for longer than 30 days, except for urinary incontinence (UI) and erectile dysfunction (ED). Acute kidney injury (AKI) and urinary tract infections (UTI) had a higher presence in the 5^th (16.7%; 12.8% respectively) and 3^rd wave (13.3%; 12.6% respectively). Genitourinary symptoms were higher for those patients admitted in critical care units. Frequency of AKI, UI, UTI and acute urinary retention (AUR) were higher for patients who were finally deceased (26.2%; 3.5%; 13.6% and 3.6% respectively).

Conclusions

A high frequency of genitourinary symptoms in patients admitted for COVID-19 was observed, whose frequency and distribution varied according to pandemic waves. Specific genitourinary conditions were associated with worse outcomes and poorer prognosis.

Implementation of MRSA Nasal Swabs as an Antimicrobial Stewardship Intervention to Decrease Anti-MRSA Therapy in COVID-19 Infection

In the early stages of treating patients with SARS-CoV-2, limited information was available to guide antimicrobial stewardship interventions. The COVID-19 Task Force and Antimicrobial Stewardship Committee, at a 988-bed academic medical center, implemented the use of methicillin-resistant Staphylococcus aureus (MRSA) nasal swab polymerase chain reaction (PCR) testing to assist with the de-escalation of anti-MRSA therapy in patients with suspected superimposed bacterial pneumonia in COVID-19. A retrospective study was conducted to evaluate the impact of MRSA nasal swab PCR testing on the rate of anti-MRSA therapy between 13 April 2020 and 26 July 2020. A total of 122 patients were included in the analysis. Of the patients included in the final analysis, 58 (47.5%) had anti-MRSA therapy discontinued and 41 (33.6%) avoided anti-MRSA therapy completely due to a negative swab result. With the implementation of MRSA nasal swab PCR testing in COVID-19 patients, anti-MRSA therapy was reduced in 81% of patients in this study. In patients who continued with anti-MRSA therapy, nasal swabs were either positive for MRSA or an alternative indication for anti-MRSA therapy was noted. Only three patients in the cohort had MRSA identified in a sputum culture, all of whom had anti-MRSA therapy continued. MRSA nasal swab PCR testing may serve as an effective antimicrobial stewardship tool in COVID-19 pneumonia.

The role of kidney injury biomarkers in COVID-19

The coronavirus disease-2019 (COVID-19) outbreak has been declared a global pandemic. COVID-19-associated acute kidney injury (COVID-19 AKI) is related to a high mortality rate and serves as an independent risk factor for hospital death in patients with COVID-19. Early diagnosis would allow for earlier intervention and potentially improve patient outcomes. The goal of early identification of AKI has been the primary impetus for AKI biomarker research, and several kidney injury biomarkers have been demonstrated to be beneficial in predicting COVID-19 AKI as well as disease progression in COVID-19. Furthermore, such data provide valuable insights into the molecular mechanisms underlying this complex and unique disease and serve as a molecular phenotyping tool that could be utilized to direct clinical intervention. This review focuses on a number of kidney injury biomarkers, such as CysC, NAGAL, KIM-1, L-FABP, IL-18, suPAR, and [TIMP-2] • [IGFBP7], which have been widely studied in common clinical settings, such as sepsis, cardiac surgery, and contrast-induced AKI. We explore the role of kidney injury biomarkers in COVID-19 and discuss what remains to be learned.

Missing Care: the Initial Impact of the COVID-19 Pandemic on CKD Care Delivery

BACKGROUND

Chronic kidney disease (CKD) is a common condition with adverse health outcomes addressable by early disease management. The impact of the COVID-19 pandemic on care utilization for the CKD population is unknown.

OBJECTIVE

To examine pandemic CKD care and identify factors associated with a high care deficit.

DESIGN

Retrospective observational study PARTICIPANTS: 248,898 insured individuals (95% Medicare Advantage, 5% commercial) with stage G3-G4 CKD in 2018 MAIN MEASURES: Predicted (based on the pre-pandemic period of January 1, 2019-February 28, 2020) to observed per-member monthly face-to-face and telehealth encounters, laboratory testing, and proportion of days covered (PDC) for medications, evaluated during the early (March 1, 2020-June 30, 2020), pre-vaccine (July 1, 2020-December 31, 2020), and late (January 2021-August 2021) periods and overall.

KEY RESULTS

In-person encounters fell by 24.1% during the pandemic overall; this was mitigated by a 14.2% increase in telehealth encounters, resulting in a cumulative observed utilization deficit of 10% relative to predicted. These reductions were greatest in the early pandemic period, with a 19.8% cumulative deficit. PDC progressively decreased during the pandemic (range 9-20% overall reduction), with the greatest reductions in hypertension and diabetes medicines. CKD laboratory monitoring was also reduced (range 11.8-43.3%). Individuals of younger age (OR 1.63, 95% CI 1.16, 2.28), with commercial insurance (1.43, 95% CI 1.25, 1.63), residing in the Southern US (OR 1.17, 95% CI 1.14, 1.21), and with stage G4 CKD (OR 1.21, 95% CI 1.17, 1.26) had greater odds of a higher care deficit overall.

CONCLUSIONS

The early COVID-19 pandemic resulted in a marked decline of healthcare services for individuals with CKD, with an incomplete recovery during the later pandemic. Increased telehealth use partially compensated for this deficit. The downstream impact of CKD care reduction on health outcomes requires further study, as does evaluation of effective care delivery models for this population.

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.

Incidence, risk factors and outcomes of acute kidney injury among COVID-19 patients: A systematic review of systematic reviews

The COVID-19 associated acute kidney injury (CAKI) has emerged as a potential intricacy during the management of patients. Navigating the rapidly growing body of scientific literature on CAKI is challenging, and ongoing critical appraisal of this complication is essential. This study aimed to summarize and critically appraise the systematic reviews (SRs) on CAKI to inform the healthcare providers about its prevalence, risk factors and outcomes. All the SRs were searched in major databases (PubMed, EMBASE, Web of Science) from inception date to December 2021. This study followed SR of SRs methodology, all the records were screened, extracted and subjected to quality assessment by assessing the methodological quality of systematic reviews (AMSTAR-2). The extracted data were qualitatively synthesized and tabulated. This review protocol was registered in PROSPERO (CRD42022299444). Of 3,833 records identified; 42 SRs were included in this overview. The quality appraisal of the studies showed that 17 SRs were of low quality, while 8 moderate and 17 were of high-quality SRs. The incidence of CAKI ranged from 4.3% to 36.4% in overall COVID-19 patients, 36%-50% in kidney transplant recipients (KTRs), and up to 53% in severe or critical illness. Old age, male gender, cardiovascular disease, chronic kidney disease, diabetes mellitus and hypertension were frequently reported risk factors of CAKI. The need of renal replacement therapy (RRT) was up to 26.4% in overall COVID-19 patients, and 39% among those having CAKI. The occurrence of acute kidney injury (AKI) was found independent predictor of death, where mortality rate among CAKI patients ranged from 50% to 93%. This overview of SRs underscores that CAKI occurs frequently among COVID-19 patients and associated with high mortality, need of RRT and adverse outcomes. However, the confidence of these results is moderate to low which warrants the need of more SRs having established methodological standards.

Systematic review registration

[https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=299444], identifier [CRD42022299444].

The deciphering of the immune cells and marker signature in COVID-19 pathogenesis: An update

The precise interaction between the immune system and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is critical in deciphering the pathogenesis of coronavirus disease 2019 (COVID-19) and is also vital for developing novel therapeutic tools, including monoclonal antibodies, antivirals drugs, and vaccines. Viral infections need innate and adaptive immune reactions since the various immune components, such as neutrophils, macrophages, CD4⁺ T, CD8⁺ T, and B lymphocytes, play different roles in various infections. Consequently, the characterization of innate and adaptive immune reactions toward SARS-CoV-2 is crucial for defining the pathogenicity of COVID-19. In this study, we explain what is currently understood concerning the conventional immune reactions to SARS-CoV-2 infection to shed light on the protective and pathogenic role of immune response in this case. Also, in particular, we investigate the in-depth roles of other immune mediators, including neutrophil elastase, serum amyloid A, and syndecan, in the immunopathogenesis of COVID-19.

A comprehensive mini-review on amyloidogenesis of different SARS-CoV-2 proteins and its effect on amyloid formation in various host proteins

Amyloidogenesis is the inherent ability of proteins to change their conformation from native state to cross β-sheet rich fibrillar structures called amyloids which result in a wide range of diseases like Parkinson's disease, Alzheimer’s disease, Finnish familial amyloidosis, ATTR amyloidosis, British and Danish dementia, etc. COVID-19, on the other hand is seen to have many similarities in symptoms with other amyloidogenic diseases and the overlap of these morbidities and symptoms led to the proposition whether SARS-CoV-2 proteins are undergoing amyloidogenesis and whether it is resulting in or aggravating amyloidogenesis of any human host protein. Thus the SARS-CoV-2 proteins in infected cells, i.e., Spike (S) protein, Nucleocapsid (N) protein, and Envelope (E) protein were tested via different machinery and amyloidogenesis in them were proven. In this review, we will analyze the pathway of amyloid formation in S-protein, N-protein, E-protein along with the effect that SARS-CoV-2 is creating on various host proteins leading to the unexpected onset of many morbidities like COVID-induced Acute Respiratory Distress Syndrome (ARDS), Parkinsonism in young COVID patients, formation of fibrin microthrombi in heart, etc., and their future implications.

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.

Update on Innate Immunity in Acute Kidney Injury—Lessons Taken from COVID-19

The serious clinical course of SARS-CoV-2 infection is usually accompanied by acute kidney injury (AKI), worsening prognosis and increasing mortality. AKI in COVID-19 is above all a consequence of systemic dysregulations leading to inflammation, thrombosis, vascular endothelial damage and necrosis. All these processes rely on the interactions between innate immunity elements, including circulating blood cells, resident renal cells, their cytokine products, complement systems, coagulation cascades and contact systems. Numerous simultaneous pathways of innate immunity should secure an effective host defense. Since they all form a network of cross-linked auto-amplification loops, uncontrolled activation is possible. When the actions of selected pathways amplify, cascade activation evades control and the propagation of inflammation and necrosis worsens, accompanied by complement overactivity and immunothrombosis. The systemic activation of innate immunity reaches the kidney, where the damage affecting single tubular cells spreads through tissue collateral damage and triggers AKI. This review is an attempt to synthetize the connections between innate immunity components engaged in COVID-19-related AKI and to summarize the knowledge on the pathophysiological background of processes responsible for renal damage.

COVID-19 Infection in Chronic Kidney Disease Patients in Bulgaria: Risk Factors for Death and Acute Kidney Injury

Regarding COVID-19 infection, Bulgaria has one of the lowest rates of vaccination in Europe, and its COVID-19-related mortality rate has been one of the highest in the European Union. Chronic kidney disease (CKD)-COVID-19 patients are at higher risk of developing acute kidney injury (AKI) and death after hospital admission. This single-center prospective cohort study from Bulgaria included 120 in-patient COVID-19 subjects of whom 70 had CKD and 50 normal renal function. Diabetes mellitus, hypertension, obesity, and cardiovascular disease were statistically more prevalent in the CKD group as compared to the non-CKD group. At admission, D-dimer, creatinine, and urea levels were significantly higher in the CKD group, whereas estimated glomerular-filtration rate was significantly lower as compared to the non-CKD patients. During hospitalization, 23 patients (19.1%) died, of which 19 were in the CKD group (p-value = 0.0096); in addition, 38 developed AKI (31.6%), of which 31 were in the CKD group (p-value = 0.0006). Using binary logistic regression, being male, having experienced AKI, and not having been treated with remdesivir were independent risk factors for COVID-19-induced mortality. Regarding risk of AKI, having had COVID-19-related symptoms for more than 6 days before admission, having CKD at baseline, and having not received remdesivir therapy were independent predictive factors for developing AKI after admission.

Outcomes of Patients Receiving a Kidney Transplant or Remaining on the Transplant Waiting List at the Epicentre of the COVID-19 Pandemic in Europe: An Observational Comparative Study

Since the declaration of the COVID-19 pandemic, the number of kidney transplants (KT) performed worldwide has plummeted. Besides the generalised healthcare crisis, this unprecedented drop has multiple explanations such as the risk of viral transmission through the allograft, the perceived increase in SARS-CoV-2-related morbidity and mortality in immunocompromised hosts, and the virtual "safety" of dialysis while awaiting effective antiviral prophylaxis or treatment. Our institution, operating at the epicentre of the COVID-19 pandemic in Italy, has continued the KT programme without pre-set limitations. In this single-centre retrospective observational study with one-year follow-up, we assessed the outcomes of patients who had undergone KT (KTR) or remained on the transplant waiting list (TWL), before (Pre-COV) or during (COV) the pandemic. The main demographic and clinical characteristics of the patients on the TWL or receiving a KT were very similar in the two periods. The pandemic did not affect post-transplant recipient and allograft loss rates. On the contrary, there was a trend toward higher mortality among COV-TWL patients compared to Pre-COV-TWL subjects. Such a discrepancy was primarily due to SARS-CoV-2 infections. Chronic exposure to immunosuppression, incidence of delayed allograft function, and rejection rates were comparable. However, after one year, COV-KTR showed significantly higher median serum creatinine than Pre-COV-KTR. Our data confirm that KT practice could be safely maintained during the COVID-19 pandemic, with excellent patient- and allograft-related outcomes. Strict infection control strategies, aggressive follow-up monitoring, and preservation of dedicated personnel and resources are key factors for the optimisation of the results in case of future pandemics.

Interpatient variability in the pharmacokinetics of remdesivir and its main metabolite GS-441524 in treated COVID-19 subjects

Background

Remdesivir is the first antiviral drug against SARS-CoV-2 approved for use in COVID-19 patients.

Objectives

To study the pharmacokinetic inter-individual variability of remdesivir and its main metabolite GS-441524 in a real-world setting of COVID-19 inpatients and to identify possible associations with different demographic/biochemical variables.

Methods

Inpatients affected by SARS-CoV-2 infections, undergoing standard-dose remdesivir treatment, were prospectively enrolled. Blood samples were collected on day 4, immediately after (C₀) and at 1 h (C₁) and 24 h (C₂₄) after infusion. Remdesivir and GS-441524 concentrations were measured using a validated UHPLC-MS/MS method and the AUC_0–24 was calculated. At baseline, COVID-19 severity (ICU or no ICU), sex, age, BMI and renal and liver functions were assessed. Transaminases and estimated glomerular filtration rate (e-GFR) were also evaluated during treatment. Linear regression, logistic regression and multiple linear regression tests were used for statistical comparisons of pharmacokinetic parameters and variables.

Results

Eighty-five patients were included. The mean (CV%) values of remdesivir were: C₀ 2091 (99.1%) ng/mL, C₁ 139.7 (272.4%) ng/mL and AUC_0–24 2791 (175.7%) ng·h/mL. The mean (CV%) values of GS-441524 were: C₀ 90.2 (49.5%) ng/mL, C₁ 104.9 (46.6%) ng/mL, C₂₄ 58.4 (66.9) ng/mL and AUC_0–24 1976 (52.6%) ng·h/mL. The multiple regression analysis showed that age (P < 0.05) and e-GFR (P < 0.01) were independent predictors of GS-441524 plasma exposure.

Conclusions

Our results showed a high interpatient variability of remdesivir and GS-441524 likely due to both age and renal function in COVID-19 inpatients. Further research is required to understand whether the pharmacokinetics of remdesivir and its metabolites may influence drug-related efficacy or toxic effect.

The role of kidney dysfunction in COVID-19 and the influence of age

COVID-19 is strongly influenced by age and comorbidities. Acute kidney injury (AKI) is a frequent finding in COVID-19 patients and seems to be associated to mortality and severity. On the other hand, the role of kidney dysfunction in COVID-19 is still debated. We performed a retrospective study in a cohort of 174 hospitalized COVID-19 patients in Italy from March 3rd to May 21st 2020, to investigate the role of kidney dysfunction on COVID-19 severity and mortality. Moreover, we examined in depth the relationship between kidney function, age, and progression of COVID-19, also using different equations to estimate the glomerular filtration rate (GFR). We performed logistic regressions, while a predictive analysis was made through a machine learning approach. AKI and death occurred respectively in 10.2% and 19.5%, in our population. The major risk factors for mortality in our cohort were age [adjusted HR, 6.2; 95% confidence interval (CI) 1.8-21.4] and AKI [3.36 (1.44-7.87)], while, in these relationships, GFR at baseline mitigated the role of age. The occurrence of AKI was influenced by baseline kidney function, D-dimer, procalcitonin and hypertension. Our predictive analysis for AKI and mortality reached an accuracy of ≥ 94% and ≥ 91%, respectively. Our study scales down the role of kidney function impairment on hospital admission , especially in elderly patients. BIS-1 formula demonstrated a worse performance to predict the outcomes in COVID-19 patients when compared with MDRD and CKD-EPI.

Prevalence and Risk Factors for Anti-SARS-CoV-2 Antibody in Chronic Kidney Disease (Dialysis Independent and Not)

Background: The evidence in the medical literature regarding the prevalence of antibody towards SARS-CoV-2 in patients with chronic kidney disease is limited, particularly among those at the pre-dialysis stage. Aim: We have prospectively performed a cohort study at a third-level university hospital to evaluate frequency and risk factors for anti-SARS-CoV-2-positive serology among chronic kidney disease patients. Methods: We have tested a cohort of consecutive outpatients with chronic kidney disease on regular follow-up at a major metropolitan hospital, during the SARS-CoV-2 outbreak in Italy. We adopted an enzyme immunoassay for the assessment of IgM/IgG antibodies to SARS-CoV-2 in human serum or plasma (DIA.PRO COVID-19 Serological Assay); the assay detects antibodies against Spike (1/2) and Nucleocapsid proteins of the SARS-CoV-2 genome. Results: There were 199 (65.8%) out of 302 patients with dialysis-independent CKD; 2 patients were anti-SARS-CoV-2 IgM antibody positive, 23 were anti-SARS-CoV-2 IgM/IgG positive and 37 had detectable anti-SARS-CoV-2 IgG antibody in serum. The prevalence of anti-SARS-CoV-2 IgG was 20.5% (60/302). All patients positive for anti-SARS-CoV-2 antibody tested negative by nasopharyngeal swab. A significant and independent relationship between anti-SARS-CoV-2-positive serologic status and serum albumin (a marker of nutritional status) was observed (p < 0.046). The prevalence of anti-SARS-CoV-2 antibody was greater in CKD than in control populations (health care workers and blood donors) attending the hospital a few months before the current study (7.6% and 5.2%, respectively). Conclusions: The great prevalence of anti-SARS-CoV-2 antibody in our study group could be, at least partially, explained with the fact that our patients were living in Milan, an area severely hit by SARS-CoV-2 infection. It seems that a poor nutritional status supports the acquisition of SARS-CoV-2 antibody in CKD patients. Clinical studies to understand the mechanisms responsible for the high frequency of SARS-CoV-2 infection are under way.

Acute Kidney Injury among Hospital-Admitted COVID-19 Patients: A Study from Jordan

Objective

During the COVID-19 pandemic, many patients have been admitted to hospitals with severe respiratory disease and suffered complications. Acute kidney injury (AKI) is among the more dangerous complications contributing to morbidity and mortality among patients.

Methods

This retrospective study focused on all hospital-admitted COVID-19 patients between September and December 2020. A total of 1,044 patients were enrolled. Patient demographics, medical records, and laboratory data were gathered. Patients were split into two groups: AKI and non-AKI. Comparisons comprised demographics, labs, ICU transfer, need for ventilation and oxygen therapy, medications, hospital stay, and deaths.

Results

AKI incidence in the cohort was 25.3%, and a majority were stage 1 (53.3%). Among these, hemodialysis was started in 1.8%. Higher age (P<0.001), diabetes mellitus (P=0.001), hypertension (P=0.001), ACEI/ARB use (P=0.008), erythrocyte-sedimentation rate (P=0.002), CRP (P<0.0001), and ferritin (P=0.01) were predictors of AKI. Among all admitted COVID-19 patients, 30.2% died in hospital. Among those with AKI, 75.9% died in comparison to 24.1% of non-AKI patients (P<0.001). Among COVID-19 patients admitted to the ICU, 80.5% died: 70.5% were from the AKI group and 29.5% from the non-AKI group (P<0.001).

Conclusion

High mortality and morbidity is associated with COVID-19 infection, and AKI is contributing significantly to the outcomes of hospitalized patients with the infection. Early recognition of and treatment for AKI will decrease mortality and hospitalization in patients with COVID-19.

COVID-19 and Acute Kidney Injury: A Systematic Review

Introduction

Acute kidney injury (AKI) has been associated with an increased mortality rate among hospitalized patients with Coronavirus disease 2019 (COVID-19). The current review aimed to evaluate the symptoms, complications, and treatments performed to manage AKI in patients with COVID-19.

Methods

We searched PubMed/Medline, Web of Science, and Embase for the relevant scientific literature published up to February 1, 2022. The following keywords were used: “COVID-19”, “SARS-CoV-2”, and “Acute kidney injury”.

Results

Forty-four studies with a total number of 114 COVID-19 patients with AKI (Mean age: 53.6 years) were included in our systematic review. The most common comorbidities in patients with COVID-19 suffering from AKI were the history of diabetes, hypertension, and hyperlipidemia. Twelve out of the 44 included studies reported a history of chronic kidney disease (CKD) in this group of patients. Focal segmental glomerulosclerosis (FSGS) and acute tubular necrosis (ATN) were the most common pathological evidence. The average length of hospital stay was 19 days, and the average duration of need for mechanical ventilation was 3 days.

Conclusions

The current systematic review shows that AKI frequently complicates the course of COVID-19 hospitalizations and is associated with increased severity of illness, prolonged duration of hospitalization, and poor prognosis. Given the extent of the adverse impact of AKI, early detection of comorbidities and renal complications is essential to improve the outcomes of COVID-19 patients.

COVID-19-associated acute kidney injury patients treated with renal replacement therapy in the intensive care unit: A multicenter study in São Paulo, Brazil

INTRODUCTION

Multicenter studies involving patients with acute kidney injury (AKI) associated with the disease caused by the new coronavirus (COVID-19) and treated with renal replacement therapy (RRT) in developing countries are scarce. The objectives of this study were to evaluate the demographic profile, clinical picture, risk factors for mortality, and outcomes of critically ill patients with AKI requiring dialysis (AKI-RRT) and with COVID-19 in the megalopolis of São Paulo, Brazil.

METHODS

This multicenter, retrospective, observational study was conducted in the intensive care units of 13 public and private hospitals in the metropolitan region of the municipality of São Paulo. Patients hospitalized in an intensive care unit, aged ≥ 18 years, and treated with RRT due to COVID-19-associated AKI were included.

RESULTS

The study group consisted of 375 patients (age 64.1 years, 68.8% male). Most (62.1%) had two or more comorbidities: 68.8%, arterial hypertension; 45.3%, diabetes; 36.3%, anemia; 30.9%, obesity; 18.7%, chronic kidney disease; 15.7%, coronary artery disease; 10.4%, heart failure; and 8.5%, chronic obstructive pulmonary disease. Death occurred in 72.5% of the study population (272 patients). Among the 103 survivors, 22.3% (23 patients) were discharged on RRT. In a multiple regression analysis, the independent factors associated with death were the number of organ dysfunctions at admission and RRT efficiency.

CONCLUSION

AKI-RRT associated with COVID-19 occurred in patients with an elevated burden of comorbidities and was associated with high mortality (72.5%). The number of organ dysfunctions during hospitalization and RRT efficiency were independent factors associated with mortality. A meaningful portion of survivors was discharged while dependent on RRT (22.3%).

Impact of prior bariatric surgery on risk and severity of COVID-19 infection: A meta-analysis of observational studies

BACKGROUND

The association of prior bariatric surgery (BS) with infection rate and prognosis of coronavirus disease 2019 (COVID-19) remains unclear. We conducted a meta-analysis of observational studies to address this issue.

METHODS

We searched databases including MEDLINE, Embase, and CENTRAL from inception to May, 2022. The primary outcome was risk of mortality, while secondary outcomes included risk of hospital/intensive care unit (ICU) admission, mechanical ventilation, acute kidney injury (AKI), and infection rate.

RESULTS

Eleven studies involving 151,475 patients were analyzed. Meta-analysis showed lower risks of mortality [odd ratio (OR)= 0.42, 95% CI: 0.27-0.65, p < 0.001, I² = 67%; nine studies; 151,113 patients, certainty of evidence (COE):moderate], hospital admission (OR=0.56, 95% CI: 0.36-0.85, p = 0.007, I² =74.6%; seven studies; 17,810 patients; COE:low), ICU admission (OR=0.5, 95% CI: 0.37-0.67, p < 0.001, I² =0%; six studies; 17,496 patients, COE:moderate), mechanical ventilation (OR=0.52, 95% CI: 0.37-0.72, p < 0.001, I² =57.1%; seven studies; 137,992 patients, COE:moderate) in patients with prior BS (BS group) than those with obesity without surgical treatment (non-BS group). There was no difference in risk of AKI (OR=0.74, 95% CI: 0.41-1.32, p = 0.304, I² =83.6%; four studies; 129,562 patients, COE: very low) and infection rate (OR=1.05, 95% CI: 0.89-1.22, p = 0.572, I² =0%; four studies; 12,633 patients, COE:low) between the two groups. Subgroup analysis from matched cohort studies demonstrated associations of prior BS with lower risks of mortality, ICU admission, mechanical ventilation, and AKI.

CONCLUSION

Our results showed a correlation between prior BS and less severe COVID-19, which warrants further investigations to verify.

Acute kidney injury in moderate and severe COVID-19 patients: Report of two university hospitals

Acute kidney injury (AKI) is one of the most severe complications of SARS-CoV-2 infection. In a retrospective study, we aimed to describe the influence of COVID-19-related factors on the severity, outcome and timing of AKI in 268 patients admitted in two large COVID-19-designated university hospitals over a period of 6 months. In the univariate analysis, there was a significant relationship between KDIGO stage and the extension of COVID-19 pneumonia on computed tomography (CT), need for oxygen supplementation, serum levels of ferritin, interleukin-6, and procalcitonin, but none of these variables had a value for predicting KDIGO stage in multinomial regression. The odds of recovery of renal function were significantly diminished by d-dimer values. Lack of immunomodulatory treatment was found to be correlated with increased need for renal replacement therapy (RRT). Compared with AKI at admission, hospital-acquired AKI was predicted by the severity of lung damage on CT, evolved more frequently with incomplete recovery of renal function, and was significantly associated with antiviral therapy.

Racial differences in cardiopulmonary outcomes of hospitalized COVID-19 patients with acute kidney injury

In-hospital acute kidney injury (IH-AKI) has been reported in a significant proportion of patients with COVID-19 and is associated with increased disease burden and poor outcomes. However, the mechanisms of injury are not fully understood. We sought to determine the significance of race on cardiopulmonary outcomes and in-hospital mortality of hospitalized COVID-19 patients with AKI. We conducted a retrospective cohort study of consecutive patients hospitalized in Grady Health System in Atlanta, Georgia between February and July 2020, who tested positive for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) on qualitative polymerase-chain-reaction assay. We evaluated the primary composite outcome of in-hospital cardiac events, and mortality in blacks with AKI versus non-blacks with AKI. In a subgroup analysis, we evaluated the impact of AKI in all blacks and in all non-blacks. Of 293 patients, effective sample size was 267 after all exclusion criteria were applied. The mean age was 61.4 ± 16.7, 39% were female, and 75 (28.1%) had IH-AKI. In multivariable analyses, blacks with IH-AKI were not more likely to have in-hospital cardiac events (aOR 0.3, 95% Confidence interval (CI) 0.04-1.86, p = 0.18), require ICU stay (aOR 0.80, 95% CI 0.20-3.25, p = 0.75), acute respiratory distress syndrome (aOR 0.77, 95% CI 0.16-3.65, p = 0.74), require mechanical ventilation (aOR 0.51, 95% CI 0.12-2.10, p = 0.35), and in-hospital mortality (aOR 1.40, 95% CI 0.26-7.50, p = 0.70) when compared to non-blacks with IH-AKI. Regardless of race, the presence of AKI was associated with worse outcomes. Black race is not associated with higher risk of in-hospital cardiac events and mortality in hospitalized COVID-19 patients who develop AKI. However, blacks with IH-AKI are more likely to have ARDS or die from any cause when compared to blacks without IH-AKI.

A Potential Role of the CD47/SIRPalpha Axis in COVID-19 Pathogenesis

The coronavirus SARS-CoV-2 is the cause of the ongoing COVID-19 pandemic. Most SARS-CoV-2 infections are mild or even asymptomatic. However, a small fraction of infected individuals develops severe, life-threatening disease, which is caused by an uncontrolled immune response resulting in hyperinflammation. However, the factors predisposing individuals to severe disease remain poorly understood. Here, we show that levels of CD47, which is known to mediate immune escape in cancer and virus-infected cells, are elevated in SARS-CoV-2-infected Caco-2 cells, Calu-3 cells, and air-liquid interface cultures of primary human bronchial epithelial cells. Moreover, SARS-CoV-2 infection increases SIRPalpha levels, the binding partner of CD47, on primary human monocytes. Systematic literature searches further indicated that known risk factors such as older age and diabetes are associated with increased CD47 levels. High CD47 levels contribute to vascular disease, vasoconstriction, and hypertension, conditions that may predispose SARS-CoV-2-infected individuals to COVID-19-related complications such as pulmonary hypertension, lung fibrosis, myocardial injury, stroke, and acute kidney injury. Hence, age-related and virus-induced CD47 expression is a candidate mechanism potentially contributing to severe COVID-19, as well as a therapeutic target, which may be addressed by antibodies and small molecules. Further research will be needed to investigate the potential involvement of CD47 and SIRPalpha in COVID-19 pathology. Our data should encourage other research groups to consider the potential relevance of the CD47/ SIRPalpha axis in their COVID-19 research.

Presence of a SARS-CoV-2 Protein Enhances Amyloid Formation of Serum Amyloid A

A marker for the severeness and disease progress of COVID-19 is overexpression of serum amyloid A (SAA) to levels that in other diseases are associated with a risk for SAA amyloidosis. To understand whether SAA amyloidosis could also be a long-term risk of SARS-CoV-2 infections, we have used long all-atom molecular dynamic simulations to study the effect of a SARS-CoV-2 protein segment on SAA amyloid formation. Sampling over 40 μs, we find that the presence of the nine-residue segment SK9, located at the C-terminus of the envelope protein, increases the propensity for SAA fibril formation by three mechanisms: it reduces the stability of the lipid-transporting hexamer shifting the equilibrium toward monomers, it increases the frequency of aggregation-prone configurations in the resulting chains, and it raises the stability of SAA fibrils. Our results therefore suggest that SAA amyloidosis and related pathologies may be a long-term risk of SARS-CoV-2 infections.

Clinical characteristics and outcomes of critically ill COVID-19 patients in Sfax, Tunisia

Background

Africa, like the rest of the world, has been impacted by the coronavirus disease 2019 (COVID-19) pandemic. However, only a few studies covering this subject in Africa have been published.

Methods

We conducted a retrospective study of critically ill adult COVID-19 patients—all of whom had a confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection—admitted to the intensive care unit (ICU) of Habib Bourguiba University Hospital (Sfax, Tunisia).

Results

A total of 96 patients were admitted into our ICU for respiratory distress due to COVID-19 infection. Mean age was 62.4±12.8 years and median age was 64 years. Mean arterial oxygen tension (PaO2)/fractional inspired oxygen (FiO₂) ratio was 105±60 and ≤300 in all cases but one. Oxygen support was required for all patients (100%) and invasive mechanical ventilation for 38 (40%). Prone positioning was applied in 67 patients (70%). Within the study period, 47 of the 96 patients died (49%). Multivariate analysis showed that the factors associated with poor outcome were the development of acute renal failure (odds ratio [OR], 6.7; 95% confidence interval [CI], 1.75–25.9), the use of mechanical ventilation (OR, 5.8; 95% CI, 1.54–22.0), and serum cholinesterase (SChE) activity lower than 5,000 UI/L (OR, 5.0; 95% CI, 1.34–19).

Conclusions

In this retrospective cohort study of critically ill patients admitted to the ICU in Sfax, Tunisia, for acute respiratory failure following COVID-19 infection, the mortality rate was high. The development of acute renal failure, the use of mechanical ventilation, and SChE activity lower than 5,000 UI/L were associated with a poor outcome.

Kinetic multi-omic analysis of responses to SARS-CoV-2 infection in a model of severe COVID-19

The host response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is poorly understood due to a lack of an animal model that recapitulates severe human disease. Here, we report a Syrian hamster model that develops progressive lethal pulmonary disease that closely mimics severe coronavirus disease 2019 (COVID-19). We evaluated host responses using a multi-omic, multiorgan approach to define proteome, phosphoproteome, and transcriptome changes. These data revealed both type I and type II interferon-stimulated gene and protein expression along with a progressive increase in chemokines, monocytes, and neutrophil-associated molecules throughout the course of infection that peaked in the later time points correlating with a rapidly developing diffuse alveolar destruction and pneumonia that persisted in the absence of active viral infection. Extrapulmonary proteome and phosphoproteome remodeling was detected in the heart and kidneys following viral infection. Together, our results provide a kinetic overview of multiorgan host responses to severe SARS-CoV-2 infection in vivo.

IMPORTANCE The current pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has created an urgent need to understand the pathogenesis of this infection. These efforts have been impaired by the lack of animal models that recapitulate severe coronavirus disease 2019 (COVID-19). Here, we report a hamster model that develops severe COVID-19-like disease following infection with human isolates of SARS-CoV-2. To better understand pathogenesis, we evaluated changes in gene transcription and protein expression over the course of infection to provide an integrated multiorgan kinetic analysis of the host response to infection. These data reveal a dynamic innate immune response to infection and corresponding immune pathologies consistent with severe human disease. Altogether, this model will be useful for understanding the pathogenesis of severe COVID-19 and for testing interventions.

Exploration of the Relationship Among Key Risk Factors of Acute Kidney Injury for Elderly Patients Considering Covid-19

Background: Previous systematic reviews and meta-analyses supported the relationship between frailty and risk of acute kidney injury (AKI) in elderly patients. However, few studies evaluated proactive management to wear down AKI risk in such frail populations.

Purpose: To understand how AKI risk factors might influence each other and to identify the source factors for clinical decision aids.

Methods: This study uses the decision-making trial and evaluation laboratory (DEMATEL) method to establish influential network-relationship diagrams (INRDs) to form the AKI risk assessment model for the elderly.

Results: Based on the DEMATEL approach, the results of INRD identified the six key risk factors: comorbidity, malignancy, diabetes, creatinine, estimated glomerular filtration rate, and nutritional assessment. (The statistical significance confidence is 98.423%, which is higher than 95%; the gap error is 1.577%, which is lower than 5%). After considering COVID-19 as an additional risk factor in comorbidity, the INRD revealed a similar influential relationship among the essential aspects.

Conclusion: While evaluating the geriatric population, physicians need to pay attention to patients' comorbidities and nutritional assessment; also, they should note patients' creatinine values and glomerular filtration rate. Physicians could establish a preliminary observation index and then design a series of preventive guidelines to reduce the incidence of AKI risk for the elderly.

Incidence and Outcomes of Acute Kidney Injury in Patients Admitted to Hospital With COVID-19: A Retrospective Cohort Study

BACKGROUND

The incidence of acute kidney injury (AKI) in patients with COVID-19 and its association with mortality and disease severity is understudied in the Canadian population.

OBJECTIVE

To determine the incidence of AKI in a cohort of patients with COVID-19 admitted to medicine and intensive care unit (ICU) wards, its association with in-hospital mortality, and disease severity. Our aim was to stratify these outcomes by out-of-hospital AKI and in-hospital AKI.

DESIGN

Retrospective cohort study from a registry of patients with COVID-19.

SETTING

Three community and 3 academic hospitals.

PATIENTS

A total of 815 patients admitted to hospital with COVID-19 between March 4, 2020, and April 23, 2021.

MEASUREMENTS

Stage of AKI, ICU admission, mechanical ventilation, and in-hospital mortality.

METHODS

We classified AKI by comparing highest to lowest recorded serum creatinine in hospital and staged AKI based on the Kidney Disease: Improving Global Outcomes (KDIGO) system. We calculated the unadjusted and adjusted odds ratio for the stage of AKI and the outcomes of ICU admission, mechanical ventilation, and in-hospital mortality.

RESULTS

Of the 815 patients registered, 439 (53.9%) developed AKI, 253 (57.6%) presented with AKI, and 186 (42.4%) developed AKI in-hospital. The odds of ICU admission, mechanical ventilation, and death increased as the AKI stage worsened. Stage 3 AKI that occurred during hospitalization increased the odds of death (odds ratio [OR] = 7.87 [4.35, 14.23]). Stage 3 AKI that occurred prior to hospitalization carried an increased odds of death (OR = 5.28 [2.60, 10.73]).

LIMITATIONS

Observational study with small sample size limits precision of estimates. Lack of nonhospitalized patients with COVID-19 and hospitalized patients without COVID-19 as controls limits causal inferences.

CONCLUSIONS

Acute kidney injury, whether it occurs prior to or after hospitalization, is associated with a high risk of poor outcomes in patients with COVID-19. Routine assessment of kidney function in patients with COVID-19 may improve risk stratification.

TRIAL REGISTRATION

The study was not registered on a publicly accessible registry because it did not involve any health care intervention on human participants.

Complement activation and increased expression of Syk, mucin-1 and CaMK4 in kidneys of patients with COVID-19

Acute and chronic kidney failure is common in hospitalized patients with COVID-19, yet the mechanism of injury and predisposing factors remain poorly understood. We investigated the role of complement activation by determining the levels of deposited complement components (C1q, C3, FH, C5b-9) and immunoglobulin along with the expression levels of the injury-associated molecules spleen tyrosine kinase (Syk), mucin-1 (MUC1) and calcium/calmodulin-dependent protein kinase IV (CaMK4) in the kidney tissues of people who succumbed to COVID-19. We report increased deposition of C1q, C3, C5b-9, total immunoglobulin, and high expression levels of Syk, MUC1 and CaMK4 in the kidneys of COVID-19 patients. Our study provides strong rationale for the expansion of trials involving the use of inhibitors of these molecules, in particular C1q, C3, Syk, MUC1 and CaMK4 to treat patients with COVID-19.

Pathophysiology and Clinical Manifestations of COVID-19-Related Acute Kidney Injury-The Current State of Knowledge and Future Perspectives

The continually evolving severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has resulted in a vast number of either acute or chronic medical impairments of a pathophysiology that is not yet fully understood. SARS-CoV-2 tropism for the organs is associated with bilateral organ cross-talks as well as targeted dysfunctions, among which acute kidney injury (AKI) seems to be highly prevalent in infected patients. The need for efficient management of COVID-related AKI patients is an aspect that is still being investigated by nephrologists; however, another reason for concern is a disturbingly high proportion of various types of kidney dysfunctions in patients who have recovered from COVID-19. Even though the clinical picture of AKI and COVID-related AKI seems to be quite similar, it must be considered that regarding the latter, little is known about both the optimal management and long-term consequences. These discrepancies raise an urgent need for further research aimed at evaluating the molecular mechanisms associated with SARS-CoV-2-induced kidney damage as well as standardized management of COVID-related AKI patients. The following review presents a comprehensive and most-recent insight into the pathophysiology, clinical manifestations, recommended patient management, treatment strategies, and post-mortem findings in patients with COVID-related AKI.

COVID-19 imaging: Diagnostic approaches, challenges, and evolving advances

The role of radiology and the radiologist have evolved throughout the coronavirus disease-2019 (COVID-19) pandemic. Early on, chest computed tomography was used for screening and diagnosis of COVID-19; however, it is now indicated for high-risk patients, those with severe disease, or in areas where polymerase chain reaction testing is sparsely available. Chest radiography is now utilized mainly for monitoring disease progression in hospitalized patients showing signs of worsening clinical status. Additionally, many challenges at the operational level have been overcome within the field of radiology throughout the COVID-19 pandemic. The use of teleradiology and virtual care clinics greatly enhanced our ability to socially distance and both are likely to remain important mediums for diagnostic imaging delivery and patient care. Opportunities to better utilize of imaging for detection of extrapulmonary manifestations and complications of COVID-19 disease will continue to arise as a more detailed understanding of the pathophysiology of the virus continues to be uncovered and identification of predisposing risk factors for complication development continue to be better understood. Furthermore, unidentified advancements in areas such as standardized imaging reporting, point-of-care ultrasound, and artificial intelligence offer exciting discovery pathways that will inevitably lead to improved care for patients with COVID-19.

Acute kidney injury (AKI) in patients with Covid-19 infection is associated with ventilatory management with elevated positive end-expiratory pressure (PEEP)

Background

Acute kidney injury (AKI) in Covid-19 patients admitted to the intensive care unit (ICU) is common, and its severity may be associated with unfavorable outcomes. Severe Covid-19 fulfills the diagnostic criteria for acute respiratory distress syndrome (ARDS); however, it is unclear whether there is any relationship between ventilatory management and AKI development in Covid-19 ICU patients.

Purpose

To describe the clinical course and outcomes of Covid-19 ICU patients, focusing on ventilatory management and factors associated with AKI development.

Methods

Single-center, retrospective observational study, which assessed AKI incidence in Covid-19 ICU patients divided by positive end expiratory pressure (PEEP) tertiles, with median levels of 9.6 (low), 12.0 (medium), and 14.7 cmH₂O (high-PEEP).

Results

Overall mortality was 51.5%. AKI (KDIGO stage 2 or 3) occurred in 38% of 101 patients. Among the AKI patients, 19 (53%) required continuous renal replacement therapy (CRRT). In AKI patients, mortality was significantly higher versus non-AKI (81% vs. 33%, p < 0.0001). The incidence of AKI in low-, medium-, or high-PEEP patients were 16%, 38%, and 59%, respectively (p = 0.002). In a multivariate analysis, high-PEEP patients showed a higher risk of developing AKI than low-PEEP patients (OR = 4.96 [1.1–21.9] 95% CI p < 0.05). ICU mortality rate was higher in high-PEEP patients, compared to medium-PEEP or low-PEEP patients (69% vs. 44% and 42%, respectively; p = 0.057).

Conclusion

The use of high PEEP in Covid-19 ICU patients is associated with a fivefold higher risk of AKI, leading to higher mortality. The cause and effect relationship needs further analysis.

Graphic abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s40620-021-01100-3.

Pre-existing cardiovascular disease, acute kidney injury, and cardiovascular outcomes in hospitalized blacks with COVID-19 infection

BACKGROUND

The Corona Virus 19 (COVID-19) infection is associated with worse outcomes in blacks, although the mechanisms are unclear. We sought to determine the significance of black race, pre-existing cardiovascular disease (pCVD), and acute kidney injury (AKI) on cardiopulmonary outcomes and in-hospital mortality of COVID-19 patients.

METHODS

We conducted a retrospective cohort study of blacks with/without pCVD and with/without in-hospital AKI, hospitalized within Grady Memorial Hospital in Georgia between February and July 2020, who tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on qualitative polymerase-chain-reaction assay. The primary outcome was a composite of in-hospital cardiac events.

RESULTS

Of the 293 patients hospitalized with COVID-19 in this study, 71 were excluded from the primary analysis (for race/ethnicity other than black non-Hispanic). Of the 222 hospitalized COVID-19 patients included in our analyses, 41.4% were female, 78.8% had pCVD, and 30.6% developed AKI during the admission. In multivariable analyses, pCVD (OR 4.7, 95% CI 1.5-14.8, P=0.008) and AKI (OR 2.7, 95% CI 1.3-5.5, P=0.006) were associated with increased odds of in-hospital cardiac events. AKI was associated with increased odds of in-hospital mortality (OR 8.9, 95% CI 3.3-23.9, P<0.0001). The presence of AKI was associated with increased odds of ICU stay, mechanical ventilation, and acute respiratory distress syndrome (ARDS).

CONCLUSION

pCVD and AKI were associated with higher risk of in-hospital cardiac events, and AKI was associated with a higher risk of in-hospital mortality in blacks.