Risk factors, predictions, and progression of acute kidney injury in hospitalized COVID-19 patients: An observational retrospective cohort study

Incidence, pathophysiology, risk factors, histopathology, and outcomes of COVID-19-induced acute kidney injury: A narrative review

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has led to a significant burden on global healthcare systems. COVID-19-induced acute kidney injury (AKI) is among one of the complications, that has emerged as a critical and frequent condition in COVID-19 patients. This AKI among COVID-19 patients is associated with poor outcomes, and high mortality rates, especially in those with severe AKI or requiring renal replacement therapy. COVID-19-induced AKI represents a significant complication with complex pathophysiology and multifactorial risk factors. Indeed, several pathophysiological mechanisms, including direct viral invasion of renal cells, systemic inflammation, endothelial and thrombotic abnormalities as well as nephrotoxic drugs and rhabdomyolysis are believed to underlie this condition. Moreover, histopathological and immunohistopathological findings commonly observed in postmortem studies include acute tubular necrosis, glomerular injury, and the presence of viral particles within renal tissue and urine. Identified risk factors for developing AKI vary among studies, depending on regions, underlying conditions, and the severity of the disease. Moreover, histopathological and immunohistopathological findings commonly observed in postmortem studies include show acute tubular necrosis, glomerular injury, and viral particles within renal tissue and urine. While, identified risk factors for developing AKI vary among studies, according to regions, underlying conditions, and the gravity of the disease. This narrative review aims to synthesize current knowledge on the incidence, pathophysiology, risk factors, histopathology, and outcomes of AKI induced by COVID-19.

Identification of Age-Related Characteristic Genes Involved in Severe COVID-19 Infection Among Elderly Patients Using Machine Learning and Immune Cell Infiltration Analysis

Elderly patients infected with severe acute respiratory syndrome coronavirus 2 are at higher risk of severe clinical manifestation, extended hospitalization, and increased mortality. Those patients are more likely to experience persistent symptoms and exacerbate the condition of basic diseases with long COVID-19 syndrome. However, the molecular mechanisms underlying severe COVID-19 in the elderly patients remain unclear. Our study aims to investigate the function of the interaction between disease-characteristic genes and immune cell infiltration in patients with severe COVID-19 infection. COVID-19 datasets (GSE164805 and GSE180594) and aging dataset (GSE69832) were obtained from the Gene Expression Omnibus database. The combined different expression genes (DEGs) were subjected to Gene Ontology (GO) functional enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and Diseases Ontology functional enrichment analysis, Gene Set Enrichment Analysis, machine learning, and immune cell infiltration analysis. GO and KEGG enrichment analyses revealed that the eight DEGs (IL23A, PTGER4, PLCB1, IL1B, CXCR1, C1QB, MX2, ALOX12) were mainly involved in inflammatory mediator regulation of TRP channels, coronavirus disease-COVID-19, and cytokine activity signaling pathways. Three-degree algorithm (LASSO, SVM-RFE, KNN) and correlation analysis showed that the five DEGs up-regulated the immune cells of macrophages M0/M1, memory B cells, gamma delta T cell, dendritic cell resting, and master cell resisting. Our study identified five hallmark genes that can serve as disease-characteristic genes and target immune cells infiltrated in severe COVID-19 patients among the elderly population, which may contribute to the study of pathogenesis and the evaluation of diagnosis and prognosis in aging patients infected with severe COVID-19.

Predictive Admission Risk Factors, Clinical Features and Kidney Outcomes in Covid-19 Hospitalised Patients with Acute Kidney Injury

Introduction: In COVID-19 patients, acute kidney injury (AKI) is recognized as a cause of high mortality. The aim of our study was to assess the rate and the predictors of AKI as well as survival among COVID-19 patients. Methods: We analyzed clinical and laboratory admission data, predictors of AKI and outcomes including the need for renal replacement therapy (RRT) and mortality at 30 days. Results: Out of 115 patients, 62 (53.9%) presented with AKI: 21 (33.9%) at stage 1, 7(11.3%) at stage 2, and 34 (54.8%) at stage 3. RRT was required in 22.6% of patients and was resolved in 76%. Pre-existing CKD was associated with a 13-fold risk of AKI (p= 0.0001). Low albumin (p = 0.017), thrombocytopenia (p = 0.022) and increase of creatine kinase over 350UI (p = 0.024) were independently associated with a higher risk for AKI. Mortality rates were significantly higher among patients who developed AKI compared to those without (59.6% vs 30.2%, p= 0.003). Low oxygen blood saturation at admission and albumin were found as powerful independent predictors of mortality (OR 0.937; 95%CI: 0.917 - 0.958, p = 0.000; OR 0.987; 95%CI: 0.885-0.991, p= 0.024, respectively). Longer survival was observed in patients without AKI compared to patients with AKI (22.01± 1.703 vs 16.69 ± 1.54, log rank p= 0.009). Conclusion: Renal impairment is significant in hospitalized COVID-19 patients. The severity of the disease itself is emphasized as main contributing mechanism in the occurrence of AKI, and lower blood saturation at admission is the strongest mortality predictor, surpassing the significance of the AKI itself.

Incidence of, and Risk Factors and Outcomes Associated with, Acute Kidney Injury in COVID-19 at the National Kidney and Transplant Institute, Philippines

(1) Background: Acute kidney injury (AKI) in COVID-19 leads to an increase in patient mortality, especially among chronic kidney disease (CKD) patients. (2) Methods: A retrospective cohort of 519 adults admitted from 1 March 2020 to 1 March 2022 were reviewed for baseline characteristics and their association with renal outcomes. Patients were divided into diagnosed CKD, undiagnosed CKD, and normal eGFR. Chronic dialysis and kidney-transplant patients were excluded. Kaplan-Meier survival analysis at 7, 14, and 30 days from admission was performed. (3) Results: The overall incidence of AKI was 45.66%; the proportions among patients with diagnosed CKD, undiagnosed CKD, and normal eGFR were 76.64%, 38.75%, and 7.59%, respectively (p < 0.0001). Multivariate analysis showed that being male and inotrope use were significant risk factors for AKI, while higher eGFR was protective. AKI was associated with dialysis, invasive ventilation (p < 0.0001), prolonged hospitalization (p = 0.0001), and mortality (p < 0.0001). Renal recovery was 64%, 59%, and 23% in stages 1, 2, and 3 AKI, respectively, until 14 days from discharge (p < 0.0001). Patient survival was lower in cases of AKI: 83.16%, 70.59%, and 47.5% compared to non-AKI figures of 91.27%, 87.82%, and 76.95% at 7, 14, and 30 days respectively(p = 0.0001). (4) Conclusion: There was a higher incidence of AKI with worsening renal function. Intensified preventive measures for AKI are crucial to prevent its devastating consequences.

Factors Predictive of Development of Acute Kidney Injury in Patients With COVID-19 in Brunei Darussalam

INTRODUCTION

Acute kidney injury (AKI) in coronavirus disease 2019 (COVID-19) patients affects their health outcomes. Incidence and outcomes varied in the literature, particularly with different population and epidemiological demographics. Data remain scarce in the Southeast Asia region. We report the incidence, outcomes, pattern, types of AKI, and factors that influence AKI patient outcomes in Brunei Darussalam.

METHODS

All patients (N = 930) with COVID-19 who were admitted to the National Isolation Center (between 7th August 2021 and 30thSeptember 2021) were included in the study. The confirmation of AKI was based on the KDIGO (Kidney Disease Improving Global Outcomes) criteria.

RESULTS

The mean age of the patients was 41.9 ± 14.4 years with diabetes mellitus (DM), hypertension (HT), and chronic kidney disease (CKD) accounting for 11.7%, 29.1%, and 4.8% of comorbidities, respectively. Overall, 109 (11.7%) had AKI (KDIGO Stage 1 [67.9%], 2 [13.8%], and 3 [18.3%]), while 75.2% of the cases occurred pre-admission and 26.6% were cases of acute exacerbation of CKD. Univariate analysis identified age (odd ratio [OR] 1.06), male gender (OR 1.63), local nationality (OR 8.03), DM (OR 4.44), HT (OR 5.29), vascular disease (OR 6.08), presence of gastrointestinal symptoms (OR 2.08), antibiotic (OR 3.70) and nephrotoxins exposures (OR 8.57) as significant variables. Multivariate analysis showed age (adjusted OR [AOR] 1.04), male gender (AOR 1.67), gastrointestinal symptoms (AOR 1.61), antibiotic (AOR 2.34), and nephrotoxins exposure (AOR 4.73) as significant.

CONCLUSIONS

Our study showed that one in nine patients with COVID-19 developed AKI with almost a third having stages 2 and 3 AKI. Older age, male gender, presence of GI symptoms, and antibiotic and nephrotoxin exposures were significant predictors of AKI. Patients with these factors should be prioritized for admission and treatment. Even though manifestations are generally now less severe, findings from this study can guide the management of COVID-19 as the disease enters the endemic stage. Furthermore, lessons learned from the COVID-19 pandemic will provide useful information and knowledge for future viral outbreaks or pandemics.

Prognostic models in COVID-19 infection that predict severity: a systematic review

Current evidence on COVID-19 prognostic models is inconsistent and clinical applicability remains controversial. We performed a systematic review to summarize and critically appraise the available studies that have developed, assessed and/or validated prognostic models of COVID-19 predicting health outcomes. We searched six bibliographic databases to identify published articles that investigated univariable and multivariable prognostic models predicting adverse outcomes in adult COVID-19 patients, including intensive care unit (ICU) admission, intubation, high-flow nasal therapy (HFNT), extracorporeal membrane oxygenation (ECMO) and mortality. We identified and assessed 314 eligible articles from more than 40 countries, with 152 of these studies presenting mortality, 66 progression to severe or critical illness, 35 mortality and ICU admission combined, 17 ICU admission only, while the remaining 44 studies reported prediction models for mechanical ventilation (MV) or a combination of multiple outcomes. The sample size of included studies varied from 11 to 7,704,171 participants, with a mean age ranging from 18 to 93 years. There were 353 prognostic models investigated, with area under the curve (AUC) ranging from 0.44 to 0.99. A great proportion of studies (61.5%, 193 out of 314) performed internal or external validation or replication. In 312 (99.4%) studies, prognostic models were reported to be at high risk of bias due to uncertainties and challenges surrounding methodological rigor, sampling, handling of missing data, failure to deal with overfitting and heterogeneous definitions of COVID-19 and severity outcomes. While several clinical prognostic models for COVID-19 have been described in the literature, they are limited in generalizability and/or applicability due to deficiencies in addressing fundamental statistical and methodological concerns. Future large, multi-centric and well-designed prognostic prospective studies are needed to clarify remaining uncertainties.

Direct Application of 3-Maleimido-PROXYL for Proving Hypoalbuminemia in Cases of SARS-CoV-2 Infection: The Potential Diagnostic Method of Determining Albumin Instability and Oxidized Protein Level in Severe COVID-19

Oxidative stress and the albumin oxidized form can lead to hypoalbuminemia, which is a predisposing factor for reduced treatment effectiveness and an increased mortality rate in severe COVID-19 patients. The aim of the study is to evaluate the application of free radical 3-Maleimido-PROXYL and SDSL-EPR spectroscopy in the in vitro determination of ox/red HSA in serum samples from patients with SARS-CoV-2 infection. Venous blood was collected from patients intubated (pO₂ < 90%) with a positive PCR test for SARS-CoV-2 and controls. At the 120th minute after the incubation of the serum samples from both groups with the 3-Maleimido-PROXYL, the EPR measurement was started. The high levels of free radicals were determined through the nitroxide radical TEMPOL, which probably led to increased oxidation of HSA and hypoalbuminemia in severe COVID-19. The double-integrated spectra of 3-Maleimido-PROXYL radical showed a low degree of connectivity due to high levels of oxidized albumin in COVID-19 patients. The low concentrations of reduced albumin in serum samples partially inhibit spin-label rotation, with A_max values and ΔH₀ spectral parameters comparable to those of 3-Maleimido-PROXYL/DMSO. Based on the obtained results, we suggest that the stable nitroxide radical 3-Maleimido-PROXYL can be successfully used as a marker to study oxidized albumin levels in COVID-19.

Machine learning for acute kidney injury: Changing the traditional disease prediction mode

Acute kidney injury (AKI) is a serious clinical comorbidity with clear short-term and long-term prognostic implications for inpatients. The diversity of risk factors for AKI has been recognized in previous studies, and a series of predictive models have been developed using traditional statistical methods in conjunction with its preventability, but they have failed to meet the expectations in limited clinical applications, the rapid spread of electronic health records and artificial intelligence machine learning technology has brought new hope for the construction of AKI prediction models. In this article, we systematically review the definition and classification of machine learning methods, modeling ideas and evaluation methods, and the characteristics and current status of modeling studies. According to the modeling objectives, we subdivided them into critical care medical setting models, all medical environment models, special surgery models, special disease models, and special nephrotoxin exposure models. As the first review article to comprehensively summarize and analyze machine learning prediction models for AKI, we aim to objectively describe the advantages and disadvantages of machine learning approaches to modeling, and help other researchers more quickly and intuitively understand the current status of modeling research, inspire ideas and learn from experience, so as to guide and stimulate more research and more in-depth exploration in the future, which will ultimately provide greater help to improve the overall status of AKI diagnosis and treatment.

The incidence of acute kidney injury and its association with mortality in patients diagnosed with COVID-19 followed up in intensive care unit

INTRODUCTION

The kidneys are some of the most frequently affected organs during coronavirus disease 2019 (COVID-19). This multicenter study evaluated the incidence of and risk factors for acute kidney injury (AKI) in COVID-19 patients followed up in intensive care unit (ICU) and its association with mortality.

METHODS

Three hundred twenty-eight patients diagnosed with COVID-19 and hospitalized in ICU were included. Risk factors associated with AKI and mortality were evaluated.

RESULTS

Eighty-eight patients (27.9%) were diagnosed with AKI. AKI was significantly associated with older age, higher baseline creatinine level, lower albumin level, and coexistence of cardiovascular disease and chronic obstructive pulmonary disease. Mortality in the entire study group was significantly associated with AKI, older age, requirement of invasive mechanical ventilation, higher neutrophil level, lower lymphocyte, and albumin levels.

CONCLUSION

AKI is frequently seen during the course of COVID-19 and is associated with high mortality. Identifying AKI-related risk factors appears essential in the management of COVID-19 patients.

Acute kidney injury in critically ill COVID-19 infected patients requiring dialysis: experience from India and Pakistan

Background

Acute kidney injury (AKI) was common in the first two waves of the SARS-COV-2 pandemic in critically ill patients. A high percentage of these patients required renal replacement therapy and died in the hospital.

Methods

The present study examines the clinical presentation, laboratory parameters and therapeutic interventions in critically ill patients with AKI admitted to the ICU in two centres, one each in India and Pakistan. Patient and outcome details of all critically ill COVID 19 patients admitted to the ICU requiring renal replacement therapy were collected. Data was analysed to detect patient variables associated with mortality.

Results

A total of 1,714 critically ill patients were admitted to the ICUs of the two centres. Of these 393 (22.9%) had severe acute kidney injury (AKIN stage 3) requiring dialysis. Of them, 60.5% were men and the mean (± SD) age was 58.78 (± 14.4) years. At the time of initiation of dialysis, 346 patients (88%) were oligo-anuric. The most frequent dialysis modality in these patients was intermittent hemodialysis (48.1%) followed by slow low efficiency dialysis (44.5%). Two hundred and six (52.4%) patients died. The mortality was higher among the Indian cohort (68.1%) than the Pakistani cohort (43.4%). Older age (age > 50 years), low serum albumin altered sensorium, need for slower forms of renal replacement therapy and ventilatory support were independently associated with mortality.

Conclusion

There was a very high mortality in patients with COVID-19 associated AKI undergoing RRT in the ICUs in this cohort from the Indian sub-continent.

COVID-19 and Kidney Disease: A Clinical Perspective

Coronavirus disease-19 (COVID-19), caused by severe acute respiratory syndrome Coronavirus- 2 (SARS-CoV-2), has caused a global pandemic with high morbidity and mortality. The presence of several comorbidities has been associated with a worse prognosis, with chronic kidney disease being a critical risk factor. Regarding COVID-19 complications, other than classical pneumonia and thromboembolism, acute kidney injury (AKI) is highly prevalent and represents a poor prognostic indicator linked to increased disease severity and mortality. Its pathophysiology is multifactorial, revolving around inflammation, endothelial dysfunction, and activation of coagulation, while the direct viral insult of the kidney remains a matter of controversy. Indirectly, COVID-19 AKI may stem from sepsis, volume depletion, and administration of nephrotoxic agents, among others. Several markers have been proposed for the early detection of COVID-19 AKI, including blood and urinary inflammatory and kidney injury biomarkers, while urinary SARS-CoV-2 load may also be an early prognostic sign. Concerning renal replacement therapy (RRT), general principles apply to COVID-19 AKI, but sudden RRT surges may mandate adjustments in resources. Following an episode of COVID-19 AKI, there is a gradual recovery of kidney function, with pre-existing renal impairment and high serum creatinine at discharge being associated with kidney disease progression and long-term dialysis dependence. Finally, kidney transplant recipients represent a special patient category with increased susceptibility to COVID- 19 and subsequent high risk of severe disease progression. Rates of mortality, AKI, and graft rejection are significantly elevated in the presence of COVID-19, highlighting the need for prevention and careful management of the disease in this subgroup.

Long-term cardio-vascular risk assessment in chronic kidney disease and kidney transplanted patients following SARS-COV-2 disease: protocol for multi-center observational match controlled trial

BACKGROUND

The coronavirus disease (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) produced a pandemic since March 2020 by affecting more than 243 million people with more than 5 million deaths globally. SARS-CoV-2 infection is produced by binding to angiotensin-converting enzyme, which among other sites is highly expressed in the endothelial cells of the blood vessels, pericytes and the heart, as well as in renal podocytes and proximal tubular epithelial cells. SARS-CoV-2 and cardiovascular disease (CVD) are interconnected by risk factors association with an increased incidence of the disease and by determining de novo cardiac complications. At the same time, COVID-19 disease can lead to acute kidney injury directly, or due to sepsis, multi-organ failure and shock. Therefore, the pre-existence of both CVD and chronic kidney disease (CKD) is linked with a higher risk of severe disease and worse prognosis.

METHODS

The main aim of this study is to assess the CV risk in a CKD (stage 3 to 5), dialysis and kidney transplanted population, following SARS-CoV-2 infection, with focus on the endothelial dysfunction as compared to a control group of matched patients. By using clinical evaluation, flow-mediated dilatation, carotid-femoral pulse wave velocity, intima-media thickness, echocardiographic parameters, lung ultrasound, bioimpedance spectroscopy and a series of novel biomarkers, the investigators will determine the long-term impact of this disease on CV and renal outcomes.

DISCUSSION

This study will address the challenges and implications in long-term CV sequeale of COVID-19 and focus on a better understanding of the underlying mechanisms and possible therapeutic options.

TRIAL REGISTRATION

Patient enrolment in the trial started in January 2021 and is expected to finish at the end of 2022. The study can be found on ClinicalTrials.gov database with NCT05125913 identifier. Registered on 18 November 2021 - Retrospectively registered.

Potential impact of serpin peptidase inhibitor clade (A) member 4 SERPINA4 (rs2093266) and SERPINA5 (rs1955656) genetic variants on COVID-19 induced acute kidney injury

Background

SARS-CoV-2 has a number of targets, including the kidneys. Acute Kidney Injury (AKI) might develop in up to a quarter of SARS-CoV-2 patients. In the clinical environment, AKI is linked to a high rate of death and leads to the progression of AKI to chronic renal disease.

Aim

We aimed to investigate rs2093266 and rs1955656 polymorphisms in SERPINA4 and SERPINA5 genes, respectively, as risk factors for COVID-19 induced AKI.

Subjects and methods

A case-control study included 227 participants who were divided into three groups: 81 healthy volunteers who served as controls, 76 COVID-19 patients without AKI and 70 COVID -19 patients with AKI. The TaqMan assay was used for genotyping the SERPINA4 (rs2093266) and SERPINA5 (rs1955656) polymorphisms by real-time PCR technique.

Results

Lymphocytes and eGFR showed a significantly decreasing trend across the three studied groups, while CRP, d-Dimer, ferritin, creatinine, KIM-1and NGAL showed a significantly increasing trend across the three studied groups (P < 0.001). Rs2093266 (AG and AA) genotypes were significant risk factors among non-AKI and AKI groups in comparison to controls. Rs1955656 (AG and AA) were significant risk factors among the AKI group, while AA was the only significant risk factor among the non-AKI group. Recessive, dominant, co-dominant, and over-dominant models for genotype combinations were demonstrated. The GG v AA, GG + AG v AA, and GG v AG + AA models of the rs2093266 were all significant predictors of AKI, whilst only the GG v AA model of the rs1955656 SNP was a significant predictor. The logistic regression model was statistically significant, χ2 = 56.48, p < 0.001. AKI was associated with progressed age (OR = 0.95, 95% CI: 0.91–0.98, p = 0.006), suffering from chronic diseases (OR = 3.25, 95% CI: 1.31–8.01, p = 0.010), increased BMI (OR = 0.89, 95% CI: 0.81–0.98, p = 0.018), immunosuppressive (OR = 4.61, 95% CI: 1.24–17.16, p = 0.022) and rs2093266 (AG + AA) (OR = 3.0, 95% CI: 1.11–8.10, p = 0.030).

Conclusion

Single nucleotide polymorphisms (rs2093266) at SERPINA4 gene and (rs1955656) at SERPINA5 gene were strongly linked to the development of AKI in COVID-19 patients.