Urine abnormalities predict acute kidney injury in COVID-19 patients: An analysis of 110 cases in Chennai, South India

Urine Parameters in Patients with COVID-19 Infection

A urine test permits the measure of several urinary markers. This is a non-invasive method for early monitoring of potential kidney damage. In COVID-19 patients, alterations of urinary markers were observed. This review aims to evaluate the utility of urinalysis in predicting the severity of COVID-19. A total of 68 articles obtained from PubMed studies reported that (i) the severity of disease was related to haematuria and proteinuria and that (ii) typical alterations of the urinary sediment were noticed in COVID-19-associated AKI patients. This review emphasizes that urinalysis and microscopic examination support clinicians in diagnosing and predicting COVID-19 severity.

The Investigation of Kidney Involvement in 430 Hospitalized Patients with Omicron COVID-19 in Tianjin, China

INTRODUCTION

This study evaluated the incidence, clinical characteristics, and risk factors of kidney involvement in patients with the Omicron variant infection in the post-acute treatment phase in Tianjin, China.

METHODS

Data were collected from 430 patients with Omicron variant infection in Tianjin, China. Demographics, comorbidities, laboratory blood tests, urinalysis, vaccination status, and COVID-19 clinical classification were assessed. Patients were grouped based on kidney involvement, and associated risk factors of kidney involvement were also investigated.

RESULTS

Asymptomatic, mild, ordinary, and severe patients with Omicron COVID-19 variant comprised 1.5%, 49.1%, 48.9%, and 0.5% of the sample population, respectively, without critical illness or death. The incidences of hematuria, proteinuria, and concurrent hematuria and proteinuria were 14.7%, 14.2%, and 5.1%, respectively. Patients with and without kidney involvement differed in age, body mass index (BMI), comorbidity, creatinine levels, estimated glomerular filtration rate, and C-reactive protein (CRP) levels. Age, hypertension, higher CRP levels, and higher BMI were linked with kidney involvement.

CONCLUSION

The majority of the patients suffered from mild or ordinary symptoms of Omicron COVID-19 infection. The primary kidney involvement was hematuria and proteinuria. Proteinuria was significantly associated with Omicron variant infection, and patients with hypertensive comorbidity, higher CRP, and higher creatinine levels were at increased risk of proteinuria after Omicron variant infection.

Clinical Characteristics and Outcomes of Acute Kidney Injury in Hospitalized Patients with Coronavirus Disease 2019: Experience at a Major Tertiary Care Center in Pakistan

Limited data exist on acute kidney injury (AKI) in patients hospitalized with coronavirus disease 2019 (COVID-19), its risk factors, and the outcomes from lower and middle-income countries. We determined the epidemiology of AKI and its outcomes in a retrospective observational study at a tertiary care center in Karachi, Pakistan, from October to December 2020. Demographic data, presenting clinical symptoms, laboratory results, and patient outcomes were collected from the medical records. AKI was defined according to the Kidney Disease Improving Global Outcomes criteria. Of 301 COVID-19 patients, AKI developed in 188 (62.5%). The peak stages of AKI were Stage 1 in 57%, Stage 2 in 14.9%, and Stage 3 in 27.7%. Of these, 15 (8%) required kidney replacement therapy (KRT). Patients admitted to the intensive care unit (63.8% vs. 34.5%), and those needing vasopressors (31.9% vs. 5.3%) or mechanical ventilation (25% vs. 2.7%) had a higher risk of AKI. Independent predictors of AKI were elevated blood urea nitrogen and creatinine (Cr) at presentation, mechanical ventilation, and the use of anticoagulants. AKI, the presence of proteinuria, elevated serum Cr at presentation, use of vasopressors, and a need for KRT were significantly associated with in-hospital death, and the likelihood of mortality increased with advanced stages of AKI. Compared with other countries, AKI occurred more frequently among hospitalized patients with COVID-19 in this Pakistani cohort and was associated with 7.7-fold higher odds of in-hospital death. Patients with severe AKI had a greater likelihood of mortality than those in earlier stages or without AKI.

Serum metabolomic abnormalities in survivors of non-severe COVID-19

Metabolic reprogramming is a distinctive characteristic of SARS-CoV-2 infection, which refers to metabolic changes in hosts triggered by viruses for their survival and spread. It is current urgent to understand the metabolic health status of COVID-19 survivors and its association with long-term health consequences of infection, especially for the predominant non-severe patients. Herein, we show systemic metabolic signatures of survivors of non-severe COVID-19 from Wuhan, China at six months after discharge using metabolomics approaches. The serum amino acids, organic acids, purine, fatty acids and lipid metabolism were still abnormal in the survivors, but the kynurenine pathway and the level of itaconic acid have returned to normal. These metabolic abnormalities are associated with liver injury, mental health, energy production, and inflammatory responses. Our findings identify and highlight the metabolic abnormalities in survivors of non-severe COVID-19, which provide information on biomarkers and therapeutic targets of infection and cues for post-hospital care and intervention strategies centered on metabolism reprogramming.

Management of Acute Kidney Injury and Extracorporeal Blood Purification Therapies During the COVID-19 Pandemic: The Italian SIN-SIAARTI Joint Survey (and Recommendations for Clinical Practice)

Background and Aim

The novel coronavirus disease 2019 remains challenging. A large number of hospitalized patients are at a high risk of developing AKI. For this reason, we conducted a nationwide survey to assess the incidence and management of AKI in critically ill patients affected by the SARS-CoV-2 infection.

Methods

This is a multicenter, observational, nationwide online survey, involving the Italian Society of Nephrology and the critical care units in Italy, developed in partnership between the scientific societies such as SIN and SIAARTI. Invitations to participate were distributed through emails and social networks. Data were collected for a period of 1 week during the COVID-19 pandemic.

Results

A total of 141 responses were collected in the SIN–SIAARTI survey: 54.6% from intensivists and 44.6% from nephrologists. About 19,000 cases of COVID-19 infection have been recorded in hospitalized patients; among these cases, 7.3% had a confirmed acute kidney injury (AKI), of which 82.2% were managed in ICUs. Only 43% of clinicians routinely used the international KDIGO criteria. Renal replacement therapy (RRT) was performed in 628 patients with continuous techniques used most frequently, and oliguria was the most common indication (74.05%). Early initiation was preferred, and RRT was contraindicated in the case of therapeutic withdrawal or in the presence of severe comorbidities or hemodynamic instability. Regional anticoagulation with citrate was the most common choice. About 41.04% of the interviewed physicians never used extracorporeal blood purification therapies (EBPTs) for inflammatory cytokine or endotoxin removal. Moreover, 4.33% of interviewed clinicians used these techniques only in the presence of AKI, whereas 24.63% adopted them even in the absence of AKI. Nephrologists made more use of EBPT, especially in the presence of AKI. HVHF was never used in 58.54% of respondents, but HCO membranes and adsorbents were used in more than 50% of cases.

Conclusion

This joint SIN–SIAARTI survey at the Italian Society of Nephrology and the critical care units in Italy showed that, during the COVID-19 pandemic, there was an underestimation of AKI based on the “non-use” of common diagnostic criteria, especially by intensivists. Similarly, the use of specific types of RRT and, in particular, blood purification therapies for immune modulation and organ support strongly differed between centers, suggesting the need for the development of standardized clinical guidelines.

Urinalysis, but Not Blood Biochemistry, Detects the Early Renal Impairment in Patients with COVID-19

Background: Coronavirus 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus (SARS-CoV-2), has created a tremendous economic and medical burden. The prevalence and prognostic value of SARS-CoV-2-induced kidney impairment remain controversial. The current study aimed to provide additional evidence on the incidence of acute kidney injury (AKI) in COVID-19 patients and propose the use of urinalysis as a tool for screening kidney impairment. Methods: 178 patients with confirmed COVID-19 were enrolled in this retrospective cohort study. The laboratory examinations included routine blood tests, blood biochemical analyses (liver function, renal function, lipids, and glucose), blood coagulation index, lymphocyte subset and cytokine analysis, urine routine test, C-reactive protein, erythrocyte sedimentation, and serum ferritin. Results: No patient exhibited a rise in serum creatinine or Cystatin C and occurrence of AKI, and only 2.8% of patients were recorded with an elevated level of blood urea nitrogen among all cases. On the contrary, 54.2% of patients who underwent routine urine testing presented with an abnormal urinalysis as featured by proteinuria, hematuria, and leucocyturia. Conclusions: Kidney impairment is prevalent among COVID-19 patients, with an abnormal urinalysis as a clinical manifestation, implying that a routine urine test is a stronger indication of prospective kidney complication than a blood biochemistry test.

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

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

Using dipstick urinalysis to predict development of acute kidney injury in patients with COVID-19

BACKGROUND

Acute kidney injury (AKI) is a common complication in patients hospitalized with COVID-19 and may require renal replacement therapy (RRT). Dipstick urinalysis is frequently obtained, but data regarding the prognostic value of hematuria and proteinuria for kidney outcomes is scarce.

METHODS

Patients with positive severe acute respiratory syndrome-coronavirus 2 (SARS-CoV2) PCR, who had a urinalysis obtained on admission to one of 20 hospitals, were included. Nested models with degree of hematuria and proteinuria were used to predict AKI and RRT during admission. Presence of Chronic Kidney Disease (CKD) and baseline serum creatinine were added to test improvement in model fit.

RESULTS

Of 5,980 individuals, 829 (13.9%) developed an AKI during admission, and 149 (18.0%) of those with AKI received RRT. Proteinuria and hematuria degrees significantly increased with AKI severity (P < 0.001 for both). Any degree of proteinuria and hematuria was associated with an increased risk of AKI and RRT. In predictive models for AKI, presence of CKD improved the area under the curve (AUC) (95% confidence interval) to 0.73 (0.71, 0.75), P < 0.001, and adding baseline creatinine improved the AUC to 0.85 (0.83, 0.86), P < 0.001, when compared to the base model AUC using only proteinuria and hematuria, AUC = 0.64 (0.62, 0.67). In RRT models, CKD status improved the AUC to 0.78 (0.75, 0.82), P < 0.001, and baseline creatinine improved the AUC to 0.84 (0.80, 0.88), P < 0.001, compared to the base model, AUC = 0.72 (0.68, 0.76). There was no significant improvement in model discrimination when both CKD and baseline serum creatinine were included.

CONCLUSIONS

Proteinuria and hematuria values on dipstick urinalysis can be utilized to predict AKI and RRT in hospitalized patients with COVID-19. We derived formulas using these two readily available values to help prognosticate kidney outcomes in these patients. Furthermore, the incorporation of CKD or baseline creatinine increases the accuracy of these formulas.

Clinical profile and outcomes of COVID-19 patients with acute kidney injury: a tertiary centre experience from South India

AIM

The rates of development of acute kidney injury (AKI) in COVID-19 have been variably reported from across the world. Prevalence and outcomes of AKI in hospitalised COVID-19 patients in India has not been studied well.

METHODS

This was a retrospective observational study amongst adult hospitalised COVID-19 patients admitted at a tertiary care centre between May 1 and October 31, 2020. We estimated the prevalence of AKI and outcomes including mortality and acute kidney disease (AKD) at the time of discharge. Regression analysis was done to study the factors associated with mortality and AKD.

RESULTS

Out of 2650 hospitalised patients with COVID-19, 190 (7.2%) patients developed AKI. Mean age of patients with AKI was 62.6 years, 81.6% were male. Comorbidities included diabetes mellitus in 72.1%, hypertension in 66.8%, heart disease in 30% and chronic kidney disease (CKD) in 22.6%. Most patients had stage 1 AKI (71.1%). Overall mortality in patients with AKI was 22.1%, 75% in those requiring dialysis and 74.5% in those requiring ICU. Amongst survivors without pre-existing CKD, 40.9% patients had acute kidney disease at the time of discharge. Higher age, stage 3 AKI and need for mechanical ventilation were associated with higher mortality. On multivariable regression, factors associated with AKD at discharge included pre-existing heart disease and severe albuminuria during hospitalisation.

CONCLUSION

In our study population, we found a low prevalence of AKI. Mortality was high in AKI patients requiring ICU care and dialysis. Amongst survivors, a significant percentage had AKD at the time of discharge.

Correlation of AKI with risk factors, ventilatory support, renal replacement therapy in a cohort of COVID-19 patients

Introduction:

There is a scarcity of information on the incidence and outcomes of acute kidney injury (AKI) in COVID-19 patients in India. Therefore, we analyzed the correlation of AKI risk factors, ventilatory support, and renal replacement therapy and compared the outcomes of first and second COVID-19 waves in this tertiary care center.

Methods:

We retrospectively analyzed the patients' medical records with a positive RT-PCR for COVID-19 between July 2020 and May 2021. We looked at the clinical outcomes of the first and second COVID-19 waves and documented the frequency, risk factors for AKI, and the relationship between AKI and in-hospital mortality. Univariate and multivariate binomial logistic regression yielded odds ratios for the risk variables of AKI. Risk differences and age-adjusted odds ratios, as well as 99.5% confidence intervals, were used to compare COVID-19 outcomes between the first and second waves.

Results:

Of the 1260 hospitalized patients with COVID-19, 86 (6.8%) presented with AKI and 8 (0.7%) patients required dialysis. The most common comorbidity was diabetes mellitus (55.2%), hypertension (42.1%), hypothyroidism (11.3%), and coronary artery disease (8.1%). A total of 229 (18.17%) patients were admitted to ICU, 574 (45.5%) received ventilation, and 26 (2.0%) required mechanical ventilation.The incidence of in-hospital death in the patients with AKI as per the stage from 1 to 3 was 9 (15.8%), 7 (35%), and 5 (55.6%), respectively.Compared to the first wave, the second wave cohort had a lower risk of AKI (adj OR: 0.426; CI: 0.232–0.782) and mortality (adj OR: 0.252; CI: 0.090–0.707).

Conclusions:

In our study, AKI prevalence was 6.8%, the need for ventilation was 45.5%, ECMO 0.2%, and the mortality rate 2.9%. Second wave of COVID-19 exhibits improved clinical outcomes compared to the first wave.

Association of AKI-D with Urinary Findings and Baseline eGFR in Hospitalized COVID-19 Patients

Background

AKI is common in patients hospitalized with coronavirus disease 2019 (COVID-19). Risk factors for AKI requiring dialysis (AKI-D) are not fully understood. We aimed to identify risk factors associated with AKI-D and AKI not requiring dialysis (AKI-ND).

Methods

We reviewed electronic health records of 3186 patients aged ≥18 years old who were hospitalized with COVID-19 across six hospitals. Patient characteristics, urinalysis findings, and inflammatory markers were analyzed for association with in-hospital AKI status (AKI-D, AKI-ND, or no AKI), and we subsequently evaluated mortality.

Results

After adjustment for multiple covariates, higher baseline eGFR was associated with 30% lower odds of AKI-D and 11% lower odds of AKI-ND (for AKI-D, OR, 0.70; 95% CI, 0.64 to 0.77; for AKI-ND, OR, 0.89; 95% CI, 0.85 to 0.92). Patients with obesity and those who were Latino had increased odds of AKI-D, whereas patients with congestive heart failure or diabetes with complications had increased odds of AKI-ND. Females had lower odds of in-hospital AKI (for AKI-D, OR, 0.28; 95% CI, 0.17 to 0.46; for AKI-ND, OR, 0.83; 95% CI, 0.70 to 0.99). After adjustment for covariates and baseline eGFR, 1-4+ protein on initial urinalysis was associated with a nine-fold increase in odds of AKI-D (OR, 9.00; 95% CI, 2.16 to 37.38) and more than two-fold higher odds of AKI-ND (OR, 2.28; 95% CI, 1.66 to 3.13). Findings of 1-3+ blood and trace glucose on initial urinalysis were also associated with increased odds of both AKI-D and AKI-ND. AKI-D and AKI-ND were associated with in-hospital death (for AKI-D, OR, 2.64; 95% CI, 1.13 to 6.17; for AKI-ND, OR, 2.44; 95% CI, 1.77 to 3.35).

Conclusions

Active urine sediments, even after adjustment for baseline kidney function, and reduced baseline eGFR are significantly associated with increased odds of AKI-D and AKI-ND. In-hospital AKI was associated with in-hospital death. These findings may help prognosticate patients hospitalized with COVID-19.

Renal Thrombotic Microangiopathy in Concurrent COVID-19 Vaccination and Infection

We report on the development of nephrotic proteinuria and microhematuria, with histological features of renal thrombotic microangiopathy (TMA), following the first dose of BNT162b2 COVID-19 vaccine (Pfizer-BioNTech) and COVID-19 diagnosis. A 35-year-old previously healthy man was admitted at our hospital due to the onset of foamy urine. Previously, 40 days earlier, he had received the first injection of the vaccine, and 33 days earlier, the RT-PCR for SARS-CoV-2 tested positive. Laboratory tests showed nephrotic proteinuria (7.9 gr/day), microhematuria, serum creatinine 0.91 mg/dL. Kidney biopsy revealed ultrastructural evidence of severe endothelial cell injury suggestive of a starting phase of TMA. After high-dose steroid treatment administration, complete remission of proteinuria was achieved in a few weeks. The association of COVID-19 with renal TMA has been previously described only in patients with acute renal injury. Besides, the correlation with COVID-19 vaccine has not been reported so far. The close temporal proximity (7 days) between the two events opens the question whether the histological findings should be ascribed to COVID-19 itself or to vaccine injection.

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.