The clinical characteristics of coronavirus-associated nephropathy

Kidney damage associated with COVID-19: from the acute to the chronic phase

Severe acute respiratory syndrome coronavirus-2 (SARS-COV-2) infection is well established as a systemic disease including kidney damage. The entry point into the renal cell remains the angiotensin-converting enzyme 2 (ACE-2) receptor and the spectrum of renal lesions is broad, with a clear predominance of structural and functional tubular lesions. The most common form of glomerular injury is collapsing glomerulopathy (CG), which is strongly associated with apolipoprotein L1(APOL-1) risk variants. These acute lesions, which are secondary to the direct or indirect effects of SARS-CoV-2, can progress to chronicity and are specific to long COVID-19 in the absence of any other cause. Residual inflammation associated with SARS-CoV-2 infection, in addition to acute kidney injury (AKI) as a transitional state with or without severe histological lesions, may be responsible for greater kidney function decline in mild-to-moderate COVID-19. This review discusses the evidence for renal histological markers of chronicity in COVID-19 patients and triggers of low-grade inflammation that may explain the decline in kidney function in the post-COVID-19 period.

The relation between proteinuria and the severity of COVID-19

BACKGROUND

The association between proteinuria, which is also an indicator of chronic kidney disease (CKD), and coronavirus disease 2019 (COVID-19) severity is unclear.

METHODS

We selected 342 hospitalized patients with COVID-19 diagnosed via polymerase chain reaction testing between February 2020 and October 2022 and who had at least one urinalysis 14-365 days before admission.

RESULTS

Proteinuria before admission was associated neither with oxygen administration nor developing pneumonia in multivariate analysis (odds ratio [OR] 1.03; 95% confidence interval (CI) 0.44-2.40, p = 0.95 and OR 1.01; 95% CI 0.47-2.17, p = 0.98, respectively). Proteinuria on admission was associated both with oxygen administration and developing pneumonia in multivariate analysis (OR 3.29; 95% CI 1.37-7.88, p < 0.01 and OR 3.81; 95% CI 1.68-8.62, p < 0.01, respectively). The percentage of patients with proteinuria on admission was significantly higher than those before admission (37.4% vs. 17.8%; p < 0.01). In the subgroup analysis, proteinuria on admission among patients with eGFR ≥ 60 mL/min/1.73 m2 was associated with both oxygen administration and developing pneumonia (OR 4.86; 95% CI 1.22-19.38, p = 0.03, OR 3.65; 95% CI 1.06-12.58, p = 0.04, respectively). In contrast, proteinuria on admission among patients with eGFR < 60 mL/min/1.73 m2 was associated with developing pneumonia (OR 6.45; 95%CI 1.78-23.35, p = 0.01), not with oxygen administration (OR 3.28; 95% CI 0.92-11.72, p = 0.07).

CONCLUSIONS

Although underlying proteinuria before admission was not associated with COVID-19 severity, proteinuria on admission was associated with oxygen demand and developing pneumonia.

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

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

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

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

Renal tubular dysfunction in COVID-19 patients

Introduction

SARS-CoV-2 infection can affect other organs aside from those of respiratory system, particularly the kidney, heart, blood, digestive tract, and nervous system. COVID-19 renal compromise consists of different syndromes since proteinuria, hematuria, and acute kidney injury (AKI), until chronic kidney disease. Since COVID-19-induced renal tubular damage has been described as a potential antecedent condition to AKI installation, it was decided to evaluate how COVID-19 affects tubular function.

Materials and method

Serum inflammatory parameters, urinalysis, and classical urinary indexes in COVID-19 admitted patients who had neither AKI nor chronic kidney disease (CKD) were evaluated. Statistical analysis was performed by applying Student t test.

Results

Renal tubular function was evaluated in 41 COVID-19 admitted patients who had neither AKI nor CKD. Patients’ mean age was 56 years, males (79%), and with normal creatininemia (0.8 ± 0.2 mg/dL) and eGFR (105.7 ± 6.5 mL/min) values. It was found mild hypocalcemia and a relative increased fractional excretion (FE) of sodium, FE of calcium, FE of phosphorus, calcium-creatinine index, urinary osmolarity, and relative alkaline urine pH values.

Conclusion

Tubular dysfunction was documented in COVID-19 patients.

Differences between COVID-19-induced acute kidney injury and chronic kidney disease patients

Introduction:

This article describes the main differences between COVID-19-induced acute kidney injury (AKI-COVID19) in patients with previous normal renal function (AKI-NRF) and those with chronic kidney disease (AKI-CKD) treated in a high complexity clinic in Barranquilla (Colombia).

Material and Methods:

The patients included in this study (n: 572) were those with a positive diagnosis of COVID-19 confirmed by detection of a positive PCR for SARS-CoV-2. Of these patients, 188 developed AKI during their hospital stay. Patients’ epidemiological data, serum parameters, and clinical frailty status were recorded. Statistical analysis and comparison among AKI-NRF, AKI-CKD, and non-AKI patients were performed.

Results:

The incidence of COVID-19-induced AKI was 33%, with the majority classified as AKIN 1, 16% requiring renal replacement therapy, and AKI-COVID19 mortality of 68%. A significantly higher prevalence of hypertension, cardiac disease, and serum reactive C-protein and lower albumin values in AKI-CKD patients was recorded. Mortality rate, invasive ventilation requirement, and D-dimer levels were significantly higher in AKI-NRF patients:

Conclusion:

Different clinical patterns between AKI-NRF and AKI-CKD were documented.

COVAN Leading to ESKD Despite Minimal COVID Symptoms

We report a case of dialysis dependence in a patient with COVID-19-associated nephropathy (COVAN) who had minimal respiratory manifestations. A 25-year-old man with a history of multiple sclerosis in remission presented with mild dyspnea due to COVID-19 pneumonia and was found to have rapidly worsening kidney function. He only required nasal cannula and was able to be weaned off within a few days. Despite having only mild respiratory disease, his kidney function worsened and urgent hemodialysis was started for hyperkalemia and uremic encephalopathy. Kidney biopsy demonstrated collapsing glomerulopathy due to COVID-19 with moderate interstitial fibrosis and tubular atrophy. His kidney function did not recover, and he unfortunately now has been dependent on hemodialysis for over 3 months. Multiple case reports have described COVAN causing dialysis dependence, but to our knowledge this is the first reported case of COVAN causing dialysis dependence in a patient with such mild respiratory disease. Currently the indications for intensive COVID-19 therapies are based on oxygen requirements. This case demonstrates that the oxygen requirement may not fully reflect the severity of COVID-19 and raises the question of whether these therapies should be considered in patients with COVAN.

Use of medicines for covid-19 treatment in patients with loss of kidney function: a narrative review

Covid-19 has been identified as the cause of acute respiratory disease with interstitial and alveolar pneumonia, but it can affect several organs, such as kidneys, heart, blood, nervous system and digestive tract. The disease-causing agent (Sars-CoV-2) has a binding structure to the angiotensin-converting enzyme 2 (ACE2) receptor, enabling entry into cells that express ACE2, such as the pulmonary alveolar epithelial cells. However, studies also indicate the possibility of damage to renal cells, since these cells express high levels of ACE2. Currently, there is no evidence to indicate a specific treatment for covid-19. Several drugs have been used, and some of them may have their excretion process altered in patients with abnormal kidney function. To date, there are no studies that assist health professionals in adjusting the dose of these drugs. Thus, this study aims to review and discuss the topic, taking into account factors associated with kidney injury in covid-19, as well as pharmacokinetic aspects and dose recommendations of the main drugs used for covid-19.