Pathophysiology and Pathology of Acute Kidney Injury in Patients With COVID-19

A scoping review on adult patients with de novo glomerular diseases following COVID-19 infection or vaccine

BACKGROUND

There are increasing reports of glomerular disease (GD) following COVID-19 infection and vaccination. Current evidence on the possible link between COVID-19 infection or vaccination and GD is conflicting.

OBJECTIVE

The present study undertakes a scoping review of research to describe the relationship between COVID-19 infection and vaccination with GD and the common management strategies and overall outcomes of the disease to identify knowledge gaps and guide further research.

ELIGIBILITY CRITERIA

All original research studies published in English until 5th September 2022 were considered for inclusion in the review. Exclusion criteria were animal studies, autopsy studies, and data involving patients who were paediatric patients (< 16 years), were transplant recipients, had a recurrence of glomerular disease, had concomitant cancer or non-COVID-19 infection which may cause glomerular disease, or did not receive a renal biopsy.

SOURCES OF EVIDENCE

The five electronic databases searched were MEDLINE, PubMed, Scopus, EMBASE, and Cochrane.

METHODS

Two separate search strings related to COVID-19, and glomerular disease were combined using the Boolean operator 'AND'. Filters were used to limit publications to original research studies published in English. Search results from each database were imported into Covidence software ( www.covidence.org ) and used for de-duplication, article screening, and data extraction. Descriptive analyses were used to summarise demographics, diagnoses, and treatment outcomes.

RESULTS

After removing duplicates, 6853 titles and abstracts were screened. Of the 188 studies included, 106 studies described 341 patients with GD following COVID-19 infection and 82 described 146 patients with GD following a COVID-19 vaccination. IgA nephropathy was the most common GD pathology reported following COVID-19 vaccination with GD most common following mRNA vaccines. Collapsing focal segmental glomerulosclerosis was the most common GD following COVID-19 infection. Immunosuppressive treatment of GD was more common in the vaccine cohort than in the infection cohort.

CONCLUSION

Despite the significant number of COVID-19 infections and vaccinations around the world, our understanding of GD associated with COVID-19 infection and vaccination remains poor, and more research is needed to understand the possible relationship better.

A Case of Autoimmune Hemolytic Anemia Following COVID-19 Infection Accompanied by Acute Tubulointerstitial Nephritis in a Kidney Transplant Recipient

BACKGROUND

Acute tubular injury is one of the main causes of acute tubular injury (acute kidney injury ) in patients with COVID-19 infection. Autoimmune hemolytic anemia (AIHA) is also one of the autoimmune complications of COVID-19. However, AIHA accompanied by acute tubulointerstitial nephritis (ATIN) caused by SARS-CoV-2 is rarely reported. Here, we report a kidney transplant recipient who underwent graftectomy owing to ATIN accompanied by AIHA, possibly exacerbated by COVID-19 infection.

CASE PRESENTATION

A 32-year-old male renal allograft recipient owing to immunoglobulin A nephropathy visited the emergency department owing to dyspnea and general weakness. Three weeks earlier, the patient had been transplanted with deceased-donor kidney with full HLA-A, -B, -DR match, and had been on tacrolimus, prednisolone, and mycophenolate since then. At the time of the visit, laboratory findings revealed hemoglobin of 2.4 g/dL, reticulocyte of 21.7%, total bilirubin of 1.9 mg/dL, direct bilirubin of 0.3 mg/dL, lactate dehydrogenase of 946 U/L, haptoglobin of <10 mg/dL, and severe red cell agglutination on peripheral blood smear, which suggested AIHA. In addition, his SARS-CoV-2 real-time polymerase chain reaction test was positive. During steroid treatment for AIHA, a sudden decrease in urine volume, estimated glomerular filtration rate (from 64.9 to 35.1 mL/min/1.73 m2) and increase of creatinine (from 1.42 to 2.36 mg/dL) indicated renal function deterioration, so steroid was increased to 500 mg. On the third day of renal function deterioration, dialysis was started owing to anuria and fluid retention. On renal biopsy, C4d was absent; however, ATIN with eosinophilic infiltration was observed. On renal ultrasound examination, a severely enlarged kidney with edema was observed. At the same time, the patient had a high fever with increased C-reactive protein and procalcitonin. Graftectomy was performed to prevent secondary infection. The postgraftectomy renal biopsy showed renal parenchymal and hilar inflammatory change, endotheliitis, and lymphocytic infiltration of peripheral nerve fibers. After graftectomy, dialysis was maintained and AIHA had ameliorated.

CONCLUSION

The patient had to have his allografted kidney removed owing to ATIN possibly caused by COVID-19 infection. Acute kidney injury caused by SARS-CoV-2 can be either by direct viral infection or as consequence of immunological response. The exact immunological mechanism of AIHA secondary to COVID-19 infection remains to be elucidated.

Understanding rhabdomyolysis induced acute kidney injury in patients with COVID-19

This work comments on an article published in the recent issue of the World Journal of Virology. Rhabdomyolysis is a complex condition with symptoms such as myalgia, changes to urination, and weakness. With the potential for substantial kidney impairment, it has also been shown to be a severe complication of coronavirus disease 2019 (COVID-19). To date, various theoretical explanations exist for the development of rhabdomyolysis induced acute kidney injury (RIAKI) in COVID-19 infection, including the accumulation of released striated muscle myoglobin in the urine (myoglobinuria). In their article, they (2024) demonstrate in a retrospective study that RIAKI in COVID-19 patients tended to have elevated levels of C-reactive protein, ferritin, and procalcitonin. These patients also had poorer overall prognoses when compared to COVID-19 patients who have acute kidney injury (AKI) due to other causes. It is clear from these findings that clinicians must closely monitor and assess for the presence of rhabdomyolysis in COVID-19 patients who have developed AKIs. Moreover, additional research is required to further understand the mechanisms behind the development of RIAKI in COVID-19 patients in order to better inform treatment guidelines and protocols.

Retrospective evaluation of acute kidney injury in paediatric COVID-19 patients: a tertiary referral hospital experience

BACKGROUND

Coronavirus disease 2019 (COVID-19) has been recognised as a risk factor for acute kidney injury (AKI). Our aim was to investigate the risk factors contributing to hospitalised and outpatient paediatric COVID-19-associated AKI.

METHODS

A retrospective observational study was conducted on patients aged 1 month to 18 years with diagnosed COVID-19-associated AKI applied to a tertiary paediatric referral hospital between March 1, 2020 and March 1, 2022.

RESULTS

A total of 6683 patients were evaluated and 486 patients were included in the study. Acute kidney injury was observed in 3.7% of outpatients and 23.9% of hospitalised patients. Multivariate logistic regression analysis showed that, on admission, a history of contact with a COVID-19 positive person (p < 0.001), age below 12 months (p = 0.004), presence of comorbidities (p < 0.001), abdominal pain (p = 0.008), anorexia (p = 0.003), dyspnoea (p = 0.005), higher lactate dehydrogenase values (p = 0.004), neutrophilia (p < 0.001), higher neutrophil-to-lymphocyte ratio (NLR) (p = 0.003), higher white blood cell counts (p = 0.006), elevated C-reactive protein (CRP) levels (p = 0.002), anaemia (p = 0.015), hypoalbuminaemia (p < 0.001), hyperglycaemia (p = 0.006), and presence of proteinuria (p = 0.003) were independent predictors of AKI. Higher rates of hospitalisation (p < 0.001) and admission to the paediatric intensive care unit (PICU) (p < 0.001), longer length of hospitalisation (p < 0.001), and greater need for mechanical ventilation (p < 0.001) were associated with AKI.

CONCLUSIONS

This study reveals that not only hospitalised children, but also paediatric patients are at risk for AKI. The presence of comorbidities, abdominal pain, anorexia, dyspnoea, anaemia, inflammation, hypoalbuminaemia, proteinuria and history of contact with a COVID-19 positive person were the main risk factors for AKI. COVID-19-associated AKI was associated with worse outcomes.

Neutrophil-platelet ratio as a predictor of acute kidney injury in severe COVID-19

Acute kidney injury (AKI) is one of the most seen complications of coronavirus-2019 (COVID-19) infection. Patients with AKI caused by COVID-19 likely have higher neutrophil counts and lower platelet and lymphocyte levels. Therefore, the predictive value of many inflammation indexes calculated from the total blood count has been investigated to predict the AKI in COVID-19. According to our clinical experience, we thought that neutrophilia and thrombocytopenia may be more common in the development of AKI. For this reason, this study aimed to evaluate the predictive value of the neutrophil-to-platelet ratio (NPR) for AKI in severe COVID-19 patients. This retrospective study included 334 severe COVID-19 patients followed up in the intensive care unit (ICU). Predictive factors for AKI were analyzed. ROC curve analysis was performed to determine the inflammation indexes' cutoff values for the AKI prediction. Multivariate analyses were performed to determine correlations between the inflammation indexes and AKI. In this study, AKI was determined at the rate of 43% (n:145). Independent risk factors affecting AKI were determined to be age (HR = 1.047, 95% confidence interval [CI]: 1.021-1.072, P < .001), the need for invasive mechanical ventilation (HR = 3.003, 95% CI: 1.645-5.481, P = .001) and the need for vasopressor (HR = 8.111, 95% CI: 3.786-17.375, P < .001). The optimal cutoff values predicting AKI were determined to be 3.9 for the NPR (AUC = 0.679, 95% CI: 0.622-0.737, P < .001) with 71.7% sensitivity and 61.9% specificity, 16.1 for the neutrophil-to-lymphocyte ratio (NLR) (AUC = 0.634, 95% CI: 0.575-0.694, P < .001) with 65.5% sensitivity and 56.1% specificity, and 3872.5 × 109L for the systemic inflammatory index (SII) (AUC = 0.566, 95% CI: 0.504-0.629, P = .038) with 60% sensitivity and 55.6% specificity. In the regression model, only NPR values above the cutoff were related to AKI (HR = 3.817, 95% CI: 1.782-8.177, P = .001). The NPR has more predictive value than the NLPR, NLR, and SII in developing AKI in severe COVID-19 patients in the ICU. NPR is a new helpful index that can help clinicians predict early AKI in critical COVID-19.

Mortality and morbidity associated with new onset acute kidney injury in critically ill COVID-19 infection patients

BACKGROUND

The recent global pandemic due to severe acute respiratory syndrome coronavirus-2 resulted in a high rate of multi-organ failure and mortality in a large patient population across the world. As such, a possible correlation between acute kidney injury (AKI) and increased mortality rate in these patients has been suggested in literature.

METHODS

This is a two-year retrospective study of critically ill adult patients infected with COVID-19 that were admitted to the intensive care unit (ICU) on ventilatory support. Two groups of patients were identified in this study, those who were directly admitted to the ICU or those who were initially admitted to the Medical Floor and were later transferred to the ICU due to either worsening respiratory status or change in their hemodynamic conditions. Within each group, three subgroups were created based on the status of AKI, namely, those who did not develop AKI, those who developed AKI, and those who with previous history of dialysis dependent AKI.

RESULTS

The AKI subgroup had the highest mortality rate in the ICU and Floor patients. Of note, those patients who were directly admitted to the Floor and were later transferred to the ICU for worsening conditions also experienced a higher mortality rate if they had developed AKI during their course of hospital stay.

CONCLUSIONS

This study identified a statistically significant higher mortality in patients who developed AKI than those who did not develop AKI among critically ill patients.

TRIAL REGISTRATION

Clinicaltrials.gov registration number NCT05964088. Date of registration: July 24 2023.

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

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

Acute kidney injury in children with moderate-severe COVID-19 and multisystem inflammatory syndrome in children: a referral center experience

BACKGROUND

Data on the characteristics of acute kidney injury (AKI) in pediatric COVID-19 and MIS-C are limited. We aimed to define the frequency, associated factors and early outcome of AKI in moderate, severe or critical COVID-19 and MIS-C; and to present a tertiary referral center experience from Türkiye.

METHODS

Hospitalized patients ≤ 18 years of age with confirmed COVID-19 or MIS-C at İhsan Doğramacı Children's Hospital, Hacettepe University, between March 2020-December 2021 were enrolled. The characteristics of AKI in the COVID-19 group were investigated in moderate, severe and critically ill patients; patients with mild COVID-19 were excluded.

RESULTS

The median (Q1-Q3) age in the COVID-19 (n = 66) and MIS-C (n = 111) groups was 10.7 years (3.9-15.2) and 8.7 years (4.5-12.7), respectively. The frequency of AKI was 22.7% (15/66) in COVID-19 and 15.3% (17/111) in MIS-C; all MIS-C patients with AKI and 73.3% (11/15) of COVID-19 patients with AKI had AKI at the time of admission. Multivariate analyses revealed need for vasoactive/inotropic agents [Odds ratio (OR) 19.233, p = 0.002] and presence of vomiting and/or diarrhea (OR 4.465, p = 0.036) as independent risk factors of AKI in COVID-19 patients; and need for vasoactive/inotropic agents (OR 22.542, p = 0.020), procalcitonin and ferritin levels as independent risk factors of AKI in the MIS-C group. Age was correlated with lymphocyte count (r = -0.513, p < 0.001) and troponin level (r = 0.518, p < 0.001) in MIS-C patients. Length of hospital stay was significantly longer in both groups with AKI, compared to those without AKI. Mortality was 9.1% in the COVID-19 group; and was associated with AKI (p = 0.021). There was no mortality in MIS-C patients. AKI recovery at discharge was 63.6% in COVID-19 survivors and 100% in MIS-C patients.

CONCLUSIONS

Independent risk factors for AKI were need for vasoactive/inotropic agents and vomiting/diarrhea in moderate, severe or critical COVID-19 patients; and need for vasoactive/inotropic agents and severe inflammation in MIS-C patients. Our findings suggest that inflammation and cardiac dysfunction are associated with AKI in MIS-C patients; and the association with age in this group merits further studies in larger groups. Early outcome is favorable; long-term follow-up for kidney functions is needed.

COVID-19 in the Netherlands: lessons from a nationwide query of dutch autopsy, histology, and cytology pathological reports

Since the onset of the COVID-19 pandemic, autopsies have played a valuable role in understanding the pathophysiology of COVID-19. In this study, we have analyzed COVID-19-related pathology reports from autopsies, histology, and cytology on a nationwide level. Pathology reports from all 43 pathology laboratories in the Netherlands stating "COVID," "Corona," and/or "SARS" were queried from the Dutch Nationwide Pathology Database (Palga). Consecutive reports of the included patients were also retrieved. Out of 5065 entries, a total of 1833 eligible COVID-19-related pathology reports between January 2020 and June 2021 were included in this collection of reports. Lung histopathology reports reflected differences in the severity of abnormalities (acute diffuse alveolar damage, alveolar histiocytes, and thrombi during the first three pandemic waves (Wuhan variant) versus the fourth wave (alpha variant)). Autopsy reports from 2020 state significantly shorter disease duration and younger age of death compared to autopsy reports from 2021. All reports together reflected a more granular pathology with comorbidities such as chronic histiocytic intervillositis, perniosis, and thrombi found in a variety of organs (lungs, kidneys, and small and large intestines). This nationwide overview of pathology reports provides data related to deaths as well as comorbidities in a clinical setting of COVID-19. Certain findings reported in SARS-CoV-infected lungs and placentas were also reported in post-COVID-19 tissue of the same kind. Consecutive reports after the earliest reports with COVID-19 allowed for follow-up reports. These follow-up reports can help with post-viral studies regarding long-term effects of COVID-19 as well as identifying the effects of different SARS-CoV-2 variants.

Antimicrobial peptides and other potential biomarkers of critical illness in SARS-CoV-2 patients with acute kidney injury. AMPAKI-CoV study

Antimicrobial peptides (AMPs) constitute a complex network of 10-100 amino acid sequence molecules widely distributed in nature. While over 300 AMPs have been described in mammals, cathelicidins and defensins remain the most extensively studied. Some publications have explored the role of AMPs in COVID-19, but these findings are preliminary, and in vivo studies are still lacking. In this study, we report the plasma levels of five AMPs (LL-37, α-defensin 1, α-defensin 3, β-defensin 1, and β-defensin 3), using the ELISA technique (MyBioSource, San Diego, CA, United States, kits MBS2601339 (beta-defensin 1), MBS2602513 (beta-defensin 3), MBS703879 (alpha-defensin 1), MBS706289 (alpha-defensin 3), MBS7234921 (LL37)), and the measurement of six cytokines (tumor necrosis factor-α, interleukin-1β, interleukin-6, interleukin-10, interferon-γ, and monocyte chemoattractant protein-1), through the magnetic bead immunoassay Milliplex® and the MAGPIX® System (MilliporeSigma, Darmstadt, Germany, kit HCYTOMAG-60 K (cytokines)), in 15 healthy volunteers, 36 COVID-19 patients without Acute Kidney Injury (AKI) and 17 COVID-19 patients with AKI. We found increased levels of α-defensin 1, α-defensin 3 and β-defensin 3, in our COVID-19 population, when compared to healthy controls, along with higher levels of interleukin-6, interleukin-10, interferon-γ, and monocyte chemoattractant protein-1. These findings suggest that these AMPs and cytokines may play a crucial role in the systemic inflammatory response and tissue damage characterizing severe COVID-19. The levels of α-defensin 1 and α-defensin 3 were significantly higher in COVID-19 AKI group in comparison to the non-AKI group. Furthermore, IL-10 and the product IL-10 × IL-1B showed excellent performance in discriminating AKI, with AUCs of 0.86 and 0.88, respectively. Among patients with COVID-19, AMPs may play a key role in the inflammation process and disease progression. Additionally, α-defensin 1 and α-defensin 3 may mediate the AKI process in these patients, representing an opportunity for further research and potential therapeutic alternatives in the future.

Predictors of Acute Kidney Injury (AKI) among COVID-19 Patients at the US Department of Veterans Affairs: The Important Role of COVID-19 Vaccinations

BACKGROUND

There are knowledge gaps about factors associated with acute kidney injury (AKI) among COVID-19 patients. To examine AKI predictors among COVID-19 patients, a retrospective longitudinal cohort study was conducted between January 2020 and December 2022. Logistic regression models were used to examine predictors of AKI, and survival analysis was performed to examine mortality in COVID-19 patients.

RESULTS

A total of 742,799 veterans diagnosed with COVID-19 were included and 95,573 were hospitalized within 60 days following COVID-19 diagnosis. A total of 45,754 developed AKI and 28,573 AKI patients were hospitalized. Use of vasopressors (OR = 14.73; 95% CL 13.96-15.53), history of AKI (OR = 2.22; CL 2.15-2.29), male gender (OR = 1.90; CL 1.75-2.05), Black race (OR = 1.62; CL 1.57-1.65), and age 65+ (OR = 1.57; CL 1.50-1.63) were associated with AKI. Patients who were vaccinated twice and boosted were least likely to develop AKI (OR = 0.51; CL 0.49-0.53) compared to unvaccinated COVID-19 patients. Patients receiving two doses (OR = 0.77; CL = 0.72-0.81), or a single dose (OR = 0.88; CL = 0.81-0.95) were also less likely to develop AKI compared to the unvaccinated. AKI patients exhibited four times higher mortality compared to those without AKI (HR = 4.35; CL 4.23-4.50). Vaccinated and boosted patients had the lowest mortality risk compared to the unvaccinated (HR = 0.30; CL 0.28-0.31).

CONCLUSION

Use of vasopressors, being unvaccinated, older age, male gender, and Black race were associated with post COVID-19 AKI. Whether COVID-19 vaccination, including boosters, decreases the risk of developing AKI warrants additional studies.

Uric acid promotes interleukin-17 expression to cause kidney injury

Uric acid, an oxidation end-product of purine metabolism, is reportedly to be a risk factor for kidney injury. However, its underlying mechanism is still a mystery. This study aimed to reveal the detailed roles of uric acid in inducing kidney injury and the possible mechanisms. Injection of rats with uric acid significantly increased tubular injury score, and levels of blood urea nitrogen, serum creatinine, and urine kidney injury molecule-1. Uric acid increased the expression of collagen I, alpha-smooth muscle actin, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6. Kyoto Encyclopedia of Genes and Genomes analysis result showed the IL-17 signaling pathway as the most significantly enriched pathway involved in hyperuricemia-related kidney injury. Long-term injection of uric acid induced significant production of IL-17 and recruitment of Th17 cells. Treating rats with the anti-IL-17 mAb attenuated uric acid-induced kidney injury, accompanied by the inactivation of nuclear factor-κB (NF-κB). In conclusion, uric acid was confirmed to be a risk factor for kidney injury via inducing IL-17 expression. Neutralization of IL-17 using the specific mAb relieved uric acid-induced kidney injury via inhibition of NF-κB signaling.

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.

ICU Admission Risk Factors for Latinx COVID-19 Patients at a U.S.-Mexico Border Hospital

OBJECTIVE

Few studies have examined the impact of coronavirus disease 2019 (COVID-19) on the primarily Latinx community along the U.S.-Mexico border. This study explores the socioeconomic impacts which contribute to strong predictors of severe COVID-19 complications such as intensive care unit (ICU) hospitalization in a primarily Latinx/Hispanic U.S.-Mexico border hospital.

METHODS

A retrospective, observational study of 156 patients (≥ 18 years) Latinx/Hispanic patients who were admitted for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection at a U.S.-Mexico border hospital from April 10, 2020, to May 30, 2020. Descriptive statistics of sex, age, body mass index (BMI), and comorbidities (coronary artery disease, hypertension, diabetes, cancer/lymphoma, current use of immunosuppressive drug therapy, chronic kidney disease/dialysis, or chronic respiratory disease). Multivariate regression models were produced from the most significant variables and factors for ICU admission.

RESULTS

Of the 156 hospitalized Latinx patients, 63.5% were male, 84.6% had respiratory failure, and 45% were admitted to the ICU. The average age was 67.2 (± 12.2). Those with body mass index (BMI) ≥ 25 had a higher frequency of ICU admission. Males had a 4.4 (95% CI 1.58, 12.308) odds of ICU admission (p = 0.0047). Those who developed acute kidney injury (AKI) and BMI 25-29.9 were strong predictors of ICU admission (p < 0.001 and p = 0.0020, respectively). Those with at least one reported comorbidity had 1.98 increased odds (95% CI 1.313, 2.99) of an ICU admission.

CONCLUSION

Findings show that age, AKI, and male sex were the strongest predictors of COVID-19 ICU admissions in the primarily Latinx population at the U.S.-Mexico border. These predictors are also likely driven by socioeconomic inequalities which are most apparent in border hospitals.

Incidence of acute kidney injury (AKI) and outcomes in COVID-19 patients with and without antiviral medications: A retrospective study

BACKGROUND

Acute kidney injury is a complication of COVID-19 and is associated with severity. Despite no specific antiviral treatment strategy, lopinavir/ritonavir and remdesivir have been used. Data on the association between AKI and receiving antiviral agents with outcomes in hospitalized patients with COVID-19 is scarce. We aimed to determine the incidence of AKI and its outcomes in COVID-19 patients with and without antiviral medications.

METHODS

We conducted a retrospective study on hospitalized adult patients with SARS-CoV-2 infection in a tertiary center. The primary endpoint was determining mortality, intensive care unit (ICU) admission, and length of hospitalization affected by AKI development using antiviral agents. The logistic regression method was used to explore the predictive effects of AKI and antiviral therapy on composite outcomes (i.e., mortality, ICU admission, and prolonged hospitalization) in four defined groups by AKI development/not and utilizing antivirals/not. We used IBM SPSS version 24.0 software for statistical analysis.

RESULTS

Out of 833 COVID-19 patients who were included, 75 patients were treated with antiviral agents and developed AKI. There was a significant difference in the occurrence of AKI and using antiviral medications (p = 0.001). Also, the group using antiviral agents and the development of AKI had the highest rate of preexisting hypertension (p = 0.002). Of note, the group of patients who used antiviral agents and also developed AKI had the most remarkable association with our composite outcome (p<0.0001), especially ICU admission (OR = 15.22; 95% CI: 8.06-27.32).

CONCLUSIONS

The presence of AKI among COVID-19 patients treated with antiviral agents is linked to increased severity and mortality. Therefore, it is imperative to explore preventive measures for AKI development in patients receiving antiviral therapy. Larger-scale randomized controlled trials may be warranted to provide a more comprehensive understanding of these associations.

Calcium, Phosphorus and Magnesium Abnormalities Associated with COVID-19 Infection, and Beyond

The coronavirus disease (COVID-19) pandemic caused by the novel coronavirus SARS-CoV-2 has had a profound impact on global health, leading to a surge in research to better understand the pathophysiology of the disease. Among the various aspects under investigation, disruptions in mineral homeostasis have emerged as a critical area of interest. This review aims to provide an overview of the current evidence linking calcium, phosphorus and magnesium abnormalities with COVID-19 infection and explores the potential implications beyond the acute phase of the disease. Beyond the acute phase of COVID-19, evidence suggests a potential impact of these mineral abnormalities on long-term health outcomes. Persistent alterations in calcium, phosphorus and magnesium levels have been linked to increased cardiovascular risk, skeletal complications and metabolic disorders, warranting continuous monitoring and management in post-COVID-19 patients.

Immediate cause and the role of multimorbidity in deaths associated with COVID 19 among hospitalized patients in a low resource district in Kerala India: A record-based case-control analysis

Introduction

Multimorbidity is the coexistence of two or more chronic medical conditions in a person. The study aims to investigate the immediate cause of death and risk factors of mortality including multimorbidity among patients hospitalized with SARS CoV2 infection in Kasaragod district in Kerala, India.

Methods

A record-based case-control study was done using the hospital records and follow-up surveillance system of SARS-COV 2 patients admitted in the Kasaragod district. SARS-COV 2 patients who had expired during the study period from June to December 2020 and reported as COVID-19 deaths (N = 226) were the cases, and an equal number of hospital controls were the study participants.

Results

The mean (SD) age of the cases and controls were found to be 64.6 (14.2) years and 61.5 (13.4) years, respectively. Covid pneumonia alone was reported as the cause of death in more than half (52%) of the study participants. This was followed by cardiovascular events (8.5%) and acute kidney injury (6.5%). Among individual comorbidities among people who expired, diabetes mellitus (53%) was the most common, followed by hypertension (46%) and cardiovascular diseases (23%). More than 50% were found to have multimorbidity. Logistic regression showed chronic kidney disease (CKD) (Adjusted odds ratio (AOR) = 2.18 (1.24-3.83)) and malignancy (AOR = 3.05 (1.27-7.32)) to be significantly associated with mortality as individual determinants. Hypertension-diabetes mellitus [AOR = 1.68 (1.02-2.76), P = 0.043] and hypertension-CKD [AOR = 3.49 (1.01-12.01), P = 0.48] dyads were multimorbidities significantly associated with mortality.

Conclusion

Combinations of hypertension with diabetes mellitus and CKD were found to be significant determinants for mortality in hospitalized COVID-19 patients. Uniformity in death certification is required to understand the causes and contributors to death in COVID-19.

The Prediction Score of Acute Kidney Injury in Patients with Severe COVID-19 Infection

BACKGROUND

The incidence and risk factors for acute kidney injury in COVID-19 patients vary across studies, and predicting models for AKI are limited. This study aimed to identify the risk factors for AKI in severe COVID-19 infection and develop a predictive model for AKI.

METHOD

Data were collected from patients admitted to the ICU at Thammasat University Hospital in Thailand with PCR-confirmed COVID-19 between 1 January 2021, and 30 June 2022.

RESULTS

Among the 215 severe-COVID-19-infected patients, 102 (47.4%) experienced AKI. Of these, 45 (44.1%), 29 (28.4%), and 28 (27.4%) patients were classified as AKI stage 1, 2, and 3, respectively. AKI was associated with 30-day mortality. Multivariate logistic regression analysis revealed that prior diuretic use (odds ratio [OR] 7.87, 95% confidence interval [CI] 1.98-31.3; p = 0.003), use of a mechanical ventilator (MV) (OR 5.34, 95%CI 1.76-16.18; p = 0.003), and an APACHE II score ≥ 12 (OR 1.14, 95%CI 1.05-1.24; p = 0.002) were independent risk factors for AKI. A predictive model for AKI demonstrated good performance (AUROC 0.814, 95%CI 0.757-0.870).

CONCLUSIONS

Our study identified risk factors for AKI in severe COVID-19 infection, including prior diuretic use, an APACHE II score ≥ 12, and the use of a MV. The predictive tool exhibited good performance for predicting AKI.

COVID-19 and Kidney Disease (KD): A Retrospective Investigation in a Rural Southwestern Missouri Region Patient Population

BACKGROUND

Studies have linked pre-existing kidney disease (KD) to higher rates of mortality due to coronavirus disease 2019 (COVID-19) infection. In the rural Midwest, where KD is prevalent, the impact of COVID-19 has been significant in a population that includes many patients on Medicare or Medicaid.

METHODS

A retrospective cohort study was performed assessing patients with acute kidney injury (AKI), chronic kidney disease (CKD) and end stage renal disease (ESRD), with and without COVID-19. International Classification of Diseases 10^th Revision codes were submitted by physicians into Freeman Health System's Electronic Medical Records and gathered from April 2020 to January 2021. The data were analyzed and compared to determine whether the mortality rate in patients with varying stages of KD and COVID-19 was higher than the mortality rate in patients with KD alone, excluding variables such as sex and age.

RESULTS

The 95% confidence interval (CI) of the mortality rate of patients with COVID-19 and any degree of KD, encompassing both AKI and CKD, was between 30.21% and 37.63%. This metric was significantly higher than the 95% CI of COVID-19 infection (6.70%-9.96%, p<0.0001) or KD alone (10.89%-13.01%, p<0.0001). Within those with COVID-19 and KD, the highest rate of mortality was in patients with AKI (38.13% and 49.02%). There was not sufficient statistical support in our sample to assert that COVID-19 increased mortality in ESRD patients.

CONCLUSIONS

Based on our results, patients with KD and COVID-19 are at higher risk for mortality when compared to patients with KD alone. Further studies are warranted into individual comorbidities affecting KD patient outcomes with COVID-19.

The Incidence of Acute Kidney Injury (AKI) in Critically Ill COVID-19 Patients: A Single-Center Retrospective Cohort Study at a Tertiary Level Hospital in Oman

BACKGROUND

 Acute kidney injury (AKI) is associated with adverse outcomes in critically ill patients. Coronavirus disease 2019 (COVID-19) affects the renal system frequently and leads to AKI. This study aims to determine the incidence of AKI, risk factors including hyperglycemia, and the requirement for renal dialysis.

METHODS

 A retrospectively observational study was done at Sultan Qaboos University Hospital between March 2020 and September 2021. A total of 286 adult patients with laboratory-confirmed COVID-19 infection admitted to the intensive care unit (ICU) were included in the study. The patient's medical records were reviewed. Patients' baseline demographic characteristics, APACHE score on admission, clinical data including length of stay, oxygenation parameters, ventilator days, shock, AKI (KIDIGO guideline), dialysis, medications, lab on admission as well as during the ICU stay, and the outcome (mortality) were recorded in detail. Follow-up was done till discharge from ICU.

RESULTS

 The study population included 68.5% (196/286) males. The median age was 56 years (interquartile range, IQR: 43-66.25). The incidence of AKI was 55.2% (158/286) overall. Out of those who had AKI, 27.2% (43/158), 31.6% (50/158), and 41.1% (65/158) developed AKI stages 1, 2, and 3, respectively. Univariate analysis for the development of AKI showed the following significant variables: age (p=0.005; odds ratio, OR 1.024; 95% confidence interval, CI 1.007-1.041), creatinine level on admission (p=0.012; OR 1.005; 95%CI 1.001-1.008), APACHE score on admission (p<0.001; OR 1.049; 95%CI 1.021-1.077), P/F ratio (p<0.001; OR 0.991; 95%CI 0.987-0.995), nephrotoxic agent (p<0.001; OR 8.556; 95%CI 4.733-15.467), shock (p<0.001; OR 8.690; 95%CI 5.087-14.843), days on the ventilator (p<0.001; OR 1.085; 95%CI 1.043-1.129), and length of stay in ICU (p<0.001; OR 1.082; 95%CI 1.047-1.119). The multivariate analysis confirmed only shock (p=0.004; OR 5.893; 95%CI 1.766-19.664). A total of 41.7% (66/158) of patients received dialysis. Hyperglycemia was not associated with the development of AKI. For patients with AKI, those having high APACHE score (p<0.001), shock (p=0.56; OR 2.326; 95%CI 1.036-5.223), ischemic heart disease (IHD) (p=0.002; OR 9.000; 95%CI 1.923-42.130), and hypertension (p=0.023; OR 2.145; 95%CI 11.125-4.090) were significantly associated with the requirement of dialysis. The mortality was found to be 59.1% (169/286) overall whereas it was 83.5% (132/158) for AKI versus 28.9% (37/158) for non-AKI cases.

CONCLUSIONS

 A high incidence of AKI for critically ill COVID-19 cases was found in this study. The shock was the only significant predictor for the development of AKI. AKI is associated with high mortality in these patients.

Acute Kidney Injury in Hospitalized Patients with COVID-19: Risk Factors and Serum Biomarkers

BACKGROUND

AKI is one of the COVID-19 complications with high prognostic significance. In our research, we studied the prognostic role of several biomarkers that could help us understand AKI pathogenesis in patients with COVID-19.

METHODS

We evaluated the medical data of 500 patients hospitalized with COVID-19 in Tareev Clinic from 5 October 2020 to 1 March 2022. The diagnosis of COVID-19 was confirmed with positive RNA PCR in nasopharyngeal swabs and/or typical radiological findings on CT scans. Kidney function was assessed in accordance with KDIGO criteria. In the selected 89 patients, we evaluated serum levels of angiopoetin-1, KIM-1, MAC, and neutrophil elastase 2 and their prognostic significance.

RESULTS

The incidence of AKI in our study was 38%. The main risk factors for kidney injury were male sex, cardiovascular diseases, and chronic kidney disease. High serum angiopoetin-1 levels and a decrease in blood lymphocyte count and fibrinogen level also increased the risk of AKI.

CONCLUSIONS

AKI is an independent risk factor for death in patients with COVID-19. We propose the prognostic model of AKI development, which includes the combination of serum levels of angiopoetin-1 and KIM-1 on admission. Our model can help to prevent AKI development in patients with coronavirus disease.

A Case of Acute Kidney Injury Caused by Myoglobin Cast Nephropathy With Sars-Cov-2 Infection in a Living-Donor Kidney Transplant Recipient

When COVID-19 affects patients with risk factors such as chronic kidney disease or on immunosuppressive drugs, they often rapidly become seriously ill. We describe a 50-year-old man who was affected with SARS-CoV-2 and had undergone an ABO-compatible living-donor kidney transplantation from his father 14 years ago because of end-stage renal failure due to hypertensive nephrosclerosis. He had continued on immunosuppressive drugs and completed vaccination twice (9 months ago and 6 months ago) with messenger RNA (mRNA) vaccines against SARS-CoV-2. However, he was temporarily on a mechanical ventilator due to respiratory failure and hemodialysis due to acute kidney injury (AKI). He was finally weaned from the ventilator and hemodialysis by taking steroid and antiviral drugs. Echo-guided renal biopsy revealed myoglobin cast nephropathy. We experienced 14 outpatients after living-donor kidney transplantation infected with SARS-CoV-2, but only this case developed AKI.

Sequelae of long COVID, known and unknown: A review of updated information

Over three years have passed since the COVID-19 pandemic started. The dangerousness and impact of COVID-19 should definitely not be ignored or underestimated. Other than the symptoms of acute infection, the long-term symptoms associated with SARS-CoV-2 infection, which are referred to here as "sequelae of long COVID (LC)", are also a conspicuous global public health concern. Although such sequelae were well-documented, the understanding of and insights regarding LC-related sequelae remain inadequate due to the limitations of previous studies (the follow-up, methodological flaws, heterogeneity among studies, etc.). Notably, robust evidence regarding diagnosis and treatment of certain LC sequelae remain insufficient and has been a stumbling block to better management of these patients. This awkward situation motivated us to conduct this review. Here, we comprehensively reviewed the updated information, particularly focusing on clinical issues. We attempt to provide the latest information regarding LC-related sequelae by systematically reviewing the involvement of main organ systems. We also propose paths for future exploration based on available knowledge and the authors' clinical experience. We believe that these take-home messages will be helpful to gain insights into LC and ultimately benefit clinical practice in treating LC-related sequelae.

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.

Urinary albumin-to-creatinine ratio and serum albumin are predictors of acute kidney injury in non-ventilated COVID-19 patients: a single-center prospective cohort study

PURPOSE

Acute kidney injury (AKI) is a frequent complication among COVID-19 patients in the intensive care unit, but it is less frequently investigated in general internal medicine wards. We aimed to examine the incidence, the predictors of AKI, and AKI-associated mortality in a prospective cohort of non-ventilated COVID-19 patients. We aimed to describe the natural history of AKI by describing trajectories of urinary markers of hemodynamic, glomerular, and tubular injury.

METHODS

141 COVID-19 patients were enrolled to the study. AKI was defined according to KDIGO guidelines. Urine and renal function parameters were followed twice a week. Multivariate logistic regression was used to determine the predictors of AKI and mortality. Trajectories of urinary markers were described by unadjusted linear mixed models.

RESULTS

19.7% patients developed AKI. According to multiple logistic regression, higher urinary albumin-to-creatinine ratio (OR 1.48, 95% CI 1.04-2.12/1 mg/mmol) and lower serum albumin (OR 0.86, 95% CI 0.77-0.94/1 g/L) were independent predictors of AKI. Mortality was 42.8% in the AKI and 8.8% in the group free from AKI (p < 0.0001). According to multiple logistic regression, older age, lower albumin, and AKI (OR 3.9, 95% CI 1.24-12.21) remained independent predictors of mortality. Urinary protein-to-creatinine trajectories were diverging with decreasing values in those without incident AKI.

CONCLUSION

We found high incidence of AKI and mortality among moderately severe, non-ventilated COVID-19 patients. Its development is predicted by higher albuminuria suggesting that the originally damaged renal structure may be more susceptible for virus-associated effects. No clear relationship was found with a prerenal mechanism, and the higher proteinuria during follow-up may point toward tubular damage.

A Case of Antineutrophil Cytoplasmic Antibody Vasculitis-Associated Acute Kidney Injury in a Patient With Asymptomatic COVID-19 Infection

Vasculitis, or inflammation of blood vessels, is commonly seen with severe acute respiratory syndrome Coronavirus disease 2 (SARS-CoV-2). It is usually triggered by an autoimmune response induced by the virus, infection by the virus itself and trauma to the epithelial vessels caused by the release of cytokines. We present a case of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (pauci-immune crescentic glomerulonephritis [GN]) superimposed on acute kidney injury caused by SARS-CoV-2. Our patient is a 57-year-old Hispanic female who presented with rising creatinine and active urinary sediment in the setting of an asymptomatic COVID-19 infection. A kidney biopsy was done for declining renal function, and positive myeloperoxidase antibodies revealed pauci-immune focal crescentic glomerulonephritis. Normalization of renal function was not achieved with pulse steroids and rituximab. The patient required long-term hemodialysis. Our case here adds to the very few cases of pauci-immune crescentic glomerulonephritis reported in patients with asymptomatic SARS-CoV-2 infection. We recommend keeping this high on the differential in SARS-CoV-2-infected patients presenting with acute kidney injury.

COVID-19 and Acute Kidney Injury - Direct and Indirect Pathophysiological Mechanisms Underlying Lesion Development

COVID-19 is a pandemic disease caused by the SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) responsible for millions of deaths worldwide. Although the respiratory system is the main target of COVID-19, the disease can affect other organs, including the kidneys. Acute Kidney Injury (AKI), commonly seen in patients infected with COVID-19, has a multifactorial cause. Several studies associate this injury with the direct involvement of the virus in renal cells and the indirect damage stimulated by the infection. The direct cytopathic effects of SARS-CoV-2 are due to the entry and replication of the virus in renal cells, changing several regulatory pathways, especially the renin-angiotensin-aldosterone system (RAAS), with repercussions on the kallikrein-kinin system (KKS). Furthermore, the virus can deregulate the immune system, leading to an exaggerated response of inflammatory cells, characterizing the state of hypercytokinemia. The such exaggerated inflammatory response is commonly associated with hemodynamic changes, reduced renal perfusion, tissue hypoxia, generation of reactive oxygen species (ROS), endothelial damage, and coagulopathies, which can result in severe damage to the renal parenchyma. Thereby, understanding the molecular mechanisms and pathophysiology of kidney injuries induced by SARS-COV-2 is of fundamental importance to obtaining new therapeutic insights for the prevention and management of AKI.

Hypophosphatemia in Coronavirus Disease 2019 (COVID-19), Complications, and Considerations: A Systematic Review

Coronavirus disease 2019 (COVID-19) has various manifestations on different body organs, including the lungs, heart, kidneys, and central nervous system. However, the frequency of electrolyte abnormalities, especially hypophosphatemia, is still debated in this pandemic. Our main aim in this review is to evaluate the frequency and complications of hypophosphatemia in COVID-19-infected individuals. A systematic literature review was performed in Web of Science, Scopus, PubMed, EMBASE, and Cochrane electronic databases with the combination of different keywords till October 2021. We recruited all relevant published records (including cross-sectional and case-control studies as well as editorials and brief reports) assessing hypophosphatemia among patients with COVID-19 infection. After assessing all 928 recruited records and discarding duplicates, 4 records met the inclusion criteria. Three articles were further included during a manual search of the literature. Overall, the included studies reported 1757 subjects (males: 51.3%), with the mean age ranging from 37.2 ± 13.6 years to 65.9 ± 13.9 years. Hypophosphatemia prevalence has been reported from 7.6% to 19.5%. Patients with the severe status of COVID-19 had a higher prevalence of low serum phosphate levels than those with moderate infection. This review indicates that hypophosphatemia might be categorized as a complication in clinical settings during the COVID-19 pandemic, requiring a high clinical suspicion to implement appropriate diagnostic and therapeutic interventions to prevent life-threatening outcomes. However, it needs to be more elucidated by further studies whether hypophosphatemia in severe COVID-19 is directly related to COVID-19 or is just a complication of severe illness.

Have we missed AINything? Acute interstitial nephritis in SARS-CoV-2 infection and vaccination

Acute interstitial nephritis (AIN), defined by the presence of interstitial inflammation accompanied by tubulitis, is an often overlooked cause of acute kidney injury (AKI). It is now well established that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can cause a wide variety of kidney injuries, most commonly acute tubular injury and collapsing glomerulopathy. In comparison, AIN is rarely documented in association with SARS-CoV-2 both anecdotally and in larger series of autopsy or biopsy studies. In this issue of the Journal, León-Román describe five cases of AIN in patients with a history of coronavirus disease 2019 (COVID-19) and highlight AIN as a possibly under-reported or ignored facet of renal disease associated with SARS-CoV-2. They describe three scenarios in which AIN can be seen: (i) SARS-CoV-2 infection after diagnosis of AIN, (ii) AIN followed by SARS-CoV-2 infection in the same admission and (iii) Severe SARS-CoV-2 and AIN possibly associated with SARS-CoV-2 itself. Overall, AIN remains rare in SARS-CoV-2 and causality is difficult to ascertain. Interestingly, AIN is not only seen in association with the disease itself but also with SARS-CoV-2 vaccination. This scenario is equally rare and causality is no less difficult to prove. A history of preceding SARS-CoV-2 infection and vaccination should be actively sought when patients present with otherwise unexplained AIN.

COVID-19 infection and renal injury: where is the place for acute interstitial nephritis disease?

Novel coronavirus disease infection (coronavirus disease 2019, COVID-19) was declared a global pandemic in March 2020 and since then has become a major public health problem. The prevalence of COVID-19 infection and acute kidney injury (AKI) is variable depending on several factors such as race/ethnicity and severity of illness. The pathophysiology of renal involvement in COVID-19 infection is not entirely clear, but it could be in part explained by the viral tropism in the kidney parenchyma. AKI in COVID-19 infection can be either by direct invasion of the virus or as a consequence of immunologic response. Diverse studies have focused on the effect of COVID-19 on glomerulonephritis (GN) patients or the 'novo' GN; however, the effect of COVID-19 in acute tubulointerstitial nephritis (ATIN) has been scarcely studied. In this article, we present five cases with different spectrums of COVID-19 infection and ATIN that may suggest that recent diagnosis of ATIN is accompanied by a worse clinical prognosis in comparison with long-term diagnosed ATIN.

Early reduction of estimated Glomerular Filtration Rate (eGFR) predicts poor outcome in acutely ill hospitalized COVID-19 patients firstly admitted to medical regular wards (eGFR-COV19 study)

Background

Methods

Results

Conclusions

The Clinical Significance of Urinary Retinol-Binding Protein 4: A Review

Effective biomarkers for early diagnosis, prognostication, and monitoring in renal diseases (in general) comprise an unmet need. Urinary retinol-binding protein 4, which is the most sensitive indicator of renal tubular damage, holds great promise as a universal biomarker for renal pathologies, in which tubular injury is the driving force. Here, we summarize the most important existing data on the associations between urinary retinol-binding protein 4 and renal diseases and highlight the untapped potential of retinol-binding protein 4 in clinical use.

Clinical and Virological Features of Patients Hospitalized with Different Types of COVID-19 Vaccination in Mexico City

Coronavirus disease 2019 (COVID-19) vaccines effectively protect against severe disease and death. However, the impact of the vaccine used, viral variants, and host factors on disease severity remain poorly understood. This work aimed to compare COVID-19 clinical presentations and outcomes in vaccinated and unvaccinated patients in Mexico City. From March to September 2021, clinical, demographic characteristics, and viral variants were obtained from 1014 individuals with a documented SARS-CoV-2 infection. We compared unvaccinated, partially vaccinated, and fully vaccinated patients, stratifying by age groups. We also fitted multivariate statistical models to evaluate the impact of vaccination status, SARS-CoV-2 lineages, vaccine types, and clinical parameters. Most hospitalized patients were unvaccinated. In patients over 61 years old, mortality was significantly higher in unvaccinated compared to fully vaccinated individuals. In patients aged 31 to 60 years, vaccinated patients were more likely to be outpatients (46%) than unvaccinated individuals (6.1%). We found immune disease and age above 61 years old to be risk factors, while full vaccination was found to be the most protective factor against in-hospital death. This study suggests that vaccination is essential to reduce mortality in a comorbid population such as that of Mexico.

Rhabdomyolysis-Induced AKI (RIAKI) Including the Role of COVID-19

Rhabdomyolysis is a compound disease that may be induced by many factors, both congenital and acquired. Statin therapy is considered one of the most common acquired factors. However, recent scientific reports suggest that serious complications such as rhabdomyolysis are rarely observed. Researchers suggest that, in many cases, side effects that occur with statin therapy, including muscle pain, can be avoided with lower-dose statin therapy or in combination therapy with other drugs. One of the most recent agents discovered to contribute to rhabdomyolysis is COVID-19 disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Rhabdomyolysis is defined as a damage to striated muscle cells with escape of intracellular substances into the bloodstream. These substances, including myoglobin, creatine kinase (CK), potassium, and uridine acid, are markers of muscle damage and early complications of rhabdomyolysis. Symptoms may be helpful in establishing the diagnosis. However, in almost 50% of patients, they do not occur. Therefore, the diagnosis is confirmed by serum CK levels five times higher than the upper limit of normal. One of the late complications of this condition is acute kidney injury (AKI), which is immediately life-threatening and has a high mortality rate among patients. Therefore, the prompt detection and treatment of rhabdomyolysis is important. Markers of muscle damage, such as CK, lactate dehydrogenase (LDH), myoglobin, troponins, and aspartate aminotransferase (AST), are important in diagnosis. Treatment of rhabdomyolysis is mainly based on early, aggressive fluid resuscitation. However, therapeutic interventions, such as urinary alkalinization with sodium bicarbonate or the administration of mannitol or furosemide, have not proven to be beneficial. In some patients who develop AKI in the course of rhabdomyolysis, renal replacement therapy (RRT) is required.

Issues related to post-COVID-19 syndrome

The pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in 2019-2022 leads to a multisystem illness that results in damage to numerous organ systems. In this review, our goal was to assess current research on long-term respiratory, cardiac, neurological, digestive, rheumatological, urogenital, and dermatological system complications of coronavirus disease 2019 (COVID-19). Bibliographic searches were conducted in December 2021 using PubMed and Google Scholar, retrospectively, covering all COVID-19 literature to determine the consequences of the disease. This review may help to determine the prospects for new studies and predict the upcoming aspects requiring assessment in post-COVID-19 syndrome.

Alterations in the molecular composition of COVID-19 patient urine, detected using Raman spectroscopic/computational analysis

We developed and tested a method to detect COVID-19 disease, using urine specimens. The technology is based on Raman spectroscopy and computational analysis. It does not detect SARS-CoV-2 virus or viral components, but rather a urine ‘molecular fingerprint’, representing systemic metabolic, inflammatory, and immunologic reactions to infection. We analyzed voided urine specimens from 46 symptomatic COVID-19 patients with positive real time-polymerase chain reaction (RT-PCR) tests for infection or household contact with test-positive patients. We compared their urine Raman spectra with urine Raman spectra from healthy individuals (n = 185), peritoneal dialysis patients (n = 20), and patients with active bladder cancer (n = 17), collected between 2016–2018 (i.e., pre-COVID-19). We also compared all urine Raman spectra with urine specimens collected from healthy, fully vaccinated volunteers (n = 19) from July to September 2021. Disease severity (primarily respiratory) ranged among mild (n = 25), moderate (n = 14), and severe (n = 7). Seventy percent of patients sought evaluation within 14 days of onset. One severely affected patient was hospitalized, the remainder being managed with home/ambulatory care. Twenty patients had clinical pathology profiling. Seven of 20 patients had mildly elevated serum creatinine values (>0.9 mg/dl; range 0.9–1.34 mg/dl) and 6/7 of these patients also had estimated glomerular filtration rates (eGFR) <90 mL/min/1.73m² (range 59–84 mL/min/1.73m²). We could not determine if any of these patients had antecedent clinical pathology abnormalities. Our technology (Raman Chemometric Urinalysis—Rametrix^®) had an overall prediction accuracy of 97.6% for detecting complex, multimolecular fingerprints in urine associated with COVID-19 disease. The sensitivity of this model for detecting COVID-19 was 90.9%. The specificity was 98.8%, the positive predictive value was 93.0%, and the negative predictive value was 98.4%. In assessing severity, the method showed to be accurate in identifying symptoms as mild, moderate, or severe (random chance = 33%) based on the urine multimolecular fingerprint. Finally, a fingerprint of ‘Long COVID-19’ symptoms (defined as lasting longer than 30 days) was located in urine. Our methods were able to locate the presence of this fingerprint with 70.0% sensitivity and 98.7% specificity in leave-one-out cross-validation analysis. Further validation testing will include sampling more patients, examining correlations of disease severity and/or duration, and employing metabolomic analysis (Gas Chromatography–Mass Spectrometry [GC-MS], High Performance Liquid Chromatography [HPLC]) to identify individual components contributing to COVID-19 molecular fingerprints.

Changes of Acute Kidney Injury Epidemiology during the COVID-19 Pandemic: A Retrospective Cohort Study

To evaluate the impact of the Coronavirus Disease-19 (COVID-19) pandemic on the epidemiology of acute kidney injury (AKI) in hospitalized patients, we performed a retrospective cohort study comparing data of patients hospitalized from January 2016 to December 2019 (pre-COVID-19 period) and from January to December 2020 (COVID-19 period, including both severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-negative and positive patients). AKI was classified by evaluating the kinetics of creatinine levels. A total of 51,681 patients during the pre-COVID-19 period and 10,062 during the COVID-19 period (9026 SARS-CoV-2-negative and 1036 SARS-CoV-2-positive) were analyzed. Patients admitted in the COVID-19 period were significantly older, with a higher prevalence of males. In-hospital AKI incidence was 31.7% during the COVID-19 period (30.5% in SARS-CoV-2-negative patients and 42.2% in SARS-CoV-2-positive ones) as compared to 25.9% during the pre-COVID-19 period (p < 0.0001). In the multivariate analysis, AKI development was independently associated with both SARS-CoV-2 infection and admission period. Moreover, evaluating the pre-admission estimated glomerular filtration rate (eGFR) we found that during the COVID-19 period, there was an increase in AKI stage 2−3 incidence both in patients with pre-admission eGFR < 60 mL/min/1.73 m2 and in those with eGFR ≥ 60 mL/min/1.73 m2 (“de novo” AKI). Similarly, clinical outcomes evaluated as intensive care unit admission, length of hospital stay, and mortality were significantly worse in patients admitted in the COVID-19 period. Additionally, in this case, the mortality was independently correlated with the admission during the COVID-19 period and SARS-CoV-2 infection. In conclusion, we found that during the COVID-19 pandemic, in-hospital AKI epidemiology has changed, not only for patients affected by COVID-19. These modifications underline the necessity to rethink AKI management during health emergencies.

COVID-19: a trigger for severe thrombotic microangiopathy in a patient with complement gene variant

The evidence regarding thrombotic microangiopathy (TMA) related to Coronavirus Infectious Disease 2019 (COVID-19) in patients with complement gene mutations as a cause of acute kidney injury (AKI) are limited. We presented the case of a 23-year-old male patient admitted with an asymptomatic form of COVID-19, but with uncontrolled hypertension and AKI. Kidney biopsy showed severe lesions of TMA. In evolution patient had persistent microangiopathic hemolytic anemia, decreased level of haptoglobin and increased LDH level. Decreased complement C3 level and the presence of schistocytes were found for the first time after biopsy. Kidney function progressively decreased and the patient remained hemodialysis dependent. Complement work-up showed a heterozygous variant with unknown significance in complement factor I (CFI) c.-13G>A, affecting the 5' UTR region of the gene. In addition, the patient was found to be heterozygous for the complement factor H (CFH) H3 haplotype (involving the rare alleles of c.-331C>T, Q672Q and E936D polymorphisms) reported as a risk factor of atypical hemolytic uremic syndrome. This case of AKI associated with severe TMA and secondary hemolytic uremic syndrome highlights the importance of genetic risk modifiers in the alternative pathway dysregulation of the complement in the setting of COVID-19, even in asymptomatic forms.

Immune system changes in those with hypertension when infected with SARS-CoV-2

The coronavirus disease 2019 (COVID-19) outbreak has become an evolving global health crisis. With an increasing incidence of primary hypertension, there is greater awareness of the relationship between primary hypertension and the immune system [including CD4+, CD8+ T cells, interleukin-17 (IL-17)/T regulatory cells (Treg) balance, macrophages, natural killer (NK) cells, neutrophils, B cells, and cytokines]. Hypertension is associated with an increased risk of various infections, post-infection complications, and increased mortality from severe infections. Despite ongoing reports on the epidemiological and clinical features of COVID-19, no articles have systematically addressed the role of primary hypertension in COVID-19 or how COVID-19 affects hypertension or specific treatment in these high-risk groups. Here, we synthesize recent advances in understanding the relationship between primary hypertension and COVID-19 and its underlying mechanisms and provide specific treatment guidelines for these high-risk groups.

Renal Manifestations and their Association with Mortality and Length of Stay in COVID-19 Patients at a Safety-net Hospital

Background

Renal involvement in COVID-19 leads to severe disease and higher mortality. We study renal parameters in COVID-19 patients and their association with mortality and length of stay in hospital.

Methods

A retrospective study (n=340) of confirmed COVID-19 patients with renal involvement determined by the presence of acute kidney injury. Multivariate analyses of logistic regression for mortality and linear regression for length of stay (LOS) adjusted for relevant demographic, comorbidity, disease severity, and treatment covariates.

Results

Mortality was 54.4% and mean LOS was 12.9 days. For mortality, creatinine peak (OR:35.27, 95% CI:2.81, 442.06, p<0.01) and persistent renal involvement at discharge (OR:4.47, 95% CI:1.99,10.06, p<0.001) were each significantly associated with increased odds for mortality. Increased blood urea nitrogen peak (OR:0.98, 95%CI:0.97,0.996, p<0.05) was significantly associated with decreased odds for mortality. For LOS, increased blood urea nitrogen peak (B:0.001, SE:<0.001, p<0.01), renal replacement therapy (B:0.19, SE:0.06, p<0.01), and increased days to acute kidney injury (B:0.19, SE:0.05, p<0.001) were each significantly associated with increased length of stay.

Conclusion

Our study emphasizes the importance in identifying renal involvement parameters in COVID-19 patients. These parameters are associated with LOS and mortality, and may assist clinicians to prognosticate COVID-19 patients with renal involvement.

Acute Kidney Injury in Elderly Patients With Coronavirus Infectious Disease: A Study of Incidence, Risk Factors, and Prognosis in Brazil

Introduction

Elderly patients with COVID-19 are at a higher risk of severity and death as not only several comorbidities but also aging itself has been considered a relevant risk factor. Acute kidney injury (AKI), one of the worst complications of SARS-CoV-2 infection, is associated with worse outcomes. Studies on AKI with COVID-19 in Latin-American patients of older age remain scarce.

Objectives

To determine AKI incidence and the risk factors associated with its development, as well as to compare outcome of elderly patients with or without AKI associated with SARS-CoV-2 infection.

Methods

This retrospective cohort study evaluated patients with SARS-CoV2 infection admitted to a Public Tertiary Referral Hospital from 03/01/2020 to 12/31/2020, from admission to resolution (hospital discharge or death). Demographic, clinical, and laboratory data were collected from patients during hospitalization. Daily kidney function assessment was performed by measuring serum creatinine and urine output. AKI was diagnosed according to KDIGO 2012 criteria.

Results

Of the 347 patients with COVID-19 admitted to our hospital during the study period, 52.16% were elderly, with a median age of 72 years (65- 80 years). In this age group, most patients were males (56.91%), hypertensive (73.48%), and required ICU care (55.25%). AKI overall incidence in the elderly was 56.9%, with higher frequency in ICU patients (p < 0.001). There was a predominance of KDIGO 3 (50.48%), and acute kidney replacement therapy (AKRT) was required by 47.57% of the patients. The risk factors associated with AKI development were higher baseline creatinine level (OR 10.54, CI 1.22 -90.61, p = 0.032) and need for mechanical ventilation (OR 9.26, CI 1.08-79.26, p = 0.042). Mortality was also more frequent among patients with AKI (46.41%vs24.7%, p < 0.0001), with death being associated with CPK level (OR 1.009, CI 1.001-1.017, p = 0.042), need for mechanical ventilation (OR 17.71, CI 1.13-277.62, p = 0.002) and KDIGO 3 (OR 2.017 CI 1.039 -3.917, p = 0.038).

Conclusion

AKI was frequent among the elderly hospitalized with COVID-19 and its risk factors were higher baseline creatinine and need for mechanical ventilation. AKI was independently associated with a higher risk of death.

Cystatin C is a marker for acute kidney injury, but not for mortality among COVID-19 patients in Mexico

Background

Aim

Methods

Results

Conclusion

Post-acute COVID-19 syndrome and kidney diseases: what do we know?

COVID-19, a disease caused by a novel coronavirus (SARS-CoV-2), is a major global threat that has turned into a pandemic. Despite the emergence of multiple vaccination alternatives and developing therapeutic options, dramatic short- and long-term clinical outcomes have been recorded with more than 250 million infected people and over 5 million deaths as of November 2021. COVID-19 presents various respiratory, cardiovascular, neuropsychiatric, musculoskeletal and kidney features during the acute phase; nevertheless, renal involvement in the post-infection period has recently been emphasized. The present review aims to evaluate the growing literature on kidney involvement in the SARS-CoV-2 infection along with clinical features reported both in the acute phase of the infection and in the post-acute COVID-19 period by assessing potential pathophysiological frameworks explaining such conditions. Chronic kidney disease and development of acute kidney injury (AKI) in the course of initial hospitalization are associated with high mortality and morbidity rates. Moreover, growing evidence suggests a decline in renal function in the 6-to-12-month follow-up period even in patients without any signs of AKI during the acute phase. Despite such concerns there are no guidelines regulating the follow-up period or therapeutic alternatives for such patient population. In conclusion, the burden of COVID-19 on the kidney is yet to be determined. Future prospective large scale studies are needed with long follow-up periods assessing kidney involvement via multiple parameters such as biopsy studies, urinalysis, measurement of serum creatinine and cystatin C, directly measured glomerular filtration rate, and assessment of tubular function via urinary β²-microglobulin measurements.

Case Report: Clinical and Pathological Findings of a Recurrent C3 Glomerulopathy With Superimposed Membranoproliferative Glomerulonephritis Pattern and Cryoglobulinemia Associated With COVID-19

Coronavirus disease 2019 (COVID-19) may cause a wide spectrum of kidney pathologies. The impact of COVID-19 is unclear in the context of the complement system abnormalities, including C3 glomerulopathy (C3G). In this report, we describe a young adult receiving a kidney transplant for C3 glomerulopathy (C3G), a disorder of the alternative complement pathway. The patient developed a recurrent C3G ~7 months after transplantation. His post-transplant course was complicated by SARS-CoV-2 infection. There was a progression of glomerulonephritis, characterized by de novo immune-complex mediated membranoproliferative glomerulonephritis pattern of injury with crescentic and necrotizing features, along with positive immunoglobulins, persistent IgM staining and the presence of cryoglobulinemia. COVID-19 may have aggravated the inherent complement dysregulation and contributed to cryoglobulinemia observed in this patient. Our study of 5 sequential kidney allograft biopsy series implicates that COVID-19 in this patient promoted a superimposed immune complex-mediated glomerulonephritis with membranoproliferative glomerulonephritis (MPGN) pattern and cryoglobulinemia, which was a potentiating factor in allograft loss. This work represents the first report of cryoglobulinemic GN after COVID-19.