Acute Kidney Injury in Pediatric Acute SARS-CoV-2 Infection and Multisystem Inflammatory Syndrome in Children (MIS-C): Is There a Difference?

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.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Renal Involvement in Multisystem Inflammatory Syndrome in Children: Not Only Acute Kidney Injury

Kidney involvement has been poorly investigated in SARS-CoV-2 Multisystem Inflammatory Syndrome in Children (MIS-C). To analyze the spectrum of renal involvement in MIS-C, we performed a single-center retrospective observational study including all MIS-C patients diagnosed at our Pediatric Department between April 2020 and May 2022. Demographic, clinical, pediatric intensive care unit (PICU) admission's need and laboratory data were collected at onset and after 6 months. Among 55 MIS-C patients enrolled in the study, kidney involvement was present in 20 (36.4%): 13 with acute kidney injury (AKI) and 7 with isolated tubular dysfunction (TD). In eight patients, concomitant AKI and TD was present (AKI-TD). AKI patients needed higher levels of intensive care (PICU: 61.5%, p < 0.001; inotropes: 46.2%, p = 0.002; second-line immuno-therapy: 53.8%, p < 0.001) and showed lower levels of HCO3- (p = 0.012), higher inflammatory markers [neutrophils (p = 0.092), PCT (p = 0.04), IL-6 (p = 0.007)] as compared to no-AKI. TD markers showed that isolated TD presented higher levels of HCO3- and lower inflammatory markers than AKI-TD. Our results indicate a combination of both pre-renal and inflammatory damage in the pathogenesis of kidney injury in MIS-C syndrome. We highlight, for the first time, the presence of tubular involvement in MIS-C, providing new insights in the evaluation of kidney involvement and its management in this condition.

Case Report: Multisystem inflammatory syndrome in children with associated proximal tubular injury

Introduction

SARS-CoV-2 infection in the pediatric population can be associated with a multiorgan inflammatory syndrome called children's multisystem inflammatory syndrome (MIS-C). The kidneys can be affected by a broad spectrum of possible injuries, whose pathogenetic mechanisms are still unclear.Case report: We report the case of a 5-year-old boy with severe cardiac involvement in the context of MIS-C. After two weeks of hospitalization, an abdominal ultrasound showed massive bladder "debris", followed by the onset of normoglycemic glycosuria. Over time, there was a progressive increase in glycosuria, and the presence of a mat of amorphous phosphate crystals was evidenced on urinary sediment. Together with the findings of hypo-uricemia, increased urinary uric acid, and globally increased urinary amino acids, a clinical picture of kidney proximal tubular damage with secondary Fanconi-like syndrome took shape.

Discussion

This case report describes the case of a patient with MIS-C with cardiac and kidney involvement characterized by proximal tubular damage, which slowly improved but still persisted at the 8-month follow-up. The pathogenesis of the damage is unclear and probably multifactorial.

Multisystem Inflammatory Syndrome in Children and Acute Kidney Injury: Retrospective Study of Five Italian PICUs

OBJECTIVES

Multisystem inflammatory syndrome in children (MIS-C) manifests with heart dysfunction and respiratory failure some weeks after a severe acute respiratory syndrome coronavirus disease 2 infection. The aim of our study was to explore the prevalence, severity, timing, and duration of acute kidney injury (AKI) in MIS-C patients. Furthermore, we evaluated which clinical variables and outcomes are associated with AKI.

DESIGN

Multicenter retrospective study.

SETTING

Five tertiary hospital PICUs in Italy. Data were collected in the first 7 days of PICU admission and renal function was followed throughout the hospital stay.

PATIENTS

Patients less than 18 years old admitted to the PICU for greater than 24 hours with MIS-C.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We collected the following data, including: demographic information, inflammatory biomarkers, lactate levels, Pa o2 /F io2 , ejection fraction, N-terminal pro-B-type natriuretic peptide (NT-proBNP), renal function (serum creatinine, urinary output, fluid balance, and percentage fluid accumulation), Vasoactive-Inotropic Score (VIS), pediatric Sequential Organ Failure Assessment (pSOFA), and Pediatric Index of Mortality 3. AKI was diagnosed in eight of 38 patients (21%) and severe AKI was present in four of eight patients. In all cases, AKI was present at PICU admission and its median (interquartile range) duration was 3.5 days (1.5-5.7 d). We did not identify differences between AKI and no-AKI patients when not making correction for multiple comparisons, for example, in weight, ejection fraction, pSOFA, Pa o2 /F io2 , and lactates. We failed to identify any difference in these groups in urine output and fluid balance. Exploratory analyses of serial data between no-AKI and AKI patients showed significant differences on lymphocyte count, NT-proBNP value, ejection fraction, pSOFA, Pa o2 /F io2 , and VIS.

CONCLUSIONS

In this multicenter Italian PICU experience, MIS-C is associated with AKI in one-in-five cases. In general, AKI is characterized by an associated reduction in glomerular filtration rate with a self-limiting time course.

Multisystem Inflammatory Syndrome in Neonates Born to Mothers with SARS-CoV-2 Infection (MIS-N) and in Neonates and Infants Younger Than 6 Months with Acquired COVID-19 (MIS-C): A Systematic Review

(1) Introduction: There is an increasing literature describing neonates born to mothers with SARS-CoV-2 infection (MIS-N) and infants infected with SARS-CoV-2 who presented with a severe disease (MIS-C). (2) Methods: To investigate clinical features of multisystem inflammatory syndrome in neonates and infants under six months of age, we used a systematic search to retrieve all relevant publications in the field. We screened in PubMed, EMBASE and Scopus for data published until 10 October 2021. (3) Results: Forty-eight articles were considered, including 29 case reports, six case series and 13 cohort studies. Regarding clinical features, only 18.2% of MIS-N neonates presented with fever; differently from older children with MIS-C, in which gastrointestinal symptoms were the most common manifestation, we displayed that cardiovascular dysfunction and respiratory distress are the prevalent findings both in neonates with MIS-N and in neonates/infants with MIS-C. (4) Conclusions: We suggest that all infants with suspected inflammatory disease should undergo echocardiography, due to the possibility of myocardial dysfunction and damage to the coronary arteries observed both in neonates with MIS-N and in neonates/infants with MIS-C. Moreover, we also summarize how they were treated and provide a therapeutic algorithm to suggest best management of these fragile infants.

Pathology findings in pediatric patients with COVID-19 and kidney dysfunction

BACKGROUND

Acute kidney injury (AKI) is seen in one-fifth of pediatric patients with COVID-19 requiring hospital admission, and is associated with increased morbidity, mortality, and residual kidney impairment. The majority of kidney pathology data in patients with COVID-19 is derived from adult case series and there is an overall lack of histologic data for most pediatric patients with COVID-19.

METHODS

We assembled a multi-institutional cohort of five unvaccinated pediatric patients with COVID-19 and associated kidney dysfunction with available histology.

RESULTS

Three complex patients with current or prior SARS-CoV-2 infection had multifactorial thrombotic microangiopathy with clinical features of hemolytic uremic syndrome (in two) or disseminated intravascular coagulation (in one); one died and another developed chronic kidney disease stage 5. Two with recently preceding SARS-CoV-2 infection presented with nephrotic syndrome; one had IgA vasculitis and one had minimal change disease. Within a short follow-up time, none has returned to baseline kidney function.

CONCLUSION

Although uncommon, COVID-19-associated kidney injury can have significant morbidity in the unvaccinated pediatric and adolescent population. A higher resolution version of the Graphical abstract is available as Supplementary information.

Hematuria as an Early Sign of Multisystem Inflammatory Syndrome in Children: A Case Report of a Boy With Multiple Comorbidities and Review of Literature

Introduction: While the clinical course of SARS-CoV-2 infection seems to be milder or asymptomatic within the pediatric population, growing attention has been laid to the rare complication elicited by virus, multisystem inflammatory syndrome in children temporarily associated with COVID-19 (MIS-C). Published definition and criteria of MIS-C include persistent fever, multisystem involvement, and elevated markers of inflammation, without obvious microbial inflammation or other plausible diagnosis. However, the aim of this case report is to emphasize the diversity of symptoms of MIS-C, beyond the defined criteria. Case Presentation: We present a 10-year-old boy with 8p23.1 microdeletion syndrome and multiple comorbidities who initially came to our attention due to hematuria, persistent fever, rash, and elevated markers of inflammation. Within the next 2 days, his condition worsened despite the broad-spectrum antibiotic therapy. Assuming his past history of SARS-CoV-2 exposure, MIS-C was suspected. A high level of clinical suspicion was further supported by significant clinical features (vomiting, abdominal pain, conjunctivitis, arrhythmia, and mild left ventricular systolic dysfunction with pleural effusion) along with laboratory findings (elevated ESR, CRP, proBNP, D-dimers and fibrinogen, positive IgG SARS-CoV-2 antibodies, and negative microbiological cultures). The patient was given intravenous immunoglobulin (IVIG) and began to show instantaneous clinical and laboratory improvement. Conclusion: Despite numerous reports of MIS-C cases in children, there are still many uncertainties regarding the clinical presentation and laboratory findings, as well as mechanisms beyond this intriguing disorder. In our case, for the first time hematuria is reported as an early symptom of MIS-C. We strongly believe that reporting various manifestations and outcomes in MIS-C patients will lead to improved diagnosis, treatment, and overall understanding of this novel inflammatory condition.