COVID-19 in children and young adults with kidney disease: risk factors, clinical features and serological response

The humoral immune response to the BNT 162B2 vaccine in pediatrics on renal replacement therapy

INTRODUCTION

Since the start of the COVID-19 pandemic, data published on the immunogenicity of the SARS-CoV-2 BNT 162B2 vaccine in pediatric patients receiving renal replacement therapy are scant. Our primary objective is to study this population's humoral immune response to the COVID-19 vaccine.

METHODS

Pediatric kidney transplant recipients (PKTRs) and hemodialysis recipients (HR) at our center who received two doses of the SARS-CoV-2 BNT 162B2 vaccine were included. Transplant and HR who had PCR-positive COVID-19 infections during the study, regardless of their vaccine status, were also included. SARS-CoV-2 anti-spike protein (S1/S2) IgG was measured after the second dose of the vaccine and after any PCR-positive COVID-19 infection as routine clinical practice. Data on demographics, induction, maintenance immunosuppressants, type of transplant, and posttransplant or dialysis duration were included.

RESULTS

Of the 61 patients included, 19 were dialysis recipients who received two doses of vaccine without subsequent infection (HV), and 42 were kidney transplant recipients. All dialysis patients and 33 (78.6%) transplant recipients received two doses of the SARS-CoV-2 BNT 162b2 vaccine. A total of 33.3% (11/33) of the transplant recipients who received vaccination developed COVID-19 infection (KTH) at a median time of 13 days after the second dose of vaccine. Nine transplant patients had pure COVID-19 infection without vaccination (KTI). The seroconversion rate in the HV group was 94.7% (18/19) compared to 50% (11/22) in the kidney transplant vaccine recipients who did not develop subsequent COVID-19 infection (KTV) (p < .001). The median S1/S2 IgG titers for the HV group were 400 AU/mL versus 15 AU/mL in the KTV group (p < .0001). There was no significant difference in the duration of the test from the second dose of the vaccine between HV and KTV (55 vs. 33.5 days, p = .095). The KTH had higher titers than KTV group (370 vs. 15 p < .0001). The median duration of the test after vaccination in the vaccine group and those with hybrid immunity was similar (35 vs. 33.5 days, p = .2).There were no clear predictors for seroconversion in the PKTRs. Natural infection alone was as good as the vaccine in eliciting humoral immune response.

CONCLUSION

The humoral immune response to two doses of the SARS-CoV-2 BNT 162B2 vaccine in PKTRs without subsequent COVID-19 infection is suboptimal compared to that in hemodialysis recipients and in PKTRs with hybrid immunity from both infection and vaccination.

Risk Factors for Pediatric Critical COVID-19: A Systematic Review and Meta-Analysis

Background

Risk stratification is a cornerstone of the Pediatric Infectious Diseases Society COVID-19 treatment guidance. This systematic review and meta-analysis aimed to define the clinical characteristics and comorbidities associated with critical COVID-19 in children and adolescents.

Methods

Two independent reviewers screened the literature (Medline and EMBASE) for studies published through August 2023 that reported outcome data on patients aged ≤21 years with COVID-19. Critical disease was defined as an invasive mechanical ventilation requirement, intensive care unit admission, or death. Random effects models were used to estimate pooled odds ratios (OR) with 95% confidence intervals (CI), and heterogeneity was explored through subgroup analyses.

Results

Among 10,178 articles, 136 studies met the inclusion criteria for review. Data from 70 studies, which collectively examined 172,165 children and adolescents with COVID-19, were pooled for meta-analysis. In previously healthy children, the absolute risk of critical disease from COVID-19 was 4% (95% CI, 1%-10%). Compared with no comorbidities, the pooled OR for critical disease was 3.95 (95% CI, 2.78-5.63) for presence of one comorbidity and 9.51 (95% CI, 5.62-16.06) for ≥2 comorbidities. Key risk factors included cardiovascular and neurological disorders, chronic pulmonary conditions (excluding asthma), diabetes, obesity, and immunocompromise, all with statistically significant ORs >2.00.

Conclusions

While the absolute risk for critical COVID-19 in children and adolescents without underlying health conditions is relatively low, the presence of one or more comorbidities was associated with markedly increased risk. These findings support the importance of risk stratification in tailoring pediatric COVID-19 management.

COVID-19 in Children with Chronic Kidney Disease; Does it Differ Much?

BACKGROUND

COVID-19 is known to have a mild course in children, however more data on pediatric chronic kidney disease (CKD) is needed. We aimed to assess the incidence and severity of COVID-19 in pediatric CKD patients.

METHODS

A questionnaire including demographics, COVID-19 history, symptoms, and vaccination status was applied to patients with CKD. We also retrospectively reviewed the presentation and outcomes of SARS-CoV-2 infection in this patient group from March 2020 to December 2021.

RESULTS

220 patients were included, 48 were found to have experienced COVID-19. There was no significant difference regarding age, gender, underlying kidney disease, CKD stage, dialysis status, type or number of immunosuppressive medications, and glomerular filtration rate between patients with and without COVID-19. Most were infected by a household member (43.8%) and during outpatient or inpatient care (18.8%). Four (8.3%) were asymptomatic, and 43 (89.6%) had mild infection. Severe COVID-19 was observed in only one patient. Eleven (22.9%) patients with COVID-19 were previously vaccinated. Acute kidney injury was detected in 4 (8.3%); as stage 1 in all. Median follow-up after COVID-19 was 4.6 months. All patients fully recovered, and no renal disease flare or death was observed.

CONCLUSIONS

Although the vaccination rate was low in our cohort, the majority of the children with COVID-19 showed a mild course. Along with the vaccination, general precautions seemed to be successful for this population.

Increasing SARS-CoV-2 seroprevalence among UK pediatric patients on dialysis and kidney transplantation between January 2020 and August 2021

BACKGROUND

Coronavirus disease 2019 (COVID-19) was officially declared a pandemic by the World Health Organisation (WHO) on 11 March 2020, as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spread rapidly across the world. We investigated the seroprevalence of anti-SARS-CoV-2 antibodies in pediatric patients on dialysis or kidney transplantation in the UK.

METHODS

Excess sera samples were obtained prospectively during outpatient visits or haemodialysis sessions and analysed using a custom immunoassay calibrated with population age-matched healthy controls. Two large pediatric centres contributed samples.

RESULTS

In total, 520 sera from 145 patients (16 peritoneal dialysis, 16 haemodialysis, 113 transplantation) were analysed cross-sectionally from January 2020 until August 2021. No anti-SARS-CoV-2 antibody positive samples were detected in 2020 when lockdown and enhanced social distancing measures were enacted. Thereafter, the proportion of positive samples increased from 5% (January 2021) to 32% (August 2021) following the emergence of the Alpha variant. Taking all patients, 32/145 (22%) were seropositive, including 8/32 (25%) with prior laboratory-confirmed SARS-CoV-2 infection and 12/32 (38%) post-vaccination (one of whom was also infected after vaccination). The remaining 13 (41%) seropositive patients had no known stimulus, representing subclinical cases. Antibody binding signals were comparable across patient ages and dialysis versus transplantation and highest against full-length spike protein versus spike subunit-1 and nucleocapsid protein.

CONCLUSIONS

Anti-SARS-CoV-2 seroprevalence was low in 2020 and increased in early 2021. Serological surveillance complements nucleic acid detection and antigen testing to build a greater picture of the epidemiology of COVID-19 and is therefore important to guide public health responses. A higher resolution version of the Graphical abstract is available as Supplementary information.

Effectiveness of and Inequalities in COVID-19 Epidemic Control Strategies in Hungary: A Nationwide Cross-Sectional Study

INTRODUCTION

Before the mass vaccination, epidemiological control measures were the only means of containing the COVID-19 epidemic. Their effectiveness determined the consequences of the COVID-19 epidemic. Our study evaluated the impact of sociodemographic, lifestyle, and clinical factors on patient-reported epidemiological control measures.

METHODS

A nationwide representative sample of 1008 randomly selected adults were interviewed in person between 15 March and 30 May 2021. The prevalence of test-confirmed SARS-CoV-2 infection was 12.1%, of testing was 33.7%, and of contact tracing among test-confirmed infected subjects was 67.9%. The vaccination coverage was 52.4%.

RESULTS

According to the multivariable logistic regression models, the occurrence of infection was not influenced by sociodemographic and lifestyle factors or by the presence of chronic disease. Testing was more frequent among middle-aged adults (aOR = 1.53, 95% CI 1.10-2.13) and employed adults (aOR = 2.06, 95% CI 1.42-3.00), and was more frequent among adults with a higher education (aOR_secondary = 1.93, 95% CI 1.20-3.13; aOR_tertiary = 3.19, 95% CI 1.81-5.63). Contact tracing was more frequently implemented among middle-aged (aOR41-7y = 3.33, 95% CI 1.17-9.45) and employed (aOR = 4.58, 95% CI 1.38-15.22), and those with chronic diseases (aOR = 5.92, 95% CI 1.56-22.47). Positive correlation was observed between age groups and vaccination frequency (aOR41-70y = 2.94, 95% CI 2.09-4.15; aOR71+y = 14.52, 95% CI 7.33-28.77). Higher than primary education (aOR_secondary = 1.69, 95% CI 1.08-2.63; aOR_tertiary = 4.36, 95% CI 2.46-7.73) and the presence of a chronic disease (aOR = 2.58, 95% CI 1.75-3.80) positively impacted vaccination. Regular smoking was inversely correlated with vaccination (aOR = 0.60; 95% CI 0.44-0.83).

CONCLUSIONS

The survey indicated that testing, contact tracing, and vaccination were seriously influenced by socioeconomic position; less so by chronic disease prevalence and very minimally by lifestyle. The etiological role of socioeconomic inequalities in epidemic measure implementation likely generated socioeconomic inequality in COVID-19-related complication and death rates.

Epidemiology, severity, and risk of SARS-CoV-2-related relapse in children and young adults affected by idiopathic nephrotic syndrome: a retrospective observational cohort study

BACKGROUND

Children with underlying kidney diseases display a mild course of SARS-CoV-2 infection, but they only accounted for a minority of cases until the spread of the Omicron variant. Nonetheless, idiopathic nephrotic syndrome (INS) has been advocated as a predictor of worse outcome.

METHODS

We investigated the spread, severity, and risk of relapse related to SARS-CoV-2 infection among children with INS. The incidence and characteristics of SARS-CoV-2 infections, immunosuppression, and vaccination status were retrospectively collected from the beginning of the pandemic to May 31, 2022.

RESULTS

We enrolled 176 patients (73 females, median age 10.22 years); 28 had a steroid-resistant disease, and 108 (61.4%) were on immunosuppressive therapy. Sixty-one (34.7%) patients reported a SARS-CoV-2 infection, with incidence peaking between December 2021 and January 2022. No hospitalization or deaths were reported, and symptoms were absent or mild. The rate of SARS-CoV-2 infection was similar in children with and without immunosuppression (33.8% vs 35.2%; p = 0.85). None of the 38 immunosuppressed patients discontinued the therapy, but they had a longer time to negativization (13.31 vs. 10.04 days; p = 0.03). Proteinuria was detected in 7 patients, but only one had a relapse requiring steroid therapy, with prompt remission and a mild course.

CONCLUSIONS

After the spread of the Omicron variant, the rate of SARS-CoV-2 infection in children with INS was much higher than previously reported. In this large cohort, symptoms were mild, even in immunosuppressed patients and those with proteinuria. During the infection, transient proteinuria was common with a low rate of relapses. A higher resolution version of the Graphical abstract is available as Supplementary information.