The chondrocyte-specific miR-140 miRNAs are necessary for normal endochondral bone growth in mice. miR-140 deficiency causes dwarfism and craniofacial deformity. However, the physiologically ...important targets of miR-140 miRNAs are still unclear. The miR-140 gene (
) encodes three chondrocyte-specific microRNAs, miR-140-5p, derived from the 5' strand of primary miR-140, and miR140-3p.1 and -3p.2, derived from the 3' strand of primary miR-140. miR-140-3p miRNAs are 10 times more abundant than miR-140-5p likely due to the nonpreferential loading of miR-140-5p to Argonaute proteins. To differentiate the role of miR-140-5p and -3p miRNAs in endochondral bone development, two distinct mouse models, miR140-C > T, in which the first nucleotide of miR-140-5p was altered from cytosine to uridine, and miR140-CG, where the first two nucleotides of miR-140-3p were changed to cytosine and guanine, were created. These changes are expected to alter Argonaute protein loading preference of -5p and -3p to increase -5p loading and decrease -3p loading without changing the function of miR140-5p. These models presented a mild delay in epiphyseal development with delayed chondrocyte maturation. Using RNA-sequencing analysis of the two models, direct targets of miR140-5p, including
, were identified. Disruption of the predicted miR140-5p binding site in the 3' untranslated region of
was shown to increase Wnt11 mRNA expression and caused a modest acceleration of epiphyseal development. These results show that the relative abundance of miRNA-5p and -3p can be altered by changing the first nucleotide of miRNAs in vivo, and this method can be useful to identify physiologically important miRNA targets.
Multisystem inflammatory syndrome in children (MIS-C) consensus criteria were designed for maximal sensitivity and therefore capture patients with acute COVID-19 pneumonia.
We performed unsupervised ...clustering on data from 1,526 patients (684 labeled MIS-C by clinicians) <21 years old hospitalized with COVID-19-related illness admitted between 15 March 2020 and 31 December 2020. We compared prevalence of assigned MIS-C labels and clinical features among clusters, followed by recursive feature elimination to identify characteristics of potentially misclassified MIS-C-labeled patients.
Of 94 clinical features tested, 46 were retained for clustering. Cluster 1 patients (N = 498; 92% labeled MIS-C) were mostly previously healthy (71%), with mean age 7·2 ± 0·4 years, predominant cardiovascular (77%) and/or mucocutaneous (82%) involvement, high inflammatory biomarkers, and mostly SARS-CoV-2 PCR negative (60%). Cluster 2 patients (N = 445; 27% labeled MIS-C) frequently had pre-existing conditions (79%, with 39% respiratory), were similarly 7·4 ± 2·1 years old, and commonly had chest radiograph infiltrates (79%) and positive PCR testing (90%). Cluster 3 patients (N = 583; 19% labeled MIS-C) were younger (2·8 ± 2·0 y), PCR positive (86%), with less inflammation. Radiographic findings of pulmonary infiltrates and positive SARS-CoV-2 PCR accurately distinguished cluster 2 MIS-C labeled patients from cluster 1 patients.
Using a data driven, unsupervised approach, we identified features that cluster patients into a group with high likelihood of having MIS-C. Other features identified a cluster of patients more likely to have acute severe COVID-19 pulmonary disease, and patients in this cluster labeled by clinicians as MIS-C may be misclassified. These data driven phenotypes may help refine the diagnosis of MIS-C.
This work was funded by the US Centers for Disease Control and Prevention (75D30120C07725) and National Institutes of Health (K12HD047349 and R21HD095228).
To identify risk factors for persistent impairments after pediatric hospitalization for acute coronavirus disease 2019 (COVID-19) or multisystem inflammatory syndrome in children (MIS-C) during the ...SARS-CoV-2 pandemic.
Across 25 U.S.
Network hospitals, we conducted a prospective cohort study of patients <21-years-old hospitalized for acute COVID-19 or MIS-C (May 2020 to March 2022) surveyed 2- to 4-months post-admission. Multivariable regression was used to calculate adjusted risk ratios (aRR) and 95% confidence intervals (CI).
Of 232 children with acute COVID-19, 71 (30.6%) had persistent symptoms and 50 (21.6%) had activity impairments at follow-up; for MIS-C (
= 241), 56 (23.2%) had persistent symptoms and 58 (24.1%) had activity impairments. In adjusted analyses of patients with acute COVID-19, receipt of mechanical ventilation was associated with persistent symptoms aRR 1.83 (95% CI: 1.07, 3.13) whereas obesity aRR 2.18 (95% CI: 1.05, 4.51) and greater organ system involvement aRR 1.35 (95% CI: 1.13, 1.61) were associated with activity impairment. For patients with MIS-C, having a pre-existing respiratory condition was associated with persistent symptoms aRR 3.04 (95% CI: 1.70, 5.41) whereas obesity aRR 1.86 (95% CI: 1.09, 3.15) and greater organ system involvement aRR 1.26 (1.00, 1.58) were associated with activity impairments.
Among patients hospitalized, nearly one in three hospitalized with acute COVID-19 and one in four hospitalized with MIS-C had persistent impairments for ≥2 months post-hospitalization. Persistent impairments were associated with more severe illness and underlying health conditions, identifying populations to target for follow-up.
Refinement of criteria for multisystem inflammatory syndrome in children (MIS-C) may inform efforts to improve health outcomes.
To compare clinical characteristics and outcomes of children and ...adolescents with MIS-C vs those with severe coronavirus disease 2019 (COVID-19).
Case series of 1116 patients aged younger than 21 years hospitalized between March 15 and October 31, 2020, at 66 US hospitals in 31 states. Final date of follow-up was January 5, 2021. Patients with MIS-C had fever, inflammation, multisystem involvement, and positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reverse transcriptase-polymerase chain reaction (RT-PCR) or antibody test results or recent exposure with no alternate diagnosis. Patients with COVID-19 had positive RT-PCR test results and severe organ system involvement.
SARS-CoV-2.
Presenting symptoms, organ system complications, laboratory biomarkers, interventions, and clinical outcomes. Multivariable regression was used to compute adjusted risk ratios (aRRs) of factors associated with MIS-C vs COVID-19.
Of 1116 patients (median age, 9.7 years; 45% female), 539 (48%) were diagnosed with MIS-C and 577 (52%) with COVID-19. Compared with patients with COVID-19, patients with MIS-C were more likely to be 6 to 12 years old (40.8% vs 19.4%; absolute risk difference RD, 21.4% 95% CI, 16.1%-26.7%; aRR, 1.51 95% CI, 1.33-1.72 vs 0-5 years) and non-Hispanic Black (32.3% vs 21.5%; RD, 10.8% 95% CI, 5.6%-16.0%; aRR, 1.43 95% CI, 1.17-1.76 vs White). Compared with patients with COVID-19, patients with MIS-C were more likely to have cardiorespiratory involvement (56.0% vs 8.8%; RD, 47.2% 95% CI, 42.4%-52.0%; aRR, 2.99 95% CI, 2.55-3.50 vs respiratory involvement), cardiovascular without respiratory involvement (10.6% vs 2.9%; RD, 7.7% 95% CI, 4.7%-10.6%; aRR, 2.49 95% CI, 2.05-3.02 vs respiratory involvement), and mucocutaneous without cardiorespiratory involvement (7.1% vs 2.3%; RD, 4.8% 95% CI, 2.3%-7.3%; aRR, 2.29 95% CI, 1.84-2.85 vs respiratory involvement). Patients with MIS-C had higher neutrophil to lymphocyte ratio (median, 6.4 vs 2.7, P < .001), higher C-reactive protein level (median, 152 mg/L vs 33 mg/L; P < .001), and lower platelet count (<150 ×103 cells/μL 212/523 {41%} vs 84/486 {17%}, P < .001). A total of 398 patients (73.8%) with MIS-C and 253 (43.8%) with COVID-19 were admitted to the intensive care unit, and 10 (1.9%) with MIS-C and 8 (1.4%) with COVID-19 died during hospitalization. Among patients with MIS-C with reduced left ventricular systolic function (172/503, 34.2%) and coronary artery aneurysm (57/424, 13.4%), an estimated 91.0% (95% CI, 86.0%-94.7%) and 79.1% (95% CI, 67.1%-89.1%), respectively, normalized within 30 days.
This case series of patients with MIS-C and with COVID-19 identified patterns of clinical presentation and organ system involvement. These patterns may help differentiate between MIS-C and COVID-19.
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