Evaluation of disease severity and prediction of severe cases in children hospitalized with influenza A (H1N1) infection during the post-COVID-19 era: a multicenter retrospective study.

BACKGROUND: The rebound of influenza A (H1N1) infection in post-COVID-19 era recently attracted enormous attention due the rapidly increased number of pediatric hospitalizations and the changed characteristics compared to classical H1N1 infection in pre-COVID-19 era. This study aimed to evaluate the clinical characteristics and severity of children hospitalized with H1N1 infection during post-COVID-19 period, and to construct a novel prediction model for severe H1N1 infection. METHODS: A total of 757 pediatric H1N1 inpatients from nine tertiary public hospitals in Yunnan and Shanghai, China, were retrospectively included, of which 431 patients diagnosed between February 2023 and July 2023 were divided into post-COVID-19 group, while the remaining 326 patients diagnosed between November 2018 and April 2019 were divided into pre-COVID-19 group. A 1:1 propensity-score matching (PSM) was adopted to balance demographic differences between pre- and post-COVID-19 groups, and then compared the severity across these two groups based on clinical and laboratory indicators. Additionally, a subgroup analysis in the original post-COVID-19 group (without PSM) was performed to investigate the independent risk factors for severe H1N1 infection in post-COIVD-19 era. Specifically, Least Absolute Shrinkage and Selection Operator (LASSO) regression was applied to select candidate predictors, and logistic regression was used to further identify independent risk factors, thus establishing a prediction model. Receiver operating characteristic (ROC) curve and calibration curve were utilized to assess discriminative capability and accuracy of the model, while decision curve analysis (DCA) was used to determine the clinical usefulness of the model. RESULTS: After PSM, the post-COVID-19 group showed longer fever duration, higher fever peak, more frequent cough and seizures, as well as higher levels of C-reactive protein (CRP), interleukin 6 (IL-6), IL-10, creatine kinase-MB (CK-MB) and fibrinogen, higher mechanical ventilation rate, longer length of hospital stay (LOS), as well as higher proportion of severe H1N1 infection (all P < 0.05), compared to the pre-COVID-19 group. Moreover, age, BMI, fever duration, leucocyte count, lymphocyte proportion, proportion of CD3+ T cells, tumor necrosis factor α (TNF-α), and IL-10 were confirmed to be independently associated with severe H1N1 infection in post-COVID-19 era. A prediction model integrating these above eight variables was established, and this model had good discrimination, accuracy, and clinical practicability. CONCLUSIONS: Pediatric H1N1 infection during post-COVID-19 era showed a higher overall disease severity than the classical H1N1 infection in pre-COVID-19 period. Meanwhile, cough and seizures were more prominent in children with H1N1 infection during post-COVID-19 era. Clinicians should be aware of these changes in such patients in clinical work. Furthermore, a simple and practical prediction model was constructed and internally validated here, which showed a good performance for predicting severe H1N1 infection in post-COVID-19 era.

[Pulmonary ventilation function parameters of children aged 5-14 years in Kunming, China: a comparative analysis of measured values versus predicted values based on Zapletal equation].

OBJECTIVE: To study the percentage of the measured values of the main pulmonary ventilation function parameters in their predicted values based on Zapletal equation among healthy children aged 5-14 years in Kunming, China, and to provide a basis for accurate judgment of pulmonary ventilation function in clinical practice. METHODS: A total of 702 healthy children aged 5-14 years (352 boys and 350 girls) from Kunming were enrolled. The Jaeger spirometer was used to measure the nine indices:forced vital capacity (FVC), forced expiratory volume in one second (FEV1), ratio of forced expiratory volume in one second to forced vital capacity (FEV1/FVC), maximal mid-expiratory flow (MMEF), forced expiratory flow at 25% of forced vital capacity (FEF25), forced expiratory flow at 50% of forced vital capacity (FEF50), forced expiratory flow at 75% of forced vital capacity (FEF75), peak expiratory flow (PEF), and maximal voluntary ventilation (MVV). The values obtained from the Zapletal equation of predicted values provided by the spirometer were used as the predicted values of children, and the percentage of measured values in predicted values was calculated. RESULTS: In the 702 children, the percentages of the measured values of the main pulmonary ventilation function parameters PEF, FVC, FEV1, FEV1/FVC, and MVV in their predicted values fluctuated from 102% to 114%, 94% to 108%, 98% to 113%, 98% to 107%, and 141% to 183% respectively. As for the main airway velocity parameters, the percentages of the measured values of FEF25, FEF50, FEF75, and MMEF in their predicted values fluctuated from 98% to 116%, 85% to 102%, 71% to 98%, and 83% to 100% respectively. The percentages of the measured values of PEF, FVC, FEV1, FEV1/FVC, MVV, FEF25, FEF50, FEF75, and MMEF in their predicted values had the lower limits of normal of 88.2%, 88.4%, 92.0%, 94.4%, 118.5%, 82.9%, 70.0%, 62.1%, and 70.1% respectively. CONCLUSIONS: There are differences between pulmonary ventilation function parameter levels and normal values provided by Zapletal equation in healthy children aged 5-14 years in Kunming. As for the pulmonary ventilation function parameters of PEF, FVC, FEV, FEV1/FVC, MVV, FEF25, FEF50, FEF75, and MMEF in these children, the lower limits of normal of measured values in predicted values may be determined as 88.2%, 88.4%, 92.0%, 94.4%, 118.5%, 82.9%, 70.0%, 62.1%, and 70.1% respectively.

Evaluation of febrile seizures in children infected with SARS-CoV-2 Omicron variant in Yunnan, China: a multi-center, retrospective observational study.

Background: The SARS-CoV-2 Omicron variant was reported to be linked to febrile seizures (FSs), but studies on FSs in children with Omicron infection remain relatively scarce, especially in the Chinese population. This study aimed to investigate the characteristics of children diagnosed with Omicron infection with FSs in Yunnan, China, and evaluate the potential association between FSs and Omicron infection. Methods: This study was conducted at four hospitals in Yunnan from December 8, 2022, to January 8, 2023, and consisted of 590 pediatric subjects. According to clinical characteristics, 85, 129 and 376 subjects were divided into the FS-only, Omicron-FS, and Omicron-only groups, respectively. Demographic, clinical and laboratory data were retrospectively collected for analysis. Results: The incidence of FSs in children with Omicron infection was 25.5% (129/505). Older age, stronger male predominance, as well as lower proportions of prior history and family history of seizures were observed in Omicron-FS and Omicron-only groups than in FS-only group, but there were no differences in these four above-mentioned events between these two Omicron-related groups. Compared to FS-only group, Omicron-FS group also had a shorter fever-to-seizure onset duration and more frequent seizures during a single course of fever. Moreover, higher levels of IL-6, TNF-α and ferritin as well as decreased counts of leukocytes and lymphocytes were confirmed in Omicron-FS group than in FS-only and Omicron-only groups. Regarding COVID-19 vaccination status, Omicron-FS group revealed a higher proportion of unvaccinated children and a lower proportion of three-dose vaccination than Omicron-only group. As for clinical outcomes, proportions of mechanical ventilation and intensive care unit admission observed in the two Omicron-related groups were notably higher than those in FS-only group. Meanwhile, Omicron-FS group showed the longest length of hospital stay, followed by Omicron-only group and FS-only group, in order. Finally, all patients but one who died of fulminant myocarditis had been successfully discharged. Conclusions: The incidence of FSs in children with Omicron infection was 25.5% in Yunnan. FSs might be a clinical sign deserving more attention in children with Omicron infection. Furthermore, COVID-19 vaccination is likely to provide effective protection against Omicron-related FSs in children.

A novel de novo heterozygous variant of the KCNQ2 gene: Contribution to early­onset epileptic encephalopathy in a female infant.

Early­onset epileptic encephalopathy (EOEE) represents one of the most severe epilepsies, characterized by recurrent seizures during early infancy, electroencephalogram (EEG) abnormalities and varying degrees of neurodevelopmental delay. The KCNQ2 gene has been reported to have a major role in EOEE. In the present study, a 3­month­old female infant from the Chinese Lisu minority with EOEE was analyzed. Detailed clinical evaluations and next­generation sequencing were performed to investigate the clinical and genetic characteristics of this patient, respectively. Furthermore, the three­dimensional structure of the mutant protein was predicted by SWISS­Model and the expression of KCNQ2 protein in the patient was assessed by flow cytometry. It was observed that the patient presented with typical clinical features of EOEE, including repeated non­febrile seizures and significant EEG abnormalities. A novel heterozygous missense variant c.431G>C (p.R144P) in KCNQ2 was identified in the patient and the genotyping of KCNQ2 in the patient's parents suggested that this variant was de novo. Subsequently, the breakage of hydrogen bonds between certain amino acids was predicted by structural analysis of the mutant protein. Flow cytometric analysis detected a significant reduction buts not complete loss of native KCNQ2 protein expression in the patient (25.1%). In conclusion, a novel variant in KCNQ2 was confirmed as the genetic cause for EOEE in this patient. The present study expanded the pathogenic mutation spectrum of KCNQ2, enhanced the understanding of the molecular pathogenesis of EOEE and provided novel clues for research on the genotype­phenotype correlation in this disease.

[The proliferation-promoting effects of calcitonin gene-related peptide on type II alveolar epithelial cell exposed to hyperoxia mediated by protein kinase C alpha pathway].

OBJECTIVE: To explore the effects of calcitonin gene-related peptide (CGRP) on type II alveolar epithelial cell (AECII) exposed to hyperoxia, and to determine whether the mechanism is mediated by protein kinase C alpha/nuclear factor-KappaB (PKC alpha/NF-KappaB) signal pathway. METHODS: AECII were isolated from the lung of 21 days fetal rat and cultured for 15 hours to coalesce. Then AECII were randomly assigned into four groups: air, hyperoxia, O(2)/CGRP, and O(2)/CGRP8-37 (a receptor antagonist against CGRP). AECII were exposed to FiO(2) 21% (air) or 85% (hyperoxia) for 24 hours respectively. In O(2)/CGRP and O(2)/CGRP8-37 groups CGRP or both CGRP and CGRP8-37 were added into cultural fluid before placing the plate into 85% oxygen. Cell proliferation ability was determined by methyl thiazolyl tetrazolium (MTT) assay and cell cycles by flow cytometry. Western blotting was employed to detect the fraction of PKC alpha in membrane and cytosol, and translocation of NF-KappaB was observed under laser confocal microscopy. RESULTS: AECII in hyperoxia group showed a decreased viability of AECII [(68.752+/-5.766)% vs. (100.000+/-6.682)%] and had an enhanced percentage of G0/G1 phase [(80.652+/-6.253)% vs. (45.825+/-2.899)%] with a corresponding decline in percentage of S phase [(14.198+/-4.785)% vs. (27.470+/-2.775)%] and G2/M phases [(5.148+/-1.688)% vs. (26.708+/-1.863)%] compared with AECII in air (all P<0.01). Addition with CGRP before hyperoxia exposure promoted AECII proliferation [(94.813+/-6.102)%] and enhanced the cell proportions in S and G2/M phases [(30.547+/-9.861)% and (17.668+/-9.509)%, all P<0.01]. The ratio of membrane to cytoplasm fraction of PKC alpha declined (0.63+/-0.10 vs. 1.00+/-0.09) and the fluorescence of NF-KappaB in nucleus enhanced (22.98+/-2.20 vs. 14.54+/-2.35) in hyperoxia compared with that in air, while both the ratio of PKC alpha and intensity of NF-KappaB were increased in O(2)/CGRP group (1.41+/-0.23, 35.38+/-3.37) compared with those in hyperoxia (0.63+/-0.10, 22.98+/-2.20) and O(2)/CGRP8-37 groups (0.74+/-0.10, 24.88+/-1.81, all P<0.01). CONCLUSION: CGRP could promote proliferation of AECII when exposed to high oxygen tension. PKC alpha participates in the signal transduction process and NF-KappaB is a downstream molecular of PKC alpha, executing in part the function of PKC alpha signal.

[Influence of 60% oxygen inhalation on type II alveolar epithelial cells and protective role of calcitonin gene-related peptide from their damage induced in premature rat].

OBJECTIVE: To study in vitro the influence of 60% oxygen and the protective effect of calcitonin gene-related peptide (CGRP) on type II alveolar epithelial cells (AEC II) isolated from the lung of premature rat. METHODS: AEC II were isolated from the lung of 19-day rat fetus, and they were then cultured in six-well plates. The cells were randomly divided into four groups: air group, hyperoxia group, hyperoxia plus CGRP group, hyperoxia plus CGRP and CGRP8-37 (CGRP receptor antagonist) group. Cells of air group and hyperoxia group were exposed to 21% air or 60% oxygen, respectively, while in hyperoxia plus CGRP group CGRP was added, and in hyperoxia plus CGRP and CGRP8-37 group CGRP and CGRP8-37 were added before exposure to 60% oxygen. Cells in four groups were cultured for 24 hours, and then ground into homogenates for detection of malondialdehyde (MDA), total antioxidant capacity (TAOC) and superoxide dismutase (SOD) with ultraviolet spectrophotometer. Reactive oxygen species (ROS) and apoptosis rate of AEC II were analyzed by flow cytometry and the mRNA level of surfactant associated protein C (SPC) was measured by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: The levels of ROS, MDA and apoptosis rate were increased whereas TAOC, SOD and SPC mRNA expression declined in hyperoxia group compared with those in air group (all P<0.01). In contrast, MDA, ROS and apoptosis rate were significantly lower and levels of TAOC, SOD and SPC mRNA expression were significantly higher in hyperoxia plus CGRP group than those in hyperoxia group (all P<0.01). The differences in 6 parameters above between hyperoxia group and hyperoxia plus CGRP and CGRP8-37 group were not statistically significant. CONCLUSION: Exposure of AEC II from immature rat to 60% oxygen for 24 hours may produce oxidative injury, inducing apoptosis and decrease in SPC mRNA level of AEC II of premature rat in vitro, while CGRP may play a protective role against hyperoxic lung injury by its antioxidant property, and also inhibition of AEC II apoptosis and promotion of the SPC mRNA expression.