Identification of immune and metabolic predictors of severe hand-foot-mouth disease

Arginine depletion-induced autophagy and metabolic dysregulation are involved in the disease severity of hand, foot, and mouth disease

Amino acid metabolism provides significant insight into the development and prevention of many viral diseases. Therefore, the present study aimed to compare the amino acid profiles of hand, foot, and mouth disease (HFMD) patients with those of healthy individuals and to further reveal the molecular mechanisms of HFMD severity. Using UPLC-MS/MS, we determined the plasma amino acid expression profiles of pediatric patients with HFMD (mild, n = 42; severe, n = 43) and healthy controls (n = 25). Brain tissues from CVA6-infected mice were examined using untargeted metabolomics. Several amino acids were significantly different between the three groups. Pathway analysis revealed that arginine, proline, and tryptophan metabolism are implicated in the pathogenesis of HFMD. A similar arginine depletion was observed in the brain tissues of CVA6-infected mice. Importantly, L-arginine supplementation improved the survival rate of CVA6-infected mice, inhibited virus multiplication, and reduced pathological autophagy associated with mTOR-autophagy pathway in the brain. Collectively, arginine, as the hub amino acid metabolite of the mammalian target of rapamycin (mTOR) signaling pathway affecting autophagy, plays an important role in the pathogenesis of severe HFMD. L-arginine supplementation may serve as a potential therapeutic option for critical patients with HFMD.

Metabolomic analysis reveals an important role of sphingosine 1-phosphate in the development of HFMD due to EV-A71 infection

Hand, foot, and mouth disease (HFMD) is a serious pediatric infectious disease that causes immeasurable physical and mental health burdens. Currently, there is a lack of information on the mechanisms of HFMD severity and early diagnosis. We performed metabolomic profiling of sera from 84 Enterovirus A71 (EV-A71) infections and 45 control individuals. Targeted metabolomics assays were employed to further validate some of the differential metabolic molecules. We identified significant molecular changes in the sera of HFMD patients compared to healthy controls (HCs). A total of 54, 60, 35, and 62 differential metabolites were screened between mild cases and HCs, severe cases and HCs, severe cases and mild cases, and among the three groups, respectively. These differential metabolites implicated dysregulation of the tricarboxylic acid cycle, alanine, aspartate, and glutamate metabolism, and valine, leucine, and isoleucine biosynthesis. The diagnostic panel based on some overlapped differential metabolites could effectively discriminate severe cases from mild cases with an AUC of 0.912 (95% CI: 0.85-0.97) using the logistic regression model. Next, we found the elevation of serum sphingosine 1-phosphate (S1P) level in EV-A71 infection mice, which was similar to clinical observation. Importantly, after blocking the release of S1P by MK571, the clinical symptoms and survival of mice were significantly improved, involving the reduction of leukocyte infiltration in infected brain tissues. Collectively, our data provided a landscape view of metabolic alterations in EV-A71 infected children and revealed regulating S1P metabolism was an exploitable therapeutic target against EV-A71 infection.

Childhood hand, foot and mouth disease sequelae cohort study in Henan, China: cohort profile

PURPOSE

The childhood hand, foot and mouth disease (HFMD) sequelae cohort study (HNHFMDCS) is an ambispective cohort study of patients with HFMD based in Henan Province, China, consisting of patients treated in a key hospital for the diagnosis and treatment of HFMD in Henan Province. The study aims to investigate the long-term sequelae of HFMD survivors and to provide a comprehensive understanding of the potential harm caused by this infectious disease.

PARTICIPANTS

In the retrospective phase of the cohort study, children diagnosed with HFMD from January 2014 to January 2023 were included, and clinical and demographic information about the patients was collected through a self-developed questionnaire. Patients hospitalised with HFMD since January 2023 were enrolled in the prospective cohort phase of the study, and long-term follow-up will be performed after completion of the baseline investigation (interview and comprehensive physical examination), clinical laboratory examination and biospecimen collection.

FINDINGS TO DATE

For the retrospective analysis of the cohort, a total of 18 705 HFMD cases (11 834 males and 6871 females) were observed between 2014 and 2022, of which 17 202 were mild cases (10 839 males and 6363 females) and 1503 were severe cases (995 males and 508 females). Statistical analysis was performed on the collected clinical examination data, and descriptive statistical methods, including mean value, SD and t-test, were used to compare the intergroup data. All tests were bilateral, and p<0.05 was considered statistically significant. There were significant differences in the hospitalisation duration and clinical examination indicators, such as platelets (PLT), C reactive protein (CRP), aspartate amino transferase (AST), alanine amino transferase (ALT), T lymphocyte subsets (CD3+ and CD3+CD4+) and B lymphocytes (CD19+) between mild and severe patients. The differences in these clinical examination indicators also help to detect changes in the disease in time so as to deeply understand the potential harm and social burden of the disease, and provide strong support for the rehabilitation of patients.

FUTURE PLANS

Prospective cohort studies are currently underway, primarily enrolling hospitalised patients with HFMD to participate in our study. After the baseline investigation is completed, we will conduct long-term follow-up of the enrolled cases. In the coming year, we expect to obtain preliminary data on the incidence of sequelae in patients with HFMD 1-10 years after discharge, as well as information on the occurrence of sequelae. This dataset will be updated and expanded on an annual basis to support the continuous monitoring of patient health and disease progression. From HNHFMDCS, the study will provide a comprehensive overview of the potential harm caused by this common infectious disease, assess the social burden caused by this disease and make recommendations for the rehabilitation of survivors and prevention of further disability.

Epidemiological characterization of hand, foot, and mouth disease among hospitalized children from 2014 to 2023 in a hospital in Henan Province: Longitudinal surveillance study

Hand, foot, and mouth disease (HFMD) is an acute infectious illness primarily caused by enteroviruses. The present study aimed to describe the epidemiological characteristics of hospitalized HFMD patients in a hospital in Henan Province (Zhengzhou, China), and to predict the future epidemiological parameters. In this study, we conducted a retrospective analysis of general demographic and clinical data on hospitalized children who were diagnosed with HFMD from 2014 to 2023. We used wavelet analysis to determine the periodicity of the disease. We also conducted an analysis of the impact of the COVID-19 epidemic on the detection ratio of severe illness. Additionally, we employed a Seasonal Difference Autoregressive Moving Average (SARIMA) model to forecast characteristics of future newly hospitalized HFMD children. A total of 19 487 HFMD cases were included in the dataset. Among these cases, 1515 (7.8%) were classified as severe. The peak incidence of HFMD typically fell between May and July, exhibiting pronounced seasonality. The emergence of COVID-19 pandemic changed the ratio of severe illness. In addition, the best-fitted seasonal ARIMA model was identified as (2,0,2)(1,0,1)12. The incidence of severe cases decreased significantly following the introduction of the vaccine to the market (χ2 = 109.9, p < 0.05). The number of hospitalized HFMD cases in Henan Province exhibited a seasonal and declining trend from 2014 to 2023. Non-pharmacological interventions implemented during the COVID-19 pandemic have led to a reduction in the incidence of severe illness.

Abundant Neutrophil-Initiated Acute Myocardial Injury Following Coxsackievirus A6 Infection

Coxsackievirus A6 (CVA6) is currently considered as a predominant pathogen of hand, foot, and mouth disease (HFMD), and is occasionally linked to myocardial injury. We first established a mouse model of CVA6-induced myocardial injury. Next, we analyzed the immune cell phenotypes CVA6-infected mice hearts by fluorescence-activated cell sorting, and found that CVA6 led to massive neutrophils infiltration, suggesting their potential link with the occurrence of myocardial injury. We further used either αGr-1 or αLy6G antibody to deplete neutrophils, and found that neutrophil-depleted animals showed decreased cardiac enzymes, lower degree of pathology in hearts, and reduced inflammatory cytokine production compared to isotype controls. Finally, we confirmed the involvement of neutrophils in myocardial injury of clinical patients with severe HFMD. Our study suggests that excessive neutrophils contribute to myocardial injury caused by CVA6 infection, which provides new insights into myocardial injury during the development of HFMD severity and the outcome of immune cell-mediated therapies.

Hand, Foot, and Mouth Disease Associated With Transient Hyperphosphatasemia

A majority of pediatric outpatient practice involves managing familiar diseases that present in familiar ways. Occasionally, a familiar disease presents uniquely, which adds a diagnostic challenge and enhances the clinical experience of the clinician. We describe an 18-month-old male who presented to the clinic with a familiar disease but with unique additional findings. The patient had a one-day history of rash, subjective fever, and several episodes of non-bloody diarrhea. The rash included petechial lesions across his abdomen, groin, back, arms, and legs, as well as vesicular lesions in the mouth and on the palms and soles. A tentative diagnosis of hand, foot, and mouth disease (HFMD) was made. However, the presence of petechiae prompted further laboratory evaluation, including a complete blood count (CBC) and comprehensive metabolic panel (CMP). The CBC was unremarkable, but the CMP revealed an abnormally high serum alkaline phosphatase (ALP) level of 1,353 U/L (normal range: 53-128 U/L). The patient was subsequently diagnosed with an atypical presentation of HFMD associated with transient hyperphosphatasemia (TH). TH is characterized by a benign increase in serum alkaline phosphatase levels with an absence of liver or bone diseases. TH is usually clinically silent. Clinicians should consider the possibility of TH in pediatric patients who are found incidentally to have an elevated ALP, especially with a concomitant viral infection. An awareness and understanding of TH will prevent unnecessary additional testing and avoid undue parental anxiety.

Analysis of miRNAs Involved in Mouse Heart Injury Upon Coxsackievirus A2 Infection

Coxsackievirus A2 (CVA2) has recently been constantly detected, and is associated with viral myocarditis in children. Our previous study demonstrated that CVA2 led to heart damage in a neonatal murine model. However, the molecular mechanism of heart injury caused by CVA2 remains largely unknown. Emerging evidence suggests the significant functions of miRNAs in Coxsackievirus infection. To investigate potential miRNAs involved in heart injury caused by CVA2, our study, for the first time, conducted a RNA-seq in vivo employing infected mice hearts. In total, 87, 101 and 76 differentially expressed miRNAs were identified at 3 days post infection (dpi), 7 dpi and 7 dpi vs 3 dpi. Importantly, above 3 comparison strategies shared 34 differentially expressed miRNAs. These results were confirmed by quantitative PCR (qPCR). Next, we did GO, KEGG, and miRNA-mRNA integrated analysis of differential miRNAs. The dual-luciferase reporter assay confirmed the miRNA-mRNA pairs. To further confirm the above enriched pathways and processes, we did Western blotting and immunofluorescence staining. Our results suggest that inflammatory responses, T cell activation, apoptosis, autophagy, antiviral immunity, NK cell infiltration, and the disruption of tight junctions are involved in the pathogenesis of heart injury caused by CVA2. The dysregulated miRNAs and pathways recognized in the current study can improve the understanding of the intricate interactions between CVA2 and the heart injury, opening a novel avenue for the future study of CVA2 pathogenesis.

Characterization of Enterovirus Associated m6A RNA Methylation in Children With Neurological Symptoms: A Prospective Cohort Study

Little is known about the particular changes of N6-methyladenosine (m6A) RNA methylation in enterovirus (EV) infection among children with neurologic symptoms. Here, we determined the characterization of EV associated m6A RNA methylation in this population. A prospective cohort study was conducted from 2018/2 to 2019/12 at the Guangzhou Women and Children’s Medical Center. We included EV infected children with and without neurological symptoms. High-throughput m(6)A-RNA immunoprecipitation sequencing (MeRIP-seq) and RNA-seq analysis were used to evaluate the m6A RNA methylation and transcript expression of cerebrospinal fluid samples. The functional annotation and pathways of differentially methylated m6A genes with synchronously differential expression were analyzed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Seven patients were enrolled in the control group, and 13 cases were in the neurological symptoms (NS) group. A total of 3472 differentially expressed genes and 957 m6A modified genes were identified. A conjoint analysis of MeRIP-seq and RNA-seq data found 1064 genes with significant changes in both the m6A modifications and mRNA levels. The different m6A RNA methylation was increased in the transcriptome’s CDS regions but decreased in both the 3′UTRs and stop codon among the NS group. Functional annotation like the “oxidative phosphorylation” gene pathway, “Parkinson’s disease” and GO terms like “respiratory electron transport chain,” “cellular metabolic process,” and “oxidation-reduction process” was enriched in symptomatic patients. Our study elucidated the changes of RNA m6A methylation patterns and related cellular functions and signaling pathways in EV patients with neurologic symptoms.

Risk Factors for Severe Hand-Foot-Mouth Disease in China: A Systematic Review and Meta-Analysis

Background: This study aimed to identify potential risk factors for severe hand-foot-mouth disease (HFMD). Methods: The PubMed, Embase, the Cochrane Library, Sinomed, WanFang, CNKI, and VIP databases were searched (up to August 2021). Results: Twenty-nine studies (9,241 and 927,355 patients with severe HFMD and controls, respectively; all from China) were included. EV71 was associated with higher odds of severe HFMD compared with other agents (OR = 4.44, 95%CI: 3.12-6.33, p < 0.001). Being home-raised (OR = 1.99, 95%CI: 1.59-2.50, p < 0.001), higher number of children in the family (OR = 2.09, 95%CI: 1.93-2.27, p < 0.001), poor hand hygiene (OR = 2.74, 95%CI: 1.78-4.23, p < 0.001), and no breastfeeding (OR = 2.01, 95%CI: 1.45-2.79, p < 0.001) were risk factors for severe HFMD. First consulting to a district-level or above hospital (OR = 0.34, 95%CI: 0.25-0.45, p < 0.001) and diagnosis of HFMD at baseline (OR = 0.17, 95%CI: 0.13-0.24, p < 0.001) were protective factors against severe HFMD. Fever, long fever duration, vomiting, lethargy, leukocytosis, tic, and convulsions were each associated with severe HFMD (all p < 0.05), while rash was not. Conclusions: EV71, lifestyle habits, frequent hospital visits, and symptoms are risk factors for severe HFMD in children in China, while early diagnosis and admission to higher-level hospitals are protective factors.

Development and Validation of Diagnostic Models for Hand-Foot-and-Mouth Disease in Children

Objective

To find risk markers and develop new clinical predictive models for the differential diagnosis of hand-foot-and-mouth disease (HFMD) with varying degrees of disease.

Methods

19766 children with HFMD and 64 clinical indexes were included in this study. The patients included in this study were divided into the mild patients' group (mild) with 12292 cases, severe patients' group (severe) with 6508 cases, and severe patients with respiratory failure group (severe-RF) with 966 cases. Single-factor analysis was carried out on 64 indexes collected from patients when they were admitted to the hospital, and the indexes with statistical differences were selected as the prediction factors. Binary multivariate logistic regression analysis was used to construct the prediction models and calculate the adjusted odds ratio (OR).

Results

SP, DP, NEUT#, NEUT%, RDW-SD, RDW-CV, GGT, CK/CK-MB, and Glu were risk markers in mild/severe, mild/severe-RF, and severe/severe-RF. Glu was a diagnostic marker for mild/severe-RF (AUROC = 0.80, 95% CI: 0.78-0.82); the predictive model constructed by temperature, SP, MOMO%, EO%, RDW-SD, GLB, CRP, Glu, BUN, and Cl could be used for the differential diagnosis of mild/severe (AUROC > 0.84); the predictive model constructed by SP, age, NEUT#, PCT, TBIL, GGT, Mb, β2MG, Glu, and Ca could be used for the differential diagnosis of severe/severe-RF (AUROC > 0.76).

Conclusion

By analyzing clinical indicators, we have found the risk markers of HFMD and established suitable predictive models.

Regional-level risk factors for severe hand-foot-and-mouth disease: an ecological study from mainland China

Background

Severe hand-foot-and-mouth disease (HFMD) is a life-threatening contagious disease among young children and infants. Although enterovirus A71 has been well acknowledged to be the dominant cause of severe HFMD, there still remain other unidentified risk factors for severe HFMD. Previous studies mainly focused on identifying the individual-level risk factors from a clinical perspective, while rare studies aimed to clarify the association between regional-level risk factors and severe HFMD, which may be more important from a public health perspective.

Methods

We retrieved the clinical HFMD counts between 2008 and 2014 from the Chinese Center for Disease Control and Prevention, which were used to calculated the case-severity rate in 143 prefectural-level cities in mainland China. For each of those 143 cities, we further obtained city-specific characteristics from the China City Statistical Yearbook (social and economic variables) and the national meteorological monitoring system (meteorological variables). A Poisson regression model was then used to estimate the associations between city-specific characteristics (reduced by the principal component analysis to avoid multicollinearity) and the case-severity rate of HFMD. The above analysis was further stratified by age and gender to examine potential modifying effects and vulnerable sub-populations.

Results

We found that the case-severity rate of HFMD varied dramatically between cities, ranging from 0 to 8.09%. Cities with high case-severity rates were mainly clustered in Central China. By relating the case-severity rate to city-specific characteristics, we found that both the principal component characterized by a high level of social and economic development (RR = 0.823, 95%CI 0.739, 0.916) and another that characterized by warm and humid climate (RR = 0.771, 95%CI 0.619, 0.960) were negatively associated with the case-severity rate of HFMD. These estimations were consistent across age and gender sub-populations.

Conclusion

Except for the type of infected pathogen, the case-severity rate of HFMD was closely related to city development and meteorological factor. These findings suggest that social and environmental factors may also play an important role in the progress of severe HFMD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12199-020-00927-9.

Comparative studies of the expression of creatine kinase isoforms under immune stress in Pelodiscus sinensis

The expression and localization of different isoforms of creatine kinase in Pelodiscus sinensis (PSCK) were studied to reveal the role of PSCK isozymes (PSCK-B, PSCK-M, PSCK-S) under bacterial infection-induced immunologic stress. The computational molecular dynamics simulations predicted that PSCK-S would mostly possess a kinase function in a structural aspect when compared to PSCK-B and PSCK-M. The assay of biochemical parameters such as total superoxide dismutase (T-SOD), lactate dehydrogenase (LDH), malondialdehyde (MDA), catalase (CAT), and the content of ATP were measured along with total PSCK activity in different tissue samples under bacterial infection. The expression detections of PSCK isozymes in vitro and in vivo were overall well-matched where PSCK isozymes were expressed differently in P. sinensis tissues. The results showed that PSCK-B mostly contributes to the spleen, followed by the liver and myocardium; PSCK-M mostly contributes to the liver, followed by the myocardium and skeletal muscle, while PSCK-S contributes to the spleen and is uniquely expressed in skeletal muscle. Our study suggests that the various alterations of PSCK isozymes in tissues of P. sinensis are prone to defense the bacterial infection and blocking energetic imbalance before severe pathogenesis turned on in P. sinensis.

Association between platelet count and the risk and progression of hand, foot, and mouth disease among children

OBJECTIVE

We aimed to evaluate the association between platelet (PLT) count and the risk and progression of hand, foot, and mouth disease (HFMD).

METHODS

In total, 122 HFMD patients and 40 healthy controls were enrolled in the study. The differences between variables among the different subgroups were compared. Logistic regression analyses were performed to assess the relationship between various parameters and HFMD risk/progression. Sensitivity analysis was conducted by detecting the trend of the association between PLT count quartiles and HFMD risk/progression. A generalized additive model was used to identify the nonlinear relationship between PLT count and HFMD risk/progression. The relationship between gender and PLT count as well as the risk/progression of HFMD was detected using a stratified logistic regression model.

RESULTS

Significant differences were observed in terms of age, male/female ratio, white blood cell (WBC) count, and PLT count between patients with stage I-II, III-IV HFMD and healthy controls. Moreover, the alanine aminotransferase and magnesium levels between patients with stage I-II and III-IV HFMD significantly differed. Moreover, a significant difference was noted in the male/female ratio among the different PLT groups. The group with a low PLT count had a lower risk of HFMD progression than the group with a high PLT count (Q4) (p=0.039). Lower age, male gender, and WBC count were found to be associated with HFMD risk. Meanwhile, PLT count was correlated to HFMD progression. The sensitivity analysis yielded a similar result using the minimally adjusted model (p for trend=0.037), and minimal changes were observed using the crude and fully adjusted model (p for trend=0.054; 0.090). A significant nonlinear relationship was observed between PLT count and HFMD progression after adjusting for age, gender, and WBC (p=0.039).

CONCLUSIONS

PLT was independently associated with HFMD progression in a nonlinear manner.