Characterization of a novel HDAC2 pathogenetic variant: a missing puzzle piece for chromatinopathies.

Histone deacetylases (HDACs) are enzymes pivotal for histone modification (i.e. acetylation marks removal), chromatin accessibility and gene expression regulation. Class I HDACs (including HDAC1, 2, 3, 8) are ubiquitously expressed and they often participate in multi-molecular protein complexes. To date, three neurodevelopmental disorders caused by mutations in genes encoding for HDACs (HDAC4, HDAC6 and HDAC8) and thus belonging to the group of chromatinopathies, have been described. We performed whole exome sequencing (WES) for a patient (#249) clinically diagnosed with the chromatinopathy Rubinstein-Taybi syndrome (RSTS) but negative for mutations in RSTS genes, identifying a de novo frameshift variant in HDAC2 gene. We then investigated its molecular effects in lymphoblastoid cell lines (LCLs) derived from the patient compared to LCLs from healthy donors (HD). As the variant was predicted to be likely pathogenetic and to affect the sequence of nuclear localization signal, we performed immunocytochemistry and lysates fractionation, observing a nuclear mis-localization of HDAC2 compared to HD LCLs. In addition, HDAC2 total protein abundance resulted altered in patient, and we found that newly identified variant in HDAC2 affects also acetylation levels, with significant difference in acetylation pattern among patient #249, HD and RSTS cells and in expression of a known molecular target. Remarkably, RNA-seq performed on #249, HD and RSTS cells shows differentially expressed genes (DEGs) common to #249 and RSTS. Interestingly, our reported patient was clinically diagnosed with RSTS, a chromatinopathy which known causative genes encode for enzymes antagonizing HDACs. These results support the role of HDAC2 as causative gene for chromatinopathies, strengthening the genotype-phenotype correlations in this relevant group of disorders.

Disrupted Seasonality of Respiratory Viruses: Retrospective Analysis of Pediatric Hospitalizations in Italy from 2019 to 2023.

This multicenter study in Italian hospitals highlights the epidemiologic disruptions in the circulation of the 5 main respiratory viruses from 2019 to 2023. Our data reveal a resurgence of respiratory syncytial virus and influenza during the 2022-2023 winter season, with an earlier peak in cases for both viruses, emphasizing the importance of timely monitoring.

The Hospital Burden of Flu in Italy: a retrospective study on administrative data from season 2014-2015 to 2018-2019.

BACKGROUND: Every year in Italy, influenza affects about 4 million people. Almost 5% of them are hospitalised. During peak illness, enormous pressure is placed on healthcare and economic systems. This study aims to quantify the clinical and economic burden of severe influenza during 5 epidemic seasons (2014-2019) from administrative claims data. METHODS: Patients hospitalized with a diagnosis of influenza between October 2014, and April 2019, were analyzed. Clinical characteristics and administrative information were retrieved from health-related Administrative Databases (ADs) of 4 Italian Local Health Units (LHUs). The date of first admission was set as the Index Date (ID). A follow-up period of six months after ID was considered to account for complications and re-hospitalizations, while a lookback period (2 years before ID) was set to assess the prevalence of underlying comorbidities. RESULTS: Out of 2,333 patients with severe influenza, 44.1% were adults ≥ 65, and 25.6% young individuals aged 0-17. 46.8% had comorbidities (i.e., were at risk), mainly cardiovascular and metabolic diseases (45.3%), and chronic conditions (24.7%). The highest hospitalization rates were among the elderly (≥ 75) and the young individuals (0-17), and were 37.6 and 19.5/100,000 inhabitants/year, respectively. The average hospital stay was 8 days (IQR: 14 - 4). It was higher for older individuals (≥ 65 years, 11 days, [17 - 6]) and for those with comorbidities (9 days, [16 - 6]), p-value < 0.001. Similarly, mortality was higher in elderly and those at risk (p-value < 0.001). Respiratory complications occurred in 12.7% of patients, and cardiovascular disorders in 5.9%. Total influenza-related costs were €9.7 million with hospitalization accounting for 95% of them. 47.3% of hospitalization costs were associated with individuals ≥ 65 and 52.9% with patients at risk. The average hospitalisation cost per patient was € 4,007. CONCLUSIONS: This retrospective study showed that during the 2014-2019 influenza seasons in Italy, individuals of extreme ages and those with pre-existing medical conditions, were more likely to be hospitalized with severe influenza. Together with complications and ageing, they worsen patient's outcome and may lead to a prolonged hospitalization, thus increasing healthcare utilization and costs. Our data generate real-world evidence on the burden of influenza, useful to inform public health decision-making.

Long-lasting effects of COVID-19 pandemic on hospitalizations and severity of bronchiolitis.

Bronchiolitis is a common cause of hospitalization in infants. The long-lasting impact of hygiene and social behavior changes during the pandemic on this disease is debated. We investigated the prevalence of hospitalized cases, clinical severity, and underlying risk factors before and during pandemic. The study was conducted in 27 hospitals in Italy and included infants hospitalized for bronchiolitis during the following four periods: July 2018-March 2019, July 2020-March 2021, July 2021-March 2022, and July 2022-March 2023. Data on demographics, neonatal gestational age, breastfeeding history, underlying chronic diseases, presence of older siblings, etiologic agents, clinical course and outcome were collected. A total of 5330 patients were included in the study. Compared to 2018-19 (n = 1618), the number of hospitalizations decreased in 2020-21 (n = 121). A gradual increase was observed in 2021-22 (n = 1577) and 2022-23 (n = 2014). A higher disease severity (need and length of O2-supplementation, need for non-invasive ventilation, hospital stay) occurred in the 2021-22 and, especially, the 2022-23 periods compared to 2018-19. This tendency persisted after adjusting for risk factors associated with bronchiolitis severity.   Conclusions: Compared to adults, COVID-19 in infants is often asymptomatic or mildly symptomatic and rarely results in hospitalization. This study indicates that the pandemic has indirectly induced an increased burden of bronchiolitis among hospitalized infants. This shift, which is not explained by the recognized risk factors, suggests the existence of higher infant vulnerability during the last two seasons. What is known: • The pandemic led to a change in epidemiology of respiratory diseases • Large data on severity of bronchiolitis and underlying risk factors before and during COVID-19 pandemic are scarce What is new: • Compared to pre-pandemic period, hospitalizations for bronchiolitis decreased in 2020-21 and gradually increased in 2021-22 and 2022-23 • Compared to pre-pandemic period, higher disease burden occurred in 2021-22 and, especially, in 2022-23. This tendency persisted after adjusting for risk factors associated with bronchiolitis severity • The interplay among viruses, preventive measures, and the infant health deserves to be further investigated.

Acute otitis media diagnosis in childhood: still a problem in 2023?

BACKGROUND: Diagnosis of acute otitis media (AOM) in children can be challenging, given that symptoms are often non-specific or absent, and that the direct observation of the tympanic membrane in its entirety through otoscopy can sometimes be difficult. The aim of this study is to assess the diagnostic concordance in detection of AOM episodes between primary care paediatricians and physicians especially trained in paediatric otoscopy, and to characterize the most misleading elements in diagnostic failure. METHODS: Consecutive clinical charts of children regularly followed for recurrent AOM (RAOM, i.e.: >3 episodes in 6 months or > 4 episodes in 1 year) at our Otitis Media paediatric outpatient clinic were retrospectively screened, in order to collect any diagnosis of AOM episode (and the related clinical findings/middle ear complaints) performed by primary care paediatricians/emergency room paediatricians. Diagnosis of AOM episode was validated by the same experienced physician (FF) in case of otoscopic relief of a bulging eardrum with at least one of the following: hyperaemia or yellow-like colour. The diagnostic concordance in detection of AOM episodes between primary care/emergency room paediatricians and our internal validator was expressed as the percentage of matching diagnosis. RESULTS: One hundred and thirty-four single AOM episodes occurring in 87 children (mean age: 26.9 +/- 18.9 months) were included in the analysis. Diagnostic concordance in detection of AOM episodes between primary care/emergency room paediatricians and our internal validator was reported in 72.4% of cases. The most common pitfall found in our study was the misleading diagnosis of AOM in case of hyperaemic tympanic membrane without bulging (32/37 out of non-validated diagnoses). CONCLUSIONS: AOM diagnosis still represents a relevant issue among paediatricians in our country, and the presence of tympanic membrane hyperaemia without concomitant bulging can be confusing.

Group A Streptococcal Infections in Pediatric Age: Updates about a Re-Emerging Pathogen.

Group A Streptococcus (GAS) presents a significant global health burden due to its diverse clinical manifestations ranging from mild infections to life-threatening invasive diseases. While historically stable, the incidence of GAS infections declined during the COVID-19 pandemic but resurged following the relaxation of preventive measures. Despite general responsiveness to ß-lactam antibiotics, there remains an urgent need for a GAS vaccine due to its substantial global disease burden, particularly in low-resource settings. Vaccine development faces numerous challenges, including the extensive strain diversity, the lack of suitable animal models for testing, potential autoimmune complications, and the need for global distribution, while addressing socioeconomic disparities in vaccine access. Several vaccine candidates are in various stages of development, offering hope for effective prevention strategies in the future.

The Phenotype-Based Approach Can Solve Cold Cases: The Paradigm of Mosaic Mutations of the CREBBP Gene.

Rubinstein-Taybi syndrome (RTS) is a rare genetic disorder characterized by intellectual disability, facial dysmorphisms, and enlarged thumbs and halluces. Approximately 55% of RTS cases result from pathogenic variants in the CREBBP gene, with an additional 8% linked to the EP300 gene. Given the close relationship between these two genes and their involvement in epigenomic modulation, RTS is grouped into chromatinopathies. The extensive clinical heterogeneity observed in RTS, coupled with the growing number of disorders involving the epigenetic machinery, poses a challenge to a phenotype-based diagnostic approach for these conditions. Here, we describe the first case of a patient clinically diagnosed with RTS with a CREBBP truncating variant in mosaic form. We also review previously described cases of mosaicism in CREBBP and apply clinical diagnostic guidelines to these patients, confirming the good specificity of the consensus. Nonetheless, these reports raise questions about the potential underdiagnosis of milder cases of RTS. The application of a targeted phenotype-based approach, coupled with high-depth NGS, may enhance the diagnostic yield of whole-exome sequencing (WES) in mild and mosaic conditions.

Otitis Media With Effusion After the COVID-19 Pandemic: Return to the Past and New Lessons.

OBJECTIVE: To assess the prevalence of otitis media with effusion (OME) among children who attended a tertiary level audiologic center 2 and 3 years after the COVID-19 lockdown, and to determine the impact of temporary interruption of day care center attendance on chronic OME. STUDY DESIGN: Retrospective study. SETTING: Tertiary level referral audiologic center. METHODS: We assessed the prevalence of OME among children aged 6 months to 12 years in 3 different periods (May-June 2022, January-February 2023, and May-June 2023) and compared the results with those of the corresponding periods before the COVID-19 lockdown. We also compared the disease resolution rates between a subgroup of children with chronic OME who interrupted day care center attendance for a 2-month period (Subgroup A) and a similar subgroup who continued attending day care centers (Subgroup B). RESULTS: The prevalence of OME was 38.5% (138/358) in May-June 2022, 51.9% (193/372) in January-February 2023, and 40.9% (149/364) in May-June 2023. No significant prevalence differences were observed between the periods May-June 2019, May-June 2022, and May-June 2023 (P = .78), and between the periods January-February 2020 and January-February 2023 (P = .93). At the May-June 2023 assessment, the children belonging to Subgroup A presented a greater rate of disease resolution (85.7%, 18/21) than the children belonging to Subgroup B (32%, 8/25, P < .001). CONCLUSION: This study suggests that the prevalence of OME has returned to prelockdown levels, and that interrupting day care center attendance for a 2-month period could be effective in resolving most cases of chronic OME.

Recurrent upper respiratory tract infections in early childhood: a newly defined clinical condition.

BACKGROUND: Recurrent Upper Respiratory Tract Infections (R-URTIs) pose a significant challenge in pediatric healthcare, affecting both children and their families. This study aimed to investigate the prevalence, risk factors, and clinical implications of R-URTI in children aged 0-5 years. METHODS: This observational study involved a sample of 483 children aged 0-5 years, focusing on establishing a practical and dynamic definition of R-URTI. Family pediatricians prospectively collected socio-demographic information, medical history, and recorded the occurrence of URTI episodes. Children were followed from recruitment until March 2021, predating the COVID-19 outbreak. RESULTS: A substantial prevalence of R-URTIs was found, estimating it at 5-10% among this age group. To define R-URTI, a practical and dynamic criterion was proposed: children experiencing a minimum of four URTI episodes, each lasting four days or more, within a six-month period, with intervals of well-being in between. CONCLUSIONS: The study highlighted that specific risk factors for R-URTI were elusive, suggesting that this condition may affect children regardless of their family or clinical history. Moreover, the study's stratification by age group and times of observation facilitated patient-specific clinical decision-making. The proposed definition may represent a valuable tool for clinicians in diagnosing and addressing R-URTI cases.