Role of Vitamin D and Vitamin D Polymorphisms in COVID-19 Risk and Severity in Children: A Systematic Review.

The role of vitamin D in the susceptibility to coronavirus disease 2019 (COVID-19) disease has been investigated since the beginning of the pandemic, but there is still scarce data on children. We investigated the impact of vitamin D status and the related genetic variants on COVID-19 vulnerability and severity of the disease in children. A systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, to identify reports on vitamin D status and genetic polymorphisms, their association with the susceptibility of children to COVID-19 and multisystem inflammatory syndrome in children (MIS-C), and the effect of supplementation on the clinical course. Of an initial total of 279 articles, 26 studies, published between September 2020 and May 2023, were finally included in this review according to inclusion criteria. Quantitative data provided by 11 studies revealed that 43.05% of pediatric COVID-19 patients had low vitamin D levels. Mean serum 25(OH)D levels were observed to be significantly low in COVID-19 cases, with an estimated pooled mean value of 17 ng/mL, as provided by 16 studies. Vitamin D deficiency and the vitamin D receptor (VDR) FokI polymorphism may suggest independent risk factors for susceptibility to COVID-19 in the pediatric population. The 25(OH)D level may constitute a significant biomarker associated with the COVID-19 severity and MIS-C. While supplementation of COVID-19 cases with vitamin D showed favorable results, the effect on the outcome of the disease remains uncertain.

Vaccination coverage of patients with type 2 diabetes mellitus: Challenging issues from an outpatient secondary care setting in Greece.

Background: Increased morbidity/mortality due to vaccine preventable diseases (VPD) is encountered in type 2 diabetes (T2D) people. Aim of this study was to assess their vaccination coverage and describe trends possibly affecting compliance. Methods: Information on vaccination coverage was retrieved from either documents or interview provided by patients, and/or their vaccination record card at a specialized outpatient diabetes center. The selection of the patients was arbitrary. Results: An increasing vaccination rate for influenza was observed from 2018 to 2020 among 372 participants. The vaccination coverage for S.pneumoniae was 67.2% (PCV13), 20.4% (PPSV23), 26.3% for herpes zoster in individuals ≥60 years, 1.9% for tetanus-diphtheria-pertussis and 1.1% for hepatitis B. A 10.2% of participants were found to be unvaccinated. Vaccination uptake for influenza and PCV13 was related to age, ≥3 comorbidities and long-term follow-up. T2D individuals consecutively vaccinated for influenza were 3.78 times more likely to be also vaccinated with PCV13. Conclusions: Vaccination rates of patients with T2D show an increasing trend, especially for influenza and S. pneumoniae, although the one for S. pneumoniae was low. Older people seem more prone to vaccination, the one for herpes zoster was low with infected patients remaining unvaccinated while significantly low coverage was observed for other VPDs. The findings are important to improve effectiveness of preventative services.

Vaccine coverage in children, adolescents and adults with type 1 diabetes and their close contacts in Crete.

BACKGROUND: Individuals with type 1 diabetes (T1D) are at increased risk of infections from vaccine-preventable diseases. This study focuses on compliance of T1D patients to the recommended vaccination schedule, vaccination of their close contacts for influenza and on factors potentially contributing to vaccination program deviations. METHODS: The study population comprised children, adolescents and adults with T1D under follow-up at the Department of Pediatrics University Hospital and the Diabetic Center General Hospital, Heraklion, Crete-Greece. Data were extracted, following informed consent, from individual's vaccination booklet, medical files and telephone interview. Vaccination records, demographic parameters, glycemic control and influenza vaccination of close contacts were assessed. RESULTS: The study included 258 participants (111 children/adolescents, 147 adults). Vaccination coverage for influenza was 76.7% for children, 64.4% for adults, for PCV 90.9% for children, but only 10.8% for the 23-valent, for hepatitis B 99% for children and 78.2% for adults. Youngsters were vaccinated against Hib 91.9%, meningococcus C 98.2%, measles-mumps-rubella 90.3%, chickenpox 86.4%, hepatitis A 76.5% and HPV 42.5%. Less than 65% of all individuals were fully vaccinated for diphtheria-tetanus-pertussis and meningococcus ACWY. Approximately 50% of the 605 close contacts were not vaccinated against influenza. Individuals with better glycemic status seemed to adhere to the recommended schedule and had a better vaccinated family environment. CONCLUSIONS: Vaccination coverage for T1D individuals was sufficient regarding the majority of routine childhood vaccines, but less for adolescence and group-specific vaccines. Their family contacts were not sufficiently vaccinated for influenza. Targeted interventions are required in order to increase vaccination rates.

Cavitary tuberculosis re-emerging in immigrant children.

Cavitary pulmonary tuberculosis in children is uncommon in areas with a low tuberculosis burden. We present two cases in an 11-year old immunocompetent girl and an 8-year old immunocompromised boy. Both children were immigrants. No other cavitary tuberculosis cases have been observed in a population of 103,781 children in Crete, Greece for the past 25 years. CONCLUSION: Severe forms of tuberculosis may re-emerge and BCG vaccination should remain part of the immunisation programme in immigrant populations.

Enhanced levels of the apoptotic BAX/BCL-2 ratio in children with acute lymphoblastic leukemia and high-risk features.

It has been suggested that leukemia is characterized by an impaired balance between the proliferation of blood cells and their capacity to undergo apoptosis. The aim of this study was to examine the expression of key molecules related to apoptosis (BCL-2, BAX, FAS, FAS-L) in children with acute lymphoblastic leukemia (ALL). Measurement of BCL-2 and BAX mRNA was performed by quantitative real-time PCR, and membrane expression of FAS and FAS-L was assessed by flow cytometry in bone marrow mononuclear cells, both at diagnosis and at remission following induction chemotherapy. At diagnosis, increased levels of the apoptotic BAX/BCL-2 ratio were observed in children older than 10 years and with higher white blood cell counts. A DNA index < 1.16 was associated with increased BAX/BCL-2, both at diagnosis and at remission, and the del(9p) chromosome abnormality with increased BAX/BCL-2 at remission. The expression of the apoptotic receptor FAS was significantly higher at remission compared to diagnosis, which might reflect enhanced sensitivity of the leukemic clone to apoptosis and response to treatment. Altogether, our results highlight the association of apoptosis-related genes with clinical and cytogenetic prognostic parameters in pediatric ALL. A better understanding of the mechanisms and regulation of apoptosis should enable the design of novel targeted therapies for these patients.