Immune responses to tetanus vaccination in Italian healthy subjects and children with recurrent infections

The ability of vaccine antigen to generate protection is a challenge that cannot be restricted to the antibody response; however, the contribution of T cell-mediated mechanisms has not been extensively analyzed. Age and administration to specific categories of patients, i.e. children with recurrent infections (RI), are some of the factors that might affect the vaccine immune response. We investigated the humoral and cellular response to tetanus toxoid (TT) vaccine in 104 healthy children (HC), 11 newborns and 22 healthy adults to characterize the status of immunity according to age and compared it to 118 RI children. Humoral and cellular responses varied in both groups according to age and doses of TT administered. The prevalence of antibody and cellular response was similar in both cohorts (HC 88 percent and 82 percent versus RI 86 percent and 85 percent), however, TT antibody values were significantly higher in 12-18 months old RI children compared to HC (median: 5 IU/ml vs 1.10 IU/ml) (p = 0.02). The lack of an efficient immune response was observed in 12-15 percent of children from both cohorts. Our data showed that specific antibodies were responsible for early protection, whereas cell-mediated mechanisms may contribute to the generation of long-term immunity after an appropriate vaccine recall. The occurrence of higher TT antibody values in 12-18 months old RI children deserves additional research to determine whether they are caused by different infectious agents and/or by other environmental factors. Clarification of this issue is important for categorizing patients into an optimal vaccine policy.

Lack of Systemic Side Effects of Long-Term Inhaled Fluticasone Propionate Use in a Cohort of Asthmatic Children

Inhaled corticosteroids (ICS) are established as first-line therapy for persistent asthma in children. Fluticasone propionate (FP) has been used because it has equivalent efficacy when used at half-dose of older-generation ICS and has a comparable safety profile. However, concerns persist about the potential risk of adverse effects of long-term FP therapy on childhood growth, bone, adrenal function and immune system. To evaluate the potential adverse effects of FP, we analyzed growth, glucidic metabolism, hypothalamic-pituitary-adrenal axis, bone metabolism, bone mass density and immune system in a cohort of 19 children (average 102±18 months), with asthma who were in treatment with FP (average duration: 14 months, range: 11–17 months). Of these, 11 children homogenous for control of asthma symptoms, and compliance to therapy, were selected for a prospective study during which they were treated with FP250 mg/day for further 6 months (total period of treatment average duration: 22 months, range: 18–23 months). In all children, no alterations of growth, glucidic metabolism, hypothalamic-pituitary-adrenal axis, bone metabolism, bone mass density, immune system nor severe exacerbation of the disease were observed. Our study, showing that FP was able to control the symptoms of asthma and confirming the lack of systemic side effects at the recommended doses, supports its long-term use in children with asthma.

Demethylation analysis of the FOXP3 locus shows quantitative defects of regulatory T cells in IPEX-like syndrome

Immune dysregulation, Polyendocrinopathy, Enteropathy X-linked (IPEX) syndrome is a unique example of primary immunodeficiency characterized by autoimmune manifestations due to defective regulatory T (Treg) cells, in the presence of FOXP3 mutations. However, autoimmune symptoms phenotypically resembling IPEX often occur in the absence of detectable FOXP3 mutations. The cause of this “IPEX-like” syndrome presently remains unclear.

To investigate whether a defect in Treg cells sustains the immunological dysregulation in IPEX-like patients, we measured the amount of peripheral Treg cells within the CD3⁺ T cells by analysing demethylation of the Treg cell-Specific-Demethylated-Region (TSDR) in the FOXP3 locus and demethylation of the T cell-Specific-Demethylated-Region (TLSDR) in the CD3 locus, highly specific markers for stable Treg cells and overall T cells, respectively.

TSDR demethylation analysis, alone or normalized for the total T cells, showed that the amount of peripheral Treg cells in a cohort of IPEX-like patients was significantly reduced, as compared to both healthy subjects and unrelated disease controls. This reduction could not be displayed by flow cytometric analysis, showing highly variable percentages of FOXP3⁺ and CD25⁺FOXP3⁺ T cells. These data provide evidence that a quantitative defect of Treg cells could be considered a common biological hallmark of IPEX-like syndrome. Since Treg cell suppressive function was not impaired, we propose that this reduction per se could sustain autoimmunity.

Happy Air: a school-based educational program to maximize detection of asthma in children

OBJECTIVE

To investigate whether an active partnership among school, parents, and pediatricians allows early identification and treatment of asthmatic children.

METHODS

An asthma educational program (Happy Air), based on a strong family-physician-school interrelationship, was performed in six primary schools (2,765 children) before administering a screening questionnaire to the parents.

RESULTS

A high response rate (96%) demonstrated 2,649 responders available for the asthma screening: 135 children (5%) received a diagnosis of asthma, of which 37 (27%) were recognized de novo.

CONCLUSION

The active participation of school and parents is the determining factor for the success of an asthma screening program.