Annamaria Castellazzi

In vitro activation of mononuclear cells by two probiotics: Lactobacillus paracasei I 1688, Lactobacillus salivarius I 1794, and their mixture (PSMIX).

Background: Most studies on probiotics have described their effects on the human immune system after ingestion of LAB, but little is known about their effect on in vitro stimulation of human immune cells. Aim of the study: Evaluate the “in vitro” activity of Lactobacillus paracasei (I 1688), Lactobacillus salivarius (I 1794), and a commercial mix of the two (PSMIX, Proge Farm), on immune cells from healthy individuals. Materials: Two probiotic strains, Lactobacillus salivarius (I 1794; Proge Farm, Italy) and Lactobacillus paracasei (I 1688; Proge Farm, Italy), which are contained in the functional food ENTEROBACILLI, were evaluated for their ability to stimulate peripheral blood mononuclear cells and modulate surface phenotype and cytokine production. Results: All subjects responded to the bacteria, with different levels of response. The cell populations that showed a significant percent increase were CD4+/CD25+ cells (T-helper activated regulatory cells), CD8+/CD25+ (T-suppressor/cytotoxic activated cells), and CD16+/CD56+ (NK cells) (p<0.05). IL-12 and IFN-γ in vitro production significantly increased with exposure to probiotics (p<0.05 for both). Conclusions: This study provides the first evidence that Lactobacillus paracasei and Lactobacillus salivarius are capable of inducing a specific immune response that may be useful in the clinical setting for improving innate and adaptive immune responses.

Adenoids during childhood: the facts.

Adenoids are constantly exposed to viral and bacterial agents as well as to allergens. They play a major role in the upper airways immunity, being effector organs in both mucosal-type and systemic-type adaptive immunity. Because of both their immunological function and their specific location, adenoids are considered to be as reservoirs of viruses and bacteria. Reiterative infections may therefore contribute both to Eustachian tube dysfunction and to tissue hypertrophy. Nasal endoscopy is a key diagnostic tool to detect both adenoid hypertrophy and adenoiditis. Moreover, such a procedure may be very helpful in detecting bacterial biofilms that could justify the concomitant presence of recurrent episodes of otitis media, chronic and occult sinusitis in children. Even though the connection between allergies and adenoidal diseases is not completely clear, allergic diseases cause an inflammatory state that influences adenoidal tissue as well, configuring the picture of allergic adenoiditis, a condition in which adenoid tissue exhibit numerous IgE positive mast cells. Several studies are still needed to better understand the relationship between allergies and infections and the influence they play on adenoids during childhood.

Adenoids in children: Advances in immunology, diagnosis, and surgery.

Adenoids are strategically located for mediating local and regional immune functions as they are exposed to antigens from both the outside air and the alimentary tract. Recurrent or chronic respiratory infections can induce histomorphological and functional changes in the adenoidal immunological barrier, sometimes making surgical treatment necessary. Our aim in this review is to summarize the crucial points about not only the immunological histopathology of adenoidal tissue, especially in patients with adenoid hypertrophy, but also the most common and useful diagnostic techniques and surgical options. Clin. Anat. 27:346–352, 2014.

Deficiency of INFgamma producing cells in adenoids of children exposed to passive smoke.

Exposure to passive smoke is a very common event associated with increased susceptibility to respiratory tract infections. Many related adverse effects result from the ability of cigarette smoke extracts to interfere with the immune system, but the mechanism is not yet completly understood. The aim of the present study is to evaluate the intracellular cytokine profile in adenoids and peripheral blood cells of children exposed to passive smoke. Children undergoing adenoidectomy exposed or not exposed to passive smoke were studied. The intracellular cytokine profile of lymphocyte subsets in adenoids and in peripheral blood were evaluated by flow cytometry analysis. Children exposed to tobacco smoke showed a significantly lower percentage of INF-γ producing CD4+ and CD8+ cells in adenoids. Moreover a significant correlation was observed between the quantity of exposure and reduction in Th1 (CD4+INFγ+ and CD8+INFγ +) cells in adenoids. This reduction may be a contributing factor in the increasing susceptibility to respiratory tract infection in children exposed to tobacco smoke.

FEF(25-75) might be a predictive factor for bronchial inflammation and bronchial hyperreactivity in adolescents with allergic rhinitis.

Allergic rhinitis and asthma are closely associated. Bronchial hyperreactivity (BHR) is a pathophysiological characteristic of asthma. Allergic inflammation is characterized by eosinophilic infiltrate and may by indirectly assessed by exhaled nitric oxide (FeNO). Forced expiratory flow between 25% and 75% of vital capacity (FEF25–75) may predict BHR in adult patients with allergic rhinitis. The aim of this study was to evaluate the presence of BHR in a large group of adolescents with allergic rhinitis and whether FEF25–75 might be related with BHR and FeNO. Methods 150 adolescents with allergic rhinitis were enrolled. Clinical examination, skin prick test, spirometry, methacholine challenge, and FeNO were performed in all patients. Results Severe BHR is quite frequent in allergic adolescents. Impaired FEF25–75 values (such as ⩽ 65% of predicted) constitute a relevant predictive factor for severe BHR (OR 4.4). FeNO levels were significantly related with BHR. Conclusion This study provides evidence that impaired FEF25–75 values might predict severe BHR and BHR is related with FeNO in adolescents. Therefore, BHR should be suspected in adolescents with low FEF25–75 values.

Antigen-specific T cell response in infants after recombinant hepatitis B virus vaccination at birth: evaluation of T helper lymphocyte diversity

Recombinant hepatitis B virus antigen (rHBsAg)-specific CD4+ T cell clones (TCC) were isolated and expanded from the peripheral blood of nine children vaccinated at birth against the hepatitis B (HB) virus. Four of them responded with protective antibody production (responders), three subjects were unable to produce detectable antibody levels even after revaccination (nonresponders), and two infants produced antibodies only after revaccination (slow responders). TCC were then characterized for their ability to produce cytokines known to be important for T cell expansion (interleukin-2, IL-2) and/or effector functions (IL-4, IFN-gamma, IL-10). Results demonstrated that the frequency of rHBsAg-specific TCC in the samples of nonresponders was comparable to or higher than that in the samples of responders. Nevertheless, the majority of TCC obtained from responders or from slow responders before revaccination displayed the T helper 1 (T(H1))-dominant phenotype, while the majority of TCC obtained from nonresponders were nonpolarized T lymphocytes. After revaccination, the distribution of the different T(H) subsets in slow responders was heterogeneous. Overall, our present data suggest that an absence or delay in developing an rHBsAg-specific antibody response to vaccination is not associated with the capacity to generate an Ag-specific T cell response. However, compared to responders, nonresponding infants react to the rHBsAg vaccination with a reduced capacity to expand and differentiate toward polarized T(H) cells.

Adipokines and their role in allergies.

Both allergic disorders and obesity keep increasing in industrialized countries. Even though a strong association between obesity and allergy-related diseases has been reported in several studies, no published data show a scientific and firm link in-between the two conditions. In general, obesity and weight gain have been associated with an increased risk of asthma and allergic rhinitis. Asthma, allergic rhinitis and obesity have a common inflammatory pattern that could therefore justify their association. In fact, the chronic inflammation that characterizes the increase in white adipose tissue typically pushes the immune system toward a Th2 pattern. Such a polarization might, consequentially, worsen a pre-existing allergic disease or even stimulate the evolution from a sensitization to a respiratory form of allergy. Several studies have been published on the role of different adipokines on allergic diseases. We focus our review on the role of adipokines on asthma and allergic rhinitis.

Peripheral TH-17 cells in children with allergic rhinitis: preliminary report.

Th17 is a subset of T helper lymphocytes and exerts pro-inflammatory activities. Recently, it has been reported that serum IL-17 levels are high in the most severe patients with birch allergy studied both outside and during the pollen season. This study aims to compare the frequency of peripheral IL-17-producing T cells in children with allergic rhinitis and in healthy controls. Ten children with allergic rhinitis and 5 healthy non-allergic subjects were evaluated. Th17 were evaluated by intracellular staining in ex-vivo T cell compartment. Ex- vivo PBMNC evaluation showed that allergic patients had higher frequencies of IL-17 producing T cells, both concerning CD4+ and CD8+ cells. In particular, there is a subset co-expressing IL-17 and IFN-γ both for CD4+ and CD8+ cells. In conclusion, this preliminary study suggests a possible role of Th-17 cells in the response to allergens in children.

Inflammation of paranasal sinuses: the clinical pattern is age-dependent.

Acute rhinosinusitis (ARS) represents a common disorder, associated with consistent morbidity as well as with a large prescription of antibiotics. ARS has a significant impact on clinical practice; it usually presents with respiratory complaints persisting longer than 10 days and showing no signs of improvement. Throughout the evaluation of 256 pediatric patients (152 males and 135 females, aged between 2 and 15 yr), with ARS confirmed by nasal endoscopy, we have been able to provide evidence that age has a significant influence on clinical patterns in children with ARS.

Gut Microbiota and Obesity.

Intestinal microbiota is composed by symbiotic innocuous bacteria and potential pathogens also called pathobionts. The human gut normally hosts roughly 1014 bacterial organisms of up to 1000 different species. The genome size of this microbial organ, collectively named microbiome, exceeds the size of the human nuclear genome by 2 orders of magnitude.