HMGB1: A pleiotropic activity.

High-mobility group box 1 (HMGB1) is a nuclear protein involved in DNA replication, transcription, recombination, and repair. In the extracellular space, the HMGB1 plays an essential role in the onset and perpetuation of inflammation, belonging to the group of damage-associated molecular pattern (DAMP) molecules, also called alarmins. For this, HMGB1 has been studied in several acute and chronic inflammatory diseases as an early biomarker of inflammation. An increased concentration of HMGB1 has been detected in serum, as the expression of systemic inflammation, and in specific samples (such as stool, synovial fluid, nasal lavage fluid, sputum, and cerebrospinal fluid), as the expression of local production, in several infectious and/or inflammatory diseases. These data are particularly important because they open new futuristic possibilities for target therapies, potentially also for the COVID-19 treatment.

Recurrent respiratory infections between immunity and atopy.

Recurrent respiratory infections (RRIs) are frequent in children and are characterized by more than 6 airway infections in 1 year or more than 1 upper airway infection per month in the period between September and April or more than 3 lower airway infections in 1 year. Often pediatric RRIs are related to predisposing factors, such as reduced airway size, poor tussive reflex, and immaturity of the immune system. RRIs due to immature immune system are a transient condition, with spontaneous resolution in the school age. However, some RRIs are expression of more complex diseases. Red flags are the onset of symptoms in the first year of life, the involvement of other systems, unusual pathogens, slowing of growth, severe infections of the lower airways, and recurrence of the infection site. To help the pediatrician in the RRI differential diagnosis, we have created a roadmap based on scientific literature data and clinical practice that identifies 6 macro areas: immunodeficiencies, simple minimal genetic immunodeficiency, atopy, obesity, nutritional deficiencies, autoinflammatory diseases, and complex diseases.

Illegal immigration: the puzzling role of several risk factors for rhabdomyolysis.

A 14-year-old boy presented with low-grade fever, widespread myalgia and difficulty in walking and standing 2 days after the undocumented trip which brought him from western Africa to Italy. His serum creatine phosphokinase was markedly elevated. He was diagnosed with rhabdomyolysis and was volume-restored with normal saline and bicarbonate-containing fluid. Anamnesis revealed illegal, not well-specified, forced consumption in his fatherland, and very bad conditions of the trip (prolonged immobility, dehydration, hypothermia). Workup included a respiratory microbiological panel which was positive for Chlamydia pneumoniae Other microbiological agents were excluded. After 3 weeks, he recovered complete motility. Undocumented immigrants may present several risk factors for rhabdomyolysis that give to this group of individuals a higher risk of developing this disorder.

Neuroinflammation in Autism Spectrum Disorders: Role of High Mobility Group Box 1 Protein.

The pathogenesis of autism spectrum disorder (ASD) likely involves genetic and environmental factors, impacting the complex neurodevelopmental and behavioral abnormalities of the disorder. Scientific research studies emerging within the past two decades suggest that immune dysfunction and inflammation have pathogenic influences through different mechanisms, all leading to both a chronic state of low grade inflammation, and alterations in the central nervous system and immune response, respectively. The high mobility group box-1 protein (HMGB1) is an inflammatory marker which has been shown to play a role in inducing and influencing neuroinflammation. Current evidences suggest a possible role in the multiple pathogenic mechanisms of ASD. The aim of this manuscript is to review the major hypothesis for ASD pathogenesis, with specific regards to the immunological ones, and to provide a comprehensive review of the current data about the association between HMGB1 and ASD. A systematic search has been carried out through Medline via Pubmed to identify all original articles published in English, on the basis of the following keywords: "HMGB1", "autism", "autism spectrum disorder", "neuroinflammation", and "child".

Local Allergic Rhinitis in Pediatric Patients: Is IgE Dosage in Nasal Lavage Fluid a Useful Diagnostic Method in Children?

Local Allergic Rhinitis (LAR) is an emerging disease. However, its incidence in the pediatric popolution has not yet been studied. The gold standard for the diagnosis is the nasal provocation test that is not everywhere avalaible and difficult to apply in children. The aim of our study was to evaluate the nasal lavage fluid IgE as a biomarker of LAR in children. 54 pediatric patients [IQR 4.0-12.0 years] were divided into 3 groups: study group (26 children with rhinitis symptoms and without evidence of systemic atopy); allergic rhinitis (AR) group (15 children) and 13 healty controls (HC). Every child was subjected to nasal lavage using 2 ml/nostril of physiologic saline solution, that was therefore analyzed by ImmunoCAP to obtain the IgE concentration. Rhinofibroscopy and nasal cytology were performed. Our data showed the presence of higher value of nasal lavage fluid IgE (average of 6.005 UI/ml; range: 4.47-7.74 UI/ml) in 16 out of 26 patients of the study group who therefore may be classified as affected by LAR. We observed a statistically significant difference (P< 0.0001) between NAR/HC group and LAR group, identifying a cut-off of 3.85 UI/ml. Finally, we found a better response to previous AR therapy in the LAR group than in the NAR group. Our data showed the high incidence of LAR in pediatric patients previously classified as NAR. The measurment of IgE in nasal lavage fluid may be considered an easy and rapid method for the diagnosis of LAR in children. Besides, our data add confirmatory evidence about the good response of LAR children to the classic AR therapy.

Utility of Specific IgE to Ara h 2 in Italian Allergic and Tolerant Children Sensitized to Peanut.

Emerging data suggest that measurement of serum IgE to peanut components can be clinically helpful and more accurate than IgE to whole peanut to predict peanut allergy. Not all studies have used prospective samples, multiple components and oral challenges. Currently, there are no data on this topic involving Italian children. 32 patients (23 males; median age 9 years) with reported history for peanut allergy and evidence of peanut sensitization (skin prick test to peanut extract ≥ 3mm) have been analyzed for serum IgE to whole peanut and recombinant allergen components Ara h 1, 2, 3, 8, and 9 with Immuno CAP and completed an open oral food challenge with peanut. 12 (37.5%) children had a positive challenge to peanut and were considered allergic. No differences were seen between the median values of IgE to peanut, Ara h 1, 3, 8 and 9 in allergic and tolerant children to peanut challenge. Noteworthy, 5 of 20 tolerant children had IgE to peanut> 15 kUA/l which is commonly considered a predictive value of peanut allergy. Conversely, a significant difference was seen when comparing the median value of IgE to Ara h 2 in the two groups: 0.75 kUA/l (IQR: 0.22-4.34 kUA/l) in allergic children versus 0.1 kUA/l (IQR: 0.1-0.12 kUA/l) in tolerant ones (P< 0.001). IgE levels to Ara h 2 are significantly higher in children that react to oral peanut challenge. Our findings in Italian children have been in line with recent reports in various populations of Northern Europe, the US and Australia and add confirmatory evidence that analysis of IgE to Ara h 2 could reduce the need for peanut challenge in suspected allergic patients.

Atopy and autoimmune thyroid diseases: melatonin can be useful?

Recently, there has been growing interest in the relationship between allergic and autoimmune diseases. Allergy and autoimmunity can be considered two potential outcomes of dysregulated immunity and analysis of literature data shows a strong positive association between a history of Th2-mediated allergic disorders and Th1-mediated autoimmune disorders.Autoimmune thyroid diseases are the most common of all autoimmune pathological conditions.Currently, the mechanisms explaining an association among atopy, autoimmunity, and thyroid diseases are not fully understood.There are data in literature pointing to the relationship between melatonin and thyroid activity. Several studies have suggested a paracrine role for this molecule in the regulation of thyroid activity, documenting that administration, as an antioxidant, in thyroid tissues under conditions of increased oxidative stress, could be helpful to reduce the oxidative processes involved in autoimmune thyroid diseases.Although thyroid autoimmunity has been regularly associated with atopic conditions in children, the possible protective role of melatonin has not yet been investigated.This review summarizes what is known regarding the connection between atopy and autoimmune thyroid diseases, and analyses the probable beneficial action of melatonin.

High mobility group box 1 and tumor growth factor ß: useful biomarkers in pediatric patients receiving peritoneal dialysis.

BACKGROUND: Peritonitis, the most important limitation of peritoneal dialysis (PD), could be detected by biomarkers in dialysate effluent, representing a noninvasive method to indirectly assess the peritoneum status. The aim of our study was to test high mobility group box 1 (HMGB1) in PD patients, evaluating its role as precocious marker of peritoneum damage during peritonitis. Transforming growth factor (TGF)-ß was correlated with peritoneal transport characteristics. METHODS: Six patients, treated by ambulatory PD, were enrolled. Samples were collected at the onset of peritonitis (T1) and every day until its resolution (T-end). Serum (s) and peritoneal (p) white blood cell (WBC) count was also evaluated. Peritoneal Equilibration Test evaluated the filter activity of peritoneum. RESULTS: In patients with acute peritonitis, the highest serum and peritoneal HMGB1 values (64 ± 3.6 and 70 ± 5.3 ng/mL, respectively) were assessed, with a progressive decrease of their levels at the resolution time (T-end: sHMGB1:36 ± 2.5; pHMGB1:30.5 ± 7.0 ng/mL). While no differences of sWBC and pWBC were observed between baseline and T-end values, pHMGB1 levels remained higher at T-end than those observed at T0 (pHMGB1:30.5 ± 7.0 versus 6.9 ± 3.6; p < 0.0001). TGF-ß levels were higher in patients with low peritoneal permeability than in medium or high transporter patients (81 ± 15.5 versus 24.3 ± 7.5 pg/mL; p = 0.01). An inverse correlation was found between TGF-ß levels and dialysate/plasmatic creatinine values (r = -0.83; p = 0.03). CONCLUSION: HMGB1 represents a useful biomarker for peritoneum evaluation in PD patients. A prognostic role of this alarmin, as a marker of response to therapy, could be hypothesized. TGF-ß could predict the peritoneal transport status and dialysis technique adequacy.

A history of recurrent wheezing can delay the diagnosis of foreign body aspiration in a paediatric emergency department.

Foreign body aspiration (FBA) into the airways is a potentially life-threatening event, and more frequent in children younger than 3 years of age; it can mimic other diseases by its frequently non-specific clinical and radiological presentation. The commonest misdiagnoses in children are asthma and recurrent respiratory tract infections with wheezing. This often makes it particularly difficult for a timely and proper diagnosis, especially when there is a silent history of FBA (not a rare occurrence in the age group at highest risk). We report a case of a 2-year-old boy who arrived at the emergency department at the Hospital of Ferrara, with dyspnoea, fever and wheezing, which had started 12 h after aspiration of a pistachio. The asymptomatic period after the pistachio aspiration, a history of recurrent wheezing during respiratory infections and the non-specificity of clinical and radiological findings, delayed the right diagnosis of FBA.