Progressive Depletion of B and T Lymphocytes in Patients with Ataxia Telangiectasia: Results of the Italian Primary Immunodeficiency Network.

Ataxia telangiectasia (AT) is a rare neurodegenerative genetic disorder due to bi-allelic mutations in the Ataxia Telangiectasia Mutated (ATM) gene. The aim of this paper is to better define the immunological profile over time, the clinical immune-related manifestations at diagnosis and during follow-up, and to attempt a genotype-phenotype correlation of an Italian cohort of AT patients. Retrospective data of 69 AT patients diagnosed between December 1984 and November 2019 were collected from the database of the Italian Primary Immunodeficiency Network. Patients were classified at diagnosis as lymphopenic (Group A) or non-lymphopenic (Group B). Fifty eight out of 69 AT patients (84%) were genetically characterized and distinguished according to the type of mutations in truncating/truncating (TT; 27 patients), non-truncating (NT)/T (28 patients), and NT/NT (5 patients). In 3 patients, only one mutation was detected. Data on age at onset and at diagnosis, cellular and humoral compartment at diagnosis and follow-up, infectious diseases, signs of immune dysregulation, cancer, and survival were analyzed and compared to the genotype. Lymphopenia at diagnosis was related per se to earlier age at onset. Progressive reduction of cellular compartment occurred during the follow-up with a gradual reduction of T and B cell number. Most patients of Group A carried bi-allelic truncating mutations, had a more severe B cell lymphopenia, and a reduced life expectancy. A trend to higher frequency of interstitial lung disease, immune dysregulation, and malignancy was noted in Group B patients. Lymphopenia at the onset and the T/T genotype are associated with a worst clinical course. Several mechanisms may underlie the premature and progressive immune decline in AT subjects.

Selective IgA Deficiency and Allergy: A Fresh Look to an Old Story.

Selective IgA deficiency (SIgAD) is the most common human primary immune deficiency (PID). It is classified as a humoral PID characterized by isolated deficiency of IgA (less than 7 mg/dL but normal serum IgG and IgM) in subjects greater than 4 years of age. Intrinsic defects in the maturation of B cells and a perturbation of Th cells and/or cytokine signals have been hypothesized to contribute to SIgAD pathogenesis. The genetic basis of IgA deficiency remains to be clarified. Patients with SIgAD can be either asymptomatic or symptomatic with clinical manifestations including allergy, autoimmunity and recurrent infections mainly of the respiratory and gastrointestinal tract. Studies analyzing allergy on SIgAD patients showed prevalence up to 84%, supporting in most cases the relationship between sIgAD and allergic disease. However, the prevalence of allergic disorders may be influenced by various factors. Thus, the question of whether allergy is more common in SIgAD patients compared to healthy subjects remains to be defined. Different hypotheses support an increased susceptibility to allergy in subjects with SIgAD. Recurrent infections due to loss of secretory IgA might have a role in the pathogenesis of allergy, and vice versa. Perturbation of microbiota also plays a role. The aim of this review is to examine the association between SIgAD and atopic disease and to update readers on advances over time at this important interface between allergy and SIgAD.

Chronic cough in childhood: A systematic review for practical guidance by the Italian Society of Pediatric Allergy and Immunology.

The current systematic review presented and discussed the most recent studies on pediatric chronic cough. In addition, the Italian Society of Pediatric Allergy and Immunology elaborated a comprehensive algorithm to guide the primary care approach to a pediatric patient with chronic cough.Several algorithms on chronic cough management have been adopted and validated in clinical practice; however, unlike the latter, we developed an algorithm focused on pediatric age, from birth until adulthood. Based on our findings, children and adolescents with chronic cough without cough pointers can be safely managed, initially using the watchful waiting approach and, successively, starting empirical treatment based on cough characteristics. Unlike other algorithms that suggest laboratory and instrumental investigations as a first step, this review highlighted the importance of a "wait and see" approach, consisting of parental reassurance and close clinical observation, also due to inter-professional collaboration and communication between general practitioners and specialists that guarantee better patient management, appropriate prescription behavior, and improved patient outcome. Moreover, the neonatal screening program provided by the Italian National Health System, which intercepts several diseases precociously, allowing to treat them in a very early stage, helps and supports a "wait and see" approach.Conversely, in the presence of cough pointers or persistence of cough, the patient should be tested and treated by the specialist. Further investigations and treatments will be based on cough etiology, aiming to intercept the underlying disease, prevent potentially irreversible tissue damage, and improve the general health of patients affected by chronic cough, as well as the quality of life of patients and their family.

Acute cough in children and adolescents: A systematic review and a practical algorithm by the Italian Society of Pediatric Allergy and Immunology.

The current systematic review presented and discussed the most recent studies on acute cough in pediatric age. After that, the Italian Society of Pediatric Allergy and Immunology elaborated a comprehensive algorithm to guide the primary care approach to pediatric patients, such as infants, children, and adolescents, with acute cough. An acute cough is usually consequent to upper respiratory tract infections and is self-resolving within a few weeks. However, an acute cough may be bothersome, and therefore remedies are requested, mainly by the parents. An acute cough may significantly affect the quality of life of patients and their family.Several algorithms for the management of acute cough have been adopted and validated in clinical practice; however, unlike the latter, we developed an algorithm focused on pediatric age, and, also, in accordance to the Italian National Health System, which regularly follows the child from birth to all lifelong. Based on our findings, infants from 6 months, children, and adolescents with acute cough without cough pointers can be safely managed using well-known medications, preferably non-sedative agents, such as levodropropizine and/or natural compounds, including honey, glycerol, and herb-derived components.

Long-term follow-up of 168 patients with X-linked agammaglobulinemia reveals increased morbidity and mortality.

BACKGROUND: X-linked agammaglobulinemia (XLA) is the prototype of primary humoral immunodeficiencies. Long-term follow-up studies regarding disease-related complications and outcome are scarce. OBJECTIVE: Our aim was to describe the natural history of XLA. METHODS: A nationwide multicenter study based on the Italian Primary Immunodeficiency Network registry was established in 2000 in Italy. Affected patients were enrolled by documenting centers, and the patients' laboratory, clinical, and imaging data were recorded on an annual base. RESULTS: Data on the patients (N = 168) were derived from a cumulative follow-up of 1370 patient-years, with a mean follow-up of 8.35 years per patient. The mean age at diagnosis decreased after establishment of the Italian Primary Immunodeficiency Network registry (84 months before vs 23 months after). Respiratory, skin, and gastrointestinal manifestations were the most frequent clinical symptoms at diagnosis and during long-term follow-up. Regular immunoglobulin replacement treatment reduced the incidence of invasive infections. Affected patients developed chronic lung disease over time (47% after 40 years of follow-up) in the presence of chronic sinusitis (84%). Malignancies were documented in a minority of cases (3.7%). Overall survival for affected patients was significantly reduced when compared with that for the healthy male Italian population, and it further deteriorated in the presence of chronic lung disease. CONCLUSIONS: This is the first detailed long-term follow-up study for patients with XLA, revealing that although immunoglobulin replacement treatment reduces the incidence of invasive infections, it does not appear to influence the development of chronic lung disease. The overall survival of affected patients is reduced. Further studies are warranted to improve patients' clinical management and increase awareness among physicians.

The Italian Registry for Primary Immunodeficiencies (Italian Primary Immunodeficiency Network; IPINet): Twenty Years of Experience (1999-2019).

Primary immunodeficiencies (PIDs) are heterogeneous disorders, characterized by variable clinical and immunological features. National PID registries offer useful insights on the epidemiology, diagnosis, and natural history of these disorders. In 1999, the Italian network for primary immunodeficiencies (IPINet) was established. We report on data collected from the IPINet registry after 20 years of activity. A total of 3352 pediatric and adult patients affected with PIDs are registered in the database. In Italy, a regional distribution trend of PID diagnosis was observed. Based on the updated IUIS classification of 2019, PID distribution in Italy showed that predominantly antibody deficiencies account for the majority of cases (63%), followed by combined immunodeficiencies with associated or syndromic features (22.5%). The overall age at diagnosis was younger for male patients. The minimal prevalence of PIDs in Italy resulted in 5.1 per 100.000 habitants. Mortality was similar to other European registries (4.2%). Immunoglobulin replacement treatment was prescribed to less than one third of the patient cohort. Collectively, this is the first comprehensive description of the PID epidemiology in Italy.

Update on rhinitis and rhinosinusitis.

Rhinitis is a common, under-diagnosed condition in childhood and adolescence. Pathogenic classification of rhinitis includes allergic rhinitis (AR) and non-allergic rhinitis (NAR); the latter is characterized by non-infectious and infectious subtypes; non-infectious subtype is by far the most prevalent in infancy. Endotyping may help to predict chronic rhinosinusitis (CRS) risk factors, as well as disease progression and response to different treatments. The validation of pediatric algorithms and the implementation of novel biotherapeutics in the endotype-driven integrated pathways of CRS will lead in the next future to more successful disease management.

Is oxidative stress involved in vernal keratoconjunctivitis? Results from a pilot study in children.

BACKGROUND: Vernal keratoconjunctivitis (VKC) is a rare chronic conjunctivitis characterized by a predominantly eosinophil-mediated inflammatory disorder that could develop critical complications such as blindness. Oxidative stress plays a pivotal role in the pathogenesis of several allergic diseases. The role of oxidative stress has been hypothesized in VKC, but no study explored this issue. Furthermore, cyclosporine A (CsA) exerts an anti-inflammatory and antioxidant action on the conjunctiva. This study aimed to assess the oxidative stress in VKC patients and controls and to study the effect of CsA on oxidative stress in these subjects. METHODS: Thirty-six consecutive children, including 12 VKC (nine males, 75%; mean age 10.17; SD ± 2.48) patients without treatment, 12 VKC patients treated with CsA (nine males, 75%; mean age 9.08; SD ± 2.75), and 12 controls (CT) (seven males, 58%; mean age 8.58; SD ± 1.78), were recruited. A cross-sectional study was performed to compare H2 O2 in the serum with that in the tears of these children. RESULTS: Compared with CT and VKC children treated with CsA, VKC untreated children had significantly higher values of hydrogen peroxide (H2 O2 ) in the serum and the tears. No significant differences were observed between CT and VKC treated with CsA. A significant correlation was found at the linear regression analysis between serum and tear H2 O2 levels. CONCLUSION: This study provides the first report attesting that patients with VKC have high oxidative stress; furthermore, it suggests that CsA could have an anti-inflammatory and antioxidant action that could be useful to prevent the poor VKC outcome.

Assessing repeatability and reproducibility of Anterior Active Rhinomanometry (AAR) in children.

BACKGROUND: Repeatability and reproducibility are essential for clinicians for several purposes. Although discouraged, use of the Coefficient of Variation (CV) for assessing repeatability and reproducibility, rather than the Intraclass Correlation Coefficient (ICC), is still widespread. The aim of the present study was to highlight how using inappropriate indices may lead to misleading results, and this is done by simulation study and using real data on Anterior Active Rhinomanometry (AAR) in both healthy children and ones with rhinitis. METHODS: A simulation study was carried out to highlight how using inappropriate indices could be misleading. Then a comparison was made between CV and ICC to assess repeatability and reproducibility of AAR, for which previous studies have given underestimated results. AAR is recommended as the gold standard tool for measuring nasal resistance in clinical practice. RESULTS: A simulation study showed that the ICCs estimated from data generated assuming a true CV yielded results in agreement with estimated CVs; by contrast, if data were generated assuming a true ICC, CVs yielded conflicting results. For AAR, ICCs showed good repeatability, whereas CVs showed unacceptable repeatability. AUC and 95% CI for AAR showed good performance in predicting current symptoms of rhinitis in the overall study population. CONCLUSIONS: The present study focused on the importance of the choice of appropriate indices of repeatability and reproducibility, demonstrating the repeatability of AAR in both healthy children and ones with rhinitis. TRIAL REGISTRATION: ClinicalTrials.gov (ID: NCT03286049; Registration Date: September 15, 2017; Actual Study Start Date: January 10, 2018).

Oxidative stress and gut-derived lipopolysaccharides in children affected by paediatric autoimmune neuropsychiatric disorders associated with streptococcal infections.

BACKGROUND: Paediatric autoimmune neuropsychiatric disorders associated with streptococcal infections syndrome (PANDAS) identifies patients with acute onset of obsessive-compulsive and tic disorders. The objective of this study was to evaluate serum NOX2 levels, as well as 8-iso-prostaglandin F2α (8-iso-PGF2α) and lipopolysaccharide (LPS) of PANDAS patients. METHODS: In this study we wanted to compare serum levels of soluble NOX2-dp (sNOX-2-dp), iso-PGF2α and LPS in 60 consecutive subjects, including 30 children affected by PANDAS and 30 controls (CT) matched for age and gender. Serum zonulin was used as intestinal permeability assay. RESULTS: Compared with CT, PANDAS children had increased serum levels of sNOX-2-dp, 8-iso-PGF2α and LPS. Bivariate analysis showed that serum sNOX2-dp was significantly correlated with LPS (Rs = 0.359; p = 0.005), zonulin (Rs = 0.444; p < 0.001) and 8-iso-PGF2α (Rs = 0.704; p < 0.001). Serum LPS significantly correlated with zonulin (Rs = 0.610; p < 0.001), and 8-iso-PGF2α (Rs = 0.591; p = 0.001). Finally, a multiple linear regression analysis showed that serum 8-iso-PGF2α and zonulin were the only independent variables associated with sNOX2-dp (R2 = 68%). CONCLUSION: This study shows that children affected by PANDAS have high circulating levels of sNOX2-dp, isoprostanes and of LPS that could be involved in the process of neuroinflammation.

Nasal reactivity evaluation in children with allergic rhinitis receiving grass pollen sublingual immunotherapy.

Background: The European Academy of Allergy and Clinical Immunology guidelines, strongly recommended allergen immunotherapy (AIT) as an effective treatment to achieve long-term clinical benefits and to modify the natural history of allergic diseases. Sublingual immunotherapy (SLIT) offers the possibility of home administration, which improves patient comfort and compliance. Objective: The primary outcome of this study was to assess the change in nasal reactivity after grass-pollen AIT treatment. Methods: This was a monocentric, prospective, observational study conducted in Rome from September 2016 to June 2018, in the Pediatric Department of Policlinico Umberto I. We enrolled children, ages between 6 and 12 years, with persistent allergic rhinitis (AR), sensitized to grass pollen. At the first visit (V0, September 2016), one group received the first dose of oral immunotherapy for grass-pollen spray buccal and the other group continued only standard therapy. All the patients had nasal specific immunoglobulin I (IgE) assay (Phl p1, Phl p5), active anterior rhinomanometry with a nasal provocation test (NPT), and spirometry. The patients attended two follow-up visits, in May 2017 (V1) and May 2018 (V2), with the same examinations as at V0. Results: During the treatment, we observed, in the treated group, a significant increase in the mean nasal flow compared with untreated children (p < 0.001). In the AIT group, we found an improvement of nasal function and only 21.05% of all the children in the active group with a positive NPT result at V2. In the control group, we found, at V2, a worsening of nasal function, with 89.47% of the children with a positive NPT result. Furthermore, we found a significant reduction of nasal specific IgE levels at the end of the observation period in the treated group. Conclusion: Analysis of our data provided evidence for a clinical effect of SLIT in inducing clinical changes and allergen tolerance in children with AR.

When asthma and rhinitis coexist, could rhinitis reduce asthma control in children?

Background: Bronchial asthma and rhinitis are among the most common diseases in children and frequently coexist in the patient. The primary aim of anti-asthmatic therapy is disease control. Several questionnaires can be used in pediatrics to assess asthma control and the Children Asthma Control Test (C-ACT) is one of the most used. Objective: To evaluate the percentage of asthma control in our cohort of patients with asthma and correlate C-ACT with bronchial and nasal function tests. Methods: We enrolled all children ages between 5 and 11 years with persistent bronchial asthma, sensitized to dust mite, and who presented to our center during an 8-month period. All the children had skin-prick tests, spirometry, measurement of fractional exhaled nitric oxide levels, active anterior rhinomanometry, measurement of nasal nitric oxide level, and C-ACT. Results: Sixty patients were enrolled; 80% of these children had rhinitis. According to C-ACT, 31% of our patients had uncontrolled asthma. Nasal flow values were significantly lower in patients with uncontrolled asthma, who also had higher nasal inflammation. Conclusion: The disease is not controlled in a significant percentage of children with asthma. In patients with uncontrolled asthma, worse nasal flow was detected. These results supported the relationship between upper and lower airways, and highlighted the importance of performing nasal function tests in all patients with asthma, which could be useful to determine whether better control of asthma symptoms can be reached through an appropriate treatment of rhinitis.

Role of NADPH oxidase-2 and oxidative stress in children exposed to passive smoking.

This study explored oxidative stress, nicotinamide adenine dinucleotide phosphate oxidase-2 (Nox2) activity and endothelial function in children exposed or not to passive smoking. Compared with controls (n=57), Nox2 activity and isoprostanes were higher in children exposed to passive smoking (n=57); conversely, nitric oxide (NO) bioavailability and flow-mediated dilation were lower in children exposed to passive smoking. A bivariate analysis showed that Nox2 activity correlated with flow-mediated dilation, NO bioavailability and isoprostanes. A multivariate analysis showed that Nox2 activity was significantly associated with serum isoprostanes and cotinine levels; flow-mediated dilation was associated with isoprostanes and carotid intima-media thickness.In children exposed to passive smoking, Nox2-derived oxidative stress is upregulated and inversely associated with impaired artery dilation.

B-cell activation with CD40L or CpG measures the function of B-cell subsets and identifies specific defects in immunodeficient patients.

Around 65% of primary immunodeficiencies are antibody deficiencies. Functional tests are useful tools to study B-cell functions in vitro. However, no accepted guidelines for performing and evaluating functional tests have been issued yet. Here, we report our experience on the study of B-cell functions in infancy and throughout childhood. We show that T-independent stimulation with CpG measures proliferation and differentiation potential of memory B cells. Switched memory B cells respond better than IgM memory B cells. On the other hand, CD40L, a T-dependent stimulus, does not induce plasma cell differentiation, but causes proliferation of naïve and memory B cells. During childhood, the production of plasmablasts in response to CpG increases with age mirroring the development of memory B cells. The response to CD40L does not change with age. In patients with selective IgA deficiency (SIgAD), we observed that switched memory B cells are reduced due to the absence of IgA memory B cells. In agreement, IgA plasma cells are not generated in response to CpG. Unexpectedly, B cells from SIgAD patients show a reduced proliferative response to CD40L. Our results demonstrate that functional tests are an important tool to assess the functions of the humoral immune system.

Passive Smoking Exacerbates Nicotinamide-Adenine Dinucleotide Phosphate Oxidase Isoform 2-Induced Oxidative Stress and Arterial Dysfunction in Children with Persistent Allergic Rhinitis.

OBJECTIVE: To characterize nicotinamide-adenine dinucleotide phosphate oxidase isoform 2 (NOX2), oxidative stress, and endothelial function in children with and without allergic rhinitis and to ascertain the effect of passive smoke exposure on these factors, because there is an established association between allergic rhinitis and increased cardiovascular risk in adults. METHODS: We recruited 130 children-65 with persistent allergic rhinitis and 65 healthy controls. A cross-sectional study was performed to compare endothelial function by flow-mediated dilation, blood levels of isoprostanes, serum activity of soluble NOX2-dp (sNOX2-dp), and nitric oxide bioavailability, in these 2 groups of children. Serum cotinine levels were assessed to measure exposure to passive smoking. RESULTS: Compared with healthy controls, children with persistent allergic rhinitis had significantly higher sNOX2-dp and isoprostanes levels, lower flow-mediated dilation, and reduced nitric oxide bioavailability. Multivariable linear regression analysis showed that flow-mediated dilation, isoprostanes, and cotinine were independently associated with sNOX2-dp levels. Of note, sNOX2-dp serum levels were significantly higher in children with allergic rhinitis exposed to smoke, as compared with unexposed children with allergic rhinitis. CONCLUSION: NOX2 is activated in children with persistent allergic rhinitis and passive smoke exposure exacerbates this effect. We further demonstrate an association between higher sNOX2-dp and oxidative stress and endothelial dysfunction.

Factors That Negatively Affect the Prognosis of Pediatric Community-Acquired Pneumonia in District Hospital in Tanzania.

Community-acquired pneumonia (CAP) is still the most important cause of death in countries with scarce resources. All children (33 months ± 35 DS) discharged from the Pediatric Unit of Itigi Hospital, Tanzania, with a diagnosis of CAP from August 2014 to April 2015 were enrolled. Clinical data were gathered. Dried blood spot (DBS) samples for quantitative real-time polymerase chain reaction (PCR) for bacterial detection were collected in all 100 children included. Twenty-four percent of patients were identified with severe CAP and 11% died. Surprisingly, 54% of patients were admitted with a wrong diagnosis, which increased complications, the need for antibiotics and chest X-rays, and the length of hospitalization. Comorbidity, found in 32% of children, significantly increased severity, complications, deaths, need for chest X-rays, and oxygen therapy. Malnourished children (29%) required more antibiotics. Microbiologically, Streptococcus pneumonia (S. p.), Haemophilus influenza type b (Hib) and Staphylococcus aureus (S. a.) were the bacteria more frequently isolated. Seventy-five percent of patients had mono-infection. Etiology was not correlated with severity, complications, deaths, oxygen demand, or duration of hospitalization. Our study highlights that difficult diagnoses and comorbidities negatively affect clinical evolution. S. p. and Hib still play a large role; thus, implementation of current vaccine strategies is needed. DBS is a simple and efficient diagnostic method for bacterial identification in countries with scarce resources.

Primary school children often underestimate their nasal obstruction.

BACKGROUND: No consensus has ever been reached about the correlation between nasal resistance and the subjective sensation of nasal patency. The aim of the present study was to better de ne whether primary school and secondary school aged children correctly estimate their nasal obstruction. MATERIALS AND METHODS: Two hundred eighty four children (168 males and 116 female) aged between 6 and 14 years (9.5+2.9 years) affected by Pediatric Allergic Rhinitis underwent Rhinomanometry and they were considered as correctly estimating their nasal obstruction when the grade of nasal patency corresponded to the severity of the NOSE score, overestimating when the grade of nasal patency was <1 when compared to the severity of the score, underestimating when the grade of nasal patency was >1 when compared to the severity of the score. RESULTS: Correlation between NOSE score and nasal patency was statistically significant (r -0.74; p<0.001). Children between 6 and 9 years of age underestimate (43.7%) and children >12 overestimate (34.7%) their symptoms more frequently than children among other age ranges (p<0.001). CONCLUSION: Although NOSE score approximately allow to quantify nasal obstruction, in children, especially between 6 and 9 years of age, an objective measurement of nasal patency should be performed to better define the therapeutic approach.

High-mobility group box-1 (HMGB-1) and serum soluble receptor for advanced glycation end products (sRAGE) in children affected by vernal keratoconjunctivitis.

BACKGROUND: Vernal keratoconjunctivitis (VKC) is a chronic disease affecting conjunctiva even though the immunopathogenetic mechanisms underlying this inflammation are unclear. The aim of our study is to investigate serum levels of HMGB1 and circulating sRAGE in children affected by VKC before and after treatment with cyclosporine A (CsA) eye drops and in a group of healthy children. METHODS: Twenty-four children affected by VKC aged between 5 and 12 yrs of life were enrolled at the Department of Pediatrics, Division of Allergy and Immunology, 'Sapienza' University of Rome. Twenty-four healthy children without atopy, ocular, and systemic disease, cross-matched for sex and age to patients affected by VKC, represented the controls. All children affected by VKC were treated with CsA 1% eye drops for 4 wks, and blood samples were collected before and 2 wks after the end of treatment while the controls underwent to a single blood sample at the time of enrollment. RESULTS: Serum basal levels of HMGB1 and sRAGE were higher in children with VKC when compared with controls while, in patients affected by VKC, no difference was detected between atopic and non-atopic, and between ANA-positive and ANA-negative children. A significant reduction in serum HMGB1 and sRAGE levels was detected after the therapy while CsA serum levels were negative. CONCLUSIONS: Our study gives a support to the definition of VKC as a systemic inflammation in which HMGB1 and its soluble receptors could play a role.