Diagnostic relevance of IgE sensitization profiles to eight recombinant Phleum pratense molecules

BACKGROUND

Grass pollen-related seasonal allergic rhinoconjunctivitis (SARg) is clinically heterogeneous in severity, comorbidities, and response to treatment. The component-resolved diagnostics disclosed also a high heterogeneity at molecular level. Our study aimed at analyzing the characteristics of the IgE sensitization to Phleum pratense molecules and investigating the diagnostic relevance of such molecules in childhood.

METHODS

We examined 1120 children (age 4-18 years) with SARg. Standardized questionnaires on atopy were acquired through informatics platform (AllergyCARD™). Skin prick tests were performed with pollen extracts. Serum IgE to airborne allergens and eight P. pratense molecules (rPhl p 1, rPhl p 2, rPhl p 4, rPhl p 5b, rPhl p 6, rPhl p 7, rPhl p 11, rPhl p 12) were tested by ImmunoCAP FEIA.

RESULTS

The analysis of IgE responses against eight P. pratense molecules showed 87 profiles. According to the number of molecules recognized by IgE, the more complex profiles were characterized by higher serum total IgE, higher grass-specific serum IgE, and higher number and degree of sensitization to pollens. The most frequent IgE sensitization profile was the monomolecular Phl p 1. Sensitization to Phl p 7 was a reliable biomarker of asthma, whereas Phl p 12 of oral allergy syndrome. Sensitization to Phl p 7 was associated with a higher severity of SARg, and complex profiles were associated with longer disease duration.

CONCLUSIONS

In a large pediatric population, the complexity of IgE sensitization profiles against P. pratense molecules is related to high atopic features although useless for predicting the clinical severity. The detection of serum IgE to Phl p 1, Phl p 7, and Phl p 12 can be used as clinical biomarkers of SARg and comorbidities. Further studies in different areas are required to test the impact of different IgE molecular profiles on AIT response.

Endotypes of pollen-food syndrome in children with seasonal allergic rhinoconjunctivitis: a molecular classification

BACKGROUND

Pollen-food syndrome (PFS) is heterogeneous with regard to triggers, severity, natural history, comorbidities, and response to treatment. Our study aimed to classify different endotypes of PFS based on IgE sensitization to panallergens.

METHODS

We examined 1271 Italian children (age 4-18 years) with seasonal allergic rhinoconjunctivitis (SAR). Foods triggering PFS were acquired by questionnaire. Skin prick tests were performed with commercial pollen extracts. IgE to panallergens Phl p 12 (profilin), Bet v 1 (PR-10), and Pru p 3 (nsLTP) were tested by ImmunoCAP FEIA. An unsupervised hierarchical agglomerative clustering method was applied within PFS population.

RESULTS

PFS was observed in 300/1271 children (24%). Cluster analysis identified five PFS endotypes linked to panallergen IgE sensitization: (i) cosensitization to ≥2 panallergens ('multi-panallergen PFS'); (ii-iv) sensitization to either profilin, or nsLTP, or PR-10 ('mono-panallergen PFS'); (v) no sensitization to panallergens ('no-panallergen PFS'). These endotypes showed peculiar characteristics: (i) 'multi-panallergen PFS': severe disease with frequent allergic comorbidities and multiple offending foods; (ii) 'profilin PFS': oral allergy syndrome (OAS) triggered by Cucurbitaceae; (iii) 'LTP PFS': living in Southern Italy, OAS triggered by hazelnut and peanut; (iv) 'PR-10 PFS': OAS triggered by Rosaceae; and (v) 'no-panallergen PFS': mild disease and OAS triggered by kiwifruit.

CONCLUSIONS

In a Mediterranean country characterized by multiple pollen exposures, PFS is a complex and frequent complication of childhood SAR, with five distinct endotypes marked by peculiar profiles of IgE sensitization to panallergens. Prospective studies in cohorts of patients with PFS are now required to test whether this novel classification may be useful for diagnostic and therapeutic purposes in the clinical practice.

Neuroimaging is useful for monitoring disease activity in linear scleroderma "en coup de sabre"

Scleroderma is a group of rare chronic connective tissue disorders characterized by collagen accumulation that causes tissue hardening with consequent fibrosis. Skin involvement is mostly frequent, although several internal organs can be impaired (heart, lungs, liver, etc.). In childhood, juvenile localized scleroderma (JLS) is more frequently observed; in this subtype cutaneous lesions predominate frequently on the limbs but also on the face and scalp; in this case, it is referred to as scleroderma "en coup de sabre" (ECDS). Neurological abnormalities have been described in association with ECDS as an effect of progressive scalp and underlying tissues involvement. Up to now, no validated biomarkers exist to evaluate disease evolution and, in this way, frequently diagnosis of central nervous system (CNS) involvement occurs when patients are already symptomatic. We describe the case of a 5-year old girl, with a diagnosis of ECDS characterized by the typical scalp lesion, with slight subsidence of the underlying diploe. In this case, radiological examination has been essential to evaluate the degree of progression of skin and soft tissues lesions and to clarify the right therapeutic approach. In selected JLS children, both MRI and CT with 3D reconstruction images provide a useful tool to monitor disease evolution and to address therapeutic choices.

High-resolution global maps of 21st-century forest cover change

Quantification of global forest change has been lacking despite the recognized importance of forest ecosystem services. In this study, Earth observation satellite data were used to map global forest loss (2.3 million square kilometers) and gain (0.8 million square kilometers) from 2000 to 2012 at a spatial resolution of 30 meters. The tropics were the only climate domain to exhibit a trend, with forest loss increasing by 2101 square kilometers per year. Brazil's well-documented reduction in deforestation was offset by increasing forest loss in Indonesia, Malaysia, Paraguay, Bolivia, Zambia, Angola, and elsewhere. Intensive forestry practiced within subtropical forests resulted in the highest rates of forest change globally. Boreal forest loss due largely to fire and forestry was second to that in the tropics in absolute and proportional terms. These results depict a globally consistent and locally relevant record of forest change.

Anti-infective prophylaxis for primary immunodeficiencies: what is done in Italian Primary Immunodeficiency Network centers (IPINet) and review of the literature

Primary immunodeficiencies (PIDs) are rare diseases characterized by an increased susceptibility to infections. Early diagnosis and appropriate treatment are critical for reducing morbidity and mortality. Based on available data, the efficacy of antibiotic administration for the prophylaxis of infections remains uncertain, and recommendations supporting this practice are poor. The use of antimicrobial prophylaxis is mainly based on single institution-specific experience without controlled measurements of patient safety and quality health outcomes. To address this issue an Italian Network on Primary Immunodeficiencies (IPINet) has been set up in 1999 within the Italian Association of Pediatric Hematology and Oncology (AIEOP) to increase the awareness of these disorders among physicians. Further, diagnostic and treatment guideline recommendations have been established to standardize the best clinical assistance to all patients, including antibiotic prophylaxis, and for a national epidemiologic monitoring of PIDs. The aim of this review is not only to give a scientific update on the use of antimicrobial prophylaxis in selected congenital immunological disorders but also to draw a picture of this practice in the context of the Italian Primary Immunodeficiency Network (IPINet). Controlled multicenter studies are necessary to establish if, when and how you should start an efficacious antimicrobial prophylaxis.

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.

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.

A Prospective Study on Children with Initial Diagnosis of Transient Hypogammaglobulinemia of Infancy: Results from the Italian Primary Immunodeficiency Network

Transient hypogammaglobulinemia of infancy (THI) is a heterogenous disorder characterized by reduced serum IgG levels in early infancy. A putative diagnosis is initially made after exclusion of other causes of hypogammaglobulinemia while a definitive diagnosis of THI can only be made a posteriori in patients with normalization of IgG levels. The aim of this study is to characterize clinical and immunological features of children with an initial diagnosis of THI in correlation to natural outcome, and to assess predictive laboratory parameters of clinical evolution for this disorder. We prospectively analysed clinical and immunological characteristics of 77 THI children at initial diagnosis and of 57 patients at follow-up. Memory B cell subsets and in vitro immunoglobulin production were evaluated. Seventy patients (91%) showed clinical symptoms. Patients suffered from infections (91%), allergies (47%) and autoimmune disease (4%). During follow-up 41/57 children (72%) normalized IgG values, mostly within 24 months of age (p<0.001), allowing the diagnosis of THI. The 16 children who did not normalize their IgG levels showed a higher frequency of severe infections and autoimmune disease (p<0.01). Moreover, they expressed a reduced frequency of IgM and switched memory B cells (p<0.01) and an inability to produce IgG in vitro (p<0.02). We conclude that most patients with an initial diagnosis of THI spontaneously recover within 24 months of age and have a benign clinical course, while a subgroup of children with undefined hypogammaglobulinemia share a clinical and immunological profile with other primary immunodeficiencies. Early recognition of children with hypogammaglobulinemia during infancy who are likely to suffer from permanent immunodeficiencies later in life would allow prompt and appropriate laboratory and clinical interventions.

Necrotizing enterocolitis in a 850 gram infant receiving sorbitol-free sodium polystyrene sulfonate (Kayexalate): clinical and histopathologic findings

We report a 27-week, 850 g infant with severe Streptococcus group B sepsis and life-threatening hyperkalemia due to progressive anuria. On the fourth day of life, after he failed treatment with diuretics, salbutamol, insulin, calcium gluconate and sodium bicarbonate, he was treated with sorbitol-free Kayexalate enemas. Potassium level slowly decreased from 9.2 mmol/l to normal level along with a recovery of normal urine output. On the 11th day of life, clinical and radiological signs of a perforated necrotizing enterocolitis (NEC) occurred and the patient required surgical intestinal resection. Histologic examination of the ileum specimen revealed areas of necrosis with fibrosis and giant cell reaction to a nonpolarizable material consistent with sodium polystyrene sulfonate. Usually, Kayexalate is suspended in hyperosmolar sorbitol solutions and the elevated osmolarity seems to be responsible for hemorrhagic colitis, transmural necrosis and definitely NEC. Our case report shows that Kayexalate per se, and not necessarily suspended in sorbitol, can lead to gastrointestinal tract complications and NEC in preterm infants.

Insight into B cell development and differentiation

The main topic of this article is B cell development and differentiation, with a special focus on the mechanisms and molecules that regulate the expression of humoral immunity. Molecular epidemiological analysis was performed on the genes responsible for the X-linked agammaglobulinemia (XLA) phenotype of the majority of Italian patients and their distinct mutations were characterized. Mutations in Bruton's tyrosine kinase (BTK), a member of Tec Family of protein tyrosine kinases, have been found to be mainly responsible for XLA disease. The exact function of BTK in signal transduction is not yet known; thus, the specific role of BTK in receptor-dependent calcium signaling and the pro-antiapoptotic regulatory activity was addressed by transfecting RAMOS-1, a BTK-deficient human Burkitt's/B cell leukemia line with wild-type and mutant constructs. This work may provide clues about critical sites in the molecule and give support for gene therapy as a potential successful approach to XLA. Another aspect of this research is the identification and dissection of the molecular events that are likely to be directly related to the ability to express various isotypes of immunoglobulin with differing function and certain B cell immunodeficiency, mainly common variable disease and non-X-linked hyperIgM. B cell development and maturation steps in different compartments of the immune system are tracked by the analysis of cell-surface molecules and components of the signal transduction pathways, i.e. CD40, CD30, CD27, CD38, CD22 and CD24. A few components involved in B cell development, maturation and differentiation and their specific functional role are at least partially known, but these are far from fitting into an understandable pathway at present.

Pulmonary and sinus diseases in primary humoral immunodeficiencies with chronic productive cough

AIMS

To prospectively evaluate sinopulmonary disease in 24 patients with primary humoral immunodeficiency (11 with agammaglobulinaemia, nine with isolated IgA deficiency, and two with common variable immunodeficiency) and chronic productive cough, ascertain the usefulness of chest high resolution computed tomography (HRCT) in evaluating the progression of lung disease, and test a therapeutic approach to chronic sinusitis.

METHODS

Pulmonary abnormalities were evaluated using lung function tests and HRCT (Bhalla score); chronic sinusitis was diagnosed clinically and confirmed by flexible fibreoptic endoscopy. Sixteen patients entered the three year follow up.

RESULTS

Lung function testing revealed an obstruction in four patients; chest HRCT was abnormal in 16. There was a linear relation between the Bhalla score > or =4 and the number of months with cough/year over the previous two years (clinical score), and between the difference in clinical scores during follow up and in the previous two years and the difference in Bhalla score. The pulmonary lesions did not significantly progress over a three year period. Thirteen patients had chronic sinusitis; 6/10 patients followed up were successfully treated with antibiotics plus topical therapy and two with nasal polypoid disease with endoscopic sinus surgery.

CONCLUSIONS

In patients with primary humoral immunodeficiency and chronic productive cough, HRCT is very useful in delineating the extent of lung damage. The correlation between Bhalla score and clinical findings and the favourable outcome of the disease suggests that in most patients chest HRCT should not be repeated annually as previously suggested. Medical therapy seems to be effective in many cases of chronic sinusitis.

Evidence of clonotypic pattern of T-cell repertoire in synovial fluid of children with juvenile rheumatoid arthritis at the onset of the disease

Rheumatoid arthritis (RA) and juvenile rheumatoid arthritis (JRA) are characterized by chronic inflammation, synovial cell proliferation and progressive joint damage. It has been speculated that T cells play an important role in the pathogenesis of RA and JRA in the early stage of the disease. Previous studies have demonstrated discrepant results regarding the significance of T-cell clonality in RA or JRA lesions. It can be postulated that the heterogeneity of these data may be linked to the stage of the disease, as the relative importance of selective immunological events is different during the time from onset to established disease. To avoid this problem, we conducted the present study in nine children affected by JRA at the onset of the disease and before treatment. We analysed the T-cell receptor beta chain variable (TCRBV) of CD4+ and CD8+ lymphocytes in peripheral blood (PBL) and synovial fluid (SFL), by a panel of monoclonal antibodies (MoAbs). Furthermore, to assess the clonotypic pattern of T-cell repertoire, the CDR3 length distribution was evaluated by spectratyping analysis. Our results showed no significant expansion of distinct TCRBV subset in either synovial or peripheral compartments. Conversely, when we studied the CDR3 length distribution, an oligoclonal pattern was found in the SFL of six patients, suggesting the presence of a clonotypic restriction of T cells in SFL, which is not detectable in PBL. These findings are consistent with an antigen driven T-cell expansion sequestered at the inflammatory site.

Characterization of the T-cell receptor V-beta repertoire in Kawasaki disease

Kawasaki disease (KD) is a paediatric multisystem necrotizing vasculitis constituting the most frequent cause of acquired heart disease in childhood. Conflicting data have been reported regarding expanded T-cell populations using particular T-cell receptor (TCR) beta-chain variable (BV) gene segments, suggesting either a superantigen- or a conventional antigen-mediated immune response in this disease. In order to further investigate the role of T lymphocytes, cells were stained with an extensive panel of 21 different TCRBV specific monoclonal antibodies (MoAbs) covering almost 70% of all T-cells. Flow cytometry was employed to analyse the expression of the TCRBV repertoire in the CD4+ and CD8+ subsets separately, and of activation markers, in freshly isolated peripheral blood lymphocytes of 25 Kawasaki disease patients during the acute and convalescent phases of the disease. No abnormal usage of any TCRBV family was found, neither acutely nor during convalescence, compared with a control group of healthy children. However, a significant increase in interleukin-2 receptor (IL-2R)-expressing T lymphocytes restricted to the CD4+ subset was observed in KD patients. Our data confirm a strong immune activation in KD that might be of importance in the pathogenesis of the disease.

Erythema nodosum: a presenting sign of early onset sarcoidosis

"Early onset sarcoidosis" is a chronic granulomatous disease occurring in children younger than 5 years of age, and characterized by a classic symptom triad consisting of skin, eye and joint lesions, with on rare occasion pulmonary involvement. The disorder often goes unrecognized because of its rarity and, since polyarthritis and uveitis are the predominant symptoms, most of these children are misdiagnosed as having juvenile chronic arthritis (JCA). A child with erythema nodosum at 7 months of age, later diagnosed as JCA and definitively recognized as "early onset sarcoidosis" is reported. This case shows that, whenever possible, a biopsy showing the typical picture of sarcoid granulomas is crucial to distinguish these clinical conditions.

[Clinical comparison of different replacement milk formulas in children with allergies to cow's milk proteins. 24-month follow-up study]

The elective treatment for allergy to cow's milk protein is the elimination of these proteins from the diet. The present study with a follow-up of over two years took the form of a comparison between different replacement formulas based on soya (group A), hydrolysate of soya and bovine collagen (group B), and hydrolysate of casein (group C), randomly administered to 55 children (30 males and 25 females, aged between 2-48 months) with documented allergy to cow's milk proteins, but with different clinical symptoms. Tests to evaluate the acquisition of clinical tolerance to cow's milk proteins were performed using a day-hospital regime every 6 months. Sensitivity reactions were observed in 22% of cases in group A, 8% in group B and 37.5% in group C. It is worth underlining that 5 of the 6 children with reactions to soya protein then showed an excellent tolerance to hydrolysate of soya when it was administered subsequently until tolerance was achieved. Weight and statutory growth was uniformly good in all three groups. A high percentage of children achieved tolerance after 24 months (72%); the mean time taken to acquire clinical tolerance was 11.6 +/- 4.8 in group A, 11.6 +/- 6.02 in group B, and 14 +/- 5.6 in group C. No correlation was found between the type of initial symptoms, age at onset, method of response to first challenge and the time taken to acquire tolerance.

Analysis of polyunsaturated fatty acids in newborn sera: a screening tool for atopic disease?

It has been demonstrated that patients with atopic disease have anomalies of fatty acid composition, as a result of altered metabolism or abnormal incorporation of fatty acids into the tissues. In the present study, in 57 newborns 'at risk' for atopic disease, the polyunsaturated fatty acid (PUFA) levels were found to be lower in cord blood in infants who subsequently developed atopic disease than in non-atopics. In all babies, levels of arachidonic acid and dihomo-gamma-linolenic acid in sera at 1 and 3 months of age were lower than those in cord blood. These changes were more marked in children who subsequently developed atopic disease, and in those who, independently of signs and/or symptoms of atopic disease, were formula-fed. A comparison between IgE and PUFA levels revealed no significant differences at any tested time interval. In conclusion, our data suggest that in children 'at risk' for atopy, PUFA levels may be predictive of atopic disease.

Methylprednisolone bolus: a novel therapy for severe atopic dermatitis

Seven children suffering from severe atopic dermatitis, unresponsive to standard therapy, received an iv bolus dose of methylprednisolone (20 mg/kg/day) for three days. Immunological parameters were evaluated before and after treatment. At the end of bolus therapy both skin lesions and itching improved for several months in five of seven patients. No side effects were observed, but a significant and transient lymphopenic response occurred, with lower CD4+ than CD8+ lymphocyte counts. Our data suggest that this therapy may be a novel and safe therapeutic approach in severe atopic dermatitis.

Use of a specific oral hyposensitization therapy to Dermatophagoides pteronyssinus in children with atopic dermatitis

The aim of the present study was to evaluate the efficacy of an oral specific hyposensitization therapy in children with atopic dermatitis and positive prick skin tests and/or RAST to Dermatophagoides pteronyssinus (D.pt.). A total of 60 patients, in three different clinical groups, were selected for a three years clinical trial. Group A: children with atopic dermatitis and allergic asthma and/or rhinitis; groups B and C: children with exclusively atopic dermatitis. Groups A and B received specific hyposensitization therapy. Group C was the control group. The clinical evaluation of the dermatological lesions, at the end of our study, didn't show any significant difference among the three groups. Moreover, the onset of respiratory symptoms between the two groups with exclusively atopic dermatitis was similar and not related to the positivity of prick skin tests and/or RAST to seasonal allergens. Our study suggests that specific hyposensitisation therapy with extracts of D.pt., although with no side effects, does not affect the natural history of atopic dermatitis.

1,25-Dihydroxyvitamin D3 and phorbol esters (TPA) may induce select in vitro differentiation pathways in the HL60 promyelocytic cell line

Monocytic features can be induced in the myeloid cell line HL60 in order to provide a suitable in vitro model for the investigation of in vitro activity in mononuclear phagocytes. 1,25-Dihydroxyvitamin D3 (calcitriol) induced the HL60 cell line to express the monocytic differentiation antigen Leu M3 in about 30-50% of the cells along with an increase (up to 20%) in the expression of HLA-DR but not HLA-DQ class II antigen. Functional investigation showed that calcitriol-treated cells formed rosettes with sheep erythrocytes coated with an anti-sheep erythrocyte-specific IgG2a mouse MoAb and readily ingested them. In addition, these same sensitized erythrocytes were lysed in an 18-hr antibody-dependent cellular cytotoxicity (ADCC) assay. All together these data indicate the presence of functionally active Fc-IgG receptors (FcR). Sorting experiments demonstrated that only Leu M3+ HLA-DR+ cells contained the effector cell population; such was also the case for blood monocytes. This phenotypic profile was, however, not predictive per se of FcR presence and function, as 12,O-tetradecanoylphorbol-13-acetate (TPA)-induced HL60 cells neither formed rosettes nor phagocytosed nor exhibited ADCC activity, although they express Leu M3 and HLA-DR (as well as HLA-DQ) antigens. These results suggest that calcitriol and TPA cause the differentiation of HL60 cells along distinct pathways. On the other hand, different subpopulations with given predetermined differentiation capabilities may coexist in HL60 cell line. This hypothesis gains support by the observation that when TPA and calcitriol were added together to the undifferentiated cells, the resulting phenotypic pattern was representative of the different activities of both of the inducers as they were used separately.