DR4/DQ2 haplotype confers susceptibility to T1DM with early clinical disease onset: A retrospective analysis in a tertiary-care hospital in Italy.

INTRODUCTION: T1DM is the most frequent form of diabetes in children. It has a multifactorial pathogenesis in which genetic, environmental and immunological factors are involved. Among genetic explanations a major role is attributed to second class HLA genes, with the greatest risk associated with the simultaneous presence of the haplotypes DR3DQ2 and DR4DQ8. Based on results obtained in other countries, the aim of this research is to verify a possible association between the haplotype DRB1 * 04: 05-DQA1 * 03-DQB1 * 02 and the onset of T1DM among Italian children with possible genotype-phenotype correlations. Greater knowledge of genes which increase or decrease susceptibility is important for genome analysis. MATERIALS AND METHODS: 165 patients with type 1 diabetes treated at the Diabetology Unit of the Meyer Children's University Hospital, were clinically analyzed. Data relating to age at diagnosis, pancreatic anti-beta cell autoimmunity, comorbidities with date of diagnosis and family history were retrospectively collected from medical data. A case-control study was conducted to investigate the HLA types of the patients compared to a control group of 819 Tuscan donors enrolled in the National Bone Marrow Donor Register. Typing was carried out using the Eurospital "DIABEGEN" kit, currently in use at the immunology laboratory of the Meyer Children's University Hospital. RESULTS: Mean age at diagnosis was 9.3 years; most children (97%) had anti-pancreatic beta cell autoimmunity; the anti-insulin antibody (IAA) was more frequent among children with early clinical disease onset (0-5 years of age). From the case control comparison performed on HLA typing, it emerged that the greatest risk for the development of type 1 diabetes is conferred by the haplotypes DR3DQ2 and DR4DQ8, but in addition to these haplotypes, already known in other countries, we identified another haplotype, DR4DQ2 (DRB1 * 04: 05-DQA1 * 03-DQB1 * 02) which appears to predispose children to type 1 diabetes (p value 2.80E-08) and it is associated with early clinical disease onset (p-value = 0.002). CONCLUSIONS: We report a new haplotype which increases susceptibility to type 1 diabetes among Italian children and which is associated with early clinical disease onset. Given the central role attributed to genetic factors in the pathogenesis of T1DM and to the II class HLA genes, this new haplotype ought to be recognized as a risk factor and included in tests routinely carried out to identify patients with a genetic predisposition to type I diabetes in Italy. These findings could have practical implications in research and prevention programs.

Nut Allergy: Clinical and Allergological Features in Italian Children.

BACKGROUND: Nut allergies are an increasingly frequent health issue in the pediatric population. Tree nuts (TN) and peanuts are the second cause of food anaphylaxis in Italy. Unfortunately, knowledge of the clinical characteristics of a TN allergy in Italian children is limited. Our study aimed to identify the clinical and allergological characteristics of Italian children with a nut allergy (TN and peanut). METHODS: A retrospective observational analysis was performed on the clinical charts of children with a history of nut reaction referred to the allergy unit of the hospital from 2015 to 2019. The studied population was represented by children with a confirmed nut allergy based on positive prick by prick and/or serum-specific IgE to nut plus a positive nut oral food challenge. Demographic, clinical, and allergological features were studied and compared among different nuts. RESULTS: In total, 318 clinical charts were reviewed. Nut allergy was confirmed in 113 patients. Most patients (85/113, 75%) had a familial history of allergy and/or a concomitant allergic disorder (77/113, 68%). Hazelnut and walnut were the more common culprit nuts observed in allergic children. Anaphylaxis was the first clinical manifestation of nut allergy in a high percentage of children (54/113, 48%). The mean age of the first nut reaction was statistically higher with pine nuts. Over 75% of children reported a single nut reaction. During the OFCs, the signs and symptoms involved mainly the gastrointestinal system (82/113, 73%) and resolved spontaneously in most cases. Severe reactions were not frequent (22/113, 19%). CONCLUSION: To our knowledge, this is the first Italian study that provided a comprehensive characterization of children with a nut allergy. These results are important for clinicians treating children with a nut allergy.

Nasal Swab as Preferred Clinical Specimen for COVID-19 Testing in Children.

The first pediatric study demonstrating significantly higher positivity rate of nasal (mid-turbinate) swab testing over oropharyngeal swab testing in detecting SARS-CoV-2 (Fisher exact test 0.046, Cohen K 0.43, confidence interval 95%, 0.014-0.855). Benefits might include lower collection-related hazard for healthcare workers. We recommend it as preferred choice for swab-based SARS-CoV-2 testing in children.

[Recurrent respiratory papillomatosis in a pediatric patient: case report]. / Papilomatosis respiratoria recurrente en paciente pediátrico: reporte de un caso.

Genetic variability related to the host immune system has been proposed as one of the most influential factors in the development of diseases caused by HPV. CLINICAL CASE: We report the case of a 5-year-old child in whom chronic laryngeal papillomatosis, probably acquired vertically during labor, was detected. The diagnosis of laryngeal papillomatosis was confirmed with a biopsy after a first surgery to remove the papillomas. The Derkay classification system was used to assess the severity of papillomatosis. Biopsy genotyping was performed by demonstrating HPV-6. Later, HLA-DQA1 * 0505, -DQB1 * 0301, -DRB1 * 1101 alleles were homozygous for HLA allele typing. CONCLUSIONS: Further studies are needed to identify the most prevalent HLA alleles in the Latino population and their potential association with genetic susceptibility in Recurrent Respiratory Papillomatosis.

Papilomatosis respiratoria recurrente en paciente pediátrico: reporte de un caso / Recurrent respiratory papillomatosis in a pediatric patient: case report

La variabilidad genética relacionada al sistema inmune del huésped ha sido propuesta como uno de los factores más influyentes en el desarrollo de enfermedades causadas por HPV. Caso clínico: Reportamos el caso de un niño de 5 años en cuyo estudio por disfonía crónica se encuentra papilomatosis laríngea probablemente adquirida por vía vertical durante el parto. El diagnóstico de papilomatosis laríngea se confirmó con una biopsia tras una primera cirugía orientada a remover los papilomas. Se utilizó el sistema de clasificación Derkay para evaluar la severidad de la papilomatosis. Se realizó genotipificación en biopsia demostrándose HPV-6. Posteriormente mediante tipificación de alelos HLA se demostró homocigosis para los alelos HLA-DQA1*0505, -DQB1*0301, -DRB1*1101. Conclusiones: Se necesitan estudios adicionales que permitan identificar los alelos HLA más prevalentes en población latina y su potencial asociación con la susceptibilidad genética en Papilomatosis Respiratoria Recurrente.

Genetic variability related to the host immune system has been proposed as one of the most influential factors in the development of diseases caused by HPV. Clinical case: We report the case of a 5-year-old child in whom chronic laryngeal papillomatosis, probably acquired vertically during labor, was detected. The diagnosis of laryngeal papillomatosis was confirmed with a biopsy after a first surgery to remove the papillomas. The Derkay classification system was used to assess the severity of papillomatosis. Biopsy genotyping was performed by demonstrating HPV-6. Later, HLA-DQA1 * 0505, -DQB1 * 0301, -DRB1 * 1101 alleles were homozygous for HLA allele typing. Conclusions: Further studies are needed to identify the most prevalent HLA alleles in the Latino population and their potential association with genetic susceptibility in Recurrent Respiratory Papillomatosis.

Coeliac disease and risk for other autoimmune diseases in patients with Williams-Beuren syndrome.

BACKGROUND: A higher prevalence of coeliac disease (CD) has been reported in patients with Williams-Beuren syndrome (WBS), though coexistence with other autoimmune diseases has not been evaluated. OBJECTIVE: The aim of this study was to examine the prevalence of the more frequent autoimmune diseases and organ- and non-organ specific autoantibodies in WBS. METHODS: We longitudinally analysed 46 WBS patients to evaluate the prevalence and co-occurrence of the major autoantibodies and HLA typing for CD diagnosis. These data were compared with healthy age- and sex-matched controls and Down (DS) and Turner (TS) syndrome patients. RESULTS: CD was diagnosed in one (2.2%) WBS patient; this differed significantly from DS and TS (respectively, 10.5% and 9.4%; P < 0.005) but not from healthy controls (0.6%; P = NS). However, no patients with WBS showed anti-thyroid antibodies or other organ- and non-organ specific autoantibodies, which differed significantly from DS (respectively, 10.5% and 7.0%; P < 0.005) and TS (respectively, 9.4% and 9.3%; P < 0.005) patients but not from healthy controls (1.1% and 2.3%). The frequencies of CD-specific HLA-DQ heterodimers were not significantly higher than controls, even though the WBS patients more frequently carried the DQA1*0505 allele (57% vs. 39%; P < 0.05). CONCLUSIONS: CD may not be more frequent in patients with WBS. In fact, no evidence of a significantly higher prevalence of other autoimmune diseases or positivity of the main organ and non-organ specific autoantibodies was found in WBS, such as showed in the healthy controls and unlike by the patients with Turner or Down syndrome. This should prompt us to better understand the occurrence of CD in WBS. Other studies or longer follow-up might be useful to clarify this issue.