Immunological Aspects of Kabuki Syndrome: A Retrospective Multicenter Study of the Italian Primary Immunodeficiency Network (IPINet).

Kabuki Syndrome (KS) is a multisystemic genetic disorder. A portion of patients has immunological manifestations characterized by increased susceptibility to infections and autoimmunity. Aiming to describe the clinical and laboratory immunological aspects of KS, we conducted a retrospective multicenter observational study on patients with KS treated in centers affiliated to the Italian Primary Immunodeficiency Network.Thirty-nine patients were enrolled, with a median age at evaluation of 10 years (range: 3 m-21y). All individuals had organ malformations of variable severity. Congenital heart defect (CHD) was present in 19/39 patients (49%) and required surgical correction in 9/39 (23%), with associated thymectomy in 7/39 (18%). Autoimmune cytopenia occurred in 6/39 patients (15%) and was significantly correlated with thymectomy (p < 0.002), but not CHD. Individuals with cytopenia treated with mycophenolate as long-term immunomodulatory treatment (n = 4) showed complete response. Increased susceptibility to infections was observed in 22/32 patients (69%). IgG, IgA, and IgM were low in 13/29 (45%), 13/30 (43%) and 4/29 (14%) patients, respectively. Immunoglobulin substitution was required in three patients. Lymphocyte subsets were normal in all patients except for reduced naïve T-cells in 3/15 patients (20%) and reduced memory switched B-cells in 3/17 patients (18%). Elevated CD3 + TCRαß + CD4-CD8-T-cells were present in 5/17 individuals (23%) and were correlated with hematological and overall autoimmunity (p < 0.05).In conclusion, immunological manifestations of KS in our cohort include susceptibility to infections, antibody deficiency, and autoimmunity. Autoimmune cytopenia is correlated with thymectomy and elevated CD3 + TCRαß + CD4-CD8-T-cells, and benefits from treatment with mycophenolate.

Main human inborn errors of immunity leading to fungal infections.

BACKGROUND: The host's molecular and genetic features are essential in providing susceptibility to a broad spectrum of fungal infections; most of these do not cause disease in healthy individuals because of mutual benefits with opportunistic fungi besides the host's capacity to control the infections. In contrast, patients with primary immunodeficiency can develop mild superficial to life-threatening invasive infections. In the last years, thanks to next-generation sequencing, several inborn-error variants have been discovered in genes encoding protein acting against fungal infections, contributing to better defining the role of innate and adaptive immunity cooperation during infection resolution. Candida fungal infection that sometimes strikes healthy subjects is responsible for the chronic mucocutaneous candidiasis that is one of the principal clinical manifestations occurring in several rare primary immunodeficiencies associated with an inborn error of interleukin-17 (IL-17) immunity. OBJECTIVE: This review aimed to provide an overview of chronic mucocutaneous candidiasis-derived genetic defects, including IL17 deficiencies (IL17A, IL17F, IL17RA, IL17RC), STAT1 gain-of-function deficiency, STAT3 hyper-IgE syndrome, and CARD9 deficiency. SOURCES: We carried out detailed research work to identify interesting articles, commentaries, and reviews in the PubMed literature to ensure a correct and updated narrative review. CONTENT: We propose an in-depth description and an update of genetic and cellular mechanisms underlying fungal infections, focusing on the IL17-mediated response, a report of clinical manifestations, and a description of therapeutic options. IMPLICATIONS: This narrative review will help clinician to identify the correct management of patients based on molecular and cellular findings underlying pathogenic mechanisms of different inborn errors of immunity. Moreover, enabling clinicians to achieve the genetic diagnosis will be useful to offer genetic counselling intra- and inter-family and to ensure a personalised treatment of patients.

Brentuximab vedotin in the treatment of paediatric patients with relapsed or refractory Hodgkin's lymphoma: Results of a real-life study.

BACKGROUND: Brentuximab vedotin (BV) is an antibody drug-conjugated anti-CD30 approved for the treatment of adult classical Hodgkin's lymphoma (HL), whereas it is considered as off-label indication in paediatrics. The aim of the study was to evaluate the safety and efficacy of BV to treat patients aged less than 18 years with refractory/relapsed HL. MATERIALS AND METHODS: In this multicentre, retrospective study, 68 paediatric patients who received at least one dose of BV between November 2011 and August 2020 were enrolled. A median of nine doses of BV were administered as monotherapy (n = 31) or combined with other therapies (n = 37). BV was administrated alone as consolidation therapy after stem cell transplantation (SCT) in 12 patients, before SCT in 18 patients, whereas in 15 patients it was used before and after SCT as consolidation therapy. Median follow-up was 2.8 years (range: 0.6-8.9 years). RESULTS: The best response was observed in the 86% of patients; the overall response rate was 66%. The 3-year progression-free survival was 58%, whereas the overall survival was 75%. No statistically significant differences between patients treated with BV monotherapy or combination were highlighted. In multivariate analysis, patients with non-nodular sclerosis HL and not transplanted had an increased risk of failure. Overall, 46% of patients had grade 3-4 adverse events that led to BV discontinuation in five of them. CONCLUSION: In conclusion, our study confirms that BV was a safe and effective drug, able to induce complete remission, either as monotherapy or in association with standard therapy.

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.

Association of Immune Thrombocytopenia and Celiac Disease in Children: A Retrospective Case Control Study

Objective: The association between celiac disease (CD) and immune thrombocytopenia (ITP) is still uncertain. The aim of this study was to characterize the coexistence of these two diseases in Italian children. Materials and Methods: This is a retrospective multicenter study investigating the occurrence of CD in 28 children with ITP diagnosed from January 1, 2000, to December 31, 2019. Results: The first diagnosis was ITP in 57.1% and CD in 32.1% of patients. In 3 patients (10.7%), the two diagnoses were simultaneous. All the potential and silent cases of CD in our cohort were diagnosed in the groups of "ITP first" and "simultaneous diagnosis". In all children ITP was mild, and in 2 out of 8 not recovered from ITP at the time of CD diagnosis a normalization of platelet counts (>100,000/µL) occurred 3 and 5 months after starting a gluten-free diet, respectively. Conclusion: We think that screening for CD should be considered in children with ITP regardless of the presence of gastrointestinal symptoms. Furthermore, some patients may recover from ITP after starting a gluten-free diet.

Autoimmune Cytopenias and Dysregulated Immunophenotype Act as Warning Signs of Inborn Errors of Immunity: Results From a Prospective Study.

Inborn errors of immunity (IEI) are genetic disorders characterized by a wide spectrum of clinical manifestations, ranging from increased susceptibility to infections to significant immune dysregulation. Among these, primary immune regulatory disorders (PIRDs) are mainly presenting with autoimmune manifestations, and autoimmune cytopenias (AICs) can be the first clinical sign. Significantly, AICs in patients with IEI often fail to respond to first-line therapy. In pediatric patients, autoimmune cytopenias can be red flags for IEI. However, for these cases precise indicators or parameters useful to suspect and screen for a hidden congenital immune defect are lacking. Therefore, we focused on chronic/refractory AIC patients to perform an extensive clinical evaluation and multiparametric flow cytometry analysis to select patients in whom PIRD was strongly suspected as candidates for genetic analysis. Key IEI-associated alterations causative of STAT3 GOF disease, IKAROS haploinsufficiency, activated PI3Kδ syndrome (APDS), Kabuki syndrome and autoimmune lymphoproliferative syndrome (ALPS) were identified. In this scenario, a dysregulated immunophenotype acted as a potential screening tool for an early IEI diagnosis, pivotal for appropriate clinical management and for the identification of new therapeutic targets.

Comparison of Hodgkin's Lymphoma in Children and Adolescents. A Twenty Year Experience with MH'96 and LH2004 AIEOP (Italian Association of Pediatric Hematology and Oncology) Protocols.

Adolescents and young adults (AYAs) represent a distinct group of patients. The objectives of this study were: To compare adolescent prognosis to that of younger children; to compare the results achieved with the two consecutive protocols in both age groups; to analyze clinical characteristics of children and adolescents. Between 1996 and 2017, 1759 patients aged <18 years were evaluable for the study. Five hundred and sixty patients were treated with the MH'96 protocol and 1199 with the LH2004 protocol. Four hundred and eighty-two were adolescents aged ≥15 years. Patients in both age groups showed very favorable prognoses. In particular, OS improved with the LH2004 protocol, especially in the adolescent group and in the low risk group, where radiation therapy was spared. Adolescent characteristics differed significantly from the children's according to sex, histology, and the presence of symptoms. Remarkable is the decrease both in mixed cellularity in the children and in low stages in both age groups in the LH2004 protocol with respect to MH'96 protocol. Based on our experience, adopting pediatric protocols for AYA does not compromise patient outcomes.

Rituximab Unveils Hypogammaglobulinemia and Immunodeficiency in Children with Autoimmune Cytopenia.

BACKGROUND: Rituximab (RTX; anti-CD20 mAb) is a treatment option in children with refractory immune thrombocytopenia, autoimmune hemolytic anemia (AHA), and Evans syndrome (ES). Prevalence and clinical course of RTX-induced hypogammaglobulinemia in these patients are poorly known. OBJECTIVE: To evaluate the prevalence and risk factors for persistent hypogammaglobulinemia (PH) after RTX use. METHODS: Clinical and immunologic data from children treated with RTX for immune thrombocytopenia, AHA, and ES were collected from 16 Italian centers and 1 UK center at pre-RTX time point (0), +6 months, and yearly, up to 4 years post-RTX. Patients with previously diagnosed malignancy or primary immune deficiency (PID) were excluded. RESULTS: We analyzed 53 children treated with RTX for immune thrombocytopenia (n = 36), AHA (n = 13), and ES (n = 4). Median follow-up was 30 months (range, 12-48). Thirty-two percent of patients (17 of 53) experienced PH, defined as IgG levels less than 2 SD for age at last follow-up (>12 months after RTX). Significantly delayed B-cell recovery was observed in children experiencing PH (hazard ratio, 0.55; P < .05), and 6 of 17 (35%) patients had unresolved B-cell lymphopenia at last follow-up. PH was associated with IgA and IgM deficiency, younger age at RTX use (51 vs 116 months; P < .01), a diagnosis of AHA/ES, and better response to RTX. Nine patients with PH (9 of 17 [53%]) were eventually diagnosed with a PID. CONCLUSIONS: Post-RTX PH is a frequent condition in children with autoimmune cytopenia; a sizable proportion of patients with post-RTX PH were eventually diagnosed with a PID. In-depth investigation for PID is therefore recommended in these patients.

Clinical, Immunological, and Molecular Features of Typical and Atypical Severe Combined Immunodeficiency: Report of the Italian Primary Immunodeficiency Network.

Severe combined immunodeficiencies (SCIDs) are a group of inborn errors of the immune system, usually associated with severe or life-threatening infections. Due to the variability of clinical phenotypes, the diagnostic complexity and the heterogeneity of the genetic basis, they are often difficult to recognize, leading to a significant diagnostic delay (DD). Aim of this study is to define presenting signs and natural history of SCID in a large cohort of patients, prior to hematopoietic stem cell or gene therapies. To this purpose, we conducted a 30-year retro-prospective multicenter study within the Italian Primary Immunodeficiency Network. One hundred eleven patients, diagnosed as typical or atypical SCID according to the European Society for Immune Deficiencies criteria, were included. Patients were subsequently classified based on the genetic alteration, pathogenic mechanism and immunological classification. A positive relationship between the age at onset and the DD was found. SCID patients with later onset were identified only in the last decade of observation. Syndromic SCIDs represented 28% of the cohort. Eight percent of the subjects were diagnosed in Intensive Care Units. Fifty-three percent had an atypical phenotype and most of them exhibited a discordant genotype-immunophenotype. Pre-treatment mortality was higher in atypical and syndromic patients. Our study broadens the knowledge of clinical and laboratory manifestations and genotype/phenotype correlation in patients with SCID and may facilitate the diagnosis of both typical and atypical forms of the disease in countries where newborn screening programs have not yet been implemented.

Hyperventilation syndrome in adolescents with and without asthma.

BACKGROUND: Data on the prevalence of hyperventilation syndrome (HVS) in adolescents are scanty. OBJECTIVES: To determine the prevalence of HVS in a population of adolescents with and without asthma, and to verify whether HVS was related to asthma activity. METHODS: A population of adolescents was asked to self-complete a questionnaire, including the Nijmegen questionnaire to assess HVS, and a standardized asthma questionnaire. RESULTS: Seven hundred and sixty questionnaires were suitable for analysis. One hundred and twenty subjects (15.8%) were classified as asthmatic. Forty-seven subjects (6.2%) had a Nijmegen score ≥ 23, which was suggestive of HVS. Symptoms indicative of HVS were ten times more common in subjects with asthma (25%) than in those without asthma (2.5%). Nijmegen score was significantly higher in subjects with lifetime asthma (P < 0.001), current episodic asthma (P < 0.05) and current active asthma (P < 0.001) than in those with no asthma. In the whole population, girls presented HVS more frequently than boys (P < 0.001). There was a significant effect of gender (females, OR 3.2) and status of asthma (lifetime asthma, OR 11.2; current episodic asthma, OR 8.9; current active asthma, OR 41.5) on the probability of suffering from HVS. CONCLUSIONS: The prevalence of symptoms indicative of HVS in an unselected population of adolescents was relatively high. Symptoms were more common in girls and in subjects with asthma, and there was a significant effect of asthma activity on the probability of suffering from HVS. Further studies need to be performed in order to validate a screening tool for HVS in both adolescents and asthmatic subjects.