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Activated phosphoinositide 3-kinase delta (PI3Kδ) syndrome (APDS) is an inborn error of immunity with clinical manifestations including infections, lymphoproliferation, autoimmunity, enteropathy, bronchiectasis, increased risk of lymphoma, and early mortality. Hyperactive PI3Kδ signaling causes APDS and is selectively targeted with leniolisib, an oral, small molecule inhibitor of PI3Kδ. Here, 31 patients with APDS aged ≥12 years were enrolled in a global, phase 3, triple-blinded trial and randomized 2:1 to receive 70 mg leniolisib or placebo twice daily for 12 weeks. Coprimary outcomes were differences from baseline in the index lymph node size and the percentage of naïve B cells in peripheral blood, assessed as proxies for immune dysregulation and deficiency. Both primary outcomes were met: the difference in the adjusted mean change (95% confidence interval [CI]) between leniolisib and placebo for lymph node size was −0.25 (−0.38, −0.12; P = .0006; N = 26) and for percentage of naïve B cells, was 37.30 (24.06, 50.54; P = .0002; N = 13). Leniolisib reduced spleen volume compared with placebo (adjusted mean difference in 3-dimensional volume [cm3], −186; 95% CI, −297 to −76.2; P = .0020) and improved key immune cell subsets. Fewer patients receiving leniolisib reported study treatment-related adverse events (AEs; mostly grades 1-2) than those receiving placebo (23.8% vs 30.0%). Overall, leniolisib was well tolerated and significant improvement over placebo was notable in the coprimary endpoints, reducing lymphadenopathy and increasing the percentage of naïve B cells, reflecting a favorable impact on the immune dysregulation and deficiency seen in patients with APDS. This trial was registered at www.clinicaltrials.gov as #NCT02435173.

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.

mRNA and Adenovirus vaccines for COVID-19 are used to induce humoral and cell-mediated immunity, with the aim to generate both SARS-CoV-2 B and T memory cells. In present study, we described a simple assay to detect and quantify Spike-specific CD4+ and CD8+ T cell responses induced by vaccination in healthy donors and in subjects with B cell compart impairment, in which antibody response is absent due to primary immunodeficiencies or CD20 depleting therapy. We detect and quantified memory T cell immune responses against SARS-CoV-2 evocated by vaccination in both groups, irrespective to the humoral response. Furthermore, we identified TNF-α as the main cytokine produced by T memory cells, after antigen-specific stimulation in vitro, that could be considered, other than IFN-γ, an additional biomarker of induction of T memory cells upon vaccination. Further studies on the vaccine-induced T cell responses could be crucial, not only in healthy people but also in immunocompromised subjects, where antigen specific T cells responses play a protective role against SARS-CoV-2.

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

Chronic granulomatous disease (CGD) is a primary immunodeficiency characterized by life-threatening infections, inflammation, and autoimmunity with an impact on health-related quality of life (HRQoL). Few data are available for children, whereas no study has been conducted in adults. Here, we investigated HRQoL and emotional functioning of 19 children and 28 adults enrolled in Italian registry for CGD. PEDsQL and SDQ were used for children and their caregivers, and adults completed the SF-12 questionnaire. Mean scores were compared with norms and with patients affected by chronic diseases. Comparisons were made for CGD patients who underwent or not hematopoietic stem cell transplantation (HSCT). When compared with norms, CGD children exhibited higher difficulties in social/school areas, peer relationship, and conduct/emotional problems (

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.

Immunoglobulin G (IgG) replacement therapy is a standard treatment for patients with primary immunodeficiency diseases (PIDs). Hizentra®, a 20% human subcutaneous IgG (SCIG), is approved for biweekly administration for PIDs. The aim of the multicenter IBIS study was to prospectively investigate the efficacy of biweekly Hizentra® compared with previous IVIG or SCIG treatment regimens in patients with PIDs. The study consisted of a 12-month retrospective period followed by 12-month prospective observational period. The main endpoints included pre-infusion IgG concentrations, proportion of patients with serious bacterial infections (SBIs), other infections, hospitalizations due to PID-related illnesses, and days with antibiotics during the study periods. Of the 36 patients enrolled in the study, 35 patients continued the study (mean age 26.1 ± 14.4 years; 68.6% male). The mean pre-infusion IgG levels for prior immunoglobulin regimens during the retrospective period (7.84 ± 2.09 g/L) and the prospective period (8.55 ± 1.76 g/L) did not show any significant variations (p = 0.4964). The mean annual rate of SBIs/patient was 0.063 ± 0.246 for both prospective and retrospective periods. No hospitalizations related to PIDs were reported during the prospective period versus one in the retrospective period. All patients were either very (76.5%) or quite (23.5%) satisfied with biweekly Hizentra® at the end of the study. In conclusion, the IBIS study provided real-world evidence on the efficacy of biweekly Hizentra® in patients with PIDs, thus verifying the data generated by the pharmacometric modeling and simulation study in a normal clinical setting.

Background Autoimmune neutropenia is a chronic reduction of absolute neutrophil below the threshold for age, due to peripheral destruction by specific antibodies (AaN). "Primary autoimmune neutropenia" (pAN) usually appears in early infancy and generally resolve within 18-24 months, while "Secondary autoimmune Neutropenia" (sAN) rises later in life and is usually accompanied by autoimmune features. Very few descriptions on the topic are available in the literature. Aim of the study: to describe from a clinical and immunological point of view a cohort of subjects affected with sAN included registered in the Italian Neutropenia Registry (INR) and to compare these data with those from subjects diagnosed with pAN still in the INR . Patient and methods Subjects with neutropenia and positivity of AaN lasting for more than 2 years in subjects older than 5 years of life ( up to 18) or patients affected with neutropenia (plus AaN) associated with autoimmune features registered in the INR from 2005 to 2018 were considered eligible for the present study. Antibodies against neutrophils were always detected throught indirect test . Results: Data from 40 patients affected with sAN (26 females, 65%) were collected. Median age at diagnosis was of 11.6 years (0-21.558mo) with a median follow up of 17 months (0-159mo). The degree of Neutropenia was mild in 12.5%(5/40), moderate in 35% (14/40) and severe in 52.5% (21/40) Neutropenia was diagnosed by chance in half of the cohort and in only 10% (4/40) (10%) definitively resolved . Neutropenia coexisted with leucopenia in almost all the of subjects (36/40, 88%), and moreover, autoimmune haemolytic anemia and thrombocytopenia was concomitant to neutropenia in 12% (5/40) and 32.5% in (13/40) of cases respectively. As for clinical history, 15% (6/40) subjects (15%) were completely asymptomatic , while the remaining 85% (36/40) (85%) had clinical signs of infections and/or autoimmunity features . Infections were documented in 60% (24/40) (60%) of patients. Severe infections namely sepsis , meningitis, pneumonia, osteomyielitis and broad absesses/flemmons were identified in 21% (5/24) of the group. Other type of infections are listed Figure 1A. Apparently there was no correlation between severity of infections and degree of neutropenia ( p=0.2 Fisher' exact test) Autoimmune features and/or autoimmunity markers were present in 30/40 (75% ) of the entire cohort . Thyroiditis and artralgia/arthritis were the most common signs which accounted both for 17,5% of the total episodes. Positivity of ANA and Direct antibodies test ( DAT) were showed in 42% and 29% of cases respectively. (Fig 1B, 1C) As for immunological characteristic 37% (12/32) of the studied subjects were frankly lymphocytopenic, 19% (6/32) had borderline values , while the remaining 44% (14/32) had normal lymphocytes subclasses. In terms of frequency of sub-classes depletion CD19 + and NK were the most frequently decreased subsets. ( Fig 1D) . Dosage of serum immunoglobulin (IgG, IgM and IgA) were shown for all three classes were abnormal (either increased or diminished) in 74% (28/38) of patients (Fig 1D). Mutation analysis performed by Next Generation Sequencing in 16/40 subjects and pathogenic variants of : TACI, TINF 2, CASP 8, CASP 10, PI3K, CARD 11 genes were identified in 4/16 (25%). As for treatment, in 25 % of cases needed Granulocyte-Colony Stimulating Factor to control infections. Rapamicin, micophenolate mofetil, steroids, intravenous immunoglobulin were necessary in 25% (10/40) of patients cases, being (4 of them were already treated on with G-CSF) Comparison with a group of 236 pAN patients of the INR showed that sAN were older at diagnosis (P Conclusions This registry study describes the clinical phenotype of sAN appearing in childhood and by comparative analysis shows that sAN substantially differs from pAN. sAN indeed appears an epiphenomenon of a complex immunological disturbances rather than a disease itself. Occasionally mutations of genes of immunodeficiency/disimmunity can be demonstrated Disclosures No relevant conflicts of interest to declare.

Ewing sarcoma (ES) is the second most common type of primary bone malignancy, and retains a high propensity to metastasize; the prognosis of patients with disseminated disease is very poor, with an event-free survival rate of

SummaryGenital warts caused by human papillomavirus (HPV) are the most frequent sexually transmitted infection. We describe a case of severe perianal and genital HPV infection in a patient with acquired aplastic anemia, unresponsive to traditional therapies and treated effectively with a combination of interferon and ribavirin.

PURPOSE: A sensitive imaging technique that assesses ataxia telangiectasia (AT) lung disease without ionizing radiation is highly desirable. We designed a study to evaluate lung changes using magnetic resonance imaging (MRI), and to investigate the relationships among severity and extent of pulmonary abnormalities and clinical, microbiological and functional data in children and young adults with AT. METHODS: Fifteen AT patients (age, 11.3 years; range, 6-31) underwent 3.0-T MRI, spirometry, and deep throat or sputum culture. Images were scored using a modified Helbich score. RESULTS: Although only 8 patients (53 %) had recurrent/chronic respiratory symptoms, MRI identified lung abnormalities in all. Bronchiectasis, peribronchial thickening, mucous plugging, and collapse/consolidation were present in 60 %, 87 %, 67 %, and 13 % of cases, respectively, with no difference between subjects with or without respiratory symptoms. No difference in changes of specific scores was found between the two groups, but the total MRI score was higher in patients with respiratory symptoms (6.5 versus 5, respectively; p = 0.02). Total or specific MRI scores were not associated with patients' age. Of all scores, only mucous plugging subscore appeared significantly related to FEV1 (r = 0.7, p = 0.04) and FEF25-75% (r = 0.9, p = 0.001). MRI scores from patients with positive (n = 5) or negative (n = 10) sputum culture were not significantly different. CONCLUSIONS: MRI is valuable in the assessment of extent and severity of pulmonary changes in children and adults with AT. It represents an helpful tool for the longitudinal evaluation of patients and may be also used as an outcome surrogate to track the effects of medications.

Familial haemophagocytic lymphohistiocytosis (FHL) is a genetically heterogeneous disorder characterised by constitutive defects in cellular cytotoxicity resulting in fever, hepatosplenomegaly and cytopenia, and the outcome is fatal unless treated by chemoimmunotherapy followed by haematopoietic stem‐cell transplantation. Since 1999, mutations in the perforin gene giving rise to this disease have been identified; however, these account only for 40% of cases. Lack of a genetic marker hampers the diagnosis, suitability for transplantation, selection of familial donors, identification of carriers, genetic counselling and prenatal diagnosis. Mutations in the Munc13–4 gene have recently been described in patients with FHL. We sequenced the Munc13–4 gene in all patients with haemophagocytic lymphohistiocytosis not due to PRF1 mutations. In 15 of the 30 families studied, 12 novel and 4 known Munc13–4 mutations were found, spread throughout the gene. Among novel mutations, 2650C→T introduced a stop codon; 441del A, 532del C, 3082del C and 3226ins G caused a frameshift, and seven were mis sense mutations. Median age of diagnosis was 4 months, but six patients developed the disease after 5 years of age and one as a young adult of 18 years. Involvement of central nervous system was present in 9 of 15 patients, activity of natural killer cells was markedly reduced or absent in 13 of 13 tested patients. Chemo‐immunotherapy was effective in all patients. Munc13–4 mutations were found in 15 of 30 patients with FHL without PRF1 mutations. Because these patients may develop the disease during adolescence or even later, haematologists should include FHL2 and FHL3 in the differential diagnosis of young adults with fever, cytopenia, splenomegaly and hypercytokinaemia.

Item does not contain fulltext BACKGROUND: Mutations in the SP110 gene result in infantile onset of the autosomal recessive primary immunodeficiency disease veno-occlusive disease with immunodeficiency syndrome (VODI), which is characterized by hypogammaglobulinemia, T-cell dysfunction, and a high frequency of hepatic veno-occlusive disease. OBJECTIVES: We sought to further characterize the clinical features, B-lineage cellular immunologic findings, and molecular pathogenesis of this disorder in 9 patients with new diagnoses, including 4 novel mutations from families of Italian, Hispanic, and Arabic ethnic origin. METHODS: Methods used include clinical review; Sanger DNA sequencing of the SP110 gene; determination of transfected mutant protein function by using immunofluorescent studies in Hep-2 cells; quantitation of B-cell subsets by means of flow cytometry; assessments of B-cell function after stimulation with CD40 ligand, IL-21, or both; and differential gene expression array studies of EBV-transformed B cells. RESULTS: We confirm the major diagnostic criteria and the clinical utility of SP110 mutation testing for the diagnosis of VODI. Analysis of 4 new alleles confirms that VODI is caused by reduced functional SP110 protein levels. Detailed B-cell immunophenotyping demonstrated that Sp110 deficiency compromises the ability of human B cells to respond to T cell-dependent stimuli and differentiate into immunoglobulin-secreting cells in vitro. Expression microarray studies have identified pathways involved in B-lymphocyte differentiation and macrophage function. CONCLUSION: These studies show that a range of mutations in SP110 that cause decreased SP110 protein levels and impaired late B-cell differentiation cause VODI and that the condition is not restricted to the Lebanese population.

Hepatopathy-thrombocytopenia syndrome (HTS) is a severe complication very similar to vein occlusive disease (VOD), also known as hepatic sinusoidal obstructive syndrome (SOS), characterized by fever, hepatopathy (hepatomegaly with abnormal liver function tests), ascites, weight gain, jaundice, and thrombocytopenia (platelet count less than 25 × 10(3)/μL). It has been generally observed in patients with Wilms tumor, and is commonly associated to administration of actinomycin D. We report three children with Wilms tumor, with severe HTS/SOS, but had a different outcome, in spite of vigorous supportive therapy.

Castleman's disease (CD) is a rare, localized or generalized, lymphoproliferative disorder with a frequent mediastinal location, but possible in any lymph node or extra nodal site. It usually appears in young adults whilst it rarely occurs in childhood. There are only about 100 pediatric cases published, five of them in Italy. We report 3 cases of localized Castleman's disease, investigated in our Department in a 3 years period and reviewed the literature.

Hepatic hemangioma, adenoma and focal nodular hyperplasia are the most frequent benign lesions of the liver, but they are all infrequent among pediatric population. The reports of focal nodular hyperplasia in children have recently increased in number, with many cases associated to drug intake, particularly to chemotherapy. We here describe, to our knowledge, the first case of focal nodular hyperplasia in association with diabetes mellitus in childhood.

Chronic Granulomatous Disease (CGD) is a rare inherited disorder in which phagocytes fail to produce antimicrobial superoxide because NADPH oxidase activity is absent. In about 65% of the cases, the disease is due to mutations affecting the X-linked CYBB gene, encoding the gp91(phox) subunit of NADPH oxidase. We investigated 34 CGD male patients by DHPLC and direct sequencing. A mutation was found in the CYBB gene of 33 patients and 9 of these were novel: one non-sense mutation (c.1123 G>T), three missense mutations (c.58G>A; c.1076 G>C; c.1357 T>A), two splice site mutations (c.141+5G>T; c.142-1G>A), one duplication (c.42_45dupCATT), one deletion (c.184delT), and one rare deletion of two non-contiguous nucleotides (c.1287delT+c.1290delC). One patient had the most frequent GT homozygous deletion in exon2 of the NCF-1 gene encoding the p47(phox) subunit of NADPH oxidase. The carrier analysis was performed in 23 patients' mothers and 16 female relatives through molecular and FISH studies. No clear correlation between the severity of clinical symptoms and the type of mutation could be demonstrated. This study further supports the great heterogeneity of the disease and the notion that genetic analysis is a critical step in obtaining a definitive diagnosis for CGD.

Hypereosinophilic syndrome (HES) represents a heterogeneous group of diseases, some of which are being clarified by recent advances in molecular genetics. It is very rare in children. Uncertainties in classification and lack of prospective studies make therapeutic decisions difficult. The authors report two cases of HES in which steroid therapy was effective.

Background: PRF1 gene mutations are associated with familial haemophagocytic lymphohistiocytosis type 2 (FHL2). Genotype–phenotype analysis, previously hampered by limited numbers of patients, was for the first time performed by data pooling from five large centres worldwide. Patients and methods: Members of the Histiocyte Society were asked to report cases of FHL2 on specific forms. Data were pooled in a common database and analysed. Results: The 124 patients had 63 different mutations (including 15 novel mutations): 11 nonsense, 10 frameshift, 38 missense and 4 in-frame deletions. Some mutations were found more commonly: 1122 G→A (W374X), associated with Turkish origin, in 32 patients; 50delT (L17fsX22) associated with African/African American origin, in 21 patients; and 1090-91delCT (L364fsX), in 7 Japanese patients. Flow cytometry showed that perforin expression was absent in 40, reduced in 6 and normal in 4 patients. Patients presented at a median age of 3 months (quartiles: 2, 3 and 13 months), always with fever, splenomegaly and thrombocytopenia. NK activity was absent in 36 (51%), ⩽2% in 18 (26%), 3–⩽5% in 10 (14%), >5% in 4 (6%), “reduced” in 2 (3%) (not reported, n = 54). Nonsense mutations were significantly associated with younger age at onset (p Conclusion: PRF1 mutations are spread over the functional domains. Specific mutations are strongly associated with Turkish, African American and Japanese ethnic groups. Later onset and residual cytotoxic function are observed in patients with at least one missense mutation.

Reversible posterior leukoencephalopathy syndrome (RPLS) is a rare complication of cancer chemotherapy. We have recently observed two cases occurred simultaneously in children receiving different chemotherapy regimens, for hepatoblastoma and acute lymphoblastic leukaemia, respectively. Both children presented with altered mental status, severe visual disturbances, headache, seizures, backpain and hypertension. Magnetic resonance imaging showed cortical and subcortical lesions especially in the occipital and parietal regions, strongly consistent with RPLS. Both patients completely recovered from their neuropsychologic deficits in about ten days only with anticonvulsant and antihypertensive therapy, and chemotherapy regimen was promptly restarted according to the planned protocol, without any neuropsychological sequela. A mild left midriasis was the only neurologic defect that persisted in the patient with acute lymphoblastic leukemia.

We screened 100 children with acute lymphoblastic leukemia (ALL) to assess the incidence of single amino acid change A91V in perforin. Heterozygous A91V was found in 12/100 patients and 5/127 controls (OR, 3.4; 95%CI: 1.15-9.95; p=0.014). A91V is a novel and frequent predisposing factor for childhood ALL.

Patients with agammaglobulinemia may excrete enteroviruses, including vaccine-derived poliovirus, for prolonged periods of time. This poses a risk to the patients but it also may pose a risk to the population after eradication of poliovirus and the cessation of routine vaccination. To assess this risk, a pilot study was performed to identify potential poliovirus long-term excretors in a cohort of 38 patients with a definite/presumptive diagnosis of X-linked agammaglobulinemia (XLA). Stool samples were analyzed to detect any polio or other enteroviruses replicating in the gut and neutralizing antibodies against polioviruses were measured in the sera. No viruses were isolated from the stool samples and most sera had neutralizing antibody levels against all three poliovirus serotypes considered by the WHO to be protective in immunocompetent individuals. This suggests that long-term excretion of enteroviruses in patients with agammaglobulinemia is relatively uncommon.

The disease presentation of autosomal recessive polycystic kidney disease (OMIM #263200, ARPKD) is highly variable and includes polycystic kidneys, pulmonary hypoplasia, and congenital hepatic fibrosis. The authors report an unusual case of ARPKD presenting with hepatosplenomegaly and cytopenia mimicking acute leukemia.

Evans syndrome (ES) is a combination of autoimmune hemolytic anemia (AIHA) and immune thrombocytopenia (ITP).1 Treatment options include intravenous immunoglobulins (IVIG), corticosteroids, cyclosporine, vincristine, danazol, azathioprine, cyclophosphamide, plasmapheresis, rituximab and splenectomy.2, 3 Only one-third of patients were free of disease at 3 years after a median of five modalities of therapy in a recent survey, with seven dead, 12% with active disease on treatment, and 12% with persistent disease.4 Hematopoietic stem cell transplant (HSCT) has been used in a few cases of refractory ES.5, 6, 7, 8

Familial hemophagocytic Lymphohistiocytosis (FLH) is a rare disorder characterized by fever, hepatosplenomegaly, cytopenia, hypertriglyceridemia, hypofibrinogenemia and reduced natural killer (NK) cell activity. Several genetic defects have been recognized as associated with FHL. After identification of perforin gene (PRF1) mutation as the cause of about one third of cases of FHL (Stepp,1999), in 2003 the same group reported that another gene involved in cellular cytotoxicity, Munc13-4, encoding for a protein involved in granule release in cytotoxic lymphocyte, is associated with a subset of patients with FHL. We have analyzed for Munc13-4 mutations 16 families of patients diagnosed with FHL according to current criteria, in whom PRF1 mutations had been excluded; 14 were Italian, 1 from USA, one from UK. The 32 exons and their proximal flanking regions of Munc13-4 gene were amplified from genomic DNA and amplification products were directly sequenced by cycle sequencing approach (BigDye Terminator Applied Biosystems). Sequences of primers utilized for the amplification reactions were designed with dedicated software (Primer Express) according to the gene sequence retrived from Genebank. A total of 13 mutations were identified in 12 families; 3 had homozygous mutations, 5 had combined heterozygous mutations, and 4 had only one detectable mutated allele. Mutation 753+IG in exon 9 (splice donor site) had been already reported (Feldman 2003, zurStadt 2005); The following novel mutations were found: G175A in exon 3 (A59T), delC532 in exon 6 (178 fs), A610G in exon 7 (M204V), G1241T in exon 14 (R414L), A1847G in exon 20 (E616G), del GGAG 2346 (782 fs) in exon 24, A2599G (K867E) in exon 27, C2650T in exon 28 (Q884stop), C2782T in exon 29 (R928C), C2896T in exon 30 (R966W), 3082delC in exon 31 (1028fs), insG3226 in exon 32 (1076fs). Mutation A2599 was observed in 6 families; mutation A1847G in 3 families; C2782T and G1241T in 2 families. We have also identified the polymorphisms C279T, and A3198G. Mutations were scattered over different exons and almost entirely different from those reported so far. A2599G mutation was frequently observed and its role deserves further investigation. Screening of Munc13-4 mutations is a powerful tool to confirm the diagnosis, to refine the therapeutic choice including indication to HSCT, selection of familiar donor, and identification of carriers and prenatal diagnosis in most of the families with FHL not associated with PRF1 mutations. Due to lack of immunologic or flow-cytometric tools for rapid screening of Munc13-4 defective patients, the high number of coding exons and lack of mutation clustering, screening of Munc13-4 mutations, although expensive and time consuming, remains necessary and allowed us to identify the genetic defect in the majority of our patients with FHL not associated with PRF1 mutations.

Langerhans cell Histiocytosis (LCH) (OMIM 604856) is a rare disorder affecting any age, with a highly variable clinical course, usually related to the number and type of organs affected at the time of presentation. The symptoms range from a solitary bone lesion that does not require treatment to a disseminated disease with multiple-organ involvement and a high mortality rate, despite aggressive treatment. The pathogenesis of LCH remains unclear, although deregulated growth, activity and trafficking of Langerhans cells (LC) are implicated. The ability of LC to migrate from the epidermis to regional lymph nodes is of pivotal importance for the induction of immune response and there is increasing evidence that both cytokines and chemokines are implicated in this function. We report the analysis of polymorphisms in genes coding for different cytokines in a population of patients with LCH in comparison to an Italian control population (n=140). We studied 40 patients, with a mean age at the disease of onset of 6.1 (±5.0) years; the 15 with single-system (SS) disease had a mean age of 7.1 (±3.9) years, while the 25 with multi-system (MS) disease had a mean age of 5.3 (±5.3) years. The Cytokine Genotyping Tray (Pel-Freez, Milwaukee, USA) was used for the detection of the following polymorphisms: Il-1α-889 C/T, Il-1β (−511 C/T; +3962 T/C), IL-1R pst1 1970 C/T, IL-RA mspa1 11100 T/C, IL-4Rα +1902 G/A, IL-12 -1188 C/A, γ IFN UTR 5644 A/T, TNF α (−308 G/A; −238 G/A), IL-2 (−330 T/G; +160 G/T), IL-4 (−1098T/G; −590 T/C; −33 T/C), IL-6 (−174 G/C; nt565 G/A), IL-10 (−1082 G/A; −819 C/T; −592 C/A). The following polymorphisms showed a different distribution in patients versus controls: IL-4–33 (p=0.048); IL-4–590 (p=0.005); IL-1α-889 (p=0.009). The correspondence analysis of these variables showed that genotypes IL-4 -33TT, IL-4 -590 TC and-1β+3962TT confer an increased risk of developing SS disease, while genotypes TNF-α-238GA, IL-1α-889CC and IL-10–819CC give an increased risk of developing MS disease. The present study supports the concept that constitutional variants affecting the cytokine network may induce susceptibility to develop LCH and also affect its manifestations. Figure Figure

Background and Objectives: Subcutaneous immunoglobulin (SCIG) therapy is becoming increasingly popular as self-administration is possible because intravenous access is unnecessary, and there is a lower frequency of systemic adverse events. The aim of this study was to evaluate the shifting from intravenous immunoglobulins (IVIGs) replacement therapy to SCIG in patients with primary immunodeficiency (PID) in a routine real-life situation.Methods: In a multicenter prospective observational study, we enrolled 50 patients suffering from PID who were monitored for 24 months; 44 patients switched from IVIG and six from different SCIG preparations. The study preparation (human IgG 16 %, Vivaglobin®, CSL Behring GmbH, Germany) was subcutaneously infused weekly (maximum volume 15 mL/site; maximum infusion rate 22 mL/h). The study endpoints were: annual rate of severe bacterial infections (SBIs), local adverse reactions, quality of life, days off school/work, and days of hospitalization.Results: Thirty-three of 39 (84.6 %) patients who completed the study experienced an infection or signs thereof. Only five SBIs were observed, corresponding to an annual rate of 0.056 episodes per patient in 44 subjects [intention-to-treat (ITT) population]. A significant decrease in both days of hospitalization (1.93 ± 4.08 vs. 0.64 ± 2.94) and days off school/work (15.27 ± 23.17 vs. 2.26 ± 4.45) was recorded at 24 months. Local reactions were observed in 14/50 (28 %) patients, mainly consisting of skin manifestations at the injection site. Only three (6.8 %) patients discontinued due to infusion site reactions. In patients shifting from IVIG to SCIG, the total mean score of Life Quality Index (LQI) improved from 76.9 ± 16.8 to 90.7 ± 11.6 (P < 0.01) at 6 months; there was an improvement also in the overall patients’ evaluation.Conclusions: A total of 93.2 % patients tolerated the new route of administration and reported a significant improvement in their LQI. Our results from a routine clinical practice in a real-life population are consistent with those of phase III clinical studies.

Mutations of PRF1 and MUNC13–4 genes, involved with cellular cytotoxicity, are associated with the familial form of Hemophagocytic Lymphohistiocytosis (HLH) type 2 (FHL2) and 3 (FHL3). In all patients with HLH, in which PRF1 mutations had been excluded, we screened MUNC13–4 mutations. The 32 exons and their proximal flanking regions of MUNC13–4 gene were sequenced by “cycle sequencing” approach (BigDye Terminator, Applied Biosystems). Of 60 patients, 21 had MUNC13–4 mutations. 5 were reported mutations: 753+1G>T, 817C>T (R273X); 1389+1G>A; 1822del 12 bp (del V608-A611); 2346–9delGGAG (R782FsX12). Of 16 novel mutations 2 (2212C>T and 2650C>T) introduce a stop codon (at Q738 and Q884); 4 cause frameshift: 441delA (P147fsX14), 532delC (Q178fsX70), 3082delC (L1028fsX), and 3226insG (H1076fsX51). Of 8 missense mutations [175G>A (A59T), 419T>C (I140T), 610A>G (M204B), 1241G>T (R414L), 1847A>G (E616G), 2039G>C (R680P), 2570T>G (F857C), 2782C>T (R928C)], 6 fall within the protein functional domains; each of the 2 falling outside was associated with 2 additional pathogenic mutations. The remaining novel 1992+5 G>A and 2448insC −12 fall outside the coding region but are close enough to induce alternative splicing. We identified polymorphisms 279C>T and 3198A>G. The 2599A>G (K867E) transition was found in several unrelated families, including one homozygous parent. To assess its frequency we studied 50 consecutive newborns, of which 64% were heterozygous. To understand the effects of the mutations we analysed Munc13–4 protein expression from CTL and/or NK cells by western blot using an antibody raised against amino acids 1–262. Trace amounts of protein could be detected only in 5 patients. Analysis of granule polarisation in 2 patients with trace amounts of Munc13–4 protein showed many more docked granules visible than in controls, consistent with a block in granule secretion in these patients. Median age at diagnosis of FHL3 was 6.5 months, but 8/21 (38%) patients were diagnosed when older than 5 years, with one young adult of 18 years. CNS disease was present in 10 patients; NK was markedly reduced or absent in all patients tested. MUNC13–4 mutations were found in 35% of our HLH patients non type-2. Mutations were almost entirely different from those reported so far and scattered over different exons, but in far most cases they fall within the protein functional domain. Since these patients may develop the disease during adolescence or even later on, not only pediatric but also as adults hematologists should include FHL-2 and 3 in the differential diagnosis of children and young adults with fever, cytopenia, splenomegaly and hypercytokinemia.