Clinical and transcriptomic characteristics of a novel SMARCD2 mutation that disrupts neutrophil maturation and function.

We report a novel case of SMARCD2 (SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily D, member 2) mutation successfully treated with hematopoietic stem cell transplantation. The female patient presented delayed cord separation, chronic diarrhea, skin abscesses, skeletal dysmorphisms, and neutropenia with specific granule deficiency. Analysis of the transcriptomic profile of peripheral blood sorted mature and immature SMARCD2 neutrophils showed defective maturation process that associated with altered expression of genes related to specific, azurophilic, and gelatinase granules, such as LTF, CRISP3, PTX3, and CHI3L1. These abnormalities account for the prevalence of immature neutrophils in the peripheral blood, impaired function, and deregulated inflammatory responses.

Factors Associated With Severe Gastrointestinal Diagnoses in Children With SARS-CoV-2 Infection or Multisystem Inflammatory Syndrome.

Importance: Severe gastrointestinal (GI) manifestations have been sporadically reported in children with COVID-19; however, their frequency and clinical outcome are unknown. Objective: To describe the clinical, radiological, and histopathologic characteristics of children with COVID-19 presenting with severe GI manifestations to identify factors associated with a severe outcome. Design, Setting, and Participants: A multicenter retrospective cohort study (February 25, 2020, to January 20, 2021) enrolled inpatient and outpatient children (aged <18 years) with acute SARS-CoV-2 infection, confirmed by positive real-time reverse-transcriptase-polymerase chain reaction on nasopharyngeal swab or fulfilling the US Centers for Disease Control and Prevention criteria for multisystem inflammatory syndrome in children (MIS-C). The study was conducted by pediatricians working in primary care or hospitals in Italy participating in the COVID-19 Registry of the Italian Society of Pediatric Infectious Diseases. Main Outcomes and Measures: The occurrence of severe GI manifestations, defined by a medical and/or radiological diagnosis of acute abdomen, appendicitis (complicated or not by perforation and/or peritonitis), intussusception, pancreatitis, abdominal fluid collection, and diffuse adenomesenteritis requiring surgical consultation, occurring during or within 4 to 6 weeks after infection with SARS-CoV-2 infection. Logistic regression was used to estimate odds ratios (ORs) with 95% CIs of factors potentially associated with severe outcomes. Results: Overall, 685 children (386 boys [56.4%]; median age, 7.3 [IQR, 1.6-12.4] years) were included. Of these children, 628 (91.7%) were diagnosed with acute SARS-CoV-2 infection and 57 (8.3%) with MIS-C. The presence of GI symptoms was associated with a higher chance of hospitalization (OR, 2.64; 95% CI, 1.89-3.69) and intensive care unit admission (OR, 3.90; 95% CI, 1.98-7.68). Overall, 65 children (9.5%) showed severe GI involvement, including disseminated adenomesenteritis (39.6%), appendicitis (33.5%), abdominal fluid collection (21.3%), pancreatitis (6.9%), or intussusception (4.6%). Twenty-seven of these 65 children (41.5%) underwent surgery. Severe GI manifestations were associated with the child's age (5-10 years: OR, 8.33; 95% CI, 2.62-26.5; >10 years: OR, 6.37; 95% CI, 2.12-19.1, compared with preschool-age), abdominal pain (adjusted OR [aOR], 34.5; 95% CI, 10.1-118), lymphopenia (aOR, 8.93; 95% CI, 3.03-26.3), or MIS-C (aOR, 6.28; 95% CI, 1.92-20.5). Diarrhea was associated with a higher chance of adenomesenteritis (aOR, 3.13; 95% CI, 1.08-9.12) or abdominal fluid collection (aOR, 3.22; 95% CI, 1.03-10.0). Conclusions and Relevance: In this multicenter cohort study of Italian children with SARS-CoV-2 infection or MIS-C, 9.5% of the children had severe GI involvement, frequently associated with MIS-C. These findings suggest that prompt identification may improve the management of serious complications.

Emergence of Letermovir-resistant HCMV UL56 mutant during rescue treatment in a liver transplant recipient with ganciclovir-resistant infection HCMV: a case report.

BACKGROUND: Human Cytomegalovirus (HCMV) still represents a crucial concern in solid organ transplant recipients (SOTRs) and the use of antiviral therapy are limited by side effects and the selection of viral mutations conferring antiviral drug resistance. CASE PRESENTATION: Here we reported the case of an HCMV seronegative patient with common variable immunodeficiency (CVID), multiple hepatic adenomatosis, hepatopulmonary syndrome and portal hypertension who received a liver transplant from an HCMV seropositive donor. The patient was treated with Valganciclovir (vGCV) and then IV Ganciclovir (GCV) at 5 week post-transplant for uncontrolled HCMV DNAemia. However, since mutation A594V in UL97 gene conferring resistance to ganciclovir was reported, GCV therapy was interrupted. Due to the high toxicity of Foscarnet (FOS) and Cidofovir (CDV), Letermovir (LMV) monotherapy at the dosage of 480 mg per day was administered, with a gradual viral load reduction. However, a relapse of HCMV DNAemia revealed the presence of mutation C325Y in HCMV UL56 gene conferring resistance to LMV. CONCLUSIONS: In conclusion, even if LMV is an effective and favorable safety molecule it might have a lower genetic barrier to resistance. A warning on the use of LMV monotherapy as rescue treatments for HCMV GCV-resistant infections in transplant recipients is warranted.

Nonenteric Adenoviruses Associated with Gastroenteritis in Hospitalized Children.

The object of this study was to investigate the frequency of human adenovirus (HAdV) infections in hospitalized pediatric patients. Stool samples were collected during a 1-year period (February 2018 to January 2019). HAdV was detected by a broad-range PCR and genotyped by sequencing and phylogenetic analysis. Demographic characteristics and detailed clinical information were analyzed for each patient. HAdV was detected in 7.1% of stool samples (34/476). Among these patients, 23.5% were coinfected with other enteric viral or bacterial pathogens. The majority (85.2%) of HAdV positives were detected in children of <5 years of age. Two HAdV species (B and C) with three types were identified in this study population. HAdV species F was not detected. Genetic analysis shows that the isolates circulating in our region present high diversity and do not exhibit clonal expansion. The presence of nonenteric HAdV in subjects with gastrointestinal symptoms and in immunocompromised patients has already been reported by different studies and underlines the need to develop routine molecular assays that have wide reactivity for most types of adenovirus in order to obtain an optimal tool for their rapid and accurate diagnosis. IMPORTANCE Gastroenteritis is the second leading cause of death among infants and children worldwide. Our study shows that adenovirus types other than 40 and 41 might be related to acute gastroenteritis. Therefore, a novel approach using diagnostic methods able to detect all adenovirus types is desirable in order to overcome the limitations of the current techniques.

Activated Phosphoinositide 3-Kinase Delta Syndrome 1: Clinical and Immunological Data from an Italian Cohort of Patients.

Activated phosphoinositide 3-kinase delta syndrome 1 (APDS-1) is a recently described inborn error of immunity caused by monoallelic gain-of-function mutations in the PIK3CD gene. We reviewed for the first time medical records and laboratory data of eight Italian APDS-1 patients. Recurrent sinopulmonary infections were the most common clinical feature at onset of disease. Seven patients presented lymphoproliferative disease, at onset or during follow-up, one of which resembled hemophagocytic lymphohistiocytosis (HLH). Genetic analysis of the PIK3CD gene revealed three novel mutations: functional testing confirmed their activating nature. In the remaining patients, the previously reported variants p.E1021K (n = 4) and p.E525A (n = 1) were identified. Six patients were started on immunoglobulin replacement treatment (IgRT). One patient successfully underwent hematopoietic stem cell transplantation (HSCT), with good chimerism and no GVHD at 21 months post-HSCT. APDS-1 is a combined immune deficiency with a wide variety of clinical manifestations and a complex immunological presentation. Besides IgRT, specific therapies targeting the PI3Kδ pathway will most likely become a valid aid for the amelioration of patients' clinical management and their quality of life.

Paediatric MAS/HLH caused by a novel monoallelic activating mutation in p110δ.

This study provides evidence for the first time for APDS-1 presenting as MAS/HLH, with evident clinical implications in patient's management and prognosis.

Evidence-based provisional clinical classification criteria for autoinflammatory periodic fevers.

The objective of this work was to develop and validate a set of clinical criteria for the classification of patients affected by periodic fevers. Patients with inherited periodic fevers (familial Mediterranean fever (FMF); mevalonate kinase deficiency (MKD); tumour necrosis factor receptor-associated periodic fever syndrome (TRAPS); cryopyrin-associated periodic syndromes (CAPS)) enrolled in the Eurofever Registry up until March 2013 were evaluated. Patients with periodic fever, aphthosis, pharyngitis and adenitis (PFAPA) syndrome were used as negative controls. For each genetic disease, patients were considered to be 'gold standard' on the basis of the presence of a confirmatory genetic analysis. Clinical criteria were formulated on the basis of univariate and multivariate analysis in an initial group of patients (training set) and validated in an independent set of patients (validation set). A total of 1215 consecutive patients with periodic fevers were identified, and 518 gold standard patients (291 FMF, 74 MKD, 86 TRAPS, 67 CAPS) and 199 patients with PFAPA as disease controls were evaluated. The univariate and multivariate analyses identified a number of clinical variables that correlated independently with each disease, and four provisional classification scores were created. Cut-off values of the classification scores were chosen using receiver operating characteristic curve analysis as those giving the highest sensitivity and specificity. The classification scores were then tested in an independent set of patients (validation set) with an area under the curve of 0.98 for FMF, 0.95 for TRAPS, 0.96 for MKD, and 0.99 for CAPS. In conclusion, evidence-based provisional clinical criteria with high sensitivity and specificity for the clinical classification of patients with inherited periodic fevers have been developed.

Efficacy of adalimumab in young children with juvenile idiopathic arthritis and chronic uveitis: a case series.

BACKGROUND: Juvenile idiopathic arthritis is a relatively common chronic disease of childhood, and is associated with persistent morbidity and extra-articular complications, one of the most common being uveitis. The introduction of biologic therapies, particularly those blocking the inflammatory mediator tumor necrosis factor-α, provided a new treatment option for juvenile idiopathic arthritis patients who were refractory to standard therapy such as non-steroidal anti-inflammatory drugs, corticosteroids and/or methotrexate. CASE PRESENTATIONS: The first case was a 2-year-old girl with juvenile idiopathic arthritis and uveitis who failed to respond to treatment with anti-inflammatories, low-dose corticosteroids and methotrexate, and had growth retardation. Adalimumab 24 mg/m2 every 2 weeks and prednisone 0.5 mg/kg/day were added to methotrexate therapy; steroid tapering and withdrawal started after 1 month. After 2 months the patient showed good control of articular and ocular manifestations, and she remained in remission for 1 year, receiving adalimumab and methotrexate with no side effects, and showing significant improvement in growth. Case 2 was a 9-year-old boy with an 8-year history of juvenile idiopathic arthritis and uveitis that initially responded to infliximab, but relapse occurred after 2 years off therapy. After switching to adalimumab, and adjusting doses of both adalimumab and methotrexate based on body surface area, the patient showed good response and corticosteroids were tapered and withdrawn after 6 months; the patient remained in remission taking adalimumab and methotrexate. The final case was a 5-year-old girl with juvenile idiopathic arthritis for whom adalimumab was added to methotrexate therapy after three flares of uveitis. The patient had two subsequent episodes of uveitis that responded well to local therapy, but was then free of both juvenile idiopathic arthritis and uveitis symptoms, allowing methotrexate and then adalimumab to be stopped; the patient remained in drug-free remission. CONCLUSION: This report includes the first published case of the use of adalimumab in a child aged <3 years. Our clinical experience further supports the use of biologic therapy for the management of juvenile idiopathic arthritis and uveitis in children as young as two years of age.

Differentiating PFAPA syndrome from monogenic periodic fevers.

OBJECTIVES: To analyze whether there were clinical differences between genetically positive and negative patients fulfilling periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome criteria and to test the accuracy of the Gaslini diagnostic score for identifying patients with PFAPA syndrome with higher probabilities of carrying relevant mutations in genes associated with periodic fevers. METHODS: Complete clinical and genetic information was available for 393 children with periodic fever; 82 had positive genetic test results, 75 had incomplete genetic test results, and 236 had negative results for MVK, TNFRSF1A, and MEFV mutations. Current diagnostic criteria for PFAPA syndrome were applied. RESULTS: Of 393 children, 210 satisfied PFAPA syndrome criteria; 43 carried diagnostic mutations (mevalonate kinase deficiency: n = 33; tumor necrosis factor receptor-associated periodic syndrome: n = 3; familial Mediterranean fever: n = 7), 37 displayed low-penetrance mutations or incomplete genotypes, and 130 demonstrated negative genetic testing results. Genetically positive patients had higher frequencies of abdominal pain and diarrhea (P < .001), vomiting (P = .006), and cutaneous rash and arthralgia (P = .01). Genetically negative patients had a higher frequency of exudative pharyngitis (P = .010). Genetically undetermined patients showed the same pattern of symptom frequency as genetically negative patients. The Gaslini diagnostic score was able to identify 91% of genetically positive patients correctly, with a global accuracy of 66%. CONCLUSION: The Gaslini diagnostic score represents a useful tool to identify patients meeting PFAPA syndrome criteria and at low risk of carrying relevant mutations in genes associated with periodic fevers.

Immunoglobulin D enhances immune surveillance by activating antimicrobial, proinflammatory and B cell-stimulating programs in basophils.

Immunoglobulin D (IgD) is an enigmatic antibody isotype that mature B cells express together with IgM through alternative RNA splicing. Here we report active T cell-dependent and T cell-independent IgM-to-IgD class switching in B cells of the human upper respiratory mucosa. This process required activation-induced cytidine deaminase (AID) and generated local and circulating IgD-producing plasmablasts reactive to respiratory bacteria. Circulating IgD bound to basophils through a calcium-mobilizing receptor that induced antimicrobial, opsonizing, inflammatory and B cell-stimulating factors, including cathelicidin, interleukin 1 (IL-1), IL-4 and B cell-activating factor (BAFF), after IgD crosslinking. By showing dysregulation of IgD class-switched B cells and 'IgD-armed' basophils in autoinflammatory syndromes with periodic fever, our data indicate that IgD orchestrates an ancestral surveillance system at the interface between immunity and inflammation.

A novel immunodeficiency characterized by the exclusive presence of transitional B cells unresponsive to CpG.

The objective of this study was to describe a novel form of primary immune disorder characterized by circulating B cells with the exclusive transitional phenotype which fail to respond to CpG stimulation. The 12-year-old male patient suffered from recurrent bacterial infections since infancy. The immunological studies were based on extensive B cell immunophenotyping, humoral in vivo response to different vaccine antigens, and in vitro proliferation and immunoglobulin production after CpG stimulation. Sequence analysis for potentially candidate genes such as IRF8, MyD88, TLR9, T-bet were performed. The patient's serum immunoglobulin levels and the specific antibody response to tetanus toxoid were normal, whereas that to polysaccharide antigens was severely impaired. Flow cytometric analysis showed that almost all patient's peripheral B cells had the transitional phenotype (CD24(bright) CD38(bright) CD27(neg)). Furthermore, the patient's B cells did not proliferate and failed to secrete immunoglobulins after in vitro CpG stimulation. Sequence analysis for TLR9, MyD88, IRF8 and T-bet showed no mutations. To our knowledge, this is the first case of a novel primary immunodeficiency mimicking the clinical phenotype of common variable immunodeficiency, with a peculiar immunological phenotype characterized by normal immunoglobulin serum levels, circulating B cells with the exclusive transitional phenotype unable to respond to CpG stimulation. This defines a novel form of primary immunodeficiency mimicking common variable immunodeficiency in the presence of normal immunoglobulin serum levels.

Combined decrease of defined B and T cell subsets in a group of common variable immunodeficiency patients.

Common variable immunodeficiency disease (CVID) is a primary immune disorder affecting B cells and characterized by hypogammaglobulinemia and recurrent infections. To elucidate the clinical and immunological heterogeneity of this condition, we have studied B and T cell subsets in 25 CVID patients. In eleven of them, we observed a remarkable relative expansion of a B cell subpopulation (CD19(hi)/CD21(lo) cells) characterized by the absence of CD23 and the reduced expression of the chemokine receptors CXCR5 and CCR7. Our analyses demonstrated in these patients that the expansion of CD19(hi)/CD21(lo) cells correlates with a selective decrease of circulating naïve and CD21(hi) memory B lymphocytes. The same group of patients displayed a simultaneous severe reduction of naïve CD4+ T cells associated with decreased levels of T cell receptor excision circles. These observations suggest that a combined defect in generation of B and T subpopulations may account for the abnormal immunophenotype characterizing this subgroup of CVID patients.

Mutational analysis of human BLyS in patients with common variable immunodeficiency.

BLyS, a TNF family member, is crucial for B cell proliferation and differentiation by acting through its three receptors, TACI, BCMA and BAFF-R. The knock out model for BLyS is characterized by an immunological phenotype reminiscent of the human phenotype of common variable immunodeficiency (CVID). CVID is characterized by a defective B cell compartment, evidencing the putative importance of BLyS in its pathogenesis. On the contrary, the transgenic model for BLys is characterized by autoimmune manifestations, underlying its role in B cell regulation. In fact, mutations in TACI, one of the three BLyS receptors, are associated with CVID. Based on these facts, we hypothesized that BLyS could be a candidate gene for CVID. We screened 78 patients with CVID using DHPLC and direct sequencing: No disease causing mutations were identified. A novel heterozygous single nucleotide polymorphism (SNP) was found in exon 1 of one individual, however this SNP (G189A) does not lead to an amino acid substitution.

Role of intracellular Ca2+ and calmodulin/MAP kinase kinase/extracellular signal-regulated protein kinase signalling pathway in the mitogenic and antimitogenic effect of nitric oxide in glia- and neurone-derived cell lines.

To elucidate the mechanism of cell growth regulation by nitric oxide (NO) and the role played in it by Ca2+, we studied the relationship among intracellular Ca2+ concentration ([Ca2+]i), mitogen-activated protein kinases [extracellular signal-regulated protein kinase (ERK)] and proliferation in cell lines exposed to different levels of NO. Data showed that NO released by low [(z)-1-[2-aminiethyl]-N-[2-ammonioethyl]amino]diazen-1-ium-1,2diolate (DETA/NO) concentrations (10 microm) determined a gradual, moderate elevation in [Ca2+]i (46.8 +/- 7.2% over controls) which paralleled activation of ERK and potentiation of cell division. Functionally blocking Ca2+ or inhibiting calmodulin or MAP kinase kinase activities prevented ERK activation and antagonized the mitogenic effect of NO. Experimental conditions favouring Ca2+ entry into cells led to increased [Ca2+]i (189.5 +/- 4.8%), ERK activation and cell division. NO potentiated the Ca2+ elevation (358 +/- 16.8%) and ERK activation leading to expression of p21Cip1 and inhibition of cell proliferation. Furthermore, functionally blocking Ca2+ down-regulated ERK activation and reversed the antiproliferative effect of NO. Both the mitogenic and antimitogenic responses induced by NO were mimicked by a cGMP analogue whereas they were completely antagonized by selective cGMP inhibitors. These results demonstrate for the first time that regulation of cell proliferation by low NO levels is cGMP dependent and occurs via the Ca2+/calmodulin/MAP kinase kinase/ERK pathway. In this effect the amplitude of Ca2+ signalling determines the specificity of the proliferative response to NO possibly by modulating the strength of ERK activation. In contrast to the low level, the high levels (50-300 microm) of DETA/NO negatively regulated cell proliferation via a Ca2+-independent mechanism.

Neutrophils from patients with TNFRSF1A mutations display resistance to tumor necrosis factor-induced apoptosis: pathogenetic and clinical implications.

OBJECTIVE: To explore tumor necrosis factor (TNF)-induced apoptosis in neutrophils from patients with TNF receptor-associated periodic syndrome (TRAPS) and to correlate the results with the different kinds of TNFRSF1A mutations. METHODS: Two hundred sixty-five patients with clinically suspected inherited autoinflammatory syndrome were screened for mutations of the TNFRSF1A gene. Neutrophils were isolated from heparinized blood by dextran sedimentation and incubated with and without cycloheximide (CHX) and TNFalpha. Cell apoptosis was assessed by human annexin V binding, and caspase 8 activation was assessed by flow cytometry. RESULTS: Twenty-one patients were found to carry a variant of the TNFRSF1A gene: 13 patients had an R92Q substitution, and 8 patients presented other missense substitutions, 1 splicing mutation, and 1 in-frame interstitial deletion. Neutrophil stimulation with TNF and CHX was associated with induction of apoptosis in 12 normal controls and in 10 subjects with the R92Q mutation. Conversely, neutrophils from 8 TRAPS patients with mutations of cysteine or threonine residues or interstitial deletion did not show any induction of apoptosis after stimulation. The incidence of the R92Q mutation among patients with recurrent autoinflammatory syndromes was similar to that observed in the normal population. CONCLUSION: Resistance to TNF-mediated apoptosis is a feature in TRAPS patients who have mutations of cysteine residues or interstitial deletion, and may play a pathogenic role. The R92Q mutation does not appear to be significantly associated with TRAPS.

Mutational analysis of human BAFF receptor TNFRSF13C (BAFF-R) in patients with common variable immunodeficiency.

BAFF receptor (BAFF-R/BR3/TNFRSF13C) is a recently identified molecule that specifically binds BLyS, a protein belonging to the tumor necrosis factor (TNF) family, and is involved in survival and maturation of B cells. Recent studies have demonstrated that mice defective in BAFF-R gene exhibit an altered profile of the B cell pool, a phenotype observed in BLyS knockout mice as well. These features suggest that mutations in this gene may result in humoral immunodeficiency. To test this hypothesis, we sequenced the BAFF-R gene in 48 patients with common variable immunodeficiency (CVID) along with 57 healthy controls. We have identified three novel variants present at the heterozygous state leading to amino acid substitutions, and have also confirmed the existence of a previously reported intronic variant. The hereby described novel variants were also present in healthy controls and in the healthy patients' parents. These variants do not affect the expression of BAFF-R neither at the mRNA nor at the protein level, suggesting that these variants represent novel polymorphic variants of the BAFF-R gene.

The translationally controlled tumor protein is a novel calcium binding protein of the human placenta and regulates calcium handling in trophoblast cells.

The translationally controlled tumor protein (TPT1, also known as TCTP) is a highly conserved, abundantly expressed protein found in mammals as well as in a wide range of other organisms of both the animal and plant kingdom. Initially considered as a growth-related protein, later studies showed TPT1 is endowed with multiple biological activities, including calcium binding. The present study aimed to evaluate the expression of TPT1 in the human placenta and to examine the functional role of the protein in the calcium binding and homeostasis of trophoblast cells. Samples were analyzed by Western blot, reverse transcription-polymerase chain reaction and immunohistochemistry. The effect of TPT1 knockdown by small interfering RNA (siRNA) on calcium uptake and buffering was assessed in the HTR-8/SVneo cell line. TPT1 protein and mRNA were detected in first-trimester and term placenta. In the tissue, TPT1 was localized in the villous trophoblast. TPT1 expression significantly increased during gestation, with the higher protein and mRNA levels reached at term. Recombinant placental TPT1 bound calcium in vitro, while downregulation of the protein levels by siRNA in HTR-8/SVneo cells was associated with a reduced cellular calcium-uptake activity and buffering capacity. These data demonstrate, for the first time, the expression of TPT1 in the human placenta and support a direct role of the protein in placental calcium transport.