Mosaic IL6ST variant inducing constitutive GP130 cytokine receptor signaling as a cause of neonatal onset immunodeficiency with autoinflammation and dysmorphy.

Interleukin-6 signal transducer (IL6ST) encodes the GP130 protein which transduces the proinflammatory signaling of the IL6 cytokine family through Janus kinase signal transducers and activators of transcription pathway (JAK/STAT) activation. Biallelic loss-of-function IL6ST variants cause autosomal recessive hyper-IgE syndrome or a variant of the Stuve-Wiedemann syndrome. Somatic gain-of-function IL6ST mutations, in particular, small monoallelic in-frame deletions of which the most prevalent is the IL6ST Ser187_Tyr190del, are an established cause of inflammatory hepatocellular tumors, but so far, no disease caused by such mutations present constitutively has been described. Herein, we report a pediatric proband with a novel syndrome of neonatal onset immunodeficiency with autoinflammation and dysmorphy associated with the IL6ST Tyr186_Tyr190del variant present constitutively. Tyr186_Tyr190del was found by exome sequencing and was shown to be de novo (absent in proband's parents and siblings) and mosaic (present in approximately 15-40% of cells depending on the tissue studied-blood, urine sediment, hair bulbs and buccal swab). Functional studies were performed in the Epstein-Barr virus-immortalized patient's B cell lymphoblastoid cell line, which carried the variant in approximately 95% of the cells. Western blot showed that the patient's cells exhibited constitutive hyperphosphorylation of Tyr705 in STAT3, which is indicative of IL6-independent activation of GP130. Interestingly, the STAT3 phosphorylation could be inhibited with ruxolitinib as well as tofacitinib, which are clinically approved JAK1 and JAK3 (to lesser extent JAK2 and JAK1) inhibitors, respectively. Given our results and the recent reports of ruxolitinib and tofacitinib use for the treatment of diseases caused by direct activation of STAT3 or STAT1, we speculate that these drugs may be effective in the treatment of our patient's condition.

Neutrophilic dermatosis: a new skin manifestation and novel pathogenic variant in a rare autoinflammatory disease.

Sideroblastic anaemia, B-cell immunodeficiency, periodic fever and developmental delay (SIFD) is caused by mutations of TRNT1, an enzyme essential for mitochondrial protein synthesis, and has been reported in 23 cases. A 6-month-old girl was evaluated with recurrent fever, failure to thrive, skin lesions and anaemia. She received blood transfusions and empirical antibiotics. Skin lesions, previously interpreted as insect bites, consisted of numerous firm asymptomatic erythematous papules and nodules, distributed over trunk and limbs. Skin histopathology revealed an intense dermal neutrophilic infiltrate extending to the subcutaneous, with numerous atypical myeloid cells, requiring the diagnosis of leukaemia cutis, to be ruled out. Over the follow-up, she developed herpetic stomatitis, tonsillitis, lobar pneumonia and Metapneumovirus tracheitis, and also deeper skin lesions, resembling panniculitis. Hypogammaglobulinaemia was diagnosed. An autoinflammatory disease was confirmed by whole exome sequencing: heterozygous mutations for TRNT1 NM_182916 c.495_498del, p.F167Tfs * 9 and TRNT1 NM_182916 c.1246A>G, p.K416E. The patient has been treated with subcutaneous immunoglobulin and etanercept. She presented with developmental delay and short stature for age. The fever, anaemia, skin neutrophilic infiltration and the inflammatory parameters improved. We describe a novel mutation in SIFD and the first to present skin manifestations, namely neutrophilic dermal and hypodermal infiltration.

Usefulness of Gastric Aspirate Culture for Diagnosing Congenital Immunodeficiency in an Infant with Fungal Pneumonia Caused by Rasamsonia piperina.

Chronic granulomatous disease (CGD) is a type of primary immunodeficiency disease, which increases susceptibility to recurrent bacterial and fungal infections. Sputum and bronchoalveolar lavage fluid are often obtained using bronchoscopy from adult patients for pathogenic diagnosis, although this approach is much more invasive for infants. We report the case of a 2-month-old boy with CGD, in which gastric aspirate culture was used to diagnose fungal pneumonia. Rasamsonia piperina was isolated from the gastric aspirate, and the patient was successfully treated with micafungin based on the drug susceptibility test results for the fungal isolate. The acid tolerance test revealed that R. piperina could grow at pH 2, indicating high acid resistance. Although we can only report our experience with a single case, gastric aspirate culture may be a useful tool for detecting fungal respiratory pathogens in children with primary immunodeficiency. Detecting these pathogens may help improve outcomes, as early diagnosis and appropriate treatment are extremely important for immunocompromised patients with respiratory infections.

Allogeneic hematopoietic stem cell transplantation in congenital disorders: A single-center experience.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the treatment of choice for a variety of congenital disorders. We report the experience of children affected by congenital diseases other than bone marrow failure syndromes who received allo-HSCT over a period of 25 years at G. Gaslini Paediatric Research Institute. HSCTs were performed in 57 children with congenital diseases (25 with congenital immunodeficiencies, 10 with severe combined immunodeficiencies, and 22 with metabolic diseases). Overall survival rate at 3 years in the whole group of patients was 76.9%, with a trend in favor of better outcome in children with metabolic diseases and in those who received cord blood cells (85.9%) vs bone marrow cells (72.4%).

A congenital neutrophil defect syndrome associated with mutations in VPS45.

BACKGROUND: Neutrophils are the predominant phagocytes that provide protection against bacterial and fungal infections. Genetically determined neutrophil disorders confer a predisposition to severe infections and reveal novel mechanisms that control vesicular trafficking, hematopoiesis, and innate immunity. METHODS: We clinically evaluated seven children from five families who had neutropenia, neutrophil dysfunction, bone marrow fibrosis, and nephromegaly. To identify the causative gene, we performed homozygosity mapping using single-nucleotide polymorphism arrays, whole-exome sequencing, immunoblotting, immunofluorescence, electron microscopy, a real-time quantitative polymerase-chain-reaction assay, immunohistochemistry, flow cytometry, fibroblast motility assays, measurements of apoptosis, and zebrafish models. Correction experiments were performed by transfecting mutant fibroblasts with the nonmutated gene. RESULTS: All seven affected children had homozygous mutations (Thr224Asn or Glu238Lys, depending on the child's ethnic origin) in VPS45, which encodes a protein that regulates membrane trafficking through the endosomal system. The level of VPS45 protein was reduced, as were the VPS45 binding partners rabenosyn-5 and syntaxin-16. The level of ß1 integrin was reduced on the surface of VPS45-deficient neutrophils and fibroblasts. VPS45-deficient fibroblasts were characterized by impaired motility and increased apoptosis. A zebrafish model of vps45 deficiency showed a marked paucity of myeloperoxidase-positive cells (i.e., neutrophils). Transfection of patient cells with nonmutated VPS45 corrected the migration defect and decreased apoptosis. CONCLUSIONS: Defective endosomal intracellular protein trafficking due to biallelic mutations in VPS45 underlies a new immunodeficiency syndrome involving impaired neutrophil function. (Funded by the National Human Genome Research Institute and others.).

Primary Effusion Lymphoma (PEL)-Like Lymphoma in a Child With Congenital Immunodeficiency.

Primary effusion lymphoma (PEL) is a rare lymphoma that occurs more frequently in immunocompromised adults and has a poor survival. We report a 9-year-old female with combined immunodeficiency with an Epstein-Barr virus positive/human herpes virus 8 negative PEL-like lymphoma. The treatment with systemic chemotherapy for non-Hodgkin lymphoma, zidovudine, and interferon-α failed to control disease progression. This is the first reported pediatric case of PEL-like lymphoma. Increased diagnostic awareness and more effective treatment strategies are needed for this rare lymphoma.

[Pulmonary manifestations in adult patients with a defect in humoral immunity]. / Pul'monologicheskie proyavleniya u vzroslykh patsientov s defektom gumoral'nogo zvena immuniteta.

Primary immunodeficiencies (PIDs) are a group of congenital diseases of the immune system, which numbers more than 230 nosological entities associated with lost, decreased, or wrong function of its one or several components. Due to the common misconception that these are extremely rare diseases that occur only in children and lead to their death at an early age, PIDs are frequently ruled out by physicians of related specialties from the range of differential diagnosis. The most common forms of PIDs, such as humoral immunity defects, common variable immune deficiency, X-linked agammaglobulinemia, selective IgA deficiency, etc., are milder than other forms of PID, enabling patients to attain their adult age, and may even manifest in adulthood. Bronchopulmonary involvements are the most common manifestations of the disease in patients with a defect in humoral immunity. Thus, a therapist and a pulmonologist are mostly the first doctors who begin to treat these patients and play a key role in their fate, since only timely diagnosis and initiation of adequate therapy can preserve not only the patient's life, but also its quality, avoiding irreversible complications. Chest computed tomography changes play a large role in diagnosis. These are not specific for PID; however, there are a number of characteristic signs that permit this diagnosis to be presumed.

Prevalence and clinical impact of norovirus fecal shedding in children with inherited immune deficiencies.

We report the first prospective study describing the prevalence and clinical consequences of norovirus infection in hospitalized children with primary immunodeficiencies. Fecal samples from 62 children were systematically screened for virus. Norovirus was the most frequent pathogen (11 of 24 positive samples) found in both combined and humoral immunocompromised children. Norovirus shedding was associated with gastrointestinal symptoms and concomitant viremia in 54.5% and 25% of cases, respectively. Norovirus excretion was prolonged: 57.1% of fecal samples were still positive after a median of 9.5-months follow-up. Further large longitudinal studies are needed to evaluate the clinical consequences of norovirus shedding in patients with primary immunodeficiencies.

Epigenetics, autoimmunity and hematologic malignancies: a comprehensive review.

The relationships between immunological dysfunction, loss of tolerance and hematologic malignancies have been a focus of attention in attempts to understand the appearance of a higher degree of autoimmune disease and lymphoma in children with congenital immunodeficiency. Although multiple hypotheses have been offered, it is clear that stochastic processes play an important role in the immunopathology of these issues. In particular, accumulating evidence is defining a role of epigenetic mechanisms as being critical in this continuous spectrum between autoimmunity and lymphoma. In this review, we focus attention predominantly on the relationships between T helper 17 (Th17) and T regulatory populations that alter local microenvironments and ultimately the expression or transcription factors involved in cell activation and differentiation. Abnormal expression in any of the molecules involved in Th17 and/or Treg development alter immune homeostasis and in genetically susceptible hosts may lead to the appearance of autoimmunity and/or lymphoma. These observations have clinical significance in explaining the discordance of autoimmunity in identical twins. They are also particularly important in the relationships between primary immune deficiency syndromes, immune dysregulation and an increased risk of lymphoma. Indeed, defining the factors that determine epigenetic alterations and their relationships to immune homeostasis will be a challenge greater or even equal to the human genome project.

Overwhelming post-splenectomy infection (OPSI): a case report and review of the literature.

BACKGROUND: Overwhelming post-splenectomy infection (OPSI) is a serious disease that can progress from a mild flu-like illness to fulminant sepsis in a short time period. Although relatively rare, it has a high mortality rate with delayed or inadequate treatment, and therefore, it is important for Emergency Physicians to be familiar with it. Patients who are asplenic or hyposplenic are at an increased risk for infection and death from encapsulated organisms and other dangerous pathogens. OBJECTIVES: There is an abundance of literature discussing OPSI from the perspective of hematologists and infectious disease specialists, but an Emergency Medicine perspective is necessary to truly understand the acute nature of the disease. The objective of this article is to present a careful examination of the literature with a focus on early diagnosis and management to provide Emergency Physicians with the ability to positively affect outcomes of this deadly disease. CASE REPORT: We present the case of a well-appearing 5-month-old girl with congenital asplenia who presented to the Emergency Department with fever, and rapidly progressed to septic shock as a result of OPSI. Aggressive resuscitation was initiated, including empiric antibiotics, and after a prolonged hospital course in the pediatric intensive care unit, the child recovered. CONCLUSION: Rapid identification of patients at risk for OPSI, followed by administration of intravenous antibiotics, usually vancomycin and ceftriaxone, combined with early goal-directed therapy, are the keys to successful treatment. If initiated early in the patient's course, the 70% mortality rate can be reduced to the 10-40% range.

Herpes simplex vegetans presenting as an eyelid mass.

A 16-year-old girl with congenital T-cell immunodeficiency presented with a 2-month history of an enlarging lower eyelid mass. After complete excision of the mass, the lesion was noted to recur. Histologic and immunohistochemical analysis of the excised mass revealed infection with herpes simplex virus types 1 and 2 with exuberant inflammatory reaction and granulation tissue consistent with the diagnosis of herpes simplex vegetans. Treatment with valacyclovir resulted in complete resolution of the remaining lesions. Herpes simplex vegetans should be included in the clinical and histopathologic differential for rapidly growing cutaneous masses in patients with immunodeficiency.

The spectrum of autoantibodies in IPEX syndrome is broad and includes anti-mitochondrial autoantibodies.

IPEX syndrome is a congenital disorder of immune regulation caused by mutations in the FOXP3 gene, which is required for the suppressive function of naturally arising CD4 + CD25 + regulatory T cells. In this case series we evaluated serum samples from 12 patients with IPEX syndrome for the presence of common autoantibodies associated with a broad range of autoimmune disorders. We note that 75% of patients (9/12) had 1 or more autoantibodies, an incidence far above the cumulative rate observed in the general population. The range of autoantibodies differed between patients and there was no predominant autoantibody or pattern of autoantibodies present in this cohort. Surprisingly, one patient had high-titer anti-mitochondrial antibodies (AMA) typically associated with primary biliary cirrhosis (PBC) although the patient had no signs of cholestasis. PBC is a well-characterized autoimmune disease that occurs primarily in women and includes the serological hallmarks of serum AMA and elevated IgM which were both present in this patient. PBC is virtually absent in children with the exception of one reported child with interleukin 2 receptor α (CD25) deficiency which is associated with an IPEX-like regulatory T cell dysfunction. Based on the present data and the available literature we suggest a direct role for CD4 + CD25 + regulatory T cells in restraining B cell autoantibody production and that defects in regulatory T cells may be crucial to the development of PBC.

Cognitive and behavioral abnormalities in children after hematopoietic stem cell transplantation for severe congenital immunodeficiencies.

Hematopoietic stem cell transplantation (HSCT) is a highly successful treatment for severe congenital immunodeficiencies. However, some studies have suggested that children may experience cognitive difficulties after HSCT. This large-scale study assessed cognitive and behavioral function for the cohort of children treated by HSCT at one center between 1979 and 2003 to determine the frequency and severity of problems and to identify risk factors. A total of 105 patients were assessed on standardized measures of cognitive and emotional and behavioral function together with a control group of unaffected siblings. The average IQ for the cohort was 85 (95% confidence interval, 81-90), significantly lower than both the population average of 100 (P < .001) and unaffected siblings. Multivariate analysis indicated that the underlying genetic defect, diagnosis of adenosine deaminase-deficient severe combined immunodeficiency, and consanguinity were associated with worse outcome but that age at transplantation and chemotherapy conditioning were not. Children treated by HSCT for severe immunodeficiency have an increased risk of long-term cognitive difficulties and associated emotional and behavioral difficulties. The specific genetic diagnosis, consanguinity, and severe clinical course are associated with poor outcome. Long-term follow-up of these patients should include screening to identify and manage these problems more effectively.

WHIM syndrome: congenital immune deficiency disease.

PURPOSE OF REVIEW: Warts, hypogammaglobulinemia, infections, and myelokathexis (WHIM) syndrome is characterized by susceptibility to human papilloma virus infection-induced warts and carcinomas; neutropenia, B-cell lymphopenia and hypogammaglobulinema-related infections; and bone marrow myelokathexis (myeloid hyperplasia with apoptosis). The purpose of this report is to review new findings about WHIM. RECENT FINDINGS: Most WHIM patients have heterozygous C-terminus deletion mutations of the intracellular carboxy terminus of the chemokine receptor CXCR4. WHIM leukocytes have enhanced responses to CXCL12, the cognate ligand of CXCR4. Enhanced activity of CXCR4 delays release of mature neutrophils from bone marrow, resulting in neutropenia and apoptosis of mature neutrophils retained in the marrow. Finding two patients with WHIM who do not have detectable mutations of CXCR4 but whose cells are hyperresponsive to CXCL12 raises the possibility that there is more than one genetic basis for WHIM. One patient had low levels of G-protein receptor kinase 3, and the functional hyperactivity response to CXCL12 was corrected by forced gene transfer-mediated overexpression of G-protein receptor kinase 3, implicating defects in function of this protein as a potential alternate genetic cause of WHIM. SUMMARY: Subjects reviewed include clinical presentation, diagnosis, and treatment of WHIM and advances in understanding the genetic basis of WHIM.

Diagnosing inborn error of immunity following the presentation of a complicated acquired infection after MMRV vaccine administration.

Live vaccine-acquired infection should attest for the occurrence of inborn errors of immunity. Autosomal recessive immunodeficiency 31B, a result of a signal transducer and activator of transcription 1 genetic mutation, results in defected interferon pathways: interferon alpha/beta and interferon gamma. These interferons are crucial for the defence against viral and mycobacterial infections. Recognition is important for preventive and therapeutic approaches. Herein, we report the presentation of a newly diagnosed 13-month-old child with immunodeficiency 31B after presenting with disseminated measles and varicella infection after Measles, Mumps, Rubella and Varicella vaccination.

Tumor development after 3-methylcholanthrene in immunologically deficient athymic-nude mice.

Athymic-nude (nu/nu) mice and normal (nu/+) mice showed no differences in either latent period or incidence of local sarcomas or lung adenomas within 120 days after administration of 3-methylcholanthrene at birth. However, nu/nu mice were incapable of rejecting allogeneic skin grafts for the duration of the experiment. These results argue against an active role of thymus-dependent immunity as a surveillance mechanism preventing tumor development.

[Yellow fever vaccination in non-immunocompetent patients]. / Vaccination contre la fièvre jaune en dehors des sujets immunocompétents.

Any person travelling in countries where yellow fever (YF) is endemic and without presenting contra-indication for the vaccination against YF may be vaccinated. This vaccination can very rarely induce a potentially lethal neurotropic or viscerotropic disease. In severely immunodeficient patients, the vaccination is contra-indicated because postvaccinal encephalitis may occur after the vaccination, due to vaccine strain pathogenecity. It is important to evaluate the general health status in elderly individuals before vaccinating because of the increased risk of viscerotropic disease in people of 60 years of age and over. Pregnant women should not be vaccinated, except if departure to an endemic zone is unavoidable. YF vaccinatio is contra-indicated for newborns under six months of age. Solid organ grafts, congenital immunodeficiency, leukemia, lymphoma, cancer, and immunosuppressive treatments are contra-indications for this vaccination. Nevertheless, YF immunization is possible after a bone marrow graft and a two-year period without graft-versus-host disease or immunosuppressive treatment. There is no data to support that immunization of the dono prior to the graft could confer protection against yellow fever to the recipient. Low doses, short courses of corticosteroids either as systemic treatment or intra-articular injections are not contra-indications for YF vaccination. Patients infected with HIV with stable clinical status and T CD4-cel count above 200 cells per millimetre cube may be vaccinated. Thymic diseases, including thymoma and thymectomy, are contra-indications for YF vaccination. Finally, a substantial residual level of antibodies beyond 10 years after the latest vaccination could confer protection, thus avoiding a new vaccination when it is an issue.

SIFD as a novel cause of severe fetal hydrops and neonatal anaemia with iron loading and marked extramedullary haemopoiesis.

SIFD describes a heritable, syndromic condition characterised principally by sideroblastic anaemia (SA) with immunodeficiency, fevers and developmental delay, arising in mutations within the TRNT1 gene. Other clinical manifestations of SIFD include cardiomyopathy, seizures, sensorineural hearing loss, renal dysfunction, metabolic abnormalities, hepatosplenomegaly and retinitis pigmentosa.Presentation of SIFD is variable but typically in early childhood with SA or with fever. In this report, we extend the described SIFD phenotype. We describe a kindred in which the index case presented with fetal hydrops, and early neonatal death, and the second child had severe anaemia at delivery. Both cases had prominent extramedullary erythropoiesis and numerous circulating nucleated red blood cells.

Diminished CD40L expression on T-cells in a case of disseminated cryptococcosis.

X-linked hyperimmunoglobulin M (HIGM) syndrome may increase the susceptibility of patients to disseminated cryptococcal infections primarily due to CD40L deficiency that causes defective cross talk between T- and B-cells, thus preventing class switching. In HIGM syndrome, serum IgM levels are elevated with severe reduction in serum immunoglobulin G (IgG) and IgA levels. In addition, the expression of CD40L (CD154) on in vitro-activated T-cells is severely reduced or absent. Here, we describe a rare, and perhaps, the first reported case in India of a 3-year-old male child with X-linked HIGM immunodeficiency syndrome who developed disseminated Cryptococcosis. Evaluation of the serum IgG profile of the patient revealed increased serum IgM levels with reduced IgG and IgA levels. Both the frequency and the function of T-cells, primarily CD40L on activated T-cells, showed weak expression suggestive of HIGM syndrome.

Disseminated human malignant melanoma in congenitally immune-deficient (bg/nu/xid) mice.

Congenitally immune-deficient bg/nu/xid (BNX) mice are severely compromised in their ability to mount T-cell, B-cell, and lymphokine-activated killer (LAK) cell responses. Successful engraftment of BNX mice with human hematopoietic stem cells has been demonstrated recently. We have investigated the potential use of BNX mice for studies relating to the biology and immunotherapy of human malignant melanoma. The intravenous injection of fresh single-cell suspensions of human malignant melanomas into mice resulted in widely disseminated disease. Metastatic spread of human melanoma in BNX mice mimicked that observed in patients: eg, there were numerous tumor nodules identified in the subcutaneous tissues as well as in a variety of visceral organs, including spleen, kidneys, thyroid, adrenals, lungs, heart, and brain. BNX mouse lymph nodes were replaced consistently by human malignant melanoma cells. The presence of human tumor cells in these mice was confirmed by histologic analysis and microcytofluorometry analyses using human melanoma-specific monoclonal antibodies (MAbs). Moreover, human melanoma cells passaged in BNX mice remained lysable in vitro by specifically cytolytic, autologous human tumor-infiltrating lymphocytes (TILs). The capacity of fresh human malignant melanoma to disseminate widely in BNX mice may prove valuable not only for study of the biology of metastatic spread but also for studies of the immunotherapy of human melanoma using melanoma-specific MAbs and chemotherapeutic agents, as well as human TILs and LAK cells with or without retrovirus-mediated gene transfer modification.