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.

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.

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.

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%).

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.

Hematopoietic Stem Cell Transplantation for Primary Immune Deficiency Disorders.

Hematopoietic stem cell transplantation provides a curative option for children with primary immune deficiency disorders. Increased awareness and rapid diagnosis of these conditions has resulted in early referral and the chance to offer a curative option for affected children. Management of these children involves a multidisciplinary team including infectious disease specialists and intensivists. The use of reduced intensity conditioning chemotherapy, advances in detection and therapy of viral and fungal infections, optimal supportive care and techniques in stem cell processing, including T cell depletion has enabled doctors to transplant children with co-morbid conditions and no matched donors. Transplantation for these children has also brought in deep insights into the world of immunology and infectious diseases.

Screening for and treatments of congenital immunodeficiency diseases.

Although newborn screening (NBS) for inborn errors of metabolism has been successfully utilized in the US for decades, only recently has this screening program expanded to include disorders of immunity. Severe combined immunodeficiency (SCID) became the first disorder of immunity to be screened on a population wide basis in 2008. While NBS for SCID has been successful, the implementation of population-based screening programs is not without controversy, and there remain barriers to the nationwide implementation of this test. In addition, as the program has progressed we have learned of new challenges in the management of newborns that fail this screen.

Peri-operative considerations in the patient with primary immune deficiency: a review.

BACKGROUND: Patients with inherited immune deficiency diseases often require surgical procedures, and their immune defects may predispose them to surgical complications. METHODS: A thorough review of pertinent literature and current practice guidelines on surgery in patients with immune deficiency. RESULTS: Peri-operative infections are a key, but not a singular, consideration in managing patients with a primary immune deficiency. Bleeding diathesis, gastrointestinal complications, pulmonary complications, and poor incision healing may also be idiosyncratic features unique to particular immune deficiency diseases. Patients with complex genetic syndromes that include immune deficiency also may display non-immunologic abnormalities that are equally important to surgical care. CONCLUSION: Greater awareness of primary immune deficiencies and a comprehensive evaluation of such patients in close consultation with an immunologist can minimize surgical complications and optimize patient outcomes.

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.

Fell Pony syndrome: characterization of developmental hematopoiesis failure and associated gene expression profiles.

Fell Pony syndrome (FPS) is a fatal immunodeficiency that occurs in foals of the Fell Pony breed. Affected foals present with severe anemia, B cell lymphopenia, and opportunistic infections. Our objective was to conduct a prospective study of potential FPS-affected Fell Pony foals to establish clinical, immunological, and molecular parameters at birth and in the first few weeks of life. Complete blood counts, peripheral blood lymphocyte phenotyping, and serum immunoglobulin concentrations were determined for 3 FPS-affected foals, 49 unaffected foals, and 6 adult horses. In addition, cytology of bone marrow aspirates was performed sequentially in a subset of foals. At birth, the FPS-affected foals were not noticeably ill and had hematocrit and circulating B cell counts comparable to those of unaffected foals; however, over 6 weeks, values for both parameters steadily declined. A bone marrow aspirate from a 3-week-old FPS-affected foal revealed erythroid hyperplasia and concurrent erythroid and myeloid dysplasia, which progressed to a severe erythroid hypoplasia at 5 weeks of life. Immunohistochemical staining confirmed the paucity of B cells in primary and secondary lymphoid tissues. The mRNA expression of genes involved in B cell development, signaling, and maturation was investigated using qualitative and quantitative reverse transcriptase PCR (RT-PCR). Several genes, including CREB1, EP300, MYB, PAX5, and SPI1/PU.1, were sequenced from FPS-affected and unaffected foals. Our study presents evidence of fetal erythrocyte and B cell hematopoiesis with rapid postnatal development of anemia and B lymphopenia in FPS-affected foals. The transition between fetal/neonatal and adult-like hematopoiesis may be an important aspect of the pathogenesis of FPS.

Neonatal Sweet syndrome: a potential marker of serious systemic illness.

Sweet syndrome is an inflammatory disease characterized by fever and painful erythematous plaques with a dermal neutrophilic infiltrate. It is most common in adults, where it is often parainflammatory or paraneoplastic, but is rare in children. We describe 3 cases of neonatal Sweet syndrome, including 1 patient who had myelodysplastic syndrome and immunodeficiency, the first report of a premalignancy underlying infantile Sweet syndrome. We reviewed the literature on patients presenting with neutrophilic dermatosis in the first 6 months of life. Of 20 cases, 6 had a probable viral etiology, 4 primary immunodeficiencies, 3 neonatal lupus syndrome, 1 gastrointestinal involvement, 1 HIV, and 5 probable genetic cases. Three of these had chronic atypical neutrophilic dermatosis with lipodystrophy and elevated temperature syndrome, caused by mutations in the PSMB8 gene. Most children who presented within the first 6 weeks of life had either a serious underlying condition, such as primary immunodeficiency, or a genetic Sweet syndrome, with 2 fatalities among this latter group. The outcome of postinfective cases was good. Extracutaneous involvement was unusual, whereas postinflammatory scarring and cutis laxa occurred in a minority of patients. In conclusion, Sweet syndrome in the neonatal period often heralds a serious underlying disorder and requires thorough investigation.

[Fungal infections and congenital immune deficiencies]. / Infections fongiques et déficits immunitaires héréditaires.

Different types of hereditary immune deficiencies are at risk of severe fungal infections. Such infections can reveal the deficit. The type of micro-organisms involved, the clinical presentation, the immune reaction observed around the germ can then guide the etiological diagnosis. As often in the field of immunodeficiencies, advances in the pathophysiology provide crucial informations on the natural defense mechanisms against these organisms. Therapeutic advances have dramatically improved the prognosis of these potentially serious and disabling infections.

Social outcome in children treated by haematopoietic cell transplant for congenital immunodeficiency.

Previous studies have reported increased rates of social difficulties in children treated by haematopoietic cell transplant (HCT). This study assessed social functioning in children with congenital immunodeficiency treated by HCT and investigated two potential underlying mechanisms that may explain social difficulties: executive function skills and physical appearance. In total, 31 children (8-16 years of age) were assessed on measures of social functioning and peer relationships, executive function and physical appearance. Results were compared with a control group of 31 healthy children, matched for age, gender, ethnicity and cognitive ability. Parent, teacher and self-report data were collected. HCT survivors were described by parents and teachers, but not by themselves, as experiencing more difficulties with social functioning than the control group. Executive function was not associated with social functioning. However, an objective measure of physical appearance was significantly associated with social functioning. Results suggest that children treated by HCT for congenital immunodeficiency do experience significant difficulties in social functioning, not solely accounted for by below average intelligence. These difficulties are associated with physical appearance, but not with executive functional skills. This has clinical implications for identifying and treating children at increased risk of difficulties with social functioning.

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.

Invasive fungal infections in congenital immunodeficiencies.

Both acquired and congenital immunodeficiencies may be associated with increased susceptibility to invasive fungal infections (IFIs), depending on the type of immune deficit. IFIs frequently occur in patients with phagocytic and cellular immune defects, but are rarely observed in those with humoral or complement deficits. Among congenital immune disorders, chronic granulomatous disease and hyper-IgE syndrome are most frequently associated with IFIs; variable susceptibility to fungal pathogens is also seen in patients with severe combined immunodeficiency, X-linked hyper-IgM syndrome, Wiskott-Aldrich syndrome, DiGeorge syndrome, common variable immunodeficiency, defects in the interferon-γ-interleukin-12 axis, and myeloperoxidase deficiency. Aspergillus, Candida, Cryptococcus, Histoplasma and other fungal genera are variably implicated in causing invasive infections in these patients. Prompt diagnosis of IFIs in this patient population requires a high degree of suspicion, together with a knowledge of their clinical presentation and the limitations of diagnostic modalities. Apart from administration of appropriate antifungal agents, successful management often requires the addition of surgical intervention. Adjunctive immunotherapy may be considered, although this has not been systematically studied. Prophylactic interferon-γ and itraconazole administration have been shown to reduce the risk of IFIs in patients with chronic granulomatous disease; however, the possibility of infections with azole-resistant organisms following long-term itraconazole prophylaxis should not be overlooked.

Inflammatory bowel diseases in patients with adaptive and complement immunodeficiency disorders.

Crohn's disease and ulcerative colitis are idiopathic chronic inflammatory diseases that primarily affect the gastrointestinal tract. The underlying causes remain poorly understood, but there is a growing body of evidence advocating a likely primary pathogenic role for immunodeficiency in the development of Crohn's lesions. Concordantly, a number of congenital immunodeficiencies disrupting the cellular innate immune system strongly predispose to noninfectious, Crohn's-like inflammatory bowel disease. There are case reports and series suggesting that the same may be true for some of the congenital adaptive and complement immunodeficiencies. This review considers and critiques these potential associations.

A quadrivalent HPV vaccine induces humoral and cellular immune responses in WHIM immunodeficiency syndrome.

WHIM-syndrome is an inherited immunodeficiency disorder with abnormal susceptibility to human papillomavirus (HPV) infection and diseases. We determined safety and immunogenicity to a quadrivalent HPV vaccine in WHIM-syndrome by detection of HPV-specific antibodies and lymphoproliferation. In virus-like-particle (VLP)-ELISA, a WHIM patient showed antibody titers up to 400 for HPV-6/11/16/18, whereas immuno-competent controls developed titers of 6400-25,600. In pseudovirion assays, the patient's neutralization titers ranged from 20 to 400 to the four HPV vaccine types, while titers of 1600-25,600 were detected in healthy vaccinees. Specific proliferation of PBMC of the WHIM patient to the HPV vaccine was demonstrated. This first report on response to HPV vaccination in WHIM-immunodeficiency highlights that patients with WHIM-syndrome, and probably other immunodeficiencies, may benefit from HPV immunoprophylaxis.