Loss of function of ENT3 drives histiocytosis and inflammation through TLR-MAPK signaling.

Histiocytoses are inflammatory myeloid neoplasms often driven by somatic activating mutations in mitogen-activated protein kinase (MAPK) cascade genes. H syndrome is an inflammatory genetic disorder caused by germ line loss-of-function mutations in SLC29A3, encoding the lysosomal equilibrative nucleoside transporter 3 (ENT3). Patients with H syndrome are predisposed to develop histiocytosis, yet the mechanism is unclear. Here, through phenotypic, molecular, and functional analysis of primary cells from a cohort of patients with H syndrome, we reveal the molecular pathway leading to histiocytosis and inflammation in this genetic disorder. We show that loss of function of ENT3 activates nucleoside-sensing toll-like receptors (TLR) and downstream MAPK signaling, inducing cytokine secretion and inflammation. Importantly, MEK inhibitor therapy led to resolution of histiocytosis and inflammation in a patient with H syndrome. These results demonstrate a yet-unrecognized link between a defect in a lysosomal transporter and pathological activation of MAPK signaling, establishing a novel pathway leading to histiocytosis and inflammation.

Glomerular involvement in children with H syndrome.

BACKGROUND: H syndrome is a multisystem inflammatory disease caused by mutations in the SLC29A3 gene (OMIM #602782). The protein product, hENT3, is a nucleoside transporter essential for DNA salvage synthesis. Clinical manifestations are hyperpigmentation, hypertrichosis, hepatosplenomegaly, hearing loss, heart anomalies, hypogonadism, short stature, skeletal deformities, and diabetes mellitus. Laboratory findings are consistent with inflammatory processes. Structural kidney anomalies have been described in 6% of patients. CASE REPORTS: Three family members with genetically diagnosed H syndrome (c.1279G>A, p.Gly427Ser). Two of them presented with hypoalbuminemia and nephrotic range proteinuria. Kidney ultrasound was normal. Kidney biopsy performed in one patient presenting with generalized peripheral pitting edema revealed membranous nephropathy. Different treatments including ACE inhibitors, corticosteroids, and immunomodulatory agents failed to improve the clinical outcome. CONCLUSIONS: Generalized peripheral pitting edema and glomerulopathy broaden the clinical spectrum of H syndrome. Periodic bloodwork and urinalysis are recommended.

A novel zeta-associated protein 70 homozygous mutation causing combined immunodeficiency presenting as neonatal autoimmune hemolytic anemia.

Biallelic mutations in the zeta-associated protein 70 (ZAP70) gene cause combined immunodeficiency (CID). Neonatal screening for severe CID in Israel is implemented since 2015. We report on clinical, flow cytometry, and genetic data of an unusual ZAP70 deficiency patient. A 10-week-old Bedouin female presented with severe autoimmune hemolytic anemia. Cytomegalovirus (CMV) negative packed cell therapy was given without improvement; indexes of hemolysis worsened. At this time, thrombocytopenia was noted. The patient was treated with single dose of 1 g/kg intravenous immunoglobulin with rapid resolution of hemolysis. Serum immunoglobulin concentrations were normal; flow cytometry revealed severe CD8 lymphocytopenia. Lymphocyte proliferation test demonstrated reduced response to concanavalin A and phytohemagglutinin. Gated T cells were negative for intracellular ZAP70. A genetic analysis revealed a missense homozygous c.1388C > T (p.A463V) mutation, confirming the diagnosis of ZAP70 deficiency. She later on developed urinary tract infection due to ESBL producing E. coli treated with amikacin and severe CMV infection that partially responded to ganciclovir therapy and at 7 months of age, she successfully underwent allogeneic hematopoietic stem cell transplantation. Neonatal screening by T cell receptor excision circles (TRECs) for SCID was normal, yet very low TRECs were recorded at the time of CID diagnosis. Normal neonatal screening for SCID does not rule out the diagnosis of CID due to ZAP70 deficiency. This type of CID can present with autoimmunity as the sole initial manifestation of the disease.

Central venous catheter-associated bloodstream infections in children diagnosed with intestinal failure in Southern Israel.

OBJECTIVES: To study the clinical, epidemiological, and microbiological associations between intestinal failure (IF) and central line-associated infections (CLABSI) in patients with central vein catheters (CVCs) during 2005-2016. METHODS: We compared retrospectively CLABSI rates according to background disease, type of line access, pathogen distribution, and antibiotic susceptibilities. RESULTS: One hundred and fourteen children (64.1% < 4 years) were enrolled. Main diagnoses were persistent diarrhea (20, 17.5%), short bowel syndrome (13, 11.4%), continuous-TPN w/o diarrhea (11, 9.7%), very early-onset inflammatory bowel disease (VEO-IBD, 8, 7%), Hirschsprung's disease (3, 2.6%), non-oncologic hematologic conditions (13, 11.4%), and other diseases (46, 40.4%). 152.749 catheter days were recorded; 71.1% had Hickman's catheters. Two hundred and nine CLABSI episodes were recorded in 58 patients (82% with IF, 13.7 and 8.2/1000 catheter days in IF, and non-gastrointestinal conditions, P = 0.09). More CLABSI were recorded in continuous TPN vs. VEO-IBD or persistent diarrhea (38.8 vs.15.8 and 12.8/1000 catheter days, P < 0.004). Among patients with Hickman in jugular vein, highest CLBSI incidence was in continuous TPN, VEO-IBD, and persistent diarrhea (29.9, 15.84, and 12.49 episodes/1000 catheter days, respectively). CVCs were removed in 38.8% CLABSI. Two hundred and thirty-five pathogens were isolated (Enterobacteriaceae spp. in 39% of IF patients, mostly in persistent diarrhea and short bowel syndrome patients, 47.6% and 34.8%, respectively). Coagulase-negative Staphylococcus was the commonest pathogen in continuous TPN, VEO-IBD, and Hirschsprung's (71.4%, 55.6% and 46.1%, respectively). CONCLUSIONS: CLABSI rates in IF patients were among the highest reported. We reported a "hierarchy" in CLABSI incidence among patients with IF and showed that CLABSI incidence and etiology were different as function of background diseases and CVC insertion site.

Mycophenolate Mofetil Alone and in Combination with Tacrolimus Inhibits the Proliferation of HT-29 Human Colonic Adenocarcinoma Cell Line and Might Interfere with Colonic Tumorigenesis.

BACKGROUND/AIM: Familial adenomatous polyposis (FAP) was found to be completely reversed in a patient treated with mycophenolate mofetil (MMF) and tacrolimus following kidney transplantation. In this preliminary study, we assessed whether MMF and tacrolimus alone or in combination interfere with the cell cycle and proliferation in a human colonic adenocarcinoma cell line and in the colonic polyps of the patient with FAP. MATERIALS AND METHODS: Human colonic adenocarcinoma HT-29 cells were treated with tacrolimus and MMF alone and in combination at different concentrations. Cell viability and proliferation were assessed using the MTT assay. Cell-cycle distribution was analyzed by flow cytometry. Expression of Ki-67, a marker of mitotic activity, was evaluated in the patient's colonic polyps before and under drug treatment. RESULTS: MMF in combination with tacrolimus induced S-phase cell-cycle arrest and markedly inhibited HT-29 cell proliferation. Ki-67 expression in the patient's colonic polyps was significantly reduced following combined tacrolimus and MMF treatment. CONCLUSION: MMF and tacrolimus synergistically inhibited proliferation of a human colonic adenocarcinoma cell line and interfered with the expansion of colonic crypt proliferation in the polyp from a patient with FAP. The results confirm our clinical observation and indicate the possibility of novel approach to therapy of colorectal neoplasia.

Complete Reversion of Familial Adenomatous Polyposis Phenotype Associated with Tacrolimus and Mycophenolate Mofetil Treatment Following Kidney Transplantation.

Numerous germline mutations in the adenomatous polyposis coli (APC) tumor-suppressor gene are responsible for development of multiple adenomatous colorectal polyps with their inevitable progression to cancer. Multiple attempts at dietary and pharmacological prevention of colorectal carcinoma development in patients with familial adenomatous polyposis (FAP) have provided conflicting results. Immunosuppressive treatment with tacrolimus is known to be associated with an increased risk of malignancy and should be avoided in patients with high propensity for development of neoplasia. We observed a complete reversion of FAP phenotype in a male teenager carrying a germline mutation in APC gene who underwent a kidney transplant due to end-stage kidney disease secondary to congenital dysplastic kidneys. The patient was treated with tacrolimus and mycophenolate mofetil after transplantation. The possible chemopreventative role of these agents should be evaluated and confirmed in a larger cohort. The elucidation of molecular mechanisms underpinning the observed chemopreventative effect of tacrolimus and mycophenolate mofetil might lead to the development of a novel colorectal cancer therapy.

Management of Ingested Hijab-Pin.

BACKGROUND AND STUDY AIMS: Accidental swallowing of hijab (or turban) pin was reported mainly among adolescent girls. Current guidelines indicate emergent intervention endoscopy in case a long sharp object is found in the gastrointestinal tract. The aims of the current study are to present the results of an observational approach and to assess the need for intervention. PATIENTS AND METHODS: A retrospective cohort study was conducted including all 5-18-year-old patients who presented with hijab-pin ingestion between 2003 and 2014. The need for intervention was assessed using both univariable and multivariable statistical analyses. RESULTS: Two hundred three cases of hijab-pin ingestion were documented. In the majority of cases, the pin was observed in the stomach (137/203, 67.4%) upon arrival. Most pins that were located at the upper gastrointestinal tract (proximal to the ligament of Treitz) ejected spontaneously (120/169, 71%, Pv = 0.005). The absence of pin progression in an X-ray performed 12 h following presentation was significantly more frequent in the intervention group (46/51, 90%, Pv = 0.001). CONCLUSIONS: In most cases, the outcome is spontaneous ejection from the digestive tract. However, if needle location remains unchanged on two consecutive X-rays, an endoscopic intervention is recommended.

Incidence of typically Severe Primary Immunodeficiency Diseases in Consanguineous and Non-consanguineous Populations.

PURPOSE: Primary immunodeficiency diseases are considered to be rare diseases; however, data on the exact birth incidences of these diseases are sparse. Southern Israel is inhabited by two major populations: a relatively non-consanguineous Jewish population and a highly consanguineous Muslim Bedouin population. We sought to calculate the incidences of typically severe primary immunodeficiency diseases and compare the incidences in these populations. METHODS: A retrospective analysis of all typically severe primary immunodeficiency diseases evaluated at a single center from January 1, 1996 to December 31, 2016. The amount of live births by population was the denominator for calculating the incidences by population. RESULTS: A total of 95 patients were included, 85 of Bedouin and 10 of Jewish ethnicities. There were 152,331 births in the Bedouin and 160,998 births in the Jewish populations. The total incidence of typically severe primary immunodeficiency diseases was higher in the Bedouin population than expected based on previous studies. The total incidences were 55.8/105 births in the Bedouin population compared with 6.2/105 births in the Jewish population (P < 0.001). The incidences of all combined immunodeficiency diseases, ataxia telangiectasia, and infantile IBD due to interleukin 10 receptor defects were all significantly higher in the Bedouin population (P < 0.001). The incidence of X-linked agammaglobulinemia was not significantly different between both populations (P = 0.11). CONCLUSIONS: Typically, severe primary immunodeficiency diseases are not rare diseases in a consanguineous population; these diseases are significantly more common in the Bedouin population. This finding is probably also applicable to other consanguineous populations, and in these populations, primary immunodeficiency diseases should not be regarded as rare diseases.

IL-12 receptor 1ß deficiency with features of autoimmunity and photosensitivity.

Primary immunodeficiences are often accompanied by autoimmune phenomena. IL-12 receptor deficiency is a well characterized primary immunodeficiency that leads to propensity to intracellular infections mainly with mycobacteria and Salmonella. We report on two patients with IL-12 receptor ß1 deficiency that presented with autoimmune manifestations and photosensitivity dermatitis and describe possible pathogenetic mechanisms leading to development of clinically significant autoimmune phenomena.

Neonatal ascites in autosomal recessive polycystic kidney disease (ARPKD).

BACKGROUND: Neonatal ascites is a rare entity, which is usually biliary, urinary, or chylous. Congenital hepatic fibrosis as part of the manifestations of autosomal recessive polycystic kidney disease (ARPKD) is usually a histological adjunct to the diagnosis of this mainly clinically renal entity in the neonatal period. Case-diagnosis: We describe a rare case of severe ascites in a newborn child complicating ARPKD, which was later confirmed by clinical, histological, and genetic studies. CONCLUSION: ARPKD should be considered in differential diagnosis of neonatal ascites.