Background Primary immunodeficiencies are a rare group of inborn diseases characterized by a broad clinical and genetic heterogeneity. Substantial advances in the identification of the underlying ...molecular mechanisms can be achieved through the study of patients with increased susceptibility to specific infections and immune dysregulation. We evaluated 3 siblings from a consanguineous family presenting with EBV-associated B-cell lymphoproliferation at an early age (12, 7½, and 14 months, respectively) and profound naive T-cell lymphopenia. Objective On the basis of the hypothesis of a rare inborn immunodeficiency of autosomal recessive inheritance, we sought to characterize the underlying genetic defect. Methods We performed genome-wide homozygosity mapping, followed by whole-exome sequencing. Results We identified a homozygous inherited missense mutation in the gene encoding Coronin-1A (CORO1A) in the 3 siblings. This mutation, p. V134M, results in the substitution of an evolutionarily conserved amino acid within the β-propeller domain, which abrogates almost completely the protein expression in the patients' cells. In addition to a significant diminution of naive T-cell numbers, we found impaired development of a diverse T-cell repertoire, near-to-absent invariant natural killer T cells, and severely diminished mucosal-associated invariant T cell numbers. Conclusions Our findings define a new clinical entity of a primary immunodeficiency with increased susceptibility to EBV-induced lymphoproliferation in patients associated with hypomorphic Coronin-1A mutation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
...neither patient displayed autoimmune cytopenia. Because no infectious cause of colitis could be demonstrated in patient 7, both manifestations might be explained by immune dysregulation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Background Mastocytosis is a heterogeneous disease characterized by mast cell accumulation in 1 or more organs. Gastrointestinal manifestations of systemic mastocytosis have been previously studied ...in small cohorts of patients, and no specific histologic description is available. Objective We sought to assess the clinical and pathologic features of gastrointestinal manifestations in patients with mastocytosis. Methods Medical history and gastrointestinal symptoms of patients with mastocytosis (n = 83) were compared with those of matched healthy subjects (n = 83) by means of patient questionnaire. Data were analyzed for epidemiologic, clinical, biological, and genetic factors associated with gastrointestinal symptoms for patients with mastocytosis. A comparative analysis of gastrointestinal histology from patients with mastocytosis (n = 23), control subjects with inflammatory bowel disease (n = 17), and healthy subjects (n = 19) was performed. Results The following gastrointestinal symptoms occurred more frequently and were more severe in patients with mastocytosis than in healthy subjects: bloating (33% vs 7.2%, P < .0001), abdominal pain (27.3% vs 4.8%, P < .0001), nausea (23% vs 8.4%, P = .02), and diarrhea (33.85% vs 1.2%, P < .0001). Patients with mastocytosis had a significantly higher incidence of personal history of duodenal ulcer ( P = .02). Wild-type (WT) c-Kit was associated with diarrhea ( P = .03). Specific histologic lesions were present in patients with mastocytosis but were not correlated with clinical symptoms. Conclusion Gastrointestinal manifestations in patients with mastocytosis are highly prevalent and often severe. Clinical symptoms do not correspond to histologic findings, are nonspecific, and can simulate irritable bowel syndrome.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Background Crohn disease is an inflammatory bowel disease (IBD) with a complex mode of inheritance. Although nucleotide binding and oligomerization domain containing 2 (NOD2) is the strongest risk ...factor, the cause of Crohn disease remains unknown in the majority of the cases. X-linked inhibitor of apoptosis (XIAP) deficiency causes X-linked lymphoproliferative syndrome type 2. IBD has been reported in some XIAP-deficient patients. Objective We characterize the IBD affecting a large cohort of patients with mutations in XIAP and examine the possible pathophysiologic mechanisms. Methods We performed a phenotypical and histologic analysis of the IBD affecting 17 patients with hemizygous mutations in XIAP , including 3 patients identified by screening 83 patients with pediatric-onset IBD. The X chromosome inactivation was analyzed in female carriers of heterozygous XIAP mutations, including 2 adults with IBD. The functional consequences of XIAP deficiency were analyzed. Results Clinical presentation and histology of IBD in patients with XIAP deficiency overlapped with those of patients with Crohn disease. The age at onset was variable (from 3 months to 41 years), and IBD was severe and difficult to treat. In 2 patients hematopoietic stem cell transplantation fully restored intestinal homeostasis. Monocytes of patients had impaired NOD2-mediated IL-8 and monocyte chemoattractant protein 1 (MCP-1) production, as well as IL-10, in response to NOD2 and Toll-like receptor 2/4 costimulation. Nucleotide binding and oligomerization domain containing 1 (NOD1)–mediated IL-6 and IL-8 production was defective in fibroblasts from XIAP-deficient patients. The 2 heterozygous female carriers of XIAP mutations with IBD displayed abnormal expression of the XIAP mutated allele, resulting in impaired activation of the NOD2 pathway. Conclusion IBD in patients with XIAP deficiency is similar to Crohn disease and is associated with defective NOD2 function in monocytes. Importantly, we report that it is not restricted to male patients because we identified 2 symptomatic female heterozygous carriers of XIAP mutations.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Summary Detection of MUM1+ cells in follicular lymphoma (FL) tissues was previously found to be associated with poor prognosis in a single report, whereas the usefulness of Ki-67 immunostaining ...remains debated. Our goal was to establish whether these markers have predictive value for patients with FL. We analyzed MUM1 and Ki-67 expression using immunohistochemistry in biopsy samples from 434 patients from the PRIMA randomized trial. The MUM1 prognostic value was then validated in a cohort of 138 patients from the FL2000 randomized trial, using the optimal cutoff value obtained from the PRIMA cohort. The surface of positive staining was quantified using computerized image analysis. In the PRIMA cohort, both high levels of MUM1 positivity (cutoff value of 0.80%) and high levels of Ki-67 positivity (cutoff value of 10.25%) were significantly associated with a shorter progression-free survival (PFS) ( P = .004 and P = .007 for MUM1 and Ki-67, respectively). In a multivariate Cox proportional hazards regression model, only MUM1 retained a statistical significance (hazards ratio 1.56; 95% confidence interval, 1.02-2.37; P = .038) after adjustment for the maintenance arm of treatment and the follicular lymphoma international prognostic index score. In the FL2000 cohort, high levels of MUM1 positivity were significantly associated to a shorter PFS ( P = .004) and to a trend toward a shorter overall survival ( P = .043). This remained significant using a multivariate Cox regression model after adjustment for the follicular lymphoma international prognostic index and the treatment arm for PFS ( P = .016). These results show that MUM1 is a strong and robust predictive immunohistochemical marker in patients with FL.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Summary Background Indolent systemic mastocytosis, including the subvariant of smouldering systemic mastocytosis, is a lifelong condition associated with reduced quality of life. Masitinib inhibits ...KIT and LYN kinases that are involved in indolent systemic mastocytosis pathogenesis. We aimed to assess safety and efficacy of masitinib versus placebo in severely symptomatic patients who were unresponsive to optimal symptomatic treatments. Methods In this randomised, double-blind, placebo-controlled, phase 3 study, we enrolled adults (aged 18–75 years) with indolent or smouldering systemic mastocytosis, according to WHO classification or documented mastocytosis based on histological criteria, at 50 centres in 15 countries. We excluded patients with cutaneous or non-severe systemic mastocytosis after a protocol amendment. Patients were centrally randomised (1:1) to receive either oral masitinib (6 mg/kg per day over 24 weeks with possible extension) or matched placebo with minimisation according to severe symptoms. The primary endpoint was cumulative response (≥75% improvement from baseline within weeks 8–24) in at least one severe baseline symptom from the following: pruritus score of 9 or more, eight or more flushes per week, Hamilton Rating Scale for Depression of 19 or more, or Fatigue Impact Scale of 75 or more. We assessed treatment effect using repeated measures methodology for rare diseases via the generalised estimating equation model in a modified intention-to-treat population, including all participants assigned to treatment minus those who withdrew due to a non-treatment-related cause. We assessed safety in all patients who received at least one dose of study drug. This trial is registered with ClinicalTrials.gov , number NCT00814073. Findings Between Feb 19, 2009, and July 15, 2015, 135 patients were randomly assigned to masitinib (n=71) or placebo (n=64). By 24 weeks, masitinib was associated with a cumulative response of 18·7% in the primary endpoint (122·6 responses of 656·5 possible responses weighted generalised estimating equation) compared with 7·4% for placebo (48·9 of 656·5; difference 11·3%; odds ratio 3·6; 95% CI 1·2–10·8; p=0·0076). Frequent severe adverse events (>4% difference from placebo) were diarrhoea (eight 11% of 70 in the masitinib group vs one 2% of 63 in the placebo group), rash (four 6% vs none), and asthenia (four 6% vs one 2%). The most frequent serious adverse events were diarrhoea (three patients 4% vs one 2%) and urticaria (two 3% vs none), and no life-threatening toxicities occurred. One patient in the placebo group died (unrelated to study treatment). Interpretation These study findings indicate that masitinib is an effective and well tolerated agent for the treatment of severely symptomatic indolent or smouldering systemic mastocytosis. Funding AB Science (Paris, France).
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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