14 research outputs found

    Segmented filamentous bacterium uses secondary and tertiary lymphoid tissues to induce gut IgA and specific T helper 17 cell responses.

    Get PDF
    Segmented filamentous bacterium (SFB) is a symbiont that drives postnatal maturation of gut adaptive immune responses. In contrast to nonpathogenic E. coli, SFB stimulated vigorous development of Peyer's patches germinal centers but paradoxically induced only a low frequency of specific immunoglobulin A (IgA)-secreting cells with delayed accumulation of somatic mutations. Moreover, blocking Peyer's patch development abolished IgA responses to E. coli, but not to SFB. Indeed, SFB stimulated the postnatal development of isolated lymphoid follicles and tertiary lymphoid tissue, which substituted for Peyer's patches as inductive sites for intestinal IgA and SFB-specific T helper 17 (Th17) cell responses. Strikingly, in mice depleted of gut organized lymphoid tissue, SFB still induced a substantial but nonspecific intestinal Th17 cell response. These results demonstrate that SFB has the remarkable capacity to induce and stimulate multiple types of intestinal lymphoid tissues that cooperate to generate potent IgA and Th17 cell responses displaying only limited target specificity

    Segmented filamentous bacterium uses secondary and tertiary lymphoid tissues to induce gut IgA and specific T helper 17 cell responses

    No full text
    Segmented filamentous bacterium (SFB) is a symbiont that drives postnatal maturation of gut adaptive immune responses. In contrast to nonpathogenic E. coli, SFB stimulated vigorous development of Peyer's patches germinal centers but paradoxically induced only a low frequency of specific immunoglobulin A (IgA)-secreting cells with delayed accumulation of somatic mutations. Moreover, blocking Peyer's patch development abolished IgA responses to E. coli, but not to SFB. Indeed, SFB stimulated the postnatal development of isolated lymphoid follicles and tertiary lymphoid tissue, which substituted for Peyer's patches as inductive sites for intestinal IgA and SFB-specific T helper 17 (Th17) cell responses. Strikingly, in mice depleted of gut organized lymphoid tissue, SFB still induced a substantial but nonspecific intestinal Th17 cell response. These results demonstrate that SFB has the remarkable capacity to induce and stimulate multiple types of intestinal lymphoid tissues that cooperate to generate potent IgA and Th17 cell responses displaying only limited target specificity.</p

    Semen Cryopreservation in Adolescents and Young Adults with Hematologic Diseases: from Bed to Benchside

    No full text
    International audiencePurpose: Infertility in adolescents and young adult (AYA) survivors of malignant disease remains a major long-term adverse effect, but semen collection for fertility preservation in fertility centers is not always feasible and makes AYAs uncomfortable. We evaluated the feasibility of collecting sperm samples on the ward versus in fertility centers. Methods: Consecutive hospitalized AYA-aged male patients in the Hematology AYA unit (Saint-Louis Hospital, France) between August 2010 and June 2016 with hematological disease and indication of semen collection (n = 95) were included in this retrospective study. Semen quality was analyzed according to World Health Organization guidelines and was compared according to semen collection place: on the ward (n = 46) or in fertility center (n = 49). Results: The median age was median age 19.1 years (range: 13.7-33.3; interquartile range: 17.1-22.8) and 85 patients successfully collected semen. Sperm collection failure was ∼11% and was comparable between the two modalities as were main sperm quality characteristics (semen volume, sperm concentration, total sperm count, progressive motility and vitality, sperm morphology, and multiple anomalies index). Oligospermia was significantly higher in the samples obtained in fertility center (47.7%) than on the ward (26.8%), p = 0.047. Average frozen straws were comparable, 12.2 ± 6.4 on the ward versus 11.9 ± 6.3 in fertility center. Conclusion: Semen collection on the ward is feasible and would be particularly interesting for AYA male patients without altering semen quality characteristics

    Accuracy in Diagnosis of Celiac Disease Without Biopsies in Clinical Practice.

    No full text
    BACKGROUND & AIMS: The guidelines of the European Society of Pediatric Gastroenterology, Hepatology, and Nutrition allow for diagnosis of celiac disease without biopsies in children with symptoms and levels of immunoglobulin A against tissue-transglutaminase (TGA-IgA) 10-fold or more the upper limit of normal (ULN), confirmed by detection of endomysium antibodies (EMA) and positivity for HLA-DQ2/DQ8. We performed a large, international prospective study to validate this approach. METHODS: We collected data from consecutive pediatric patients (18 years or younger) on a gluten-containing diet who tested positive for TGA-IgA from November 2011 through May 2014, seen at 33 pediatric gastroenterology units in 21 countries. Local centers recorded symptoms; measurements of total IgA, TGA, and EMA; and histopathology findings from duodenal biopsies. Children were considered to have malabsorption if they had chronic diarrhea, weight loss (or insufficient gain), growth failure, or anemia. We directly compared central findings from 16 antibody tests (8 for TGA-IgA, 1 for TGA-IgG, 6 for IgG against deamidated gliadin peptides, and 1 for EMA, from 5 different manufacturers), 2 HLA-DQ2/DQ8 tests from 2 manufacturers, and histopathology findings from the reference pathologist. Final diagnoses were based on local and central results. If all local and central results were concordant for celiac disease, cases were classified as proven celiac disease. Patients with only a low level of TGA-IgA (threefold or less the ULN) but no other results indicating celiac disease were classified as no celiac disease. Central histo-morphometry analyses were performed on all other biopsies and cases were carefully reviewed in a blinded manner. Inconclusive cases were regarded as not having celiac disease for calculation of diagnostic accuracy. The primary aim was to determine whether the nonbiopsy approach identifies children with celiac disease with a positive predictive value (PPV) above 99% in clinical practice. Secondary aims included comparing performance of different serological tests and to determine whether the suggested criteria can be simplified. RESULTS: Of 803 children recruited for the study, 96 were excluded due to incomplete data, low level of IgA, or poor-quality biopsies. In the remaining 707 children (65.1% girls; median age, 6.2 years), 645 were diagnosed with celiac disease, 46 were found not to have celiac disease, and 16 had inconclusive results. Findings from local laboratories of TGA-IgA 10-fold or more the ULN, a positive result from the test for EMA, and any symptom identified children with celiac disease (n = 399) with a PPV of 99.75 (95% confidence interval [CI], 98.61-99.99); the PPV was 100.00 (95% CI, 98.68-100.00) when only malabsorption symptoms were used instead of any symptom (n = 278). Inclusion of HLA analyses did not increase accuracy. Findings from central laboratories differed greatly for patients with lower levels of antibodies, but when levels of TGA-IgA were 10-fold or more the ULN, PPVs ranged from 99.63 (95% CI, 98.67-99.96) to 100.00 (95% CI, 99.23-100.00). CONCLUSIONS: Children can be accurately diagnosed with celiac disease without biopsy analysis. Diagnosis based on level of TGA-IgA 10-fold or more the ULN, a positive result from the EMA tests in a second blood sample, and the presence of at least 1 symptom could avoid risks and costs of endoscopy for more than half the children with celiac disease worldwide. HLA analysis is not required for accurate diagnosis. Clinical Trial Registration no: DRKS00003555

    Turner syndrome: French National Diagnosis and Care Protocol (NDCP; National Diagnosis and Care Protocol)

    No full text
    International audienceTurner syndrome (TS; ORPHA 881) is a rare condition in which all or part of one X chromosome is absent from some or all cells. It affects approximately one in every 1/2500 liveborn girls. The most frequently observed karyotypes are 45,X (40-50%) and the 45,X/46,XX mosaic karyotype (15-25%). Karyotypes with an X isochromosome (45,X/46,isoXq or 45,X/46,isoXp), a Y chromosome, X ring chromosome or deletions of the X chromosome are less frequent. The objective of the French National Diagnosis and Care Protocol (PNDS; Protocole National de Diagnostic et de Soins) is to provide health professionals with information about the optimal management and care for patients, based on a critical literature review and multidisciplinary expert consensus. The PNDS, written by members of the French National Reference Center for Rare Growth and Developmental Endocrine disorders, is available from the French Health Authority website. Turner Syndrome is associated with several phenotypic conditions and a higher risk of comorbidity. The most frequently reported features are growth retardation with short adult stature and gonadal dysgenesis. TS may be associated with various congenital (heart and kidney) or acquired diseases (autoimmune thyroid disease, celia
    corecore