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Balart MT, Russell L, Narula N, Bajaj G, Chauhan U, Khan KJ, Marwaha AN, Ching E, Biro J, Halder S, Tse F, Marshall JK, Collins SM, Moayyedi P, Bercik P, Verdu EF, Leontiadis GI, Armstrong D, Pinto-Sanchez MI. Declining Use of Corticosteroids for Crohn's Disease Has Implications for Study Recruitment: Results of a Pilot Randomized Controlled Trial. J Can Assoc Gastroenterol 2021; 4:214-221. [PMID: 34617003 PMCID: PMC8489529 DOI: 10.1093/jcag/gwaa037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 10/01/2020] [Indexed: 11/25/2022] Open
Abstract
Background Corticosteroids (CS) have been used extensively to induce remission in Crohn’s disease (CD); however, they are associated with severe side effects. We hypothesized that the administration of an exclusive enteral nutrition (EEN) formula to CS would lead to increased CD remission rates and to decreased CS-related adverse events. We proposed to undertake a pilot study comparing EEN and CS therapy to CS alone to assess decrease symptoms and inflammatory markers over 6 weeks. Aim The overall aim was to assess study feasibility based on recruitment rates and acceptability of treatment in arms involving EEN Methods The pilot study intended to recruit 100 adult patients with active CD who had been prescribed CS to induce remission as part of their care. The patients were randomized to one of three arms: (i) standard-dose CS; (ii) standard-dose CS plus EEN (Modulen 1.5 kcal); or (iii) short-course CS plus EEN. Results A total of 2009 CD patients attending gastroenterology clinics were screened from October 2018 to November 2019. Prednisone was prescribed to only 6.8% (27/399) of patients with active CD attending outpatient clinics. Of the remaining 372 patients with active CD, 34.8% (139/399) started or escalated immunosuppressant or biologics, 49.6% (198/399) underwent further investigation and 8.8% (35/399) were offered an alternative treatment (e.g., antibiotics, surgery or investigational agents in clinical trials). Only three patients were enrolled in the study (recruitment rate 11%; 3/27), and the study was terminated for poor recruitment. Conclusion The apparent decline in use of CS for treatment of CD has implications for CS use as an entry criterion for clinical trials.
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Affiliation(s)
- M T Balart
- Farncombe Family Digestive Health Research Institute, Hamilton, ON, Canada.,McMaster University Medical Centre, Hamilton, ON, Canada
| | - L Russell
- McMaster University Medical Centre, Hamilton, ON, Canada
| | - N Narula
- McMaster University Medical Centre, Hamilton, ON, Canada
| | - G Bajaj
- McMaster University Medical Centre, Hamilton, ON, Canada.,Brampton Endoscopy Centre, Brampton, ON, Canada
| | - U Chauhan
- Farncombe Family Digestive Health Research Institute, Hamilton, ON, Canada
| | - K J Khan
- Farncombe Family Digestive Health Research Institute, Hamilton, ON, Canada.,McMaster University Medical Centre, Hamilton, ON, Canada.,St. Joseph's Health Care Centre, Hamilton, ON, Canada
| | | | - E Ching
- GI Health Centre, Burlington, ON, Canada
| | - J Biro
- McMaster University Medical Centre, Hamilton, ON, Canada
| | - S Halder
- McMaster University Medical Centre, Hamilton, ON, Canada
| | - F Tse
- Farncombe Family Digestive Health Research Institute, Hamilton, ON, Canada.,McMaster University Medical Centre, Hamilton, ON, Canada
| | - J K Marshall
- Farncombe Family Digestive Health Research Institute, Hamilton, ON, Canada.,McMaster University Medical Centre, Hamilton, ON, Canada
| | - S M Collins
- Farncombe Family Digestive Health Research Institute, Hamilton, ON, Canada.,McMaster University Medical Centre, Hamilton, ON, Canada
| | - P Moayyedi
- Farncombe Family Digestive Health Research Institute, Hamilton, ON, Canada.,McMaster University Medical Centre, Hamilton, ON, Canada
| | - P Bercik
- Farncombe Family Digestive Health Research Institute, Hamilton, ON, Canada.,McMaster University Medical Centre, Hamilton, ON, Canada
| | - E F Verdu
- Farncombe Family Digestive Health Research Institute, Hamilton, ON, Canada.,McMaster University Medical Centre, Hamilton, ON, Canada
| | - G I Leontiadis
- Farncombe Family Digestive Health Research Institute, Hamilton, ON, Canada.,McMaster University Medical Centre, Hamilton, ON, Canada
| | - D Armstrong
- Farncombe Family Digestive Health Research Institute, Hamilton, ON, Canada.,McMaster University Medical Centre, Hamilton, ON, Canada
| | - M I Pinto-Sanchez
- Farncombe Family Digestive Health Research Institute, Hamilton, ON, Canada.,McMaster University Medical Centre, Hamilton, ON, Canada
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Biro J, Würch A, Potocnik AJ, Falk I, Mossmann H, Eichmann K. Regulation of T cell receptor (TCR) beta gene expression by CD3 complex signaling in immature thymocytes: implications for TCRbeta allelic exclusion. Proc Natl Acad Sci U S A 1999; 96:3882-7. [PMID: 10097132 PMCID: PMC22389 DOI: 10.1073/pnas.96.7.3882] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
During alphabeta thymocyte development, clonotype-independent CD3 complexes are expressed at the cell surface before the pre-T cell receptor (TCR). Signaling through clonotype-independent CD3 complexes is required for expression of rearranged TCRbeta genes. On expression of a TCRbeta polypeptide chain, the pre-TCR is assembled, and TCRbeta locus allelic exclusion is established. We investigated the putative contribution of clonotype-independent CD3 complex signaling to TCRbeta locus allelic exclusion in mice single-deficient or double-deficient for CD3zeta/eta and/or p56(lck). These mice display defects in the expression of endogenous TCRbeta genes in immature thymocytes, proportional to the severity of CD3 complex malfunction. Exclusion of endogenous TCRbeta VDJ (variable, diversity, joining) rearrangements by a functional TCRbeta transgene was severely compromised in the single-deficient and double-deficient mutant mice. In contrast to wild-type mice, most of the CD25(+) double-negative (DN) thymocytes of the mutant mice failed to express the TCRbeta transgene, suggesting defective expression of the TCRbeta transgene similar to endogenous TCRbeta genes. In the mutant mice, a proportion of CD25(+) DN thymocytes that failed to express the transgene expressed endogenous TCRbeta polypeptide chains. Many double-positive cells of the mutant mice coexpressed endogenous and transgenic TCRbeta chains or more than one endogenous TCRbeta chain. The data suggest that signaling through clonotype-independent CD3 complexes may contribute to allelic exclusion of the TCRbeta locus by inducing the expression of rearranged TCRbeta genes in CD25(+) DN thymocytes.
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MESH Headings
- Alleles
- Animals
- Animals, Genetically Modified
- DNA Primers
- Gene Expression Regulation/immunology
- Gene Rearrangement, beta-Chain T-Cell Antigen Receptor
- Genes, T-Cell Receptor beta
- Lymphocyte Specific Protein Tyrosine Kinase p56(lck)/deficiency
- Lymphocyte Specific Protein Tyrosine Kinase p56(lck)/genetics
- Lymphocyte Specific Protein Tyrosine Kinase p56(lck)/physiology
- Mice
- Mice, Knockout
- Receptor-CD3 Complex, Antigen, T-Cell/deficiency
- Receptor-CD3 Complex, Antigen, T-Cell/genetics
- Receptor-CD3 Complex, Antigen, T-Cell/physiology
- Receptors, Antigen, T-Cell, alpha-beta/biosynthesis
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Reverse Transcriptase Polymerase Chain Reaction
- Signal Transduction
- T-Lymphocytes/immunology
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Affiliation(s)
- J Biro
- Max-Planck-Institut für Immunbiologie, D-79108 Freiburg, Germany
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Würch A, Biro J, Falk I, Mossmann H, Eichmann K. Reduced generation but efficient TCR beta-chain selection of CD4+8+ double-positive thymocytes in mice with compromised CD3 complex signaling. J Immunol 1999; 162:2741-7. [PMID: 10072519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Maturation to the CD4+8+ double-positive (DP) stage of thymocyte development is restricted to cells that have passed TCRbeta selection, an important checkpoint at which immature CD4-8- double-negative (DN) cells that express TCRbeta polypeptide chains are selected for further maturation. The generation of DP thymocytes following TCRbeta selection is dependent on cellular survival, differentiation, and proliferation, and the entire process appears to be mediated by the pre-TCR/CD3 complex. In this study, we investigate the signaling requirements for TCRbeta selection using mice single deficient and double deficient for CD3zeta/eta and/or p56lck. While the numbers of DP cells are strongly reduced in the single-deficient mice, a further drastic reduction in the generation of DP thymocytes is seen in the double-deficient mice. The poor generation of DP cells in the mutant mice is primarily due to an impaired ability of CD25+ DN thymocytes to proliferate following expression of a TCRbeta-chain. Nevertheless, the residual DP cells in all mutant mice are strictly selected for expression of TCRbeta polypeptide chains. DN thymocytes of mutant mice expressed TCRbeta and CD3epsilon at the cell surface and contained mRNA for pre-Talpha, but not for clonotypic TCRalpha-chains, together suggesting that TCRbeta selection is mediated by pre-TCR signaling in all cases. The data suggest differential requirements of pre-TCR signaling for cell survival on the one hand, and for the proliferative burst associated with TCRbeta selection on the other.
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Affiliation(s)
- A Würch
- Max-Planck-Institut für Immunbiologie, Freiburg, Germany
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Würch A, Biro J, Potocnik AJ, Falk I, Mossmann H, Eichmann K. Requirement of CD3 complex-associated signaling functions for expression of rearranged T cell receptor beta VDJ genes in early thymic development. J Exp Med 1998; 188:1669-78. [PMID: 9802979 PMCID: PMC2212509 DOI: 10.1084/jem.188.9.1669] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
During alpha beta thymocyte development, the clonotypic alpha beta-T cell receptor (TCR) is preceded by sequentially expressed immature versions of the TCR-CD3 complex: the pre-TCR, containing a clonotypic TCR-beta chain and invariant pre-Talpha, is expressed on pre-T cells before rearrangement of the TCR-alpha locus. Moreover, clonotype-independent CD3 complexes (CIC) appear on pro-T cells before VDJ rearrangements of TCR-beta genes. The pre-TCR is known to mediate TCR-beta selection, the prerequisite for maturation of CD4(-)8(-) double negative (DN) thymocytes to the CD4(+)8(+) double positive stage. A developmental function of CIC has so far not been delineated. In mice single deficient and double deficient for CD3zeta/eta and/or p56(lck), we observe a pronounced reduction in the proportions of CD25(+) DN thymocytes that express intracellular TCR-beta chains. TCR-beta transcripts are reduced in parallel with TCR-beta polypeptide chains whereas no reduction in TCR-beta locus rearrangements could be detected. Wild-type levels of TCR-beta transcripts and of cells expressing TCR-beta polypeptide chains are induced by treatment with anti-CD3epsilon mAb. The data suggest that the initial expression of rearranged TCR-beta VDJ genes in pro-T cell to pre-T cell progression is dependent on CD3 complex signaling, and thus define a putative developmental function for CIC.
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Affiliation(s)
- A Würch
- Max-Planck-Institut für Immunbiologie, D-79108 Freiburg, Germany
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Abstract
After productive rearrangement of a TCR beta chain gene, CD4-8- double negative (DN) thymocytes express TCR beta polypeptide chains on the cell surface together with pre-T alpha and the CD3 complex forming the pre-TCR. Signals transmitted through the pre-TCR select TCR beta + DN thymocytes for further maturation to the CD4+8+ double positive stage, whereas DN cells that fail to generate a productive TCR beta gene rearrangement do not continue in development. This process is termed TCR beta chain selection. Although it is likely that differences between proliferation dynamics of TCR beta + and TCR beta-cells may play a role, the exact mechanisms of TCR beta chain selection have not been elucidated. We therefore studied the proliferation dynamics of TCR beta + and TCR beta-thymocytes during fetal development, i.e., when TCR beta chain selection takes place for the first time. We analyzed in situ accumulation of TCR beta + thymocytes by confocal microscopy, and determined cell cycle and division parameters of TCR beta + and TCR beta-populations by flow cytometry. About 600 TCR beta + cells/thymic lobe are generated by independent induction events between days of gestation (dg) 13.5, and 15.5. As of dg 14.5, most TCR beta + cells have entered S/G2 phase of cell cycle, followed by seven to eight rapid cell divisions in fetal thymic organ culture, suggesting a corresponding burst of nine cell divisions within 4 d in vivo. By dg 18.5, the division rate of TCR beta + cells has slowed down to less than 1/d. About three quarters of TCR beta-cells divide at a slow rate of 1/d on dg 14.5, the proportion of nondividing cells increasing to 50% within the following four d. From dg 16.5 onwards, TCR beta-cells, but not TCR beta + cells, contain a significant proportion of apoptotic cells. The results suggest that failure to become selected results in shutdown of proliferation and eventual programmed cell death of fetal TCR beta-cells. Positive selection of fetal TCR beta + cells is achieved by an increased rate of cell divisions lasting for approximately 4 d.
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Affiliation(s)
- I Falk
- Max-Planck-Institut für Immunbiologie, Freiburg, Germany
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