Browsing by Author "Kaufman, Dixon B."

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    The demise of islet allotransplantation in the United States: A call for an urgent regulatory update
    (Wiley, 2021-04) Witkowski, Piotr; Philipson, Louis H.; Kaufman, Dixon B.; Ratner, Lloyd E.; Abouljoud, Marwan S.; Bellin, Melena D.; Buse, John B.; Kandeel, Fouad; Stock, Peter G.; Mulligan, David C.; Markmann, James F.; Kozlowski, Tomasz; Andreoni, Kenneth A.; Alejandro, Rodolfo; Baidal, David A.; Hardy, Mark A.; Wickrema, Amittha; Mirmira, Raghavendra G.; Fung, John; Becker, Yolanda T.; Josephson, Michelle A.; Bachul, Piotr J.; Pyda, Jordan S.; Charlton, Michael; Millis, J. Michael; Gaglia, Jason L.; Stratta, Robert J.; Fridell, Jonathan A.; Niederhaus, Silke V.; Forbes, Rachael C.; Jayant, Kumar; Robertson, R. Paul; Odorico, Jon S.; Levy, Marlon F.; Harland, Robert C.; Abrams, Peter L.; Olaitan, Oyedolamu K.; Kandaswamy, Raja; Wellen, Jason R.; Japour, Anthony J.; Desai, Chirag S.; Naziruddin, Bashoo; Balamurugan, Appakalai N.; Barth, Rolf N.; Ricordi, Camillo; Surgery, School of Medicine
    Islet allotransplantation in the United States (US) is facing an imminent demise. Despite nearly three decades of progress in the field, an archaic regulatory framework has stymied US clinical practice. Current regulations do not reflect the state-of-the-art in clinical or technical practices. In the US, islets are considered biologic drugs and “more than minimally manipulated” human cell and tissue products (HCT/Ps). In contrast, across the world, human islets are appropriately defined as “minimally manipulated tissue” and not regulated as a drug, which has led to islet allotransplantation (allo-ITx) becoming a standard-of-care procedure for selected patients with type 1 diabetes mellitus. This regulatory distinction impedes patient access to islets for transplantation in the US. As a result only 11 patients underwent allo-ITx in the US between 2016 and 2019, and all as investigational procedures in the settings of a clinical trials. Herein, we describe the current regulations pertaining to islet transplantation in the United States. We explore the progress which has been made in the field and demonstrate why the regulatory framework must be updated to both better reflect our current clinical practice and to deal with upcoming challenges. We propose specific updates to current regulations which are required for the renaissance of ethical, safe, effective, and affordable allo-ITx in the United States.
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    Th17 Responses to Collagen Type V, kα1-Tubulin, and Vimentin Are Present Early in Human Development and Persist Throughout Life
    (Wiley, 2017-04) Sullivan, Jeremy A.; Jankowska-Gan, Ewa; Hegde, Subramanya; Pestrak, Matthew A.; Agashe, Vrushali V.; Park, Arick C.; Brown, Matthew E.; Kernien, John F.; Wilkes, David S.; Kaufman, Dixon B.; Greenspan, Daniel S.; Burlingham, William J.; Medicine, School of Medicine
    T helper 17 (Th17)-dependent autoimmune responses can develop after heart or lung transplantation and are associated with fibro-obliterative forms of chronic rejection; however, the specific self-antigens involved are typically different from those associated with autoimmune disease. To investigate the basis of these responses, we investigated whether removal of regulatory T cells or blockade of function reveals a similar autoantigen bias. We found that Th17 cells specific for collagen type V (Col V), kα1-tubulin, and vimentin were present in healthy adult peripheral blood mononuclear cells, cord blood, and fetal thymus. Using synthetic peptides and recombinant fragments of the Col V triple helical region (α1[V]), we compared Th17 cells from healthy donors with Th17 cells from Col V-reactive heart and lung patients. Although the latter responded well to α1(V) fragments and peptides in an HLA-DR-restricted fashion, Th17 cells from healthy persons responded in an HLA-DR-restricted fashion to fragments but not to peptides. Col V, kα1-tubulin, and vimentin are preferred targets of a highly conserved, hitherto unknown, preexisting Th17 response that is MHC class II restricted. These data suggest that autoimmunity after heart and lung transplantation may result from dysregulation of an intrinsic mechanism controlling airway and vascular homeostasis.