title: Absence of peripheral blood chimerism in graft-vs-host disease following orthotopic liver transplantation: case report and review of the literature.
abstract: BACKGROUND
  Graft-vs-host disease (GVHD) is a rare and often fatal complication of orthotopic liver transplantation (OLT). The skin is frequently involved early in disease progression, but clinical and histopathological features may be nonspecific, presenting a diagnostic challenge. While the detection of peripheral blood chimerism has been proposed as a diagnostic criterion for post-OLT GVHD, it is not known whether peripheral blood chimerism is an absolute requirement for the diagnosis.
  
  
  METHODS
  We report a case of a 57-year-old man who developed post-OLT GVHD with cutaneous, enteric, and bone marrow involvement. We also review the epidemiology, pathogenesis, clinical presentation, histopathology, molecular diagnostic techniques, and treatment of GVHD following liver transplantation.
  
  
  RESULTS
  In our patient, analysis of the peripheral blood by short-tandem repeat polymerase chain reaction did not detect circulating donor lymphocytes. Donor lymphocytes were detected in the buccal mucosa, however, confirming the diagnosis. A review of chimerism patterns in 63 previously published cases of post-OLT GVHD reveals that this is the first reported case in which chimerism was absent in the peripheral blood but present in another site.
  
  
  CONCLUSIONS
  Peripheral blood chimerism may be absent in cases of post-OLT GVHD. A combination of clinical, histopathological, and molecular features is therefore required to make this challenging diagnosis.
authors.affiliation: Department of Dermatology, University of California, San Francisco, CA, USA.
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Schulman
authors.forename: Christina
authors.initials: C
authors.lastname: Yoon
authors.forename: Jennifer
authors.initials: J
authors.lastname: Schwarz
authors.forename: Parsia A
authors.initials: PA
authors.lastname: Vagefi
authors.forename: Thaddeus W
authors.initials: TW
authors.lastname: Mully
authors.forename: Kanade
authors.initials: K
authors.lastname: Shinkai
mesh_terms: D001853:Bone Marrow / Q000473:pathology; D046528:Chimerism; D012809:Colon, Sigmoid / Q000473:pathology; D006086:Graft vs Host Disease / Q000097:blood* / Q000175:diagnosis* / Q000188:drug therapy; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D016031:Liver Transplantation / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D012871:Skin Diseases / Q000276:immunology*
chemical_list: D007166:Immunosuppressive Agents