title: Diagnosis of intestinal graft-versus-host disease and thrombotic microangiopathy after allogeneic stem cell transplantation.
abstract: Severe diarrhea is a serious complication after allogeneic hematopoietic stem cell transplantation (HSCT).  Acute graft-versus-host disease (GVHD) has been one of the major causes of diarrhea after HSCT, which is triggered by donor-derived cytotoxic T-lymphocytes.  On the other hand, intestinal thrombotic microangiopathy (TMA) sometimes coexists with acute GVHD, and intensified immunosuppression to treat acute GVHD could exacerbate intestinal TMA, presumably through the vascular endothelial cell damage.  The differential diagnosis between intestinal TMA and acute GVHD of the gut has mainly relied on the pathological findings, as clinical diagnosis of intestinal TMA has not been established.  Therefore, we aimed to assess the feasibility of our clinical diagnosis for the patients with diarrhea after HSCT.  We made tentative clinical criteria for intestinal TMA and acute GVHD of the gut, based on the clinical manifestations, laboratory data and colonoscopic findings, and started treatment before pathological diagnosis were made.  Subsequently, a pathologist retrospectively assessed the accuracy of clinical diagnosis in a blind manner.  In this study, we enrolled 19 patients complicating watery diarrhea after HSCT, and diagnosed as having acute GVHD (n = 10), intestinal TMA (n = 3), or both (n = 6) according to our criteria.  We demonstrated that our clinical diagnosis for intestinal TMA and acute GVHD of the gut was overall correct, in terms of the response to the therapy and the pathological diagnosis.  The present study may provide a clue on making clinical diagnosis of patients with watery diarrhea after HSCT, which enables us to start a prompt therapy.
authors.affiliation: Department of Hematology and Rheumatology, Tohoku University Graduate School of Medicine, Sendai, Japan. yminami@snh.go.jp
authors.forename: Minami
authors.initials: M
authors.lastname: Yamada-Fujiwara
authors.forename: Koichi
authors.initials: K
authors.lastname: Miyamura
authors.forename: Tohru
authors.initials: T
authors.lastname: Fujiwara
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Tohmiya
authors.forename: Katsuya
authors.initials: K
authors.lastname: Endo
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Onishi
authors.forename: Kenichi
authors.initials: K
authors.lastname: Ishizawa
authors.forename: Junichi
authors.initials: J
authors.lastname: Kameoka
authors.forename: Masafumi
authors.initials: M
authors.lastname: Ito
authors.forename: Hideo
authors.initials: H
authors.lastname: Harigae
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D003113:Colonoscopy; D003937:Diagnosis, Differential; D003967:Diarrhea / Q000175:diagnosis / Q000209:etiology; D005260:Female; D006086:Graft vs Host Disease / Q000175:diagnosis* / Q000188:drug therapy / Q000209:etiology; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects*; D006801:Humans; D007410:Intestinal Diseases / Q000175:diagnosis* / Q000188:drug therapy / Q000209:etiology; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000175:diagnosis* / Q000188:drug therapy / Q000209:etiology; D015203:Reproducibility of Results; D012189:Retrospective Studies; D057049:Thrombotic Microangiopathies / Q000175:diagnosis* / Q000188:drug therapy / Q000209:etiology; D014184:Transplantation, Homologous; D055815:Young Adult