RT Book, Section
A1 Lichtman, Marshall A.
A1 Kaushansky, Kenneth
A1 Prchal, Josef T.
A1 Levi, Marcel M.
A1 Burns, Linda J.
A1 Linch, David C.
SR Print(0)
ID 1189336872
T1 Antibody-Mediated Thrombotic Disorders: Thrombotic Thrombocytopenic Purpura and Heparin-Induced Thrombocytopenia
T2 Williams Manual of Hematology, 10e
YR 2022
FD 2022
PB McGraw-Hill Education
PP New York, NY
SN 9781264269204
LK hemonc.mhmedical.com/content.aspx?aid=1189336872
RD 2024/04/18
AB Thrombotic  microangiopathies  are  characterized  by  thrombocytopenia,  microangiopathic  hemolytic  anemia,  and  microvascular  thrombosis,  leading  to  variable  injury  of  the  central  nervous  system,  kidney,  and  other  organs.The  classic  form  of  thrombotic  microangiopathy  (ie,  thrombotic  thrombocytopenic  purpura  [TTP])  is  usually  associated  with  an  acquired  (autoimmune)  deficiency  of  ADAMTS13,  a  metalloprotease  that  cleaves  the  ultra-large  multimers  of  von  Willebrand  factor  normally  produced  by  endothelial  cells  but  that  are  hypercoagulable.  An  inherited  form  of  the  loss  of  ADAMTS13  also  occurs,  termed  Upshaw-Shulman  syndrome.Hemolytic  uremic  syndrome  (HUS)  refers  to  the  thrombotic  microangiopathy  that  mainly  affects  the  kidney  and  may  be  diarrhea-associated  (caused  by  enteric  infection  with  Shiga  toxin–producing  gram-negative  microorganisms)  or  atypical,  often  due  to  abnormalities  in  the  regulation  of  the  complement  cascade.Secondary  thrombotic  microangiopathies  occur  in  association  with  infections,  certain  drugs,  metastatic  cancer,  malignant  hypertension,  or  after  stem  cell  transplantation.Heparin-induced  thrombocytopenia  (HIT)  is  a  significant  complication  of  heparin  treatment,  associated  with  mild  to  moderate  thrombocytopenia  and  a  high  frequency  of  both  arterial  and  venous  thrombosis.  HIT  is  caused  by  the  formation  of  anti–heparin/platelet  factor-4  antibodies  that  activate  platelets,  leukocytes,  and  endothelial  cells.