Platelet count and prothrombin time help distinguish thrombotic thrombocytopenic purpura-hemolytic uremic syndrome from disseminated intravascular coagulation in adults

Am J Clin Pathol. 2010 Mar;133(3):460-5. doi: 10.1309/AJCPPNF63FLIORCI.


Thrombotic thrombocytopenic purpura-hemolytic uremic syndrome (TTP-HUS) and disseminated intravascular coagulation (DIC) may have identical manifestations in adults. Because TTP-HUS is 90% fatal without plasma exchange, prompt diagnosis is essential. To test the hypothesis that routine laboratory assays can discriminate between the 2 entities, we retrospectively identified adult patients with TTP-HUS and matched each with 2 patients with DIC. Although the platelet count, prothrombin time (PT), and partial thromboplastin time were different (P < .05) between the 2 patient groups, after regression analysis, only PT and profound thrombocytopenia remained associated with TTP-HUS (P = .001 and P = .003, respectively). A platelet count of less than 20 x 10(3)/microL (20 x 10(9)/L) and a PT within 5 seconds of the upper limit of the reference interval had a specificity of 92% for TTP-HUS. Our data confirm that readily available laboratory assays in the proper clinical scenario can increase the likelihood of TTP-HUS over DIC.

MeSH terms

  • Adult
  • Case-Control Studies
  • Diagnosis, Differential
  • Disseminated Intravascular Coagulation / diagnosis*
  • Hemolytic-Uremic Syndrome / diagnosis*
  • Humans
  • Platelet Count*
  • Prothrombin Time*
  • Purpura, Thrombotic Thrombocytopenic / diagnosis*
  • Regression Analysis
  • Retrospective Studies