Glanzmann Thrombasthenia Workup

Updated: Mar 18, 2021
  • Author: Zonera Ashraf Ali, MBBS; Chief Editor: Srikanth Nagalla, MD, MS, FACP  more...
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Laboratory Studies

The workup for Glanzmann thrombasthenia may include the following:

  • Complete blood cell (CBC) count
  • Peripheral blood smear
  • Prothrombin time (PT)
  • Activated partial thromboplastin time (aPTT)
  • Platelet Function Analyzer 100 (PFA-100) study
  • Flow cytometry
  • Monoclonal antibody assays
  • Platelet aggregation studies

Results are as follows:

  • The platelet count and coagulation tests should be normal.
  • The red blood cell count may be decreased due to bleeding and/or concomitant iron deficiency.
  • The platelet morphology on peripheral blood smears is normal.
  • The bleeding times should be prolonged.
  • On PFA-100 testing in patients with Glanzmann thrombasthenia, the platelets fail to plug the collagen-based filter.
  • Flow cytometry and monoclonal antibodies confirm the diagnosis of Glanzmann thrombasthenia.
  • On platelet aggregation studies, the primary platelet aggregation response to platelet agonists such as adenosine diphosphate (ADP), epinephrine, and collagen are decreased, whereas the response to ristocetin is normal; if the secondary platelet aggregation response is abnormal, suspect a platelet storage pool defect or an abnormality in platelet signal transduction.