Glanzmann Thrombasthenia Workup

Updated: Dec 29, 2017
  • Author: Zonera Ashraf Ali, MBBS; Chief Editor: Srikanth Nagalla, MBBS, MS, FACP  more...
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Laboratory Studies

The workup for Glanzmann thrombasthenia may include the following:

  • Complete blood cell (CBC) count

  • 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 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


Histologic Findings

The platelet morphology on peripheral blood smears is normal in patients with Glanzmann thrombasthenia.