The use of light transmission aggregometry for monitoring platelet transfusion response in a small case cohort of Glanzmann thrombasthenia patients: a hypothesis-generating study.

Light transmission aggregometry (LTA) is commonly used to diagnose platelet disorders and has a specific pattern in Glanzmann thrombasthenia (GT). As there is currently no adequate test to assess the efficacy of platelet transfusion, we explored whether LTA can be used to monitor the platelet response following platelet transfusion. We retrospectively evaluated LTA results after platelet transfusion in four patients with GT. After transfusion of two units of platelets, aggregation assessed by LTA remained reduced for all platelet agonists except ristocetin, despite a satisfactory clinical effect on hemostasis. One patient received seven units, after which a change in LTA results was observed. In this heterogeneous case cohort, the LTA response did not correlate with the clinical response after platelet transfusion in GT. To draw definitive conclusions, a study in a larger population that controls for influencing factors - such as the timing and dose of platelet transfusion and the use of a standardized LTA procedure - should be conducted.