1. Presented by Curtis Gravenmier, MD and Reviewed By Eric Gehrie, MD.

Clinical vignette:

A middle-aged patient is admitted to the hospital for management of gastrointestinal bleeding. The patient's initial platelet count is between 20-30 K/uL. The clinical team orders several platelet transfusions over a two-day period in hopes of maintaining her platelet count above 50 K/uL, but no increase is ever observed. In fact, the patient's platelet count decreases to 15 K/uL despite transfusion. You are consulted due to platelet refractoriness. Chart review is remarkable for an extensive transfusion history related to prior esophageal and gastrointestinal bleeding in the setting of liver disease.

Question:

Which of the following patterns is most suggestive of platelet refractoriness due to HLA alloimmunization?