Case 145

1. Presented by: Chinelo P. Onyenekwu, MD and reviewed by: Lorraine Blagg, EdD, MA, MLS(ASCP)CMSBB, AHI(AMT)

Clinical Vignette:
The blood bank is experiencing a low platelet inventory and is triaging all platelet requests. There is a platelet transfusion request for a patient with complaints of headache, paresthesia, and vomiting of two days duration. The patient had hematuria on admission, with easy bruising.  They require central venous catheter placement, and the Interventional Radiologist requests transfusion of one platelet product prior to the placement of the catheter. Your review of the chart shows the following laboratory results:

CBC:
White blood cell count: 10.61 K/cu mm (4.50-11.00)
Hemoglobin: 8.2 g/dL (12.0-15.0)
Hematocrit: 26.2% (36.0-46.0)
Platelet count: 6 K/cu mm (150-350)
Immature platelet fraction: 13.8% (0.1-6.3)

Peripheral blood smear (Outside Institution’s Review): Schistocytes and thrombocytopenia

ADAMTS13 Activity:  <5% (70-150)
ADAMTS13 Inhibitor:  63.1% (0-44)

Question: What is the most likely diagnosis and the best way to handle the request for a unit of platelets?