A 44-year-old woman is newly diagnosed with a B-cell lymphoma involving her central nervous system. Her platelet count is 15,000, but she needs a platelet count of 50,000 to start intraspinal chemotherapy. Several different platelet transfusions fail to increase her platelet count (platelet refractory).
A solid-phase red-cell adherence platelet crossmatch (SPRCA XM) is conducted. Random ABO-matched donor platelets are coated onto round-bottomed wells and then reacted with her plasma. Indicator red blood cells are added and attach to any platelet-bound antibodies (see image). If there are no anti-platelet antibodies bound, the indicator red blood cells accumulate in a pellet at the bottom of the round-bottom well (negative control). If there are anti-platelet antibodies bound, some of the indicator cells will bind along the walls of the round-bottom well (positive control). Please see the image of the patient's platelet crossmatch below:
Justin Juskewitch, M.D., Ph.D.
Resident, Division of Anatomic and Clinical Pathology
Justin Kreuter, M.D.
Consultant, Division of Transfusion Medicine
Instructor in Laboratory Medicine and Pathology
Mayo Clinic College of Medicine
Follow him on Twitter: @KreuterMD