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Platelet Donation 301 — Platelets and HLA Typing

January 10, 2018 at 6:58 pm

Most of you probably know that when you donate blood products, they test for your blood type (A-positive, O-negative, etc.). But you might not know that when you donate platelets, they test for an additional type — your HLA type.

HLA stands for Human Leukocyte Antigen. These antigens are found on most organs and tissues in the body, as well as on lymphocytes and platelets. At Stanford Blood Center (SBC), platelet donations are tested for each donor’s specific HLA type. While the majority of patients can receive platelets with any HLA type, it is possible for a patient’s body to create antibodies against certain ones, which means they could have a negative reaction to or get no benefit from a platelet transfusion of that type. So, in this case, the patient would need to receive platelets that have a compatible HLA type.

That’s where SBC comes in. Because all platelet donors are HLA typed, we can reach out directly to those donors who could be a match for a patient. Here’s how it works: first, our Special Donations team receives word that there is a patient in need of a specific HLA type. They then get to work combing our database for a donor who could be a match — they must meet the requirements of a regular platelet donor (a certain weight, hemoglobin count, and historical platelet count) — and while blood type doesn’t typically matter in these cases, they must not have the HLA type for which the patient has built up antibodies. Taking all this information into account, they are able to create a list of donors who are a match; typically around five to 15 donors.

After these potential donors are identified, one of our Special Donations team members reaches out let them know that there is a patient who needs specific HLA type platelets, and that they are a match. Typically, we need the donor to come in that day or the next, although occasionally there is an ongoing need (a patient who needs multiple transfusions in a period of time, for example). While the number of these types of orders in a day ebbs and flows, “a day rarely goes by that we don’t get a new order,” says Karen Hendryk, SBC’s Donor Recruitment Manager.

Any platelet donor could receive a call for a special request at any time. If you are currently part of our platelet program, you may one day receive a call that you are a match for a patient in need. If you haven’t donated platelets before and are interested in becoming part of the program, please ask one of our team members to see if you’re eligible the next time you come in to donate. We have a constant need for platelets, so your contribution could save lives each and every time you come in to donate. And who knows, maybe one day you’ll get the call that you are someone’s perfect match!


To make an appointment to donate, please visit sbcdonor.org or give us a call at 888-723-7831.