The Hemostasis Research Laboratory at Loyola University Medical Center is a CAP-approved facility providing tests to detect heparin antibodies, to aid in confirming the diagnosis of Heparin Induced Thrombodytopenia (HIT). Both activity and antigen tests are available:

• Serotonin Release Assay (SRA) – uses donor platelets labeled with radioactive (¹⁴C) serotonin to detect platelet activation (release of granules) in response to HIT-positive serum in the presence of heparin.

• Heparin:Platelet Factor 4 Antibody - ELISA - detects the presence of antibodies to the complex of heparin and platelet factor 4 by enzyme-linked immunosorbent assay (ELISA).

Specimen Requirements:
Serotonin Release Assay: frozen serum-minimum volume 1.0 ml
Heparin: Platelet Factor 4 Antibody ELISA: frozen serum or citrated plasma-minimum volume 0.5 ml
Note: Both SRA and ELISA can be run on the same specimen.

Turn Around Time:
The Serotonin Release Assay is run every Tuesday and Thursday beginning at 9:00 am. The test requires approximately 6 hours to run, and counting of the radioactivity occurs overnight.  Results are calculated in the morning on Wednesday and Friday, and reports are Faxed immediately.  Because the Serotonin Release Assay requires recruitment of specific platelet donors, and involves a daylong process, we are unable to accept STAT orders.  Heparin-Platelet Factor 4 Antibody ELISAs are run weekday mornings and reported by Fax the following day.

Shipping Instructions:
Pack shipments with enough dry ice to keep specimens frozen until delivery. Include a requisition listing patient's name and date of birth, specimen collection date and time, medical record number or accession number (or identifier of your choice), billing address, and the name, phone number and Fax number of a contact person to receive the results.  Please follow IATA guidelines for safe shipping of diagnostic specimens on dry ice.  Ship to:

Customer Service – Bldg. 103, Room 0134
Loyola University Medical Center
2160 S. First Avenue
Maywood, IL 60153
Phone: (708) 216-3941

Overnight deliveries via commercial carriers should arrive Monday through Friday only, when receiving dock personnel are available. Since SRA specimens are collected from Special Hematology Lab by 9:00 am on Tuesdays and Thursdays, it is optimal for shipment to arrive by Monday or Wednesday afternoon, to insure that they are processed and ready for pick-up the next morning. Local couriers may deliver specimens to Special Hematology at any time.

Hours of Operation:
The Serotonin Release Assay Laboratory is staffed Monday-Friday, 8:30 am - 5:00 pm. Closed on Holidays.

Contact Information:
Dr. Margaret Prechel
(708) 327-2840 for technical information on Serotonin Release Assay or ELISA performance, verification of specimen receipt, or tracking of results.|
Dr. Jeanine Walenga
(708) 327-2838 for questions on the laboratory diagnosis of HIT.
Bernice Gregorio
(708) 216-9191 for information on CPT codes and pricing.
Laboratory phone: (708) 327-2840
Fax:  (708) 327-2849

Platelet aggregation testing to detect HIT antibodies is available through the Special Coagulation Laboratory.