Donor blood must be tested for infectious diseases to enhance the safety of blood components prior to release for transfusion. The scope and characteristics of donor tests have changed over the years, to keep in step with the latest technology and emerging diseases.
Each test on donor blood is performed in strict compliance with current instructions provided by the manufacturer of the test materials and in compliance with regulations from the Food and Drug Administration (FDA).
Each blood donation intended for allogeneic use (transfusion to another individual) must undergo complete testing. Donors must be notified of any medically significant abnormality detected as a result of laboratory testing. Test results are confidential and will not be released to anyone (other than the donor) without the donor’s written consent.
The following is a list of the tests required on donor blood:
ABO Blood Group (O, A, B or AB) Retested with each donation
Rh Rh Type (Positive or Negative) Retested with each donation Weak D positive is labeled as Rh positive
Antibody Screen (IAT) Screening test for red cell antibodies Detects unexpected red blood cell antibodies, which occur only after blood transfusion or pregnancy. Presence of antibodies is NOT a cause for donor deferral. Plasma products are discarded; red cells may be transfused.
Syphilis (STS) Antibodies to Treponema pallidum(hemagglutination test) Tests for Syphilis. Blood donors with a confirmed positive test are deferred for one year.
HBsAg Hepatitis B surface antigen First marker to appear with Hepatitis B infection. A positive test indicates the donor is infectious for Hepatitis B. Blood donors with a confirmed positive test are permanently deferred
Anti-HBc (HBC) Antibody to Hepatitis B core antigen A positive test may indicate a current or previous Hepatitis B infection. Donors with a reactive test on two occasions are permanently deferred.
Anti-HCV (HCV) Antibody to Hepatitis C virus A positive test indicates possible infection with Hepatitis C. Blood donors with a confirmed positive test are permanently deferred.
Anti-HTLV-I/II(HTLV-I/II) Antibody to Human T cell lymphotropic viruses types I and II This combination test screens for both HTLV-I and HTLV-II. HTLV-I can cause adult T cell leukemia and Tropical Spastic Paraparesis (TSP). HTLV-II has not been clearly associated with any disease. Donors with a positive test on two occasions are permanently deferred.
Anti-HIV 1/2 Plus (HIV-1/2) Antibody to Human Immunodeficiency Virus types 1 and 2 and HIV-1 Group O This combination test screens for both HIV-1 and HIV-2, and HIV-1 Group O. A positive test may indicate infection with HIV-1 or HIV-2, the viruses that cause AIDS. Blood donors with a confirmed positive test are permanently deferred.
Anti-T cruzi (Chagas) (TCA) Antibodies to Trypanosoma cruzi T. cruzi is the infectious agent for Chagas disease, which is common in Latin America. Donors with a positive test are permanently deferred. A “/” for test result indicates the donor was tested nonreactive on a previous donation.
HIV-1 and HCV and HBV by NAT testing(NHIV, NHCVand NHBV) Test for genetic material of HIV-1,HCV and HBV by Nucleic Acid Amplification Technology (NAT) NAT is a highly sensitive method for detecting small amounts of virus (HIV-1 or HCV RNA or HBV DNA) in donor blood, which indicates a recent infection with HIV-1, HCV or HBV. Blood donors with a positive test are permanently deferred.
WNV NAT testing(WNV) Test for genetic material of WestNile Virus (WNV) by Nucleic Acid Amplification Technology Nucleic Acid test for detecting small amounts of WNV virus. Blood donors with a positive test are deferred for 120 days. In addition to these required tests, optional tests may be performed on units intended for recipients (patients) with special needs. A few examples are described below:
About 10% of our donors are screened for CMV (cytomegalovirus). CMV is a common virus that causes widespread infection. In healthy individuals, CMV infection is usually asymptomatic, but a CMV infection can be serious in premature infants and immunocompromised patients. CMV negative blood products are provided for these patients. Patients who have been transfused in the past, or have been pregnant, may develop antibodies to other red cell factors, called antigens. To avoid transfusion reactions, blood products are screened for specific red cell antigens for these patients. For example, a patient with an anti-E should only receive E negative blood. Some donations are tested for the sickle cell trait. Carriers of the sickle cell trait are welcome as donors and provide units that meet the transfusion needs for the majority of the patients we serve.
There are special circumstances where a unit from a donor with sickle cell trait may not be the best choice, such as:
Transfusions for premature infants Infants requiring large amounts of blood transfused Transfusions for some patients with sickle cell disease Red cell units that will be frozen Red cell units that will be put through a special leukoreduction filter to remove white blood cells