Infection Screening Tests for Allogeneic HSCT Donors
Allogeneic HSCT donors require comprehensive infectious disease screening that overlaps substantially with recipient testing, but with critical differences in the interpretation and management of positive results.
Core Screening Panel for Both Donors and Recipients
The following tests should be performed on both allogeneic HSCT donors and recipients 1, 2:
- HIV 1/2 antibody testing using enzyme-linked immunoassay (EIA) for both antibodies and antigen, with repeatedly reactive results confirmed by Western immunoblot 1
- Hepatitis B surface antigen (HBsAg) and total core antibody (HBcAb) 1, 2
- Hepatitis C antibody (HCV) 1, 2
- Cytomegalovirus (CMV) IgG antibody 1, 2
- Epstein-Barr virus (EBV) IgG antibody 1
- Syphilis serology (rapid plasma reagin or equivalent) 1, 2
- Medical and social history with physical examination 1
Additional Donor-Specific Testing
Nucleic acid testing (NAT) for HIV, hepatitis B, and hepatitis C is required for all deceased and living donors to detect window-period infections not yet detectable by serology 3. High-risk donors (such as those with history of drug use) should specifically undergo NAT screening for HIV 1.
Blood cultures are recommended for donors to exclude active bacteremia, though positive cultures do not automatically contraindicate donation if the recipient receives appropriate targeted antibiotic therapy 1.
Additional Recipient-Specific Testing
Tuberculin skin testing is recommended specifically for recipients to identify latent tuberculosis that may reactivate post-transplant 1.
Chest radiography is recommended for recipients to evaluate for active pulmonary disease 1.
Key Differences in Management of Positive Results
The critical distinction between donor and recipient screening lies not in the tests performed, but in how positive results are managed:
- HIV-positive donors: Contraindicated except when transplanting to HIV-positive recipients 1
- HBsAg-positive donors: Contraindicated except for HBsAg-positive recipients or those with protective immunity 1
- HCV-positive donors: Contraindicated except for HCV-positive recipients 1
- CMV-positive donors: Not contraindicated, but serostatus matching is essential for defining prophylactic strategy post-transplant 1
- EBV-positive donors: Not contraindicated, but EBV-negative recipients (especially children) require close monitoring 1
- Syphilis-positive donors: Not contraindicated but recipient requires treatment 1
- Bacteremia in donors: Not contraindicated if targeted antibiotic therapy initiated and recipient treated appropriately 1
Geographic and Endemic Considerations
Toxoplasma IgG antibody screening should be considered in areas of high endemicity, particularly for heart transplant recipients, though this is more relevant to solid organ transplantation 1.
Additional parasitic disease screening may be warranted based on donor travel history or residence in endemic areas, though the specific burden in HSCT remains difficult to quantify 4.
Common Pitfalls to Avoid
The most critical error is failing to recognize that serologic testing alone may miss window-period infections, which is why NAT testing has become mandatory for donors 3. A donor with recent high-risk exposure may be seronegative but viremic.
Another common mistake is automatically excluding CMV-positive donors, when in fact CMV serostatus matching and prophylaxis strategies allow safe transplantation 1.
Do not delay screening until immediately before transplant—comprehensive evaluation should occur early in the donor evaluation process to allow time for confirmatory testing and risk assessment 1.