What do positive or negative results for infectious disease tests, such as Hepatitis B (HBV) Core Total Antibody, Quantiferon Test for Latent Tuberculosis (TB), Cytomegalovirus (CMV) Immunoglobulin G (IgG), Coccidioides Antibody Immunoassay, Human T-Lymphotropic Virus (HTLV) Antibody, Hepatitis B (HBV) Surface Antigen (HBsAg) Quantitation, Hepatitis C Antibody, Human Immunodeficiency Virus (HIV) Antigen/Antibody Screen, Rapid Plasma Reagin (RPR) with Reflex to Titer, and Strongyloides Immunoglobulin G (IgG) Antibody, mean for organ donation eligibility?

Interpretation of Infectious Disease Test Results for Organ Donation Eligibility

The results of infectious disease tests are critical for determining organ donation eligibility, with positive results potentially limiting donation options but not necessarily precluding donation in all cases, depending on the specific infection and recipient factors. 1

Hepatitis B Testing Interpretation

• Hepatitis B Core Total Antibody (anti-HBc): A positive result indicates previous exposure to HBV. When positive but HBsAg negative, it could represent: resolved infection with immunity (most common), false-positive result, occult chronic infection, or resolving acute infection 1
• Hepatitis B Surface Antibody (anti-HBs) Quantitative: A positive result (≥10 IU/mL) indicates immunity to HBV, either from vaccination or resolved infection 1
• Hepatitis B Surface Antigen (HBsAg): A positive result indicates active HBV infection and generally contraindicates donation except for HBsAg-positive recipients or those with protective immunity 1

HBV Status Interpretation Table:

• HBsAg(-)/anti-HBc(-)/anti-HBs(-): No infection or immunity
• HBsAg(-)/anti-HBc(+)/anti-HBs(+): Natural immunity from resolved infection
• HBsAg(-)/anti-HBc(-)/anti-HBs(+): Vaccine-induced immunity
• HBsAg(+)/anti-HBc(+)/IgM anti-HBc(+): Acute infection
• HBsAg(+)/anti-HBc(+)/IgM anti-HBc(-): Chronic infection 1

Other Infectious Disease Tests

• Quantiferon Test for Latent TB: A positive result indicates latent tuberculosis infection, which does not contraindicate donation but requires recipient treatment 1
• CMV IgG: A positive result indicates prior CMV infection. Not a contraindication but essential for determining post-transplant prophylaxis strategy 1
• Coccidioides Antibody Immunoassay with Reflex to CF: A positive result indicates prior or current coccidioidomycosis infection, which may require recipient treatment depending on clinical context 1
• HTLV I & II Antibody: A positive result indicates HTLV infection, which may limit donation options due to risk of HTLV-associated diseases 1
• Hepatitis C Antibody: A positive result indicates HCV exposure and generally contraindicates donation except for HCV-positive recipients or in emergency situations 1
• HIV Antigen/Antibody Screen: A positive result indicates HIV infection and generally contraindicates donation except for HIV-positive recipients in certain jurisdictions 1
• RPR with Reflex to Titer: A positive result indicates possible syphilis infection; not a contraindication but requires recipient treatment 1
• Strongyloides IgG Antibody: A positive result indicates prior or current strongyloidiasis, which requires treatment in the recipient to prevent hyperinfection syndrome post-transplant 2
• EBV Viral Capsid Antigen IgG: A positive result indicates prior EBV infection. Not a contraindication but important for monitoring EBV-negative recipients, especially children, due to post-transplant lymphoproliferative disorder risk 1

Impact on Organ Donation Eligibility

• Organs from donors with certain infections may still be used with appropriate recipient matching and prophylaxis strategies 1
• HBsAg-positive organs may be considered for HBsAg-positive recipients or those with protective immunity (anti-HBs ≥10 IU/mL) 1
• Anti-HBc-positive organs (with negative HBsAg) can be used with consideration of antiviral prophylaxis for liver recipients and HBV non-immune recipients 1
• HCV-positive organs are generally used only for HCV-positive recipients or in emergency situations 1
• HIV-positive organs are generally contraindicated except for HIV-positive recipients in certain jurisdictions 1

Clinical Pitfalls and Considerations

• False-negative results may occur due to hemodilution from transfusions or infusions; testing should ideally use pre-transfusion samples 1
• Window period infections may be missed by antibody testing alone; nucleic acid testing (NAT) reduces this risk for HIV, HBV, and HCV 1
• All OPOs in the US now perform prospective NAT for HIV, HBV, and HCV on all donors, which has improved detection of early infections 2
• The risk of disease transmission varies by organ type; liver transplants carry higher risk of HBV transmission from anti-HBc positive donors compared to non-hepatic organs 1, 3
• Recipient prophylaxis and monitoring strategies should be tailored based on donor and recipient infection status 1

The interpretation of these test results requires careful consideration of both donor and recipient factors to maximize organ utilization while minimizing infection transmission risk 4, 5.