Donor evaluation and infectious-disease testing

Donor evaluation is the structured assessment of a potential organ donor's medical suitability and transmissible-infection risk that occurs before any organ is accepted for transplantation. For deceased donors it is carried out by the organ procurement organization after hospital referral; for living donors it is carried out by the transplant center. The infectious-disease component is anchored in the United States by the U.S. Public Health Service (PHS) guideline, most recently revised in 2020, and by OPTN policy, both of which now require universal nucleic acid testing (NAT) of every donor for human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV).[1][2]

The evaluation balances two goals: maximizing the use of viable organs to address the persistent organ shortage, and limiting the risk that an organ transmits a serious infection or malignancy to the recipient. Because no test can exclude every infection, the process culminates in an informed-consent discussion in which the residual, "window-period" risk of an organ is disclosed to the candidate before transplant.[1][3]

The donor evaluation

A complete donor evaluation combines several streams of information. A medical and social history is obtained, for a deceased donor through a structured interview with the next of kin or another knowledgeable informant (a "donor risk assessment interview"), covering past illnesses, cancers, infections, travel, transfusions, and behavioral risk factors for recent bloodborne infection.[1] This is supplemented by a physical examination, review of the hospital record, organ-specific function testing (for example serum creatinine for the kidney, transaminases and coagulation studies for the liver, echocardiography and catheterization for the heart, and bronchoscopy and oxygenation challenge for the lung), and imaging.[4] The integrated picture supports a per-organ judgment of suitability and feeds donor-quality indices used in allocation, such as the Kidney Donor Profile Index and the Kidney Donor Risk Index. Physiologic management of the donor before recovery is addressed in donor management and optimization.

The PHS guideline

A U.S. Public Health Service guideline has governed infectious-risk donor screening since 1994, when the first guideline addressed prevention of HIV transmission through transplantation.[1] A 2013 revision broadened the scope and introduced the "increased risk donor" terminology together with expanded NAT.[1] The current guideline, published as a CDC Morbidity and Mortality Weekly Report (MMWR) Recommendations and Reports in 2020, consolidated the screening of HIV, HBV, and HCV into a single framework and made three notable changes: it retired the stigmatizing "increased risk donor" label in favor of describing specific risk criteria; it shortened the look-back window for behavioral risk factors from 12 months to the 30 days before procurement and removed several risk factors (such as hemodialysis); and it formalized universal NAT for HIV, HBV, and HCV in all donors, not only those with identified risk factors.[1] A companion 2022 PHS update addressed testing of transplant candidates for these viruses.[5]

Serologic and NAT testing panel

Under OPTN policy, every deceased donor is tested for a defined panel of transmissible infections, and the laboratory methods combine serology (antibody/antigen detection) with NAT (direct detection of viral nucleic acid). The 2020 PHS guideline specifies serologic testing, anti-HIV antibody, hepatitis B surface antigen (HBsAg), total anti-HBc, and anti-HCV, plus NAT for all three viruses on every donor.[1] OPTN policy additionally requires testing for cytomegalovirus (CMV), Epstein-Barr virus (EBV), syphilis (commonly by a non-treponemal test such as RPR with treponemal confirmation), and Toxoplasma gondii.[2][6]

| Pathogen | Typical method(s) | Purpose | |---|---|---| | HIV | Anti-HIV antibody + NAT | Detect chronic and recent infection | | HBV | HBsAg, total anti-HBc + NAT | Detect active, prior, or occult infection | | HCV | Anti-HCV + NAT | Detect chronic and recent infection | | CMV, EBV | Serology (IgG) | Recipient risk stratification / prophylaxis | | Syphilis | RPR (non-treponemal) + treponemal confirmation | Detect treponemal infection | | Toxoplasma gondii | Serology | Relevant especially for heart recipients |

NAT shortens the diagnostic "window period", the interval after infection during which antibody tests remain negative, because it detects viral nucleic acid days to a few weeks earlier than serology. Universal NAT therefore reduces, but does not eliminate, the chance of an undetected recent infection in a donor who acquired the virus very shortly before death.[1][7]

Risk assessment and informed consent of the recipient

Because even a fully tested donor carries an irreducible residual risk, the transplant team discloses that risk to the candidate as part of informed consent before accepting an organ. The disclosure addresses the donor's risk criteria (if any) and the window-period limitation of the tests, and the candidate's acceptance is documented. The 2020 guideline's removal of the "increased risk" label was intended in part to prevent that label from causing clinically appropriate organs to be declined, while preserving a substantive, individualized risk conversation.[1][3] OPTN informed-consent policy governs how transmittable-disease risk is communicated.[8]

Disease transmission and surveillance

When a donor-derived infection or malignancy is suspected after transplant, it is reported to the OPTN and reviewed by the Ad Hoc Disease Transmission Advisory Committee (DTAC), which classifies events as proven, probable, possible, or excluded using a standardized algorithm.[9] DTAC reporting has shown that confirmed donor-derived transmissions are uncommon relative to the number of organs transplanted: in a ten-year analysis of reports from 2008 to 2017, 335 of 2,185 reports (about 15 percent) were classified as proven or probable transmission events, most commonly infections, followed by malignancies.[10] These data underpin ongoing refinement of testing requirements and consent practice.[9][10]

Emerging considerations

The most significant recent shift is the routine, deliberate use of organs from HCV-viremic donors in HCV-negative recipients, made possible by highly effective direct-acting antiviral (DAA) therapy. In the THINKER pilot study and subsequent trials, HCV-negative recipients of kidneys from HCV-viremic donors were cured of the transmitted infection with DAA therapy and achieved allograft function comparable to recipients of HCV-negative kidneys, converting a category of organs that had often been discarded into a usable resource.[11] Parallel "transmit-and-treat" experience exists for other organs. Ongoing areas of attention include optimizing the timing and duration of DAA prophylaxis, refining donor-derived infection surveillance, and assessing emerging pathogens, which keeps donor screening an actively evolving field rather than a fixed checklist.[11][9]

See also

• The donation pathway
• Hospital referral and the duty to notify the OPO
• Donor management and optimization
• KDPI and KDRI
• Transplant immunology

References

• Jones JM, Kracalik I, Levi ME, et al. Assessing Solid Organ Donors and Monitoring Transplant Recipients for Human Immunodeficiency Virus, Hepatitis B Virus, and Hepatitis C Virus Infection, U.S. Public Health Service Guideline, 2020. MMWR Recomm Rep. 2020;69(4):1-16. doi:10.15585/mmwr.rr6904a1. PMCID: PMC7337549. https://www.cdc.gov/mmwr/volumes/69/rr/rr6904a1.htm
• Organ Procurement and Transplantation Network. Policy 2.9, Required deceased donor infectious disease testing (HIV, HBV, HCV, CMV, EBV, syphilis, Toxoplasma). https://optn.transplant.hrsa.gov/policies-bylaws/policies/
• Should my patient accept a kidney from a hepatitis C virus-infected donor? (residual-risk and consent discussion). PMC8809094. https://pmc.ncbi.nlm.nih.gov/articles/PMC8809094/
• American Society of Transplantation, Infectious Diseases Community of Practice. Screening of donor and recipient in solid organ transplantation, Guidelines. Am J Transplant (Clinical Practice Guidelines, 4th ed.). https://www.amjtransplant.org/article/S1600-6135(22)26256-X/fulltext
• Updated U.S. Public Health Service Guideline for Testing of Transplant Candidates Aged ≥12 Years for Infection with HIV, Hepatitis B Virus, and Hepatitis C Virus, United States, 2022. MMWR Morb Mortal Wkly Rep. 2022;71(26). https://www.cdc.gov/mmwr/volumes/71/wr/mm7126a2.htm
• Theodoropoulos NM, et al. Testing deceased organ donors for infections: An organ procurement organization survey. Am J Transplant. 2021. doi:10.1111/ajt.16552. https://onlinelibrary.wiley.com/doi/10.1111/ajt.16552
• OPTN. Align OPTN policy with U.S. Public Health Service Guideline, 2020 (briefing paper on universal NAT). https://optn.transplant.hrsa.gov/media/4225/bp_202012_align_2020_phs_guideline.pdf
• OPTN. Informed consent policies for transmittable-disease risk. https://optn.transplant.hrsa.gov/policies-bylaws/public-comment/clarify-informed-consent-policies-for-transmittable-disease-risk/
• OPTN. Ad Hoc Disease Transmission Advisory Committee (DTAC); resource for reporting potential donor-derived disease transmission events. https://optn.transplant.hrsa.gov/professionals/by-topic/guidance/resource-for-reporting-potential-donor-derived-disease-transmission-events-pddte/
• Kaul DR, et al. Ten years of donor-derived disease: A report of the Disease Transmission Advisory Committee. Am J Transplant. 2021;21(2):689-702. doi:10.1111/ajt.16178. https://onlinelibrary.wiley.com/doi/abs/10.1111/ajt.16178
• Reese PP, Abt PL, Blumberg EA, et al. Twelve-month outcomes after transplant of hepatitis C-infected kidneys into uninfected recipients (THINKER). Hepatitis C virus treatment and solid organ transplantation. PMC9053510. https://pmc.ncbi.nlm.nih.gov/articles/PMC9053510/