Solid Organ Transplantation: The Evaluation Process

Vocabulary flashcards covering the comprehensive evaluation process for solid organ transplantation, including multidisciplinary roles, UNOS and Eurotransplant requirements, immunological testing (PRA, CPRA, HLA), and pretransplant virology screening.

Solid Organ Transplantation (SOT)

A viable treatment option for end-stage disease that requires strict posttransplant adherence to a complex medical regimen and immunosuppressants, which can exacerbate pre-existing conditions.

Transplant Coordinator

The member of the interdisciplinary transplant team who oversees the evaluation process, often serves as the patient's first contact, and provides comprehensive education to patients and their support systems.

Scientific Registry for Transplant Recipients (SRTR)

The organization that provides transplant center-specific survival statistics, which the transplant team must share with patients and their families during the evaluation process.

Estimated Glomerular Filtration Rate (eGFR)

A baseline laboratory evaluation specifically required for candidates undergoing evaluation for extrarenal solid organ transplantation.

ABO Blood Typing Protocol

A UNOS requirement mandating that prospective recipients have blood typing performed on two separate occasions, recorded in the medical record, and verified by a second transplant team member in the UNOS UNet system at listing.

Panel Reactive Antibody (PRA)

A test measuring circulating antibodies in recipient serum reactive against human leukocyte antigens (HLA) to predict hyperacute rejection, expressed as a percent reactivity between $0\%$ and $99\%$.

Solid-Phase Immunoassay (Luminex)

The predominant technique used by most SOT programs for PRA testing, utilizing solubilized HLA molecules bound to polystyrene beads and analyzed on a fluoroanalyzer.

Calculated PRA (CPRA)

A calculated risk assessment that evaluates specific antigens deemed unacceptable by a transplant program based on the degree of immunological risk the center is willing to assume.

CPRA Approval Requirement ($>98\%$)

A UNOS guideline requiring that before a candidate with a CPRA score $>98\%$ receives organ offers, the HLA laboratory director and transplant physician or surgeon must sign a written approval of listed unacceptable antigens documented in the medical record.

Mean Fluorescence Intensity (MFI)

The reporter signal value that quantifies the level of HLA-specific antibody binding, utilized by transplant programs to determine whether specific antigens are unacceptable.

Human Leukocyte Antigen (HLA)

Six separate polymorphic genetic loci clustered together in a single area of the human genome and expressed on lymphocytes that can predict graft rejection.

Eurotransplant HLA Typing Protocol

A requirement that every potential recipient and donor be typed on two different occasions using two different samples for HLA-A, -B, -DR, HLA-C, and -DQ.

72-Hour HLA Testing Rule

The clinical standard to avoid molecular HLA typing within $72\,\text{hours}$ of a blood transfusion because the high sensitivity of the assay can detect transfused donor antigens and obscure recipient typing.

Human Immunodeficiency Virus (HIV) Evaluation

Pretransplant viral screening conducted initially via enzyme immunoassay and confirmed by Western blot; historically an absolute contraindication, but selectively performed under highly active antiretroviral therapy (HAART).

Anti-HCV (Hepatitis C Antibody)

A serological screening test in the convalescent hepatitis battery where a positive finding indicates past or present exposure to hepatitis C.

HBsAg (Hepatitis B Surface Antigen)

A screening marker indicating active infection with hepatitis B, which requires follow-up diagnostic testing including HBeAg, HBeAb, HBV DNA, and HBcAb IgM.

HBsAb (Hepatitis B Surface Antibody)

A serological marker in the convalescent hepatitis screening battery whose positive result indicates immunity to hepatitis B.

HBcAb IgG (Hepatitis B Core Antibody IgG)

A serological marker in the convalescent screening battery whose positive result demonstrates previous hepatitis B infection or exposure.

HBcAb IgM (Hepatitis B Core Antibody IgM)

A specialized follow-up diagnostic marker evaluated when HBsAg is positive; a positive result indicates acute hepatitis B or viral reactivation.

Herpesviridae Family

The family of viruses identified as the most common disease-causing viral pathogens encountered in the solid organ transplant population.

Cytomegalovirus (CMV)

A member of the Betaherpesvirinae family establishing lifelong latency, which historically causes CMV disease in up to $85\%$ of seronegative recipients receiving an organ from a seropositive donor.

CMV IgG Screening

A serologic blood test identifying CMV immunoglobulin G antibodies in prospective recipients and donors to establish status and guide the requirement and duration of prophylactic therapy.

Epstein-Barr Virus (EBV)

A Gammaherpesvirinae virus and group 1 carcinogen acquired in adolescence or early adulthood, associated with infectious mononucleosis, Burkitt's lymphoma, nasopharyngeal carcinoma, Hodgkin's disease, and posttransplant lymphoproliferative disease.