PlexEBV^TM

EBV

Epstein-Barr virus (EBV) is a common virus. Half of all adults have been infected by EBV at some time. (www.cdc.gov/cmv/index.html). Most infections do not cause symptoms. EBV persists in a latent state after the initial infection and can reactivate in individuals whose immune systems are compromised by immunosuppressive drugs, viral infections, or genetic changes. This reactivation can progress from virus that is only detected in the blood (viremia), to involvement of tissues and organs (disease), which can cause major illness. In transplant recipients, EBV can cause post-transplant lymphoma-like disease.

Rationale

Reactivation of EBV is accompanied by loss of cell-based immunity to the virus. Currently available antiviral drugs are not very effective. In transplant patients, reactivation leads physicians to lower immunosuppression. Reduction of immmunosuppression can lead to rejection in some patients. In transplant patients, a first time EBV infection or reactivation of the virus can lead to persistence of the virus in blood. Persistence of high viral load in the blood can lead to tissue invasive EBV disease or post-transplant lymphoma. Knowing whether cell-based immunity to EBV is intact or decreased can further guide how to best manage immunosuppression.

Intended Use

PlexEBV^TM is a lab developed blood test to measure the level of cellular immunity to Epstein-Barr virus (EBV). Decreased anti-EBV immunity increases the risk of EBV infection.*

Purpose

Knowledge about immunity to EBV and therefore the risk of EBV infection can be combined with available clinical data to plan additional treatment for your patient.

Test Description

PlexEBV^TM measures functional cell-mediated immunity to EBV.

• Whole blood, 3 ml from children, 5 ml from adults in sodium heparin green top tubes, is shipped at ambient temperature overnight to Plexision’s reference laboratory.
• EBV-specific T-cells and their subsets, which express the inflammatory marker, CD154 are measured after stimulation with EBV antigen.
• Simultaneously, recipient T-cell stimulation with mitogen measures general T-cell responsiveness.

Results

• Are reported within 30 hours after blood samples reach the laboratory.
• Are reported as frequencies of EBV-specific T-cells and their subsets along with thresholds for the level of EBV immunity. These thresholds have been established from studies of transplant recipients with high and low viral loads in blood. These thresholds determine whether immunity to EBV is decreased or not.
• Immunosuppression protocols can vary with different types of patients and organ transplants. Establishing the level anti-EBV immunity at baseline and during periods of high dose immunosuppression permits the level of anti-EBV immunity to be assessed in each patient. This can help formulate personalized preventive measures or treatment.

References: US Patent 9606109
*PlexEBV^TM is not FDA-approved