Sponsor decided not to go forward with study for FDA submission.

To compare the performance of the QuantiFERON Monitor assay against existing methodology.

Solid Organ Transplant Recipient

Inclusion Criteria:

• Provide Informed Consent
• Received a solid organ transplant

Exclusion Criteria:

• Pregnancy or recent lactation (<1yr)
• Treatment of Rejection

Healthy Control

Inclusion Criteria:

• Provide Informed Consent

Exclusion Criteria:

• Currently taking any immunomodulatory medication
• A history of immunosuppressive disease or immunosuppression condition or history of autoimmune diseases
• Current pregnancy or recent lactation (<1yr)
• Currently taking antiviral medication
• Currently being treated for infectious diseases

Subjects who have either received a solid organ transplant or who are healthy.