The T-SPOT assay quantifies the number of peripheral blood interferon-γ producing effector T cells [spot forming cells/million peripheral blood mononuclear cells - PBMC)]. The T-SPOT platform technology can be applied to diagnose and monitor any major disease process driven by a T cell response, including a viral disease such as cytomegalovirus (CMV) infection (the T-SPOT.CMV assay) or an allograft rejection (the T-SPOT.PRT assay).

Approximately 600 subjects who meet inclusion/exclusion criteria will be enrolled in the prospective, non-randomized, observational study. Sample size is based on having an adequate overall number of subjects to assess the T-SPOT.PRT endpoint (350) and the T-SPOT.CMV endpoint (250) in the defined populations. Subjects may be enrolled from pre-transplantation to post-transplantation up to completion of antiviral prophylaxis.

Study duration: 37 months; 25 months to enroll all subjects with 12 months (365 days) of patient participation.

Study population:

All subjects enrolled in this study will be men or women, aged 18 years or older and recipients of a first or subsequent renal transplant.

Inclusion criteria:

1. Active candidate or recipient of a kidney transplant. Patients enrolled post-transplant must be within 6 months of transplantation and on active CMV anti-viral prophylaxis.
2. Age ≥ 18 years.
3. CMV serology of donor and recipient confirmed prior to enrollment. For seronegative subjects (R-), CMV serostatus should be confirmed within eight weeks prior to transplant by the site local laboratory.
4. Able to provide T-SPOT pre-transplant samples up to a maximum of one month prior to transplant (in the interval between Day -30 and Day 0), or at the time of enrollment if this occurs following transplantation.
5. IRB approved written Informed Consent and privacy language per national regulation (e.g., Health Insurance Portability and Accountability Act for US sites) must be obtained from the subject or legally authorized representative prior to any study related procedures, including screening evaluations and tests.

Exclusion criteria:

1. Anemia prior to transplant that indicates not a candidate for blood draw.
2. On active immunosuppression within two months prior to transplant.
3. Multi-organ transplant (dual-kidney allocation is allowed).
4. Subject has received prior exposure to a CMV vaccine.
5. Subject has undergone or is planning to undergo plasmapheresis.
6. Subject requires desensitization for ABO blood type incompatibility or a positive T or B-cell crossmatch.
7. Subject is known to be HIV positive.
8. Subject is known to have a clinically significant medical or psychiatric condition considered a high risk for participation in an investigational study.

Active candidate for a kidney transplant. Age equal to or greater than 18 years.

Male or female.