The purpose of this study is to determine if certain genes found in a kidney biopsy performed at one-year post transplant can predict which transplanted kidneys will have decreased kidney function within five years post-transplant.

Gene expression profiling is used to study the activity of genes. Each gene has an "on/off" switch that controls how they are expressed in a cell, as well as a "volume control" that increases or decreases the level of expression of a particular gene as necessary. Researchers want to see if the presence and abundance of certain transcripts in a kidney biopsy at one year after transplant can predict which kidneys will have reduced function over time.

Inclusion Criteria:

• Adult (≥18 years) conventional renal transplant recipient.
• Patients who have given informed consent and are willing to comply with the protocol.

Exclusion Criteria:

• ABO incompatible kidney transplants.
• Positive crossmatch kidney transplants (T cell crossmatch >100, B flow cytometric crossmatch >150).
• Simultaneous kidney and extra-renal organ transplants including pancreas, liver, heart, lung, etc. Subjects who had previous extra renal transplants may be included in the study.
• Patients taking chronic anticoagulation, which includes Coumadin, Plavix and any type of heparin. Aspirin is acceptable but must be stopped 5 days prior to the renal biopsy.
• An inability to have the 1-year renal biopsy performed within the acceptable protocol window (Months 11-14 [Days 301-420] post-transplant).

Kidney transplant recipients