TruGraf and TRAC In Pediatrics Study

Inclusion Criteria:

• Patients aged 1-≤ 18 years and recipients of either living or deceased donortransplants Undergoing a protocol biopsy at either 3, 6, 12, 24 or 36 months
• Serum creatinine at the time of the clinic visit prior to the scheduled biopsy within 30% of a baseline calculated as the mean of the recipient's last 3 serum creatininelevels
• Serum creatinine level at the time of protocol biopsy ≤ 1.7 mg/dl.
• Patient receiving immunosuppression with a calcineurin inhibitor (either tacrolimus orcyclosporine) and/or an antimetabolite (either mycophenolate mofetil, mycophenolicacid EC or azathioprine) and/or an mTOR inhibitor (either sirolimus or everolimus)and/or corticosteroids.
• Absence of any systemic or urinary bacterial, viral or fungal infection
• Absence of significant BK viremia (as determined by the laboratory where thedetermination is run) at the time of the last clinical determination and at the timeof the protocol biopsy
• Parents or guardians are capable of reading and understanding the Informed Consentdocument and willing to participate; if appropriate, patient is also able tounderstand the Informed Consent. If patient is older than 13 years, patient should beable to give Assent as written on Assent Form.
• For females of child-bearing age, a negative pregnancy test within 6 weeks of theprotocol biopsy.

Exclusion Criteria:

• Refusal to undergo clinical standard-of-care protocol biopsy by either parent/guardianor patient.
• Inability to obtain adequate tissue on protocol biopsy
• Current participation in another interventional research study; patients who havecompleted the drug in another interventional study are eligible if they meet all otherinclusion criteria.
• Serum creatinine at the clinic visit prior to the biopsy is > 30% of a baselinecalculated as the mean of the recipient's last 3 serum creatinine levels.
• Serum creatinine at the time of the protocol biopsy ≥ 1.8 mg/dl. If the patient had abaseline < 1.8, and the creatinine on the day of biopsy is ≥ 1.8, at the discretion ofthe PI, the patient will be instructed to hydrate for 4 days and a serum creatininewill be obtained at that time. This is standard clinical practice. If the creatininereturns to the baseline (i.e., ≤ 30%) range, the patient will be classified as havingstable renal function, while if the patient's serum creatinine does not return to the ≤ 30% range, he/she will be classified as having renal dysfunction
• Patients who, in the estimation of the investigator, are undergoing "for-cause"biopsies.
• Presence of any current and active bacterial, viral or fungal infection
• Presence of BK viremia judged to be significant by the site PI.
• Presence of BK nephropathy
• History of PTLD or malignancy
• Parents / guardians do not understand Informed Consent and / or are unwilling toparticipate; patient, if of appropriate age, is unwilling to participate
• Patients manifesting recurrent disease in their transplant (such as FSGS/nephroticsyndrome, C3 Glomeruopathy, MPGN, hyperoxaluria)
• Abnormal proteinuria as determined by a urinary protein: creatinine ratio of >1.
• Recipients of multi-organ transplants.