Acute rejection is still a major risk factor affecting the prognosis of kidney transplant patients. Alloreactive cells of the recipient infiltrate the kidney graft and cause inflammatory reaction which damages the graft structure and function. Conventional diagnosis of acute rejection is based on clinical symptoms and kidney biopsy examination. The clinical symptoms are a result of the kidney damage, which occurs days after the initiation of the rejection reaction. Kidney biopsy is an invasive and expensive procedure. It has been wished to have new parameters that can replace/supplement the conventional procedures. Chemokines are small molecules that attract inflammatory cells. Changes of chemokine levels in the urine may correlate with the immune status in the kidney. A systematic study to evaluate the chemokine levels in urine and correlation with the kidney biopsy pathology will answer the question whether monitoring of urinary chemokines would be useful in predicting graft rejection/damage.

Inclusion Criteria:

• One hundred subjects undergoing kidney biopsy for suspected rejection
• Forty subjects that have stable graft function with normal level of blood creatinine (No biopsy is needed at the time of sample collection).

Exclusion Criteria:

• Subjects under the age of 18
• Gender of potential subjects male or female
• Age Limits greater than 18 years of age