The Impact of Early Protocol Biopsy in Kidney Transplant

* All recipients will receive induction therapy with basiliximab or rATG and triple maintenance immunosuppression with TAC/MMF and corticosteroid. * PB at 2 weeks and 1 year after transplantation will be performed using an 18-gauge needle under ultrasound guidance. * Patients who will get PB can be the candidate of this study. * Methylprednisolone 0.5 g daily for 3 days will be administered in patients with SCR. * Information of enrolled patient including age, sex, height, body weight, serum creatinine level, modality of dialysis, duration of dialysis, panel reactive antibody, donor specific antibody, HLA mismatch, ABO incompatibility and history of previous transplantation will be collected. These data will be safely controlled by the person in charge. Patient name will be changed in to initials and registration number of hospital will be changed into new registration number of this study. * laboratory tests including WBC, BUN, creatinine, FK level, MPA level, CMV virus DNA load, BK virus DNA load, urine nitrate, urine leukocyte esterase, urine BK virus DNA load, urine culture and chest X-ray will be checked on 14th post-operative day and every month until 1year after KT. * Enrolled patients will be followed for 1 year and routinely undergo 1-year protocol biopsy. * Within 1 year follow up period, clinical biopsy is performed when recipients' serum creatinine level raised more than 25% of baseline level. * The primary end point * Biopsy proven acute rejection event within 1 year after renal transplantation * Histologic feature including persistent SCR (the presence of SCR at both 2-week and 1-year protocol biopsy), chronic nephropathy at 1-year protocol biopsy. * Graft kidney function estimated by serum creatinine level and eGFR * The incidence of opportunistic infection including pneumonia, urinary tract infection, tuberculosis, fungal infection, and viral infections (such as cytomegalo, polyoma, and parvo-virus) within 1 year * Secondary end points include effect of early detection of polioma BK virus associated nephritis (BKVAN) and relapsed underlying disease