Background: Although the short-term results of kidney transplantation have improved greatly during the past decades, the long-term results have not improved according. Graft loss due to chronic allograft dysfunction (CAD) is a major concern in renal transplant recipients (RTRs). There is little data about disease progression in this patient population. In this paper, we investigated history of kidney function as the pattern, waiting time and rate of pass from intermediate stages in RTR with CAD.

Methods: In a single-center retrospective study, 214 RTRs with CAD investigated at the Urmia University Hospital urmia, Iran from 1997 to 2005. Kidney function at each visit assessed with GFR. We apply NKF and K/DOQI classification of chronic kidney disease (CKD) staging system to determine pattern of disease progression per stage in this group of patients.
Results: The pure death-censored graft loss was 26% with mean waiting time 81.7 months. 100% of RTRs passed from stage I to II in mean waiting time 26.3 months. The probability of prognostic factors transition from stage II to III was 88.9% with mean waiting time 25.5 months, transition from III to IV was 55.7% with mean waiting time of 24.9 months and transition for stage 4 to IV was 53.5% with mean waiting time of 18.2 months. In overall rate of transition from stage i to j in patients with stage III at the beginning of the study (time of start CAD's process) was faster than others.
Conclusions: This study revealed, that kidney function in first years after transplantation is one of the most important II to III of survival probability per stage and death-censored graft loss. Therefore care of RTRs in first year could potentially increase long-term kidney survival.