Causes of graft failure in simultaneous pancreas-kidney transplantation by various time periods.

Data collected by the United Network for Organ Sharing from all approved United States transplant programs was analyzed. The data included 26,572 adult diabetic patients who received a primary pancreas transplant between January 1987 and December 2012. Simultaneous pancreas-kidney (SPK) transplantation was the major therapeutic option for diabetes patients. SPK had better graft survival than pancreas transplant alone (PTA) or pancreas-after-kidney (PAK) or pancreas-with-kidney (from a living donor, PWK). The 5-year pancreas graft survival rates for SPK, PWK, PAK, and PTA were 70.0%, 57.2%, 54.0%, and 48.2%, respectively. When long-term SPK pancreas graft survival was examined by various transplant time periods, it was found that survival has remained almost stable since 1996. Graft survival rates were high among the pancreas recipients transplanted in the periods 1996-2000, 2001-2005, and 2006-2012, and the rates were similar: the 5-year rates were 68.9%, 72.4%, and 73.8%, respectively. Technical failure was the leading cause of graft loss during the first year post-transplant, regardless of period: 61.3%, 68.6%, 64.2%, and 71.9% for 1987-1995, 1996-2000, 2001-2005, and 2006-2012, respectively. After one year, chronic rejection was the leading cause of graft loss in all periods: 51.8%, 53.2%, 44.3%, and 40.7% for 1987-1995, 1996-2000, 2001-2005, and 2006-2012, respectively. Chronic rejection accounted for around 50% (or more) of the grafts that survived over five years. Survival of long-term pancreas grafts as well as long-term causes of graft loss remained almost unchanged across the different transplant periods. Clearly, there is a need for a means to identify early markers of chronic rejection, and to control it to improve long-term survival.