A single centre in-depth analysis of death with a functioning kidney graft and reasons for overall graft failure

BACKGROUND: High numbers of unknown classifications and inconsistent methodologies in previous studies make the interpretation of causes leading to graft loss difficult. In addition, data on a holistic view looking at both death with a functioning graft (DWFG) and death-censored graft failure (DCGF) are sparse. METHODS: In this single-centre study we included 1477 adult kidney transplants performed between 1997 and 2017, of which all 286 DWFGs until the end of observation were analysed and causes for death assigned. Additionally, the results were compared with the causes of 303 DCGFs of the same cohort to evaluate the impact of causes for overall graft loss. RESULTS: The most frequent causes for DWFG were cardiovascular disease (CVD) in 30.8%, malignancy in 28.3% and infections in 21%. Only 9.4% of reasons for DWFG were unknown. Sudden death occurred in 40% (35/88) of patients classified as DWFG due to CVD. Overall graft loss was related to the effect of immunosuppression in 36.2% [infection 20.9% (123/589), malignancy 15.3% (90/589)] and CVD in 22.4% (132/589). In 27.4% (161/589), graft failure was associated with underimmunosuppression (rejection). For infections (60 DWFG, 63 DCGF) and CVD (88 DWFG, 44 DCGF), a considerable overlap was observed between DWFG and DCGF. For patients >70 years of age at transplantation, medical events accounted for 78% of overall graft losses and only 6.5% were associated with rejection. CONCLUSIONS: DWFG and DCGF share more causes for graft loss than previously reported and sudden death plays an underestimated role in death with a functioning graft.