Preemptive reduction of immunosuppression upon high urinary polyomavirus loads improves patient survival without affecting kidney graft function.

BACKGROUND: Polyomavirus (PV) is a major cause of kidney graft disease. Monitoring by polymerase chain reaction (PCR) on blood is currently recommended. In order to avoid irreversible lesions, we investigated the clinical impact of preemptive reduction of immunosuppression (IS) in kidney transplant recipients (KTR) upon detection of high urinary PV (Upv) load, including BK virus and JC virus. MATERIAL AND METHODS: From 2000 to 2011, in our single center, 789 consecutive KTR were distributed into 4 groups, according to the maximal Upv levels (by PCR) during the first year and the therapeutic option: (A) Upv <104 copies (cp)/mL (n=573), (B) ≥104 Upv <107 cp/mL (n=100), and (C) Upv ≥107 cp/mL (n=116); in group C, the IS drug doses were reduced in subgroup Ca (n=102) only, as 14 patients (subgroup Cb) were at risk for graft rejection. RESULTS: The preemptive reduction of IS (group Ca) increased patient survival as compared with all other groups (P<.05), did not modify graft function, and increased graft survival vs group A (risk ratio: 5.7, confidence interval: 1.8-18.1, P=.003). Differences for risk factors are as follows (groups Ca vs A): incidence of human leukocyte antigen (HLA) immunization (>5% panel reactive antibodies): 3% vs 8% (P=.05), number of HLA mismatches: 2.7 vs 2.5 (P=.049), and incidence of acute rejection: 9.8% vs 24.2% (P=.005). PV-associated nephropathy occurred only in group Ca (2% of total grafts) without effect on patient or graft outcome. CONCLUSION: The reduction of IS in patients with high Upv loads is beneficial for patient survival and does not affect graft survival or graft function.

Delayed Graft Function in Kidney Transplants: Time Evolution, Role of Acute Rejection, Risk Factors, and Impact on Patient and Graft Outcome.

Background. Although numerous risk factors for delayed graft function (DGF) have been identified, the role of ischemia-reperfusion injury and acute rejection episodes (ARE) occurring during the DGF period is ill-defined and DGF impact on patient and graft outcome remains controversial. Methods. From 1983 to 2014, 1784 kidney-only transplantations from deceased donors were studied. Classical risk factors for DGF along with two novel ones, recipient's perioperative saline loading and residual diuresis, were analyzed by logistic regression and receiver operating characteristic (ROC) curves. Results. Along with other risk factors, absence of perioperative saline loading increases acute rejection incidence (OR = 1.9 [1.2-2.9]). Moreover, we observed two novel risk factors for DGF: patient's residual diuresis ≤500 mL/d (OR = 2.3 [1.6-3.5]) and absence of perioperative saline loading (OR = 3.3 [2.0-5.4]). Area under the curve of the ROC curve (0.77 [0.74-0.81]) shows an excellent discriminant power of our model, irrespective of rejection. DGF does not influence patient survival (P = 0.54). However, graft survival is decreased only when rejection was associated with DGF (P < 0.001). Conclusions. Perioperative saline loading efficiently prevents ischemia-reperfusion injury, which is the predominant factor inducing DGF. DGF per se has no influence on patient and graft outcome. Its incidence is currently close to 5% in our centre.