Posttransplant inflammation associated with onset of chronic kidney disease

Abstract

Background: Chronic allograft nephropathy (CAN), a major complication in renal transplant patients, is an important cause of graft loss. Inflammation as measured in the pretransplant and posttransplant phases, using various markers, has been associated with worse renal function and a greater risk of cardiovascular disease and of long-term graft loss.

Objective: The objective of our study was to evaluate whether worsening inflammation in the first 3 months postoperatively was a risk factor for developing CAN.

Patients and methods: We performed a cross-sectional study in 207 patients. The following markers of inflammation (MIF) were determined pretransplant and at 3 months after grafting: C-reactive protein (CRP) (mg/L), interleukin (IL)-6 (pg/mL), IL-10 (pg/mL), tumor necrosis factor (TNF)-α (pg/mL), and its soluble receptor (ng/mL), soluble-IL2R (UI/mL), pregnancy-associated plasma protein A (PAPP-A; mUI/L), and IL-4 (pg/mL). We also calculated the ratio at 3 months versus the pre value of MIF.

Results: CAN was diagnosed after the first year in 23 patients (11.3%) always by renal biopsy performed for clinical indications. Patients with CAN showed worse inflammation, eg, MIF ratios over one, with statistically significant differences for the ratios of TNF-α and PAPP-A (P=.032 and P=.051 respectively). Upon multivariate logistic regression analysis, using CAN as the dependent variable and age, sex, donor age, months on dialysis, acute tubular necrosis, acute rejection, and MIF ratios as covariates, we observed that an acute rejection episode (OR=13.03; CI=2.8-60.9; P=.001), CRP ratio (OR=1.36; CI=1.07-1.73; P=.013), and PAPP-A ratio (OR=1.80; CI=0.92-3.53; P=.005) were independent markers of CAN.

Conclusions: Among other factors, inflammation may determine the onset of CAN as diagnosed by renal biopsy.