Inflammation in the early phase after kidney transplantation is associated with increased long-term all-cause mortality

Abstract

In the general population, low-grade inflammation has been established as a risk factor for all-cause mortality. We hypothesized that an inflammatory milieu beyond the time of recovery from the surgical trauma could be associated with increased long-term mortality in kidney transplant recipients (KTRs). This cohort study included 1044 KTRs. Median follow-up time post-engraftment was 10.3 years. Inflammation was assessed 10 weeks after transplantation by different composite inflammation scores based on 21 biomarkers. We constructed an overall inflammation score and five pathway-specific inflammation scores (fibrogenesis, vascular inflammation, metabolic inflammation, growth/angiogenesis, leukocyte activation). Mortality was assessed with Cox regression models adjusted for traditional risk factors. A total of 312 (29.9%) patients died during the follow-up period. The hazard ratio (HR) for death was 4.71 (95% CI: 2.85–7.81, p < .001) for patients in the highest quartile of the overall inflammation score and HRs 2.35–2.54 (95% CI: 1.40–3.96, 1.52–4.22, p = .001) for patients in the intermediate groups. The results were persistent when the score was analyzed as a continuous variable (HR 1.046, 95% CI: 1.033–1.056, p < .001). All pathway-specific analyses showed the same pattern with HRs ranging from 1.19 to 2.70. In conclusion, we found a strong and consistent association between low-grade systemic inflammation 10 weeks after kidney transplantation and long-term mortality.