Despite the evidences showing the relevance of regulatory immune-mediated mechanisms to guarantee the stable graft function in renal transplanted patients, studies focusing on the immune response observed over a long-term period after renal transplantation are still limited. Several efforts have been done to establish novel biomarkers with relevant predictive values that could be used as prognostic laboratorial tools to monitor the complex network triggered through time after kidney transplantation. In this study, we have evaluated the pro-inflammatory and regulatory patterns of plasma cytokines in a group of 120 renal transplanted patients with stable graft function ranging from 1 to 160months. Our data demonstrated an overall predominance of regulatory cytokines short-term after renal transplantation (1–24months) with peaks of IL-4, IL-5 and IL-10. Moreover, a slight peak of TNF-α was observed 25–60months after renal transplantation. Following a gap of stable cytokine profile (61–120months), peaks of pro-inflammatory cytokines IL-8, IL-6, IL1β, TNF-α and IL-12 were observed later on (>120months) after renal transplantation. Additionally, the categorical analysis of “low” or “high” cytokine producers re-enforce the occurrence of an overall regulatory status early-after stable renal graft function with a predominant pro-inflammatory pattern later on long-term renal transplantation. Taken together, our data suggest that IL-5 is a good biomarker associated with short-term stable renal function, whereas IL-12 seems to be a relevant pro-inflammatory element in long-term renal transplanted patients.
