Biomarkers

Introduction Nowadays the gold standard test to detect kidney allograft inflammation is kidney biopsy. Because of subclinical inflammation has a very important roll on long term allograft survival some groups are performing follow-up biopsies to detect this inflammation early and to individualize the immunosuppressive treatment. Inflammation urinary biomarkers can become a new non invasive tool to detect this subclinical inflammation early. The aim of our work is to study the correlation between different subclinical lesions in follow-up biopsies and urinary biomarkers (miRNA-155, miRNA-210 and miRNA-142) Materials and Methods Prospective study where we have included kidney transplant (KT) patients from April 2014 until May 2015. We have determined in urine these biomarkers: miRNA-155, miRNA-210 and miRNA-142 one week after KT and one, two, three and six months after KT. We have performed follow-up biopsies at 4th month after KT and we have analysed the presence of tubulitis, interstitial infiltrate, arteritis and IFTA. Lastly we have correlationed these findings with urinary biomarkers levels. Results We have included 25 recipients from a first KT, all of them with low immunological risk. 60% man. Average age 45 years. 76% recipients from living donor. Average time on dyalisis: 10 months (50% preemptive kT). Induction immunosuppressive treatment: Basiliximab (two doses), tacrolimus, sodic micophenolate and prednisone. Average seric creatinine at 4 month after KT: 100umol/L. Anatomo-pathologic findings: 4% of biopsies with some degree of tubulitis, 63% with some degree of interstitial infiltrate, 9% with some degree of arteritis and 18% with some degree of IFTA. Correlation analysis: miRNA-155 levels are significantly higher in the patients with tubulitis. miRNA-142 levels are significantly higher in the patients with tubulitis, in the patients with arteritis and in the patients with interstitial infiltrate. miRNA-210 levels are significantly lower in the patients with tubulitis and in the patients with arteritis. There isn’t correlation between some biomarker and the presence of IFTA. Conclusion Urinary biomarkers can become in a future a new tool to detect subclinical inflammation early and could replace follow-up kidney biopsies. In this study, mi-RNA 142 would be the most associated with the presence of subclinical inflammation. On the other hand, tubulitis would be the lesion most detected for biomarkers. Are necessary more studies to confirm these results.