Evaluation of Immunobiogram® as a Tool in Adjustment of Immunosuppressant Therapy for Renal Transplant

Inclusion Criteria: * Age \> 25 years and \< 70 years. * Male and Female. * Renal transplant performed at least 1 year before inclusion. ARM 1: * Bad clinical evolution: patients with renal dysfunction and positive biopsy to rejection OR significant increase in strength of DSA expressed as Luminex MFI. Specifically, the following two criteria must comply: * Renal function progressive deterioration, with significant creatinine increase of at least 15% for 18 months and/or proteinuria over \> 500 mg/day or ratio protein/creatinine\> 500 mg/g DE NOVO or increase in 50%. * Biopsy in the last 12 months that shows positive signs attributable to any kind of immunological response compatible with any type of rejection AND/OR at least 50% increase in strength of DSA expressed as Luminex MFI in comparison with previous determination and always at titers more than 3000UI. * Good clinical evolution: patients without rejection episodes, negative DSA, stable renal function and no changes in treatment in the past 12 months. ALL the following criteria must apply * Stable renal function in the past 12 months * NO DSA titers * No history of previous rejection episodes * Stable immunosuppressive medication (No change in prednisone or MPA dose and tacrolimus dose with changes \<20% of the dose) in the past 12 months ARM 2: * Stable renal function * No DSA titers * No history of previous rejection episodes * Stable immunosuppressive medication (No change in prednisone or MPA dose and tacrolimus dose with changes \<20% of the dose) at least in the past 18 months Exclusion Criteria: * Rejection of informed consent * Active systemic infections that needed antimicrobial treatment in the past two months * Active immune-based diseases with acute outbreaks in the past 12 months, despite immunosuppressive treatment * Severe ischemia-reperfusion injury of current renal transplant with delayed graft function objectively evident at more than 20 days after transplant AND/OR kidney transplanted from a deceased, very elderly donor (\>80 years) * Double transplant (renal + another organ) * HIV, HBV, HCV infection or other severe infectious diseases that prevent blood samples from being processed in a conventional laboratory * Chronic Allograft Injury (CAI) unlikely related to immune processes, by the Investigator´s judgement * Recurrent primary kidney disease