Metabolic alterations serve a significant role in the pathogenesis of kidney disease. Long non-coding RNA (lncRNA) taurine upregulated gene 1 (TUG1) is a known regulator of podocyte health and mitochondrial biogenesis. Although TUG1 protects against podocyte loss in models of diabetic nephropathy, it is unknown if urinary TUG1 expression is associated with clinical and histopathological findings in non-diabetic patients diagnosed with glomerulonephritides. In the present study, the expression of TUG1, podocyte-specific markers (nephrin and podocin) and mitochondrial biogenesis-associated mRNAs (transcription factor A mitochondrial, cytochrome C oxidase subunit 5A and peroxisome proliferator-activated receptor γ coactivator 1α) were examined in urinary sediment of non-diabetic patients with biopsy-confirmed glomerulonephritides and healthy controls. Urinary expression of TUG1 was significantly lower in patients with glomerulonephritides, particularly those diagnosed with Focal Segmental Glomerulosclerosis (FSGS). Furthermore, TUG1 levels were associated with urinary expression of podocyte-specific markers and mRNAs associated with mitochondrial biogenesis. Loss of TUG1 expression in urinary sediment was strongly associated with FSGS, highlighting the potential of this lncRNA and its mitochondrial biogenesis-associated targets as non-invasive biomarkers of assessing podocytopathy.

Minimization in immunosuppression could contribute to the appearance the donor-specific HLA antibodies (DSA) and graft failure. The objective was to compare the incidence of DSA in renal transplantation (RT) in recipients with immunosuppression with and without steroids. A prospective cohort from March 1st, 2013 to March 1st, 2014 and follow-up (1 year), ended in March 2015, was performed in living donor renal transplant (LDRT) recipients with immunosuppression and early steroid withdrawal (ESW) and compared with a control cohort (CC) of patients with steroid-sustained immunosuppression. All patients were negative cross-matched and for DSA pre-transplant. The regression model was used to associate the development of DSA antibodies and acute rejection (AR) in subjects with immunosuppressive regimens with and without steroids. Seventy-seven patients were included (30 ESW and 47 CC). The positivity of DSA class I (13% vs 2%; P < 0.05) and class II (17% vs 4%, P = 0.06) antibodies were higher in ESW versus CC. The ESW tended to predict DSA class II (RR 5.7; CI (0.93–34.5, P = 0.06). T-cell mediated rejection presented in 80% of patients with DSA class I ( P = 0.07), and 86% with DSA II ( P = 0.03), and was associated with DSA class II, (RR 7.23; CI (1.2–44), P = 0.03). ESW could favor the positivity of DSA. A most strictly monitoring the DSA is necessary for the early stages of the transplant to clarify the relationship between T-cell mediated rejection and DSA.

Renal transplantation is currently the best alternative for patients with end-stage renal disease. Immune responses activated against the allograft are a decisive factor in transplantation outcomes and patient survival. Although short-term graft and patient survival have improved significantly as a result of better donor matching systems, novel immunosuppressive agents and enhanced care, long-term outcomes remain unfavorable and reflect sub-clinical injury caused by chronic rejection. The immune system lies at the intersection of immunogenic tolerance and graft failure; thus, it is a major determinant of pathology in the context of renal transplantation. During the early stages of transplantation increased expression of cytokines has been observed in addition to increased expression of adhesion proteins and immune cells. This early inflammatory response does not necessarily end in graft rejection, although this will depend on the severity of the inflammation. Activation of Toll-like Receptors (TLRs), damaging molecular patterns (DAMPs), and other components of innate immunity is key to the formation of atherosclerotic plaques and the development of autoimmune diseases. Initially the donor antigens are presented to the T lymphocytes of the recipient. This activation induces their proliferation, differentiation and cytokine production. Successful kidney transplant recipients need to develop immunologic tolerance against donor antigens. In this chapter, we address some of the innate and adaptive immune mechanisms associated with kidney transplantation; emphasizing their role in allograft rejection.

Background. The evidence supporting a starting dose of 2 g/day of mycophenolate mofetil (MMF) in combination with tacrolimus (TAC) in renal transplant (RT) is still limited but maintaining the dose of less than 2g could result in worse clinical outcomes in terms of acute rejection (AR). Research Question: This study aim was to determine the association between AR, infectious and non-infectious complications after RT with the dose of 1.5g vs. 2g of MMF. Design. A prospective cohort was performed with a 12-month follow-up in recipients of RT from living donors with low doses of MMF (1.5 g/day) or use of standard dosage (2 g/day). The association between adverse effects and complications and doses of MMF were examined in Cox proportional hazard models and survival free of AR, infectious diseases, and non-infectious complications was evaluated by the Kaplan-Meier test. Results. At the end of the follow-up, the incidence of infectious diseases was 52% vs. 50% (p=0.71) and AR was 5% vs. 5% (p=0.86), respectively. Survival free of GI complications requiring medical attention was higher in the low dose group compared to the standard dose (88% vs. 45%, respectively; p<0.001). Discussion. The use of 1.5 g/day of MMF is safe in Mexican population with RT from living donors without increasing the risk of AR, and it confers a reduction of adverse events.