Association between the Perioperative Antioxidative Ability of Platelets and Early Post-Transplant Function of Kidney Allografts: A Pilot Study

BACKGROUND: Recent studies have demonstrated that the actions of platelets may unfavorably influence post-transplant function of organ allografts. In this study, the association between post-transplant graft function and the perioperative activity of platelet antioxidants was examined among kidney recipients divided into early (EGF), slow (SGF), and delayed graft function (DGF) groups. METHODOLOGY/PRINCIPAL FINDINGS: Activities of superoxide dismutase, catalase, glutathione transferase (GST), glutathione peroxidase, and glucose-6-phosphate dehydrogenase (G6P) were determined and levels of glutathione, oxidized glutathione, and isoprostane were measured in blood samples collected immediately before and during the first and fifth minutes of renal allograft reperfusion. Our results demonstrated a significant increase in isoprostane levels in all groups. Interestingly, in DGF patients, significantly lower levels of perioperative activity of catalase (p<0.02) and GST (p<0.02) were observed. Moreover, in our study, the activity of platelet antioxidants was associated with intensity of perioperative oxidative stress. For discriminating SGF/DGF from EGF, sensitivity, specificity, and positive and negative predictive values of platelet antioxidants were 81-91%, 50-58%, 32-37%, and 90-90.5%, respectively. CONCLUSIONS: During renal transplantation, significant changes occur in the activity of platelet antioxidants. These changes seem to be associated with post-transplant graft function and can be potentially used to differentiate between EGF and SGF/DGF. To the best of our knowledge, this is the first study to reveal the potential protective role of platelets in the human transplantation setting

Renalase Gene Polymorphism in Patients After Renal Allograft Transplantation

Background/Aims: Renalase is a recently discovered protein, which is likely involved in regulation of blood pressure in humans and animals. Previous studies suggest that renalase reflects kidney functioning. A common missense polymorphism in the flavin-adenine dinucleotide-binding domain of human renalase (Glu37Asp) has been described. In this study we examined the association between (Glu37Asp) polymorphism (rs2296545) in renalase gene and kidney allograft function. Methods: The study enrolled 270 Caucasian kidney allograft recipients. SNP within the renalase was genotyped using TaqMan genotyping assays. Results: There were no statistically significant associations between renalase gene rs2296545 polymorphism and delayed graft function, acute rejection, chronic allograft dysfunction as well as creatinine serum concentrations and blood pressure values after transplantation. Conclusions: The results of this study suggest, that renalase gene rs2296545 polymorphism is not important factor determining renal allograft function

Urinary Metalloproteinases-9 and -2 and Their Inhibitors TIMP-1 and TIMP-2 are Markers of Early and Long-Term Graft Function After Renal Transplantation

Background/Aims: Renal ischemia-reperfusion (I-R) injury (IRI) is an inseparable feature of organ transplantation and may have a negative impact on the graft, its function and survival. Acute tubular necrosis, which is reversible thanks to the regenerative capacity of renal tubular epithelial cells, is the main cause of acute renal failure secondary to IRI. MMP-2 and MMP-9 are proteolytic enzymes involved in digesting proteins that are components of the extracellular matrix (ECM) and the basement membrane of the nephrons. This way post-reperfusion MMP activation allows the inflammatory process to spread. Methods: In our studies, we focused on identifying whether the concentrations of MMP-2 and MMP-9 and their natural inhibitors TIMP-1 and TIMP-2 in urine sample at day 1 and day 30 as well as after 12 months following renal transplantation are markers of early and long-term renal function during meanly five-years observation. Moreover, in urine sampled at months 6 and 12 after renal transplantation, we determined the content of TGF-β as a graft fibrosis indicator. Results: MMP-9 concentration in the early post-transplant period is a major marker of early and long-term function of the transplanted kidney. Its increased concentration was correlated with lesions related to tubular atrophy and fibrosis in renal biopsies performed at months 3 and 12 after transplantation. Its concentration is correlated with TGF-β content in a later period. Conclusions: TIMP-1 and-2 are primarily markers of an early function of the transplanted kidney. Early post-transplant concentration of MMP-2 is a marker of proteinuria in early and long-term post-transplant periods

IL17A and IL17F genes polymorphisms are associated with histopathological changes in transplanted kidney

Abstract Background Interleukin 17 is a proinflammatory cytokine involved in immune response after allograft transplantation. IL-17 family of proinflammatory cytokines includes IL-17A and IL-17F. Previous studies have demonstrated that the rs2275913 IL17A and the rs11465553 IL17F gene polymorphism are associated with kidney allograft function. Because of the association between these polymorphisms and post-transplant immune response, we assume that these single nucleotide polymorphisms may affect morphological structure of transplanted kidney. The aim of this study was to examine the association of rs2275913 IL17A and rs2397084, rs11465553 and rs763780 IL17F gene polymorphisms with histopathological changes in transplanted kidney biopsies such as: glomerulitis, tubulitis, arteritis, cell infilitration and fibrosis. Methods The study enrolled 82 patients after renal graft transplantation in whom a kidney biopsy was performed because of impaired graft function. The rs2397084 T > C (Glu126Gly), rs11465553 G > A (Val155Ile) and rs763780 T > C (His167Arg) polymorphisms within the IL17F gene and the rs2275913 A > G (− 197 A > G) polymorphism within the IL17A gene promoter were genotyped using TaqMan genotyping assays on a 7500 FAST Real-Time PCR System (Applied Biosystems, USA). Results There was a significant association between the rs2275913 IL17A gene polymorphism and the grade of tubulitis, which was more severe among patients with the A allele, compared to recipients with the GG genotype (GG vs. AG + AA, P = 0.02), and with the grade of arteriolar hyaline thickening and mesangial matrix increase, which were more severe among patients with the G allele compared to recipients with the AA genotype (AA vs. AG + GG, P = 0.01 and P = 0.04, respectively). Tubular atrophy and interstitial fibrosis were more severe among individuals with the C allele at the rs763780 IL17F gene polymorphism (TT vs. TC, P = 0.09 and P = 0.017, respectively). However, it should be taken into account that the statistical significance was achieved without correction for multiple testing, and no significant association would remain significant after such correction. Conclusions The results of this study may suggest a possible association between the rs2275913 IL17A and rs2275913 IL17A gene polymorphisms and some histopathological changes in transplanted kidney biopsies

Renalase in Haemodialysis Patients with Chronic Kidney Disease

Chronic kidney disease (CKD) is an inflammatory disease leading to kidney insufficiency and uremia. Renalase is a novel flavoprotein with enzymatic activities. Previous studies have shown that chronic kidney disease may influence renalase serum levels. Renalase metabolises catecholamines and therefore may be involved in the pathogenesis of hypertension and other diseases of the circulatory system. In this study, we examined renalase levels in serum, erythrocytes and urine from haemodialysis CKD patients. The study enrolled 77 haemodialysis CKD patients and 30 healthy subjects with normal kidney function as the control group. Renalase serum and urine concentrations in CKD patients were significantly increased when compared with control subjects (185.5 ± 64.3 vs. 19.6 ± 5.0 ng/mL; p p = 0.00040, respectively). In contrast, renalase levels in erythrocytes were significantly lower in CKD patients when compared with control subjects (176.5 ± 60.9 vs. 233.2 ± 83.1 ng/mL; p = 0.00096). Plasma levels of dopamine, adrenaline and noradrenaline were also significantly lower in CKD patients when compared with controls. Conclusions: Increased serum and urine concentrations of renalase in haemodialysis CKD patients are likely related to compensatory production in extrarenal organs as a result of changes in the cardiovascular system and hypertension. The decreased plasma concentrations of catecholamines may be due to their increased degradation by plasma renalase. Decreased renalase levels in erythrocytes may be probably due to lower renalase synthesis by the kidneys in CKD. The results indicate the presence of renalase in erythrocytes

Urine proteome of autosomal dominant polycystic kidney disease patients.

ABSTRACT: BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is responsible for 10% of cases of the end stage renal disease. Early diagnosis, especially of potential fast progressors would be of benefit for efficient planning of therapy. Urine excreted proteome has become a promising field of the search for marker patterns of renal diseases including ADPKD. Up to now however, only the low molecular weight fraction of ADPKD proteomic fingerprint was studied. The aim of our study was to characterize the higher molecular weight fraction of urinary proteome of ADPKD population in comparison to healthy controls as a part of a general effort aiming at exhaustive characterization of human urine proteome in health and disease, preceding establishment of clinically useful disease marker panel. RESULTS: We have analyzed the protein composition of urine retentate (>10 kDa cutoff) from 30 ADPKD patients and an appropriate healthy control group by means of a gel-free relative quantitation of a set of more than 1400 proteins. We have identified an ADPKD-characteristic footprint of 155 proteins significantly up- or downrepresented in the urine of ADPKD patients. We have found changes in proteins of complement system, apolipoproteins, serpins, several growth factors in addition to known collagens and extracellular matrix components. For a subset of these proteins we have confirmed the results using an alternative analytical technique. CONCLUSIONS: Obtained results provide basis for further characterization of pathomechanism underlying the observed differences and establishing the proteomic prognostic marker panel

hTERT, BICD1 and Chromosome 18 Polymorphisms Associated with Telomere Length Affect Kidney Allograft Function After Transplantation

Background/Aims: It has been confirmed that telomere length (TL) correlates with chronological donor age and that telomere shortening is accelerated in allografts. The aim of this study was to analyse the associations between graft rs2735940 hTERT and rs2630578 BICD1 gene polymorphisms and rs7235755/rs2162440 chromosome 18 polymorphisms, relative TL and kidney function after transplantation. Methods: The study enrolled 119 Polish Caucasian kidney allograft recipients (64M/55F, mean age 47.3±14.0 years). The relative TL was assessed in biopsy specimens. To identify genotypes of the studied polymorphisms, real-time PCR was performed. Results: The graft rs2735940 hTERT gene polymorphism TT genotype was associated with a significantly lower risk of delayed graft function (DGF) (TT vs. TC+CC; OR=0, p=0.009) and significantly shorter TL in the ‘0' biopsy (TT vs. CC: 207±153 vs. 400±161, p=0.036). The graft rs2630578 BICD1 gene polymorphism CC genotype was associated with lower creatinine concentrations in the first month (CC vs. GC: 1.11±0.06 vs. 2.0±1.25 mg/dL, p=0.03). The AA genotype of the graft rs7235755 chromosome 18 polymorphism was associated with longer relative TL in specimens collected 12 to 60 months after transplantation (AA vs. GG+GA p=0.04; AA vs. GG: 489±152 vs. 246±145, p=0.035) and the presence of A allele was associated with higher creatinine concentrations one month after transplantation (GA+AA vs. GG p=0.026; GA vs. GG: 2.18±1.59 vs. 1.76±0.88 mg/dL, p=0.02). It was found that shorter TL in the first six months was associated with higher creatinine concentrations 12 and 18 months after transplantation (Rs=-0.32; p=0.07 and Rs=-0.54; p=0.006, respectively). Conclusions: Graft rs2735940 hTERT and rs2630578 BICD1 gene polymorphisms and rs7235755/rs2162440 chromosome 18 polymorphisms, apart from the association with TL, affect early kidney function after transplantation. Relative TL correlated negatively with creatinine concentrations, allowing the use of TL as a predictor of long-term kidney function