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 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

Soluble and Endogenous Secretory Receptors for Advanced Glycation End Products in Threatened Preterm Labor and Preterm Premature Rupture of Fetal Membranes

The aim of the study was to compare sRAGE and esRAGE plasma levels in pregnant women with (A) threatened premature labor (n=41), (B) preterm premature rupture of membranes (n=49), and (C) preterm rupture of membranes at term (n=48). The relationship between these and classic intrauterine infection markers and the latent time from symptoms up to delivery depending on RAGE’s concentration were investigated. In groups A and B, a positive correlation was found between plasma sRAGE and latent time (r = 0,422; p = 0,001; r = 0,413, p = 0,004, resp.). High prognostic values were found in both groups for plasma sRAGE concentration and the latent time from symptoms up to delivery. Groups B and C presented higher levels of esRAGE than group A (526,315 ± 129,453 pg/mL and 576,212 ± 136,237 pg/mL versus 485,918 ± 133,127 pg/mL, p< 0,05). The conclusion is that sRAGE concentration can be a favorable prognostic factor in the presence of symptoms of threatened premature labor. Higher esRAGE plasma level in case of the rupture of membranes in mature and premature pregnancy suggests its participation in fetal membranes destruction