Development of Ureteral Stenosis/Obstruction in Kidney Transplant.

This retrospective study describes the incidence and prevalence of ureteral stenosis/obstruction (US/O) in a cohort of 334 renal transplants recipients in our center over the last 5 years and evaluates the risk factors that may influence the occurrence of US/O. The parameters studied included the following: history of prostate disease, smoking, urinary tract infection, renal lithiasis, ureterovesical reflux, presence and level of polar artery, type of ureterovesical anastomosis, delayed graft function, double J catheter, lymphocele, urinoma, acute rejection, prolonged catheterization, post-transplant infravesical obstruction and BK virus infection, age of the donor and recipient, and months on dialysis. Also evaluated were the nadir creatinine and instances of cold ischemia, asystole, reanastomosis, and double J catheter removal. The average incidence of US/O was 7.6% and was significantly correlated with factors of alteration of the uretero-bladder dynamics without finding a relation to vascular factors.

Renal Transplant Immunosuppression in Patients With Hemolytic Uremic Syndrome: Four Case Reports.

A high rate of recurrence has been described in atypical hemolytic uremic syndrome renal transplant recipients, favored by certain immunosuppressant drugs that can induce complement activation. We present four case series in which three patients were diagnosed pretransplantation and a fourth who had onset in the very early post-transplantation period. The patients received different immunosuppression schedules, and all had improvement after more than 2-years. We suggest the need to stratify the risk of atypical hemolytic uremic syndrome recurrence using genetic studies and the available drugs as the main factors that allow graft survival improvement today.

Evolution of left ventricular mass in renal transplant recipients: the influence of glucose homeostasis and oxidative stress.

BACKGROUND: Left ventricular hypertrophy, considered an independent factor for cardiovascular mortality, is frequent among renal transplant recipients (RTR), in whom we investigated changes in left ventricular mass (LVM) after grafting and associations with possible causal factors, especially glucose metabolism and oxidative stress. METHODS: We performed a prospective study of 37 RTR without prior diabetes mellitus who were evaluated at three times after transplantation (medians of 0.6, 16 and 28 months) by means of the LVM index (LVMI, echocardiographic measure of LVM related to body surface area, g/m(2)), oral glucose tolerance test and determinations of malondialdehyde and total glutathione (GSH), as well as glomerular filtration rate (GFR) estimate by the Modification of Diet in Renal Disease formula. We calculated the overall increment (DeltaLVMI) and percent change of LVMI. Patients were diagnosed to be prediabetic (PD) or new-onset diabetes after transplant (NODAT) according to ADA criteria. RESULTS: The mean LVMI decreased significantly over time among whole group baseline = 108.34 ± 27.71 g/m(2) versus middle: 100.03 ± 27.53 g/m(2) versus final: 90.62 ± 24.06 g/m(2) (P = .000). However, 13.5% of subjects showed an increased LVMI and 59.5%, a decrease less than 20%. Patients with NODAT at the end of the study showed a positive DeltaLVMI, which was negative in nondiabetics (0.24 ± 16.14 versus -19.86 ± 12.61 g/m(2), P = .018). Compared with DeltaLVMI(-) recipients, patients with DeltaLVMI(+) showed a greater proportion of PD and NODAT at baseline (60% and 40% versus 18.8% and 12.5%, P = .017), and significantly higher all-time fasting glycemia, lower estimated GFR, and greater increments of malondialdehyde and GSH over time. Those with a <20% LVMI decrease experienced progressive GFR impairment over time, as opposed to those with an LVMI decrease > 20%, who showed greater and improving GFR over the whole study. CONCLUSIONS: LVMI does not always improve in RTR; the evolution of ventricular mass after renal transplantation is influenced by glucose metabolism disorders, oxidative stress, and graft function.

Treatment with N-acetylcysteine in stable renal transplantation.

The primary cause of morbidity and mortality in renal transplantation is cardiovascular disease. Increased oxidative stress implies a greater degree of atherogenesis in these patients. N-acetylcysteine (NAC) which has a thiol group that is the source of l-cysteine and reduced glutathione, acts against atherosclerosis via a decrease in apoptosis, vasoconstriction, and endothelial dysfunction. Experimental models have examined the antioxidant effects of NAC during and after ischemia-reperfusion, but few studies have shown an effect in renal transplantation in human beings. In 8 months, we studied the effect of NAC treatment on oxidative stress, lipids, and renal function in 25 patients with stable renal function and no diabetes after transplantation. Data were collected on oxidative parameters: malondialdehyde, glutathione peroxidase, catalase, superoxide dismutase, glutathione reductase, lipid profile, and renal function (creatinine concentration, Cockroft-Gault formula, and Modified Diet in Renal Disease study). There were no significant differences in oxidative profile before and after treatment with NAC. The mean serum high-density lipoprotein cholesterol fraction increased after treatment and showed a significant positive correlation with glutathione peroxidase (r = 0.495). Serum creatinine concentration decreased, and Cockroft-Gault and Modified Diet in Renal Disease study estimates of renal function increased in the treatment period. In conclusion, NAC treatment in patients with stable renal function after transplantation increased high-density lipoprotein cholesterol and antioxidant molecules in relation to glutathione peroxidase, with a positive influence on renal function.