Total hip arthroplasty in patients with renal failure: a comparison between transplant and dialysis patients

This study analyzed the outcome of total hip arthroplasty (THA) from a single institution of patients with renal failure, including renal dialysis patients (9 patients, 9 hips) and renal transplant patients (28 patients, 36 hips). There were 12 revisions and a 61% complication rate in the transplant group. In the dialysis group, 1 patient was revised, and there was a 33% complication rate. Transplant patients were younger, more active, and lived longer, but had higher cumulative rates of revision and complications with longer follow-up. Dialysis patients, in contrast, had a short survival but a lower rate of complications and revisions. These data differ from previous reports of acceptable outcomes with low complication rates of THA in transplant patients. Efforts to minimize complications in these patients are justified.     

Exercise capacity and physical fitness in pediatric dialysis and kidney transplant patients

Studies of exercise capacity in children with chronic kidney disease (CKD) are limited. We tested 25 pediatric kidney transplant (TX) recipients and 15 pediatric dialysis (DX) patients. Nine children in the DX group received kidney transplants and were retested 3 months following surgery (pre/post). Testing involved treadmill testing with measurement of peak oxygen uptake (VO_2peak), muscle strength, body composition (percent fat), and “field” tests of physical fitness using the FITNESSGRAM, which included the PACER test. Values obtained were compared with gender- and age-based criterion-referenced standards [healthy fitness zone (HFZ)]. The previous day physical activity recall (PDPAR) was used to assess physical activity participation. There were no differences between TX and DX subjects for VO_2peak and muscle strength measurements, and all values were below the normative values. The TX group achieved significantly higher PACER scores, but only one TX and no DX subjects achieved the HFZ for the PACER test. No improvement in any measures were observed from pre- to post-TX in the nine subjects tested, except for a significant increase in percent fat, which negatively affected the change in muscle strength and VO_2peak. All subjects were physically inactive, with less than 10% of nonschool time being physical activity participation. Pediatric patients with CKD had low exercise capacity, were physically inactive, and gained significant fat weight following TX. Counseling and encouragement for more physical activity is warranted as a part of routine medical care in these children. Funding source This study was supported by Satellite HealthCare Research Grants Program. This study was carried out in part in the General Clinical Research Center, Moffitt Hospital, University of California, San Francisco, with funds provided by the National Center for Research Resources, MO1 RR-0079, US Public Health Service.     

Slowing the progression of chronic kidney disease: comparison between predialysis and dialysis Jordanian patients

Currently, obesity has reached an epidemic stage and represents a challenge for health authorities across the globe. Certainly, with emergence of obesity epidemic, we started to see an increase in the prevalence of chronic kidney disease (CKD) and nephrolithiasis. Interestingly, epidemiologic studies have shown that the incident stone risk increases with body mass index (BMI), and no further increase in risk is noticed when the BMI > 30 kg/m². Furthermore, metabolic syndrome and diabetes are also associated with an increase in the incidence of renal stones disease. The shared links between these metabolic disorders are insulin resistance. Furthermore, insulin resistance is thought to alter renal acid–base metabolism, resulting in a lower urine pH and increased risk of uric acid stone disease. Obesity is also associated with excess nutritional intake of lithogenic substances such as refined sugars, low fluid intake, calcium, oxalate, and purine-rich foods. Obesity is also associated with an increase in incidence of urinary tract infection. Recent reports suggested that renal stone disease carries risk of myocardial infarction, progression of CKD, and diabetes. Alarmingly, orlistat (obesity medication) and bariatric surgery are associated with hyperoxaluria and associated stone formation and even oxalate nephropathy. Certainly, the many health risks of obesity, including nephrolithiasis, will add more burden on urologists and nephrologists. Shockwave lithotripsy, percutaneous nephrolithotomy, and ureteroscopy are all safe procedures in obese individuals. Further research is urgently needed to address the pathophysiology and management of obesity-induced renal stones disease.     

Hepatitis G virus infection in chronic dialysis patients and kidney transplant recipients

Background: The cloning of the hepatitis G virus (HGV), a novel RNA virus of the Flaviviridae family, has been very recently developed. HGV is known to be parenterally transmitted and has been detected in several patients with cryptogenic hepatitis. However, little information exists about the epidemiology of HGV infection in renal patients. We studied 178 chronic dialysis patients and 11 renal transplant individuals to evaluate prevalence risk factors and clinical manifestations of HGV infection in this population. Method: Hepatitis G virus infection has been detected by a modified PCR technology which incorporates digoxigenin-labelled nucleotides into the amplicon. Primers from the non-coding region and the NS-5 region of HGV are utilized for a single round amplification. Using a streptavidin surface and a biotin-labelled capture probe the labelled nucleic acid is bound through the capture probe to the surface, and the amplified nucleic acid is detected using antibody to digoxigenin. Results: HGV RNA was detected in 6% of chronic haemodialysis (HD) patients (11/172), 36% of renal transplant recipients (4/11), and 17% (1/6) of patients on peritoneal dialysis treatment (CAPD). There were no significant differences between HGV positive and negative patients on chronic HD treatment with regard to several demographic, biochemical and virological features. However, the frequency of anti-HCV antibody was significantly higher in HGV-positive than HGV-negative patients (9/11 (82%) vs 51/161 (32%), P=0.006). In the whole group of HGV RNA-positive patients, 78% (11/14) had a history of blood transfusion requirements, 14/16 (87%) had co-infection with HCV, and 1 (6%) had co-infection with HBsAg. There was no significant association between HCV genotypes and HGV RNA positivity. Six (27.5%) of 16 HGV RNA-positive patients showed raised aminotransferase values in serum. Conclusion: Patients on maintenance dialysis and kidney transplant recipients are at increased risk of HGV infection; HGV is very frequently associated to hepatitis C co-infection, regardless of HCV genotype. HGV may be transmitted by blood transfusions but transmission routes other than transfusion are possible; 37.5% of HGV RNA-positive patients showed raised serum amoinotransferase levels. Further investigations are necessary to clarify the role of HGV infection in the development of liver disease in this clinical setting.     

Correlation between circulating endothelial progenitor cell function and allograft rejection in heart transplant patients

Endothelial progenitor cells (EPCs) may contribute to rejection and cardiac allograft vasculopathy (CAV) by being intrinsically involved in the rejection process and causing neointimal hyperplasia. The mammalian target of rapamycin inhibitors (mTORi), sirolimus and everolimus, have been demonstrated to attenuate the progression of CAV and are cytotoxic to EPC. Thus, one mechanism by which mTORi may protect against CAV is by altering EPC function. Our study measured circulating EPC function and correlated this assessment with rejection episodes in heart transplant (HT) recipients. In addition, we examined the effect of mTORi on EPCs. Patients who received HT at our institution between 1995 and 2007 were included and stratified by International Society for Heart and Lung Transplantation (ISHLT) rejection grade. Group A (n = 13) consisted of patients with at least one moderate/severe rejection episode (grade ≥ 2). Group B (n = 28) patients had no moderate/severe episodes (grade < 2). Patients were also independently stratified based on exposure as mTORi (n = 21) vs. non mTORi (n = 20). To assess EPC functional capacity, we counted the number of colony‐forming units (CFU) of EPCs in peripheral blood samples from HT recipients. There were no significant differences in baseline characteristics between groups. The mean EPC‐CFU counts/plate for group A (rejecting) were 30 ± 6 vs.16 ± 3 for group B (nonrejecting) (P = 0.03). The EPC‐CFU counts/plate in the mTORi group (15 ± 3) were lower compared to the non mTORi (27 ± 5) group (P = 0.04). We found that EPC colony‐forming capacity was higher in HT patients who experienced moderate/severe rejection episodes. Patients on mTORi showed a reduced EPC colony count consistent with our previous findings of EPC cytotoxicity. Detection of circulating EPC function post‐transplant may reliably identify patient risk level for subsequent allograft rejection and allow for appropriate adjustments to immunosuppression. Converting to mTORi therapy may reduce EPC function and provide a novel mechanism to prevent rejection and possibly attenuate the development of CAV.     

Neuropsychological performance after kidney transplantation: a comparison between transplant types and in relation to dialysis and normative data.

BACKGROUND: Neuropsychological (NP) performance after kidney transplantation (TX) has received little attention. This study compared NP functioning between dialysis and transplant patients and between living-related donor (LRD) and cadaver (CAD) transplant recipients. The association between immunosuppressive medication and NP outcomes was also examined. METHODS: One hundred and seventeen transplant recipients (25 LRD and 92 CAD patients) and 145 dialysis patients (77 haemodialysis and 68 peritoneal dialysis) were administered an NP test battery to assess learning and verbal recall, attention and concentration, and psychomotor abilities/speed. Biochemical markers of renal function were also assessed. RESULTS: Overall, transplant patients showed normal cognitive functioning in all domains assessed. NP performance was found to be equivalent in both transplant groups and in patients on cyclosporin and those on tacrolimus. ANCOVAs showed that TX patients performed significantly better than dialysis patients on selective NP tests, i.e. the two memory tasks and two out of the four tests of attention. No differences were found in motor tasks. CONCLUSIONS: Our results reveal no evidence of NP deficits in TX patients. The NP advantage of TX relative to dialysis is evident mainly in verbal memory.     

Assessment of health-related quality of life in renal transplant recipients and dialysis patients

Health-related quality of life (HRQoL) is becoming an important outcome measure in evaluation of various forms of renal replacement therapy (RRT). The Short Form-36 (SF-36), Giessen Subjective Complaints List (GBB-24), and Zerssen's Mood Scale (Bf-S) are internationally validated questionnaires for the assessment of HRQoL. The goal of the current study was to evaluate the HRQoL of renal transplant recipients and compare it with that of patients on different forms of RRT. The study population consisted of: (1) 120 patients on hemodialysis (HD); (2) 43 patients on peritoneal dialysis (PD); (3) nine recipients who lost their grafts and went back to dialysis; (4) 120 age- and sex-matched healthy individuals (controls); and (5) 48 renal transplant recipients. The mean SF-36 scores were not significantly different between control group and transplant recipients as well as HD and PD patients including previously transplanted patients. The dialysis patients scored significantly worse in all eight SF-36 domains compared with transplant recipients and healthy subjects. In all GBB-24 components, the transplant recipients scored significantly higher than HD and PD patients. In the “fatigue tendency,” “limb pain,” and “cardiac complaints” components, recipients scored significantly higher than control group subjects. The mood analysis (Bf-S) showed that the scores of transplant recipients and controls did not differ, being significantly higher than those of dialysis patients. The HRQoL of patients on HD and PD were similar and lower than that of the general population. Renal transplantation significantly improved HRQoL at least to the level of healthy individuals. Graft loss was associated with significant worsening of HRQoL.     

Assessment of female sexual function and quality of life in predialysis,peritoneal dialysis,hemodialysis, and renal transplant patients

Introduction  Chronic renal failure (CRF) and renal replacement treatments have a negative effect on sexual function and quality of life (QoL). The literature on female sexual dysfunction (FSD) in patients with CRF is limited. The aim of this study is to compare the sexual function and QoL in predialysis (PreD), dialysis, and transplant patients. Materials and methods  A total of 106 women including 21 PreD, 45 dialysis, 20 renal transplantation (Tx), and 20 control patients were enrolled in the study. The Female Sexual Function Index (FSFI) and SF-36 scales were used to assess all patients, and demographic and clinical variables were documented. The FSFI and QoL scale scores were compared among the groups. Results  The rates of FSD were 50, 81, 66.7, 75, and 50% in the control, PreD, peritoneal dialysis (PD), hemodialysis (HD) and Tx patients respectively. Total FSFI scores for desire, arousal and orgasm scores in the PreD group were significantly lower than those in Tx and control patients (P < 0.05). Physical components of QoL in CRF patients were significantly worse than in the control group (P < 0.0001). On logistic regression analysis, age, glucose and creatinine were significantly associated with FSD. Conclusion  This preliminary study documented that Tx is the most effective way to retain good sexual function in women, and a diagnosis of FSD should be made routinely in CRF patients.     

Assessment of renal function in renal transplant patients using cystatin C. A comparison to other renal function markers and estimates

To date, little evidence is available to define the role of cystatin C in patients with renal transplants. Thus, to assess, whether cystatin C (CysC) provides better information on renal function than other markers, CysC, creatinine clearance (CrCl), serum creatinine (SCr), beta2-microglobulin (beta2-M), and 125I-Iothalamate clearance were determined in 30 patients. Correlation and ROC curves were obtained and characteristics like sensitivity and specificity were calculated. Further, to evaluate the usefulness of these markers for monitoring, intraindividual coefficients of variation for CysC and SCr measurements were compared in 85 renal transplant patients. CysC correlated best with GFR, whereas SCr, CrCl and beta2-M all had lower correlation coefficients. CysC was superior to SCr, even when renal function equations of were used. The diagnostic accuracy of CysC was significantly better than SCr. but did not differ significantly from CrCl and beta2-M. Together, our data show that in patients with renal transplants, CysC has a similar diagnostic value as CrCl. However, it is superior to determinations of SCr. The intraindividual variation of CysC is significantly greater than that of SCr. This might be due to better ability of CysC to reflect temporary changes especially in mildly impaired GFR, most critical for early detection of rejection and other function impairment. In conclusion, CysC allows for easy and accurate assessment of renal function (GFR) in steady state renal transplant patients and is clearly superior to the commonly used serum creatinine.     

Methods of assessment of the renal function in kidney transplant patients

Glomerular filtration rate (GFR), which evaluates the evolution of the renal function, can be directly assessed by the measure of urinary or plasmatic clearance of a specific marker that ideally should be freely filtrated, without haemodynamic or toxic effects and easily dosed. Unfortunately, such a sensible marker of renal function variations does not yet exist. Particularly for GFRs in the range of 60ml/min estimation formulas generally over or under-estimate the true GFR, especially the Cockcroft formula that estimates creatinine clearance. Therefore, it is recommended to use validated markers for the measurement of the true GFR (inulin, iohexol, Cr EDTA...), in particular for the follow-up of cohorts and for studies using GFR as an outcome measure. For daily clinical practice, it is possible to use estimation formulas, preferably the 4-variables MDRD equation. However, to optimize the accuracy of GFR measures estimated from these formulas, it is first necessary to control the homogenous calibration of creatinine measurement devices.