Zeynep Biyik

Pregabalin versus gabapentin in the treatment of neuropathic pruritus in maintenance haemodialysis patients: a prospective, crossover study.

Aim:  Pruritus is common in dialysis patients. Peripheral neuropathy is also prevalent in this patient population. However, the role of neuropathy in the genesis of uraemic itch has not been adequately studied to date. Therefore, we aimed to investigate the effects of gabapentin and pregabalin on uraemic pruritus along with neuropathic pain in patients receiving haemodialysis.

Sleep Quality and Depression in Peritoneal Dialysis Patients

Background. Sleep quality (SQ) is a significant problem in peritoneal dialysis (PD) patients, yet the underlying factors are not well known. In addition, depression and impaired quality of life (QOL) are main problems in PD patients. We measured the SQ and investigated the effect of depression, QOL, and some other factors on SQ in PD patients. Methods. Data were collected from 124 PD patients (59 male, 65 female) in our center. Demographic data and laboratory values were analyzed. All patients were asked to complete the Pittsburgh Sleep Quality Index (PSQI), Beck Depression Index (BDI), and SF-36. Results. Mean age of the patients was 52.6 ± 14.3 year. The prevalence of poor SQ was 43.5%, defined as global PSQI score >5. The prevalence of depression was 25.8%, defined as BDI scores >17. The poor sleepers had higher BDI scores, poor QOL, older age, and lower duration of PD compared to the good sleepers. There was not a difference in hemoglobin, albumin, C-reactive protein, Kt/V, urea, creatinine, lipid parameters, gender, marital status, cigarette smoking, mode of PD, and comorbidity between poor and good sleepers. The global PSQI score was correlated negatively with both PCS and MCS (r = −0.414, r = −0.392, respectively; p < 0.001) and correlated positively with BDI scores and age (r = 0.422, p < 0.001 and r = 0.213, p = 0.018, respectively). In multivariate analysis, only BDI scores were found to be factors that could predict the patients being poor sleepers. Conclusion. Poor SQ is a significant problem in PD patients, and we found an association with depression, QOL, and age. Regular assessment and management of SQ may be important especially with PD patients who are depressive and elderly to increase QOL.

Epicardial Adipose Tissue and Coronary Artery Calcification in Diabetic and Nondiabetic End-Stage Renal Disease Patients

Background/aims: Atherosclerosis, coronary artery calcification, diabetes mellitus, inflammation, endothelial dysfunction, and left ventricular hypertrophy are the most commonly encountered risk factors in the pathogenesis of cardiovascular disease in end-stage renal disease (ESRD) patients. Epicardial adipose tissue (EAT) is the true visceral fat depot of the heart. The relationship between coronary artery disease (CAD) and EAT was shown in healthy subjects and patients with high risk of CAD. To date, there is not enough data about EAT in diabetic and nondiabetic ESRD patients. Therefore, we aimed to investigate the EAT and coronary artery calcification score (CACS) in diabetic and nondiabetic ESRD patients and healthy subjects. Methods: Sixty ESRD patients (17 diabetic, 43 nondiabetic ESRD patients) and 20 healthy subjects were enrolled in the study. EAT and CACS were performed by a 64-slice multidetector computed tomography scanner. Results: There were no differences in age, gender, body mass index, predialysis systolic and diastolic blood pressure levels, biochemical parameters including serum low-density lipoprotein and high-density lipoprotein cholesterol, triglycerides, and C-reactive protein between healthy subjects, diabetic, and nondiabetic ESRD patients. Total CACSs and EAT measurements were significantly higher in diabetic ESRD patients when compared with nondiabetic ESRD patients and healthy subjects. There was statistically significant relationship between EAT and CACS in ESRD patients (p < 0.0001, r = 0.48). Conclusion: In conclusion, we found a significant increase in terms of EAT and CACS in diabetic ESRD patients when compared with nondiabetic ESRD patients and healthy subjects.

Soluble TWEAK independently predicts atherosclerosis in renal transplant patients

BackgroundCardiovascular risk is increased in the early stages of chronic kidney disease (CKD) and also found to be ongoing in renal transplant (Rtx) patients. As a sign of atherosclerosis, increased carotid intima-media thickness (CIMT) has been widely accepted as a strong predictor of cardiovascular disease (CVD) and mortality in CKD patients. A novel markers, soluble tumor necrosis factor-like weak inducer of apoptosis (sTWEAK) and neutrophil-to-lymphocyte ratio (NLR) were introduced as potential markers in inflammatory disorders including CKD. The role of Rtx in terms of atherogenesis is still unclear. We aimed to investigate the relationship between sTWEAK, NLR and CIMT in Rtx patients without overt CVD and to compare these results with those obtained from healthy subjects.MethodsCross-sectional analysis in which CIMT measurements, NLR and serum TWEAK levels were assessed in 70 Rtx patients (29 females; mean age, 40.6 ± 12.4 years) and 25 healthy subjects (13 females, mean age; 37.4±8.8 years).ResultssTWEAK levels were significantly decreased (p=0.01) and hs-CRP, NLR and CIMT levels of Rtx patients were significantly increased compared to healthy subjects (p<0.0001, p=0.001, p<0.0001, respectively). sTWEAK was also found to be decreased when eGFR was decreased (p=0.04 between all groups). CIMT was positively correlated with sTWEAK and NLR in Rtx patients (r=0.81, p<0.0001 and r=0.33, p=0.006, respectively). sTWEAK was also positively correlated with NLR (r=0.37, p=0.002). In the multivariate analysis only sTWEAK was found to be an independent variable of increased CIMT.ConclusionsTWEAK might have a role in the pathogenesis of ongoing atherosclerosis in Rtx patients.

Serum uric acid may predict development of progressive acute kidney injury after open heart surgery

Abstract Objectives: Acute kidney injury (AKI) is a common complication of cardiac surgery developing in 25–35% cases. Recently, neutrophil gelatinase-associated lipocalin (NGAL) was shown to predict AKI development earlier than serum creatinine. Some studies demonstrated the predictive role of post-operative serum uric acid (SUA) as an early marker of AKI. We aimed to study the role of serum and urine NGAL as well as SUA to predict progression of AKI. Design and methods: This is a prospective observational study of patients undergoing cardiac surgery. Blood and urine samples for measurement of uric acid, serum and urine NGAL levels were collected prior to cardiac surgery (0 h), and in the time course at 2nd and 24th hours after surgery. Patients who developed AKI were divided into two subgroups as progressing and non-progressing AKI. Results: Sixty patients (42 males, 18 females) were included. After cardiac surgery, 40 patients developed AKI, 20 of whom non-progressing AKI, and 20 progressing AKI. All of the markers significantly increased in AKI patients. A receiver operator characteristics (ROC) curve analysis showed higher predictive ability of SUA for progressing AKI compared with serum and urine NGAL. When compared markers obtained at the second hour after surgery, UA had significantly large AUC than NGAL to predict AKI developed at 24 and 48 h, particularly in patients, who require renal replacement therapy (RRT). Conclusion: Uric acid seems to predict the progression of AKI and RRT requirement in patients underwent cardiac surgery better than NGAL.

Colchicine toxicity in end-stage renal disease patients: a case-control study.

Colchicine has been used in a number of disorders. Because colchicine is partially excreted from the kidney, there is a need for dose reduction in case of renal functional impairment. There are no data with regards to safe dosing schedule of colchicine in hemodialysis patients. We aimed to evaluate adverse effects of colchicine use in a hemodialysis cohort. We screened hemodialysis patients who were using colchicine for any reason. All patients were interviewed regarding possible toxicities of colchicine use and were examined with a special focus on neuromuscular system. Creatine kinase and myoglobin were used to detect any subclinical muscle injury or rhabdomyolysis, respectively. Twenty-two maintenance hemodialysis patients who were on colchicine for more than 6 months and 20 control hemodialysis patients not using colchicine were included in the study. Four of 22 patients were using 0.5 mg/day, 4 patients were using 1.5 mg/day, and 14 patients were using 1 mg/day colchicine. Mean duration for colchicine use was 8.9 ± 8.2 years. There was no difference between the groups in terms of myoneuropathic signs and symptoms and blood counts except for white blood cell count, which was significantly higher in patients on colchicine. Serum creatine kinase (56.3 ± 39.5 and 52.1 ± 36.1 for colchicine and control groups, respectively, P = 0.72) and myoglobin (191.4 ± 108.8 and 214.6 ± 83.5 for colchicine and control groups, respectively, P = 0.44) levels were not different between the groups. We conclude that in a small number of haemodialysis patients who were apparently tolerating colchicine, detailed assessment revealed no evidence of sublinical toxicity when compared with controls.

Colchicine treatment in autosomal dominant polycystic kidney disease: Many points in common

Autosomal dominant polycystic kidney disease (ADPKD) is the most common of the inherited renal cystic diseases and constitutes 10% of the end stage kidney disease population. ADPKD is caused by PKD1 and PKD2 gene mutations in 85% and 15% of the cases respectively. Its high prevalence and negative impact on health outcomes fostered efforts to explain pathophysiologic pathways of cyst formation in kidneys. Among these are increased apoptosis, unopposed proliferation of tubule cells, impaired polarization and planar cell polarity, impaired cAMP pathway, cilier dysfunction, activated mTOR pathway, increased tumor necrosis factor-alpha (TNF-alpha) production. Many drugs have been tried in an attempt to halt cystogenesis in some point. Despite success to some extent in experimental studies, none reached clinical armamentarium yet. Colchicine, originally extracted from Colchicum autunale, is an anti-inflammatory drug that has been in continuous use for more than 3000 years. It has been used successfully to prevent attacks of familial mediterranien fever and amyloidosis, to treat gout and pseudogout attacks for a few decades. Colchicine principally is a microtubule inhibitor, thus prevents cell migration, division, and polarization. It also has anti-apoptotic, anti-proliferative and anti-inflammatory effects and down-regulates (TNF-alpha) receptors. As can easily be seen, many of the effects of colchicine have pathophysiologic counterparts in ADPKD. Thus, we hypothesized that colchicine would be beneficial to prevent or at least delay cyst formation in ADPKD patients. Indirect evidence also support our hypothesis, in which taxol and paclitaxel, other two microtubule inhibitors, were shown to delay cyst formation in experimental models of ADPKD. To our opinion, despite its narrow therapeutic index, widespread experience makes colchicine a suitable candidate for prolonged clinical use, should experimental studies show any benefit in ADPKD.

Coenzyme Q10 supplementation and diastolic heart functions in hemodialysis patients: A randomized double-blind placebo-controlled trial

Coenzyme Q10 (CoQ10) supplementation has been shown to improve diastolic heart function in various patient cohorts. Systolic and diastolic dysfunctions are common in patients with end‐stage renal disease. Favorable effects of CoQ10 on cardiac functions are yet to be seen in hemodialysis patients. We aimed to evaluate effect of CoQ10 supplementation on diastolic function in a cohort of maintenance hemodialysis patients. This was a prospective, double‐blind, placebo‐controlled, crossover study in which all patients received placebo and oral CoQ10 200 mg/d during the 8 weeks in each phase, with a 4‐week washout period. Participants underwent conventional and tissue Doppler echocardiography before and after each study phase. Parameters characterizing left ventricle diastolic function and other standard echocardiographic measurements were recorded. Twenty‐eight patients were randomized, but 22 patients completed study protocol. Intraventricular septum (IVS) thickness and left ventricle mass were significantly decreased in CoQ10 group (P = 0.03 and P = 0.01, respectively). Myocardial peak systolic and early diastolic velocities derived from IVS were significantly increased (P = 0.048 and P = 0.04, respectively). Isovolumetric relaxation time and E/Em ratio calculated for IVS also significantly reduced in CoQ10 group (p = 0.02 and p = 0.04, respectively). There was no significant difference in any of the studied echocardiographic parameters in placebo group. The results of this study showed that CoQ10 supplementation did not significantly improved diastolic heart functions compared with placebo in maintenance hemodialysis patients.

Community-acquired carbapenem-resistant Acinetobacter baumannii urinary tract infection just after marriage in a renal transplant recipient

Y. Solak, H. Atalay, K. Turkmen, Z. Biyik, N. Genc, M. Yeksan. Community‐acquired carbapenem‐resistant Acinetobacter baumannii urinary tract infection just after marriage in a renal transplant recipient.
Transpl Infect Dis 2011: 13: 638–640. All rights reserved

Brucella Peritonitis in Peritoneal Dialysis: A Case Report and Review of the Literature

Brucellosis is a zoonotic infection that humans contract usually by ingestion of unpasteurized milk and milk products or by direct contact with raw infected animal products. Infection is endemic in many countries, including Turkey. Being a systemic disease, brucellosis may affect almost any part of the body. The peritoneum is a site rarely involved in brucellosis. Most peritonitis episodes involving Brucella species have been spontaneous cases reported in cirrhotic patients with ascites. To our knowledge, the literature contains only 5 cases of Brucella peritonitis related to continuous ambulatory peritoneal dialysis. Here, we report Brucella peritonitis in a continuous ambulatory peritoneal dialysis patient, and we discuss the relevant literature.