The Prevalence of Fabry Disease in Patients with Chronic Kidney Disease in Turkey: The TURKFAB Study

BACKGROUND/AIMS

Fabry disease is a treatable cause of chronic kidney disease (CKD) characterized by a genetic deficiency of α-galactosidase A. European Renal Best Practice (ERBP) recommends screening for Fabry disease in CKD patients. However, this is based on expert opinion and there are no reports of the prevalence of Fabry disease in stage 1-5 CKD. Hence, we investigated the prevalence of Fabry disease in CKD patients not receiving renal replacement therapy.

METHODS

This prospective study assessed α-galactosidase activity in dried blood spots in 313 stage 1-5 CKD patients, 167 males, between ages of 18-70 years whose etiology of CKD was unknown and were not receiving renal replacement therapy. The diagnosis was confirmed by GLA gene mutation analysis.

RESULTS

Three (all males) of 313 CKD patients (0.95%) were diagnosed of Fabry disease, for a prevalence in males of 1.80%. Family screening identified 8 aditional Fabry patients with CKD. Of a total of 11 Fabry patients, 7 were male and started enzyme replacement therapy and 4 were female. The most frequent manifestations in male patients were fatigue (100%), tinnitus, vertigo, acroparesthesia, hypohidrosis, cornea verticillata and angiokeratoma (all 85%), heat intolerance (71%), and abdominal pain (57%). The most frequent manifestations in female patients were fatigue and cornea verticillata (50%), and tinnitus, vertigo and angiokeratoma (25%). Three patients had severe episodic abdominal pain attacks and proteinuria, and were misdiagnosed as familial Mediterranean fever.

CONCLUSIONS

The prevalence of Fabry disease in selected CKD patients is in the range found among renal replacement therapy patients, but the disease is diagnosed at an earlier, treatable stage. These data support the ERBP recommendation to screen for Fabry disease in patients with CKD of unknown origin.

Toll-Like Receptors in the Progression of Autosomal Dominant Polycystic Kidney Disease

Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary cause of chronic kidney disease. The intriguing role of innate immune system and inflammation become a target for potential therapeutic approach to slow progression. When toll-like receptors (TLRs) signaling and their receptors activate, they start a cascade of intracellular signaling that induces the production of the inflammatory cytokines and chemokines. Thus, we aim to investigate the association of TLRs between progression of ADPKD. Ninety ADPKD patients and ninety matched controls were enrolled this prospective study and were followed during 3 years. TLR-2 and TLR-4 gene polymorphisms and expressions were measured. Hypertension was diagnosed with ambulatory blood pressure monitoring. Rapid progression was defined as sustained decline in estimated glomerular filtration rate (eGFR) of more than 5 mL/min per 1.73 m² per year. TLR-4Asp299Gly polymorphisms were significantly different between patient and control group (P < 0.05). Also, TLR-2 and TLR-4 gene expressions were significantly different between the ADPKD patients and the control subjects (P < 0.05). The expression levels of both TLR-2 and TLR-4 were found to be higher in the rapid progression groups comparing the slow progression group (P < 0.05). TLR-2 gene expression, hypertension and uric acid were found to be independent risk factors in identifying rapid progression in ADPKD patients. TLR-2 and TLR-4 gene expressions are associated with rapid progression in ADPKD patients. TLRs may play a role in the progression of ADPKD.

Vasopressin-related copeptin is a novel predictor of early endothelial dysfunction in patients with adult polycystic kidney disease

Background

In this study, we examined the relative usefulness of serum copeptin levels as a surrogate marker of vasopressin (AVP) in adult polycystic kidney disease (ADPKD) by correlating it with baseline and longitudinal changes in markers of both renal function and common CVD manifestations (hypertensive vascular disease, atherosclerosis and endothelial dysfunction) that accompany the progression of this disease.

Methods

We studied a cohort of young and otherwise healthy ADPKD patients (n = 235) and measured cardiovascular function using flow-mediation dilatation (FMD), carotid intima media thickness (cIMT) and pulse wave velocity (PWV), as well as serum copeptin (commercial ELISA, a stable marker of AVP activity). The same analyses were carried out at baseline and after 3 years of follow-up.

Results

At baseline, median eGFR was 69 mL/min./1.73 m², mean FMD 6.9 ± 0.9%, cIMT 0.7 ± 0.1 mm, and PWV 8.1 ± 1.2 m/s. At follow-up, equivalent values were 65 (44–75) mL/min./1.73 m², 5.8 ± 0.9%, 0.8 ± 0.1 mm. and 8.2 ± 1.3 m/s. with all changes statistically significant. Plasma copeptin also rose from 0.62 ± 0.12 to 0.94 ± 0.19 ng/mL and this change correlated with ΔeGFR (-0.33, p < 0.001), ΔFMD (0.599, p < 0.001), ΔcIMT (0.562, p < 0.001) and ΔPWV (0.27, p < 0.001) also after linear regression modeling to correct for confounders. Finally, ROC analysis was done for a high baseline copeptin with ΔeGFR [cut-off:≤59], ΔFMD [cut-off: ≤7.08], ΔcIMT [cut-off:>0.76], and ΔPWV [cut-off:≤7.80].

Conclusions

Vascular dysfunction as reflected by FMD and cIMT, but not PWV or an altered cardiac geometry, precede most other signs of disease in ADPKD but is predicted by elevated levels of the circulating AVP-marker copeptin.

The association of endothelial progenitor cell markers with arteriovenous fistula maturation in hemodialysis patients

AIMS

Arteriovenous fistula (AVF) failure is one of the most important clinical problems in end-stage renal disease. Endothelial progenitor cells (EPCs) have a role on vascular angiogenesis and endothelialization. We aimed to investigate the association markers of EPCs on AVF maturation by measuring the surface expressions of CD34, CD309 and CD133 on the monocytes.

METHODS

This prospective observational study was conducted in 54 voluntary patients with end-stage renal disease who were admitted for their first renal replacement therapy and were available for AVF creation. Venography was performed in all patients before AVF creation. Six patients were excluded due to inadequate veins after venographic imaging, and also seven patients were excluded due to postoperative thrombosis. The blood samples were analyzed a day before the fistula operation, and the expressions of CD34, CD133 and CD309 on the surface of monocytes were measured.

RESULTS

Patients were divided into two groups after the evaluation of AVF maturation, as the mature group and the failure group. The CD309 expression level on the monocytes was 338.00 (35.00-479.00) in the mature group; however, it was 36.00 (5.50-237.00) (p 0.031) in the failure group. Multiple logistic regression analyses showed that both BMI and the mean fluorescence intensity level of CD309 expression on monocytes independently predicted AVF maturation.

CONCLUSIONS

The presence of DM and increased BMI negatively correlated with AVF maturation. High intensity of CD309 expression on monocytes was observed in patients with successful AVF maturation.

The efficacy of theophylline in preventing cisplatin-related nephrotoxicity in patients with cancer

OBJECTIVE

Cisplatin is a potent antineoplastic agent used and its major limiting side effect is nephrotoxicity. The aims of the study are early detection of acute kidney injury (AKI) with biomarkers and investigation of the potential nephron-protective effects of theophylline.

METHODS

Glomerular filtration rates (GFR), neutrophil gelatinase-associated lipocalin (NGAL), cystatin C were measured at 5th day of treatment in all of the patients. In addition, these parameters were measured repeatedly after the administration of cisplatin, at 2nd hour, 5th and 20th days.

PATIENTS

Sixty patients who are planned to receive cisplatin for the first time were included in the study. Patients were divided into two groups as Group 1 (n = 30) (standard treatment arm) and Group II (n = 30) (theophylline arm).

RESULTS

In both groups after the administration of cisplatin, GFR showed a significant decrease within time (p = 0.006). Urine NGAL levels were significantly high after 2 h of cisplatin administration (p < 0.001), no significant difference was observed between groups. However, when the time*group effects were considered together, higher NGAL levels were detected in the group not receiving theophylline (p = 0.025). After 5 days of cisplatin administration, urine protein levels were significantly higher in both groups (p < 0.001).

CONCLUSION

Results showed that urine NGAL level is a superior biomarker compared to serum creatinine and serum cystatin C in the detection of early AKI. Theophylline was found not to bring a complete protection for the kidneys, but less nephrotoxicity was developed when compared to the group not receiving theophylline.

Atrial electromechanical delay and left atrial mechanical functions in hemodialysis and peritoneal dialysis patients

INTRODUCTION

Left atrium (LA) mechanical functions and atrial electromechanical delay (AEMD) times were considered independent predictors of cardiovascular morbidity in general population. Data are scant about these parameters in end-stage renal disease (ESRD) patients receiving hemodialysis (HD) and peritoneal dialysis (PD). We aimed to evaluate AEMD times and LA mechanical functions and associated risk factors in HD and PD patients.

METHODS

Forty-four healthy individuals, 62 HD and 50 PD patients were enrolled in the study. Echocardiography was performed before midweek dialysis session for HD patients and on admission for PD patients. Data were expressed as mean ± SD. Spearman's test was used to assess linear associations. Predictors of left intra-atrial EMD time and LA active emptying volume (LAaeV) were assessed by regression analysis.

RESULTS

Left intra-atrial-AEMD times were significantly longer in HD patients compared to PD patients. LAaeV was positively correlated with inter-atrial time, left intra-atrial time, systolic and diastolic BP, calcium and neutrophil-to-lymphocyte ratio (NLR) (r 0.22, p 0.016; r 0.28, p 0.002; r 0.34, p < 0.001; r 0.35, p < 0.001; r 0.37, p < 0.001; r 0.46, p < 0.001, respectively) and negatively correlated with serum uric acid (r -0.31, p 0.013) in ESRD patients. We found positive correlations between left intra-atrial time and LAaeV, LAVmax, LAVp and NLR (r 0.28, p 0.002; r 0.27, p 0.003; r 0.27, p 0.003; r 0.22, p 0.03, respectively) and negative correlations with albumin, uric acid and potassium (r -0.24, p 0.008; r -0.19, p 0.04; r -0.26, p 0.037, respectively). Advanced age, decreased serum albumin and increased NLR were found to be independent predictors of LAaeV; however, only NLR was found to be an independent predictor of AEMD time in this population.

CONCLUSIONS

Increased inflammation might be a risk factor of AEMD and LA mechanical dysfunction in ESRD patients.

The course of peritoneal membrane transport in patients on long-term peritoneal dialysis: what is it affected by?

BACKGROUND

The aim of this study was to investigate the course of peritoneal membrane transport in patients on long-term peritoneal dialysis (PD) and to identify possible factors affecting its course.

METHODS

This study included 101 patients on long-term PD. The median duration of PD was 106 (range, 80-189) months. All patients had least 2 peritoneal equilibration tests (PET). The patients were divided to 3 groups according to the change between the peritoneal transport types at the first PET and the last PET. In the first group, peritoneal transport type stayed stable. It tended to increase in second group whereas there was a trend toward to decrease in the third group.

RESULTS

Mean dialysate/plasma creatinine was significantly increased with time. It was 0.64±0.1 and 0.74±0.1 at the first and the last PET, respectively (P<0.001). Number of patients in low and low-average groups was significantly decreased whereas number of patients in high average and high groups was significantly increased with time (P<0.001). There was significant difference among 3 groups with regard to glucose exposure (P=0.018). It was significantly higher in second group compared to other two groups. There was no significant difference among 3 groups with regard to other demographic, clinical, and biochemical parameters (P>0.05).

CONCLUSION

Peritoneal membrane permeability was increased in patients on long-term PD with time and the increase in the permeability was affected by glucose exposure.

Risk factor(s) related to high membrane permeability in peritoneal dialysis

AIM

Peritoneal dialysis (PD) patients have different peritoneal membrane permeability (transport) characteristics. High peritoneal membrane permeability is associated with increased mortality risk in the patient population. In this study, we aimed to investigate possible risk factor(s) related to high peritoneal membrane permeability.

PATIENTS AND METHOD

The study included 475 PD patients (46.1 ± 14.5 years of mean age; 198 female and 277 male). The patients were divided two groups according to peritoneal equilibration test (PET) result: high-permeability group (high and high-average) and low- permeability group (low-average and low).

RESULTS

In both the univariate and multivariate logistic regression analyses, it was found that diabetes mellitus and hypoalbuminemia was significantly associated with high peritoneal membrane permeability [relative risk (RR): 1.90, 95% confidence interval (CI): 1.26-2.86, p: 0.002 and RR: 2.14, 95% CI: 1.44-3.18, p<0.001, respectively].

CONCLUSION

Diabetes mellitus and hypoalbuminemia were closely associated with high peritoneal membrane permeability. Diabetic patients had 1.9 times the likelihood of having high permeability. However, the relationship between hypoalbuminemia and high peritoneal permeability appears to be a result rather than cause.

Predictive Value of Atrial Electromechanical Delay on Long-Term Cardiovascular Outcomes in Hemodialysis Patients

BACKGROUND

Atrial electromechanical delay (AEMD) times were considered independent predictors of cardiovascular morbidity among the general population. We aimed at evaluating AEMD times and other risk factors associated with 2-year combined cardiovascular (CV) events in HD patients.

MATERIAL AND METHODS

Sixty hemodialysis (HD) and 44 healthy individuals were enrolled in this prospective study. Echocardiography was performed before the mid-week dialysis session for HD patients. Data were expressed as mean ± SD. Spearman test was used to assess linear associations. Survival was examined with the Kaplan-Meier method. Multivariate Cox regression analysis was used to determine the predictors of combined CV events in this cohort.

RESULTS

At the beginning of the study, left intra-atrial-AEMD times were significantly longer in HD patients compared to the left intra-atrial-AEMD times in healthy individuals. After 24 months, 41 patients were still on HD treatment and 19 (31.6%) had died. Serum triglyceride, total cholesterol and albumin were found to be higher and C-reactive protein (CRP) levels, left intra-atrial EMD time (LIAT) and interatrial EMD times were found to be lower in survived HD patients. With the cut-off median values of 3.5 g/dl for albumin, 0.87 mg/dl for CRP, 157 mg/dl for total cholesterol and 151 mg/dl for triglyceride, the Kaplan-Meier curves demonstrated significant differences in terms of all-cause mortality. We also demonstrated the Kaplan-Meier survival curves of HD patients according to tertile values of LIAT. Cox regression analysis revealed that increased CRP and higher LIAT were found to be independent predictors of combined CV events.

CONCLUSIONS

Increased LIAT and inflammation were found to be closely associated with 2 years combined CV events and all-cause mortality in HD patients.

Serum paraoxonase activity is associated with epicardial fat tissue in renal transplant recipients

AIMS

Cardiovascular disease is a major cause of mortality in renal transplant recipients. Paraoxonase-1 (PON-1) has been shown to protect against atherosclerosis by modifying lipoproteins. Epicardial fat tissue (EFT) has been proposed as a new cardiovascular risk factor. The aim of this study was to investigate the relationship between PON-1 activity and EFT in renal transplant recipients.

METHODS

Eighty renal transplant recipients were enrolled in this cross-sectional study. PON-1 activity was assessed from the rate of enzymatic hydrolysis of paraoxon to p-nitrophenol. EFT was measured by echocardiography.

RESULTS

The mean age of the patients was 40.4 ± 12.3 years and mean post transplant follow-up duration was 57.2 ± 46 months. Mean PON-1 activity was 68.5 ± 30 U/L. PON-1 activity was positively correlated with age and body mass index and negatively correlated with parathyroid hormone, dialysis duration and EFT. The mean EFT thickness was 0.64 ± 0.17 cm. Multiple linear regression analysis was used to define independent determinants of EFT in renal transplant recipients. According to linear regression analysis, PON-1 levels and age were found to be independent predictors of EFT.

CONCLUSION

Reduced PON-1 activity was negatively associated with EFT and PON-1 activity independently predicts EFT in renal transplant recipients.

Relationships Between Metabolic Syndrome, Microalbuminuria, and C-Reactive Protein in Turkish Kidney Transplant Recipients

AIM

The aims of this study were to report the prevalence of metabolic syndrome (MS) in a cohort of Turkish kidney transplant recipients and to define the relationships between MS, microalbuminuria and C-reactive protein (CRP), which are cardiovascular risk factors, in kidney transplant setting.

METHODS

This cross sectional study included 170 adult renal transplantation recipients with a mean follow-up of 53.1 ± 49.9 months. The diagnosis of MS was made according to the National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATP III) criteria. Microalbuminuria was defined as a urinary albumin/creatinine ratio of 30-300 mg/g. CRP levels ≥6.0 were classified as high CRP.

RESULTS

Mean age was 39.3 ± 11 years. The prevalence of MS was 45.8% (n = 78). The prevalence of microalbuminuria was not different in patients with MS compared to those without MS (39.7% vs 37%, P = .428). In multivariate logistic regression analyses, systolic blood pressure (SBP) (odds ratio 1.68; 95% confidence interval [CI] 1.12-2.52; P = .011) and high fasting glucose (odds ratio 2.82; 95% confidence interval [CI] 1.16-6.86; P = .022) were significantly associated with microalbuminuria. When patients with MS and high CRP were compared with patients with normal CRP and without MS, microalbuminuria did not differ between the groups (P = .213).

CONCLUSION

The prevalence of MS in our kidney recipient cohort was found to be increased compared to general population. MS was not related to increased prevalence of microalbuminuria, even when combined with high CRP. Microalbuminuria was associated with elevated SBP and hyperglycemic status.

Inflammation is associated to volume status in peritoneal dialysis patients

AIM

The aim of this study is to investigate whether there is a relationship between inflammation and volume status in patients underwent peritoneal dialysis (PD).

PATIENTS AND METHOD

This cross-sectional study included 159 PD patients. The median duration of PD was 17 (range, 1-151) months. All patients were examined using bioelectrical impedance analysis to estimate the ratio of extracellular water to total body water (ECW/TBW), which was used to assess their volume status. The patients were categorized as having one of the following three volume statuses: hypervolemic (above +2 SD from the mean, which was obtained from healthy controls), normovolemic (between +2 SD and -2 SD), or hypovolemic (below -2 SD from the mean). Five patients with hypovolemia were excluded from the study. Fifty-six patients were hypervolemic whereas 98 patients were euvolemic. High-sensitive C-reactive protein (hs-CRP) levels were measured to evaluate inflammation in all patients.

RESULTS

hs-CRP value levels were significantly higher in hypervolemic patients compared with euvolemic patients [7.1 (3.1-44.0) mg/L vs. 4.3 (3.1-39.6), p: 0.015, respectively]. Left ventricular hypertrophy was more frequent in hypervolemic patients compared with euvolemic patients (53.6% vs. 30.6%, p: 0.004, respectively). ECW/TBW ratio positively correlated with hs-CRP (r: 0.166, p: 0.039). Gender, hs-CRP, and residual Kt/V urea were found to be independent risk factors for hypervolemia in multivariate analysis.

CONCLUSION

Inflammation is associated with hypervolemia in PD patients. Residual renal functions play an important role to maintain euvolemia in PD patients.

Renal tubular acidosis in renal transplant patients: the effect of immunosuppressive drugs

BACKGROUND

Renal tubular acidosis (RTA) is a non-anion gap metabolic acidosis and is generally mild and asymptomatic in kidney recipients. Calcineurine inhibitors (CNIs) increase the frequency of RTA but the frequency of RTA development in kidney transplant recipients receiving mammalian target of rapamycin inhibitors (mTORi) treatment remains unclear. In this study, we aimed to investigate the frequency of RTA in kidney transplant recipients on mTORi and CNI treatment and to compare both groups.

MATERIAL AND METHODS

We enrolled 137 adult renal transplant patients - 82 patients on mTORi and 55 patients on CNI who had similar age, sex, posttransplant follow-up period, and graft functions. We recorded the parameters of venous blood gas analysis, including serum pH value, serum bicarbonate (HCO3) concentration, presence of metabolic acidosis defined as low HCO3 (<22 mEq/L), and serum pH value (<7.35), as well as base excess and urine pH at last follow-up. RTA was defined to be metabolic acidosis with normal serum anion gap and positive urine anion gap.

RESULTS

The mean age of our study population was 41.2±11.3 years. RTA frequency was 35% in the mTORi group and 41% in the CNI group. mTORi and CNI groups did not differ significantly in terms of the development of metabolic and renal tubular acidosis. Type I RTA was common in both groups. RTA was affected by duration of time since transplantation and graft functions in both groups.

CONCLUSIONS

The rates of RTA development in patients on long-term CNI and mTORi treatment were similar.

Effects of dialysis solution on the cardiovascular function in peritoneal dialysis patients

Objective Peritoneal dialysis (PD) patients have an increased cardiovascular burden. In this study, we aimed to compare certain PD solutions (Physioneal(®) and Dianeal(®)) in terms of the ambulatory blood pressure, echocardiographic parameters (ECHO), carotid atherosclerosis, endothelial function and serum asymmetric dimethylarginine (ADMA) level. Methods A total of 45 PD patients were enrolled in this prospective randomized controlled study: 23 patients in the Dianeal(®) group and 22 patients in the Physioneal(®) group. Ambulatory blood pressure measurements, echocardiography, carotid artery intima-media thickness measurements and flow mediated dilatation (FMD) and ADMA values were obtained at baseline and 12 months. Results The baseline parameters were similar between the groups with respect to the echocardiographic parameters, 24-hour ambulatory blood monitoring measurements and ADMA and FMD levels. All 24-hour blood pressure monitoring measurements, except for the average daytime systolic blood pressure, were significantly decreased in both groups at the first year. In the Physioneal(®) group, a significant decrease was observed with regard to the ADMA levels. Considering the FMD values, significant augmentation was seen at the end of the first year in both groups. Improvements in the FMD measurements were prominent in the Physioneal(®) group; however, this finding was not statistically significant. Conclusion The use of solutions with a neutral pH in PD patients results in decreased ADMA levels, which may be an important contributor to reductions in the incidence of cardiovascular events and deaths in this population.

Endothelial nitric oxide synthase gene expression is associated with hypertension in autosomal dominant polycystic kidney disease

BACKGROUND/AIMS

Early occurrence of hypertension is the prominent feature of autosomal dominant polycystic kidney disease (ADPKD). The role of angiotensin-converting enzyme (ACE) gene polymorphism and endothelial nitric oxide synthase (eNOS) gene polymorphism in the clinical course of ADPKD is not well understood. However, data about the expression of these genes are lacking. Thus, we aimed to investigate the polymorphisms and expressions of both the ACE and eNOS genes that affect hypertension in ADPKD.

METHODS

Whole blood samples were obtained from all participants. ACE and eNOS gene polymorphisms and their expressions were analyzed in 78 ADPKD patients and 30 controls. Gene expressions were assessed by quantitative real-time PCR. Twenty-four-hour blood pressure monitoring was performed for the diagnosis of hypertension in all study participants.

RESULTS

eNOS expression and the estimated glomerular filtration rate were found to be significantly higher in ADPKD patients without hypertension than in those with hypertension. Each unit of increase in eNOS expression led to a 0.88-fold decrease (95% CI: 0.80-0.96) in the risk of hypertension in multiple logistic regression analysis.

CONCLUSIONS

eNOS gene expression is independently predictive of hypertension in the ADPKD population. This study showed, for the first time, a novel link between eNOS gene expression and hypertension in ADPKD.

The serum YKL-40 level is associated with vascular injury and predicts proteinuria in nephrotic syndrome patients

AIM

Nephrotic syndrome (NS) is associated with an increased rate of cardiovascular events. The YKL-40 level is associated with atherosclerosis, endothelial dysfunction and proteinuria in renal and non-renal populations. The aim of this study was to investigate the relationships between the YKL-40 level and both vascular injury and proteinuria in NS patients.

METHODS

Sixty-nine NS patients and 20 healthy subjects were enrolled in the present study. The endothelial function was assessed according to the flow mediated dilatation (FMD) and the degree of arterial stiffness was determined based on the pulse wave velocity (PWV). The serum YKL-40 levels were measured using ELISA.

RESULTS

The YKL-40 levels and PWV values were higher and the FMD values were lower in the NS patients than in the healthy controls. However, the CA-IMT and LVEF levels were not statistically different between the two groups. The patients were divided into three groups with respect to the extent of proteinuria: the normoproteinuria group (n:18), non-nephrotic proteinuria group (n:33) and nephrotic proteinuria group (n:18). Consequently, the YKL-40 levels and PWV values were significantly increased and the FMD values were decreased in the nephrotic proteinuria group compared to that observed in both the non-nephrotic proteinuria and normoproteinuria groups. Furthermore, the YKL-40 level correlated with the FMD and PWV values in the NS patients. In addition, proteinuria correlated with the YKL-40, FMD, PWV, eGFR and fasting LDL cholesterol values in this patient group. Multivariate linear regression analyses showed that the YKL-40 and eGFR values were effective in predicting proteinuria in the NS patients.

CONCLUSIONS

The serum YKL-40 level is associated with endothelial dysfunction and increased arterial stiffness in NS patients and may be an indicator of the level of proteinuria in this patient population.

Preventing amikacin related ototoxicity with N-acetylcysteine in patients undergoing peritoneal dialysis

Amikacin is a frequently used antibiotic in the treatment of peritoneal dialysis (PD)-related peritonitis. Ototoxicity is a well-known complication of amikacin for which increased oxidative stress and free oxygen radicals are thought to be responsible. In this study, the effect of N-acetyl-cysteine (NAC) on cochlear function and oxidant situation in the amikacin related ototoxicity in PD-related peritonitis patients are investigated. Forty-six patients who had their first PD-related peritonitis attacks receiving empirical amikacin treatment were enrolled in the study. The patients were randomized into two groups; the first group (n = 23) as NAC receiving and the second group (n = 23) as a placebo receiving, control group. Otoacoustic emissions were measured before, 1 week after and 4 weeks after the treatment. Oxidative stress measurements were performed concurrently in order to evaluate the effectiveness of NAC. The results of screening with otoacoustic emission testing after amikacin treatment showed that cochlear function is protected especially in higher frequencies in NAC group when compared with the control group. Evaluation of the antioxidant status of the two groups showed no differences in the basal values, but at the first week there was an increase in the NAC group compared with the control group, and this increase became significant at the fourth week. NAC is found to be safe and effective in amikacin-related ototoxicity in patients with PD-related peritonitis. We suggest a close monitoring of the patients receiving amikacin containing treatment protocols and if amikacin is administrated supplementing the treatment with NAC.