Tevfik Ecder

Impaired IL-18 processing protects caspase-1–deficient mice from ischemic acute renal failure

We sought to determine whether mice deficient in the proinflammatory caspase-1, which cleaves precursors of IL-1 beta and IL-18, were protected against ischemic acute renal failure (ARF). Caspase-1(-/-) mice developed less ischemic ARF as judged by renal function and renal histology. These animals had significantly reduced blood urea nitrogen and serum creatinine levels and a lower morphological tubular necrosis score than did wild-type mice with ischemic ARF. Since caspase-1 activates IL-18, lack of mature IL-18 might protect these caspase-1(-/-) mice from ARF. In wild-type animals, we found that ARF causes kidney IL-18 levels to more than double and induces the conversion of the IL-18 precursor to the mature form. This conversion is not observed in caspase-1(-/-) ARF mice or sham-operated controls. We then injected wild-type mice with IL-18-neutralizing antiserum before the ischemic insult and found a similar degree of protection from ARF as seen in caspase-1(-/-) mice. In addition, we observed a fivefold increase in myeloperoxidase activity in control mice with ARF, but no such increase in caspase-1(-/-) or IL-18 antiserum-treated mice. Finally, we confirmed histologically that caspase-1(-/-) mice show decreased neutrophil infiltration, indicating that the deleterious role of IL-18 in ischemic ARF may be due to increased neutrophil infiltration.

Cardiac and Renal Effects of Standard Versus Rigorous Blood Pressure Control in Autosomal-Dominant Polycystic Kidney Disease: Results of a Seven-Year Prospective Randomized Study

This study sought to investigate the cardiac and renal effects of rigorous versus standard BP control on autosomal-dominant polycystic kidney disease (ADPKD). A prospective, randomized, 7-yr study was performed to examine the effect of rigorous (<120/80 mmHg) versus standard (135-140/85-90 mmHg) BP control on left ventricular mass index (LVMI) and kidney function in 75 hypertensive ADPKD patients with left ventricular hypertrophy. LVMI was measured by echocardiogram at baseline and at 1 and 7 yr. Renal function was assessed by measuring serum creatinine and 24-h creatinine clearance every 6 mo for 3 yr, then annually for an additional 4 yr. The baseline characteristics were comparable in the two groups. During the study, average mean arterial pressure was 90 +/- 5 mmHg for the rigorous group and 101 +/- 4 mmHg for the standard group (P < 0.0001). The LVMI decreased by 21% in the standard group and by 35% in the rigorous group. A mixed model longitudinal data analysis revealed that rigorous BP control was significantly more effective in decreasing LVMI (P < 0.01). There was no statistically significant difference in renal function between the two groups. In conclusion, left ventricular hypertrophy, a major cardiovascular risk factor, was decreased to a significantly greater extent by rigorous than standard BP control. This finding has particular clinical importance because cardiovascular complications are the most common cause of death in ADPKD patients.

Effect of antihypertensive therapy on renal function and urinary albumin excretion in hypertensive patients with autosomal dominant polycystic kidney disease

Hypertensive patients with autosomal dominant polycystic kidney disease (ADPKD) have a faster progression to end-stage renal disease (ESRD) than their normotensive counterparts. The aim of this prospective, randomized study is to compare the effects of the calcium channel blocker amlodipine and the angiotensin-converting enzyme inhibitor enalapril as first-line therapy on blood pressure, renal function, and urinary albumin excretion in hypertensive patients with ADPKD. Twenty-four patients with ADPKD with hypertension with creatinine clearances (Ccrs) greater than 50 mL/min/1.73 m(2) were included in the study. Twelve patients received amlodipine (mean dose, 9 mg/d), and 12 patients received enalapril (mean dose, 17 mg/d). The patients were followed up for 5 years. Baseline mean arterial pressures, which were 109 +/- 3 mm Hg in the amlodipine group and 108 +/- 3 mm Hg in the enalapril group, decreased significantly after 1 year of follow-up (amlodipine, 96 +/- 3 mm Hg; P < 0.005; enalapril, 89 +/- 2 mm Hg; P < 0.0005) and remained stable at year 5 (amlodipine, 97 +/- 3 mm Hg; P < 0.0005 versus baseline; enalapril, 94 +/- 3 mm Hg; P < 0.005 versus baseline). Ccrs, which were 83 +/- 5 mL/min/1.73 m(2) in the amlodipine group and 77 +/- 6 mL/min/1.73 m(2) in the enalapril group, remained stable after 1 year of follow-up and decreased significantly at year 3 in both groups (amlodipine, 67 +/- 5 mL/min/1.73 m(2); P < 0.01 versus year 1 and baseline; enalapril, 58 +/- 4 mL/min/1.73 m(2); P < 0.05 versus year 1 and P < 0.0005 versus baseline) with no significant change thereafter. No change was observed in urinary albumin-creatinine ratio in the amlodipine group (baseline, 68 +/- 21 mg/g; year 1, 52 +/- 21 mg/g; year 5, 148 +/- 74 mg/g), whereas it decreased significantly in the enalapril group at year 1 (baseline, 23 +/- 4 mg/g; year 1, 13 +/- 3 mg/g; P < 0.05) and remained stable until the end of the study at year 5 (14 +/- 6 mg/g). The investigators concluded that blood pressure was similar in both groups but only enalapril had a significant effect to sustain decreased urinary albumin excretion for a 5-year follow-up. Although proteinuria has been considered a surrogate of renal disease progression, further studies will be necessary to confirm this hypothesis in ADPKD, because after 5 years, no differences in renal function were observed between the enalapril and amlodipine groups. In comparison with patients with ADPKD with uncontrolled hypertension, effective control of blood pressure, as undertaken in the present study, should delay the onset of ESRD by approximately 15 years.

Diuretics versus Angiotensin-Converting Enzyme Inhibitors in Autosomal Dominant Polycystic Kidney Disease

Hypertension, which occurs commonly and early in autosomal dominant polycystic kidney disease (ADPKD), affects both renal and patient outcome. However, there is no consensus about the type of antihypertensive therapy that is most appropriate for patients with ADPKD. This historical prospective, nonrandomized study was designed to investigate the effect on renal function of diuretics versus angiotensin-converting enzyme (ACE) inhibitors in hypertensive patients with ADPKD who entered the study with comparable renal function. Among hypertensive ADPKD patients followed in our center, patients taking diuretics without any ACE inhibitors were included in the diuretic group (n = 14, male/female ratio 5/9, mean age 47 years), whereas patients taking ACE inhibitors but no diuretics were included in the ACE inhibitor (ACEI) group (n = 19, male/female ratio 11/8, mean age 41 years). For comparable blood pressure control, 21% of the ACEI group and 64% of the diuretic group (p < 0.05) needed additional antihypertensive medications. After an average follow-up period of 5.2 years, the creatinine clearance decreased significantly in the diuretic group (74 vs. 46 ml/min/1.73 m2, p < 0.0001) and in the ACEI group (83 vs. 71 ml/min/1.73 m2, p = 0.0005). The decrement in creatinine clearance was significantly larger in the diuretic group than the ACEI group (p < 0.05). The annual decrease in creatinine clearance was 5.3 ml/min/1.73 m2 in the diuretic group and 2.7 ml/min/1.73 m2 in the ACEI group (p < 0.05). A significant increase in urinary protein excretion occurred in the diuretic but not in the ACEI group. Hypertensive ADPKD patients treated with diuretics had a faster loss of renal function as compared with patients treated with ACE inhibitors, despite similar blood pressure control. This result will need to be further examined in a randomized study.

Hypertension and left ventricular hypertrophy in autosomal dominant polycystic kidney disease.

Hypertension is a common problem in patients with autosomal dominant polycystic kidney disease affecting both renal and patient survival. Activation of the renin–angiotensin–aldosterone system due to cyst expansion and local renal ischemia has been proposed to play an important role in the development of hypertension in autosomal dominant polycystic kidney disease. Left ventricular hypertrophy, a major cardiovascular risk factor, is also common in patients with autosomal dominant polycystic kidney disease. Both hypertension and the activation of the renin–angiotensin–aldosterone system play a role in the development of left ventricular hypertrophy in these patients. Prospective randomized results indicate that aggressive control of blood pressure is important for the optimal reversal of left ventricular hypertrophy, thereby diminishing a major risk factor for cardiovascular morbidity and mortality of patients with autosomal dominant polycystic kidney disease. There is also substantial epidemiological support for aggressive control of blood pressure in slowing renal disease progression in autosomal dominant polycystic kidney disease patients. Blockade of the renin–angiotensin–aldosterone system should be the initial approach in the treatment of hypertension in these patients.

No effect of angiotensin-converting enzyme gene polymorphism on disease progression and left ventricular hypertrophy in autosomal dominant polycystic kidney disease

Background: Autosomal dominant polycystic kidney disease (ADPKD) shows a variable clinical course suggesting that genetic modifiers might play a role. There are conflicting results about the effect of angiotensin-converting enzyme (ACE) gene polymorphism on the progression of renal failure in ADPKD. Also, the association between ACE gene polymorphism and the occurrence of left ventricular hypertrophy (LVH) has not been investigated in patients with ADPKD. Methods: ACE genotype analysis was performed in 409 Caucasian patients (137 male, 272 female) with ADPKD. Echocardiographic examination was done in 164 of these patients. Results: There were no significant differences between different ACE genotypes regarding renal function, renal volume, urinary protein excretion, blood pressure, the rate of hypertension, the age at diagnosis of hypertension, the rate of LVH and the incidence of end-stage renal disease (ESRD). Conclusion: ACE gene polymorphism does not have a significant effect on the development of ESRD and the prevalence of LVH in patients with ADPKD.

Nutrition and dietary intake and their association with mortality and hospitalisation in adults with chronic kidney disease treated with haemodialysis: protocol for DIET-HD, a prospective multinational cohort study

Introduction Adults with end-stage kidney disease (ESKD) treated with haemodialysis experience mortality of between 15% and 20% each year. Effective interventions that improve health outcomes for long-term dialysis patients remain unproven. Novel and testable determinants of health in dialysis are needed. Nutrition and dietary patterns are potential factors influencing health in other health settings that warrant exploration in multinational studies in men and women treated with dialysis. We report the protocol of the “DIETary intake, death and hospitalisation in adults with end-stage kidney disease treated with HaemoDialysis (DIET-HD) study,” a multinational prospective cohort study. DIET-HD will describe associations of nutrition and dietary patterns with major health outcomes for adults treated with dialysis in several countries. Methods and analysis DIET-HD will recruit approximately 10 000 adults who have ESKD treated by clinics administered by a single dialysis provider in Argentina, France, Germany, Hungary, Italy, Poland, Portugal, Romania, Spain, Sweden and Turkey. Recruitment will take place between March 2014 and June 2015. The study has currently recruited 8000 participants who have completed baseline data. Nutritional intake and dietary patterns will be measured using the Global Allergy and Asthma European Network (GA2LEN) food frequency questionnaire. The primary dietary exposures will be n-3 and n-6 polyunsaturated fatty acid consumption. The primary outcome will be cardiovascular mortality and secondary outcomes will be all-cause mortality, infection-related mortality and hospitalisation. Ethics and dissemination The study is approved by the relevant Ethics Committees in participating countries. All participants will provide written informed consent and be free to withdraw their data at any time. The findings of the study will be disseminated through peer-reviewed journals, conference presentations and to participants via regular newsletters. We expect that the DIET-HD study will inform large pragmatic trials of nutrition or dietary interventions in the setting of advanced kidney disease.

Cardiac Biomarkers and Noninvasive Predictors of Atherosclerosis in Chronic Peritoneal Dialysis Patients

Background: We investigated the relationship among serum cardiac biomarkers including N-terminal pro-brain natriuretic peptide (NT-pro-BNP), cardiac troponin T (cTnT), uric acid and high-sensitive C-reactive protein (hs-CRP) and noninvasive predictors of atherosclerosis including carotid intima-media thickness (IMT), aortic stiffness (pulse wave velocity (PWV)) and transthoracic coronary flow reserve (CFR) in peritoneal dialysis (PD) patients. Methods: 37 PD patients were included in the study. We measured (1) carotid IMT, (2) PWV and augmentation index (AIx), and (3) CFR. Simultaneous measurements of serum NT-pro-BNP, cTnT, uric acid and hs-CRP were also performed. Associations among these variables were analyzed. Results: cTnT was significantly associated with carotid IMT (r = 0.747, p < 0.001), PWV (r = 0.431, p = 0.035) and CFR (r = –0.439, p = 0.007). In multivariate analysis, cTnT was a significant independent predictor of carotid IMT (β = 4.446, p < 0.001) and CFR (β = –2.272, p = 0.013). Patients with high cTnT levels (≥0.01 ng/ml) significantly hadhigher carotid IMT and PWV values. Only the aortic PWV significantly correlated with residual renal function (r = –0.574, p = 0.004). Conclusions: Serum cTnT appeared to be a useful clinical biomarker for evaluating noninvasive predictors of atherosclerosis in chronic PD patients. Arterial stiffness as determined by PWV is also correlated with residual renal function.

Demographic and Clinical Characteristics of Patients with Autosomal Dominant Polycystic Kidney Disease: A Multicenter Experience

Aim: Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disease. It accounts for 5–10% of patients with end-stage renal disease (ESRD). The aim of this multicenter study was to investigate the demographic and clinical characteristics of patients with ADPKD. Methods: 1,139 patients with ADPKD who were followed up at 12 different centers were recruited for this study. The investigated demographic and clinical characteristics were gender, age, smoking history, educational status, the existence of hypertension, hematuria, urinary tract infection, urinary tract stones and renal replacement therapy. Patients were considered as hypertensive if they were taking antihypertensive medications or if they had blood pressure (BP) of 140/90 mm Hg or greater. If the patients were currently on antihypertensive drugs, the classes of these agents were noted. Results: 548 male and 591 female patients were included and the mean age at initial diagnosis was 37.1 ± 16.3 years. 20.3% were current smokers whereas 15% were ex-smokers. The mean systolic and diastolic BPs were 136.1 ± 29.8 and 84.9 ± 17.8 mm Hg, respectively. 63.7% used antihypertensive drugs and 73.1% of those used renin-angiotensin system blockers. 11.8% had ESRD, of which 75.8% were treated with hemodialysis. Conclusion: This study showed that hypertension is the most common (72.6%) clinical finding in ADPKD patients in Turkey and renin-angiotensin system blockers are widely used.

Depression and all-cause and cardiovascular mortality in patients on haemodialysis: a multinational cohort study.

Background: Depression and early death are both common in adults with Stage 5 chronic kidney disease. Studies have shown an association between depression and total mortality, but the association between depression and cardiovascular death is less certain. Methods: We conducted a prospective multinational cohort study involving adults who were treated with long‐term haemodialysis within a single dialysis network between April and November 2010. Depression was considered present when patients reported a Beck Depression Inventory (BDI) II score ≥14 at baseline. Sensitivity analyses considered a BDI II score ≥20 to identify moderate depression. Multivariable Cox proportional hazards regression was used to assess adjusted hazards for all‐cause and cardiovascular mortality at 12 months. Results: Three thousand and eighty‐six participants in the network received the BDI II questionnaire, and 2278 (73%) provided complete responses to the survey questions. Among these, 1047 (46%) reported depression. During a mean follow‐up of 11 (standard deviation: 2.5) months (2096 person‐years), we recorded 175 deaths, of which 66 were attributable to cardiovascular causes. Depression (BDI score ≥14) was not associated with all‐cause mortality [adjusted hazard ratio: 1.26 (95% confidence interval: 0.93‐1.71)] or cardiovascular mortality [0.82 (0.50‐1.34)]. When a higher BDI score (BDI score ≥20) was used to identify moderate depression, depression was associated with total mortality [1.40 (1.02‐1.93)] but not cardiovascular mortality [1.05 (0.63‐1.77)]. Conclusions: The association between depression and cardiovascular mortality in adults with kidney failure treated with haemodialysis is uncertain. Depression is a heterogeneous disorder and may only be a risk factor for premature death when at least of moderate severity.