Mahmut Altindal

Daily Sodium Intake in Chronic Kidney Disease Patients during Nephrology Clinic Follow-Up: An Observational Study with 24-Hour Urine Sodium Measurement

Objective: To determine daily sodium intake in ‘real practice’ in a large group of chronic kidney disease (CKD) patients who were under regular follow-up in a nephrology clinic. Methods: A total of 373 consecutive outpatients with CKD stages 1–5 (not on dialysis; men: 52.3%, mean age: 51.6 ± 15.4 years) were included in the study. All patients had at least 3 or more nephrology visits and received information on reducing their sodium intake. Data for systolic and diastolic blood pressure, number of antihypertensive medications and 2 consecutive 24-hour urinary sodium levels were obtained from the patients’ medical records. Results: The mean 24-hour urinary sodium levels of 2 consecutive urine samples were 168.8 ± 70.3 and 169.3 ± 67.4 mEq/day (p > 0.05). Only 14.7% of the patients had a sodium excretion <100 mmol/day. There was no difference in daily sodium intake from stages 1 to 4, but it was significantly lower in stage 5 (126.6 ± 60.5 mEq/day, p < 0.05). No relation was found between 24-hour urinary sodium output, number of antihypertensives or thiazide use. Conclusions: This study showed that almost 85% of CKD patients under regular nephrologic care were consuming more sodium than the recommended level. More robust measures should be devised to increase patient and physician compliance with reducing sodium intake in CKD.

Elevated urinary angiotensinogen a marker of intrarenal renin angiotensin system in hypertensive renal transplant recipients: does it play a role in development of proteinuria in hypertensive renal transplant patients?

The aim of this study was to evaluate the relationship of local intrarenal renin angiotensin system (RAS) with hypertension and proteinuria in renal transplant recipients. Sixty‐nine nondiabetic renal transplant recipients (39 male, mean age: 36.3 ± 11.5 years) were included in this study. All patients were in stable condition with GFR greater than 30 ml/min/1.73 m2; (MDRD). Hypertension was defined to be present if there was a recorded diagnosis of hypertension, systolic blood pressure >130 mmHg and/or diastolic blood pressure >80 mmHg according to ambulatory blood pressure monitoring. None of the hypertensive patients were receiving RAS blockers. Spot urine samples were obtained to measure urinary angiotensinogen (AGT) using human AGT‐ELISA, urinary creatinine and protein levels. The demographic properties and laboratory findings were similar between hypertensive and normotensive transplant recipients. Urinary AGT–creatinine ratio (UAGT/UCre) was significantly higher in hypertensive patients compared with the normotensives (8.98 ± 6.89 μg/g vs. 5.48 ± 3.33 μg/g; P = 0.037). Importantly, a significantly positive correlation was found between UAGT/Ucre levels and proteinuria in hypertensive patients (P = 0.01, r = 0.405). Local intrarenal RAS probably plays an important role in the development of hypertension and proteinuria in renal transplant recipients.

The relation between urinary angiotensinogen and proteinuria in renal AA amyloidosis patients.

Objective: The aim of this study was to evaluate the relationship of local intrarenal renin angiotensin system (RAS) with proteinuria in patients with renal AA amyloidosis. Methods: Thirty-two patients with renal AA amyloidosis (19 male, mean age: 45 ± 13 years) and sixteen healthy controls (5 male, mean age: 32 ± 5 years) were included in this study. Spot urine samples were obtained to measure urinary angiotensinogen (AGT) using human AGT-ELISA, urinary creatinine and protein levels. Logarithmic transformations of urinary AGT-creatinine ratio log(UAGT/Ucre) and urinary protein-to-creatinine ratio (UPCR) were done to obtain the normal distributions of these parameters. Results: Log(UAGT/UCre) was significantly higher in patients compared with the controls (1.88 ± 0.92 µg/g vs. 1.25 ± 0.70 µg/g; p = 0.023). Importantly a significantly positive correlation was found between log(UAGT/Ucre) and logUPCR in patients (r = 0.595, p = 0.006). Conclusions: Urinary AGT levels are higher in renal AA amyloidosis patients than in controls. Also, there is a significant positive correlation between urinary AGT and proteinuria in renal AA amyloidosis.

AA type renal amyloidosis secondary to FMF: a long-term follow-up in two patients

Renal amyloidosis, which leads to renal failure, is the most important long-term complication of familial Mediterranean fever (FMF). Resolution of nephrotic syndrome secondary to amyloidosis in FMF following colchicine treatment has rarely been reported. We describe two patients with FMF and nephrotic syndrome. These patients were treated with colchicine 1.5 mg/day and had a complete remission of nephrotic syndrome with a stable clinical course over 30 years. To our knowledge, our patients have the longest follow-up time without proteinuria.

Relationship between Vitamin D Levels and Depressive Symptoms in Renal Transplant Recipients

Objective: Vitamin D deficiency might influence the development of depression; however, the association between vitamin D and depression in renal transplant recipients has not been evaluated. We aimed to test if there is a relation between 25-hydroxy (OH) vitamin D levels and depressive symptoms in patients with kidney transplantation. Methods: This was a cross-sectional and descriptive study. A total of 117 renal transplant recipients (44 female, 73 male; mean age, 39.0 ± 11.7 years) were included in the study. Patients were stratified to two groups according to the cut-off point (7) of depression subscale (D) of Hospital Anxiety Depression Scale (HADS), with or without depression risk. Blood biochemistry, glomerular filtration rate (GFR), and 25-OH vitamin D levels were determined. Results: Depression scores were higher than cut-off point in 33.3% (n = 39) of patients. The mean 25-OH vitamin D level was 19.6 ± 12.0 µg/L. In the group with depression risk, 25-OH vitamin D levels were significantly lower than the other group (15.2 ± 9.2 µg/L and 21.9 ± 12.7 µg/L, respectively; p = 0.004). No significant difference was observed between the two groups in terms of demographic parameters, blood biochemistry, and GFR. A negative correlation was detected between HADS-D score and vitamin D levels (r = −0.365, p < 0.0001). Conclusion: Lower serum 25-OH vitamin D levels are associated with higher depressive symptom levels among renal transplantation recipients. This finding should be the basis for further clinical studies and for future prospects on vitamin D supplementation for prevention and treatment of depression in these patients.

HFE gene mutation is a risk factor for tissue iron accumulation in hemodialysis patients

Introduction: HFE gene mutations are responsible from iron overload in general population. Studies in hemodialysis patients investigated the effect of presence of HFE gene mutations on serum ferritin and transferrin saturation (TSAT) with conflicting results. However effect of HFE mutations on iron overload in hemodialysis patients was not previously extensively studied.

Endothelial Dysfunction in Renal Transplant Recipients: Role of Vitamin D and Fibroblast Growth Factor-23

BACKGROUND Endothelial dysfunction can be detected at early stages of chronic kidney disease. Although endothelial functions improve after successful renal transplantation, renal transplant recipients have still worse endothelial functions compared to healthy subjects. Vitamin D deficiency and high fibroblast growth factor-23 (FGF-23) levels may have a role on endothelial dysfunction in chronic kidney disease patients. The aim of this study is to investigate the association between endothelial functions, vitamin D, and FGF-23 levels in renal transplant recipients. METHODS One hundred nine renal transplant recipients (71 male, 38 female) underwent brachial flow-mediated dilatation (FMD), serum 25-OH vitamin D, and FGF-23 level measurements. Vitamin D and FGF-23 levels were compared between patients with normal and abnormal endothelial functions. Correlations between FMD, vitamin D, and FGF-23 were also investigated. RESULTS Endothelial functions were abnormal in 72.5% of the patients. Prevalence of vitamin D deficiency was 80.7%. Vitamin D levels were significantly lower in patients with endothelial dysfunction compared to patients with normal endothelial functions (12.6 ± 6.6 μg/L vs 17.3 ± 10.0 μg/L respectively, P = .02). FGF-23 levels were not different between the two groups. 25-OH vitamin D levels had a significant positive correlation with amount of FMD (r = 0.218 and P = .02) and were an independent predictor of FMD after adjusting for potential confounding factors including age, transplantation duration, body mass index, mean blood pressure, glomerular filtration rate, proteinuria, hemoglobin, and FGF-23 in multivariate regression analysis (beta = 0.194, P = .04). FGF-23 levels were not predictive of FMD in this model (beta: -0.125, P = .197) CONCLUSION: Vitamin D deficiency is associated with endothelial dysfunction in renal transplant recipients. Further clinical and experimental studies are necessary to define a causal relationship between the parameters, discover the potential mechanisms, and observe the effect of vitamin D replacement on endothelial functions in renal transplant recipients.

Kidney transplantation for end-stage renal disease secondary to familial Mediterranean fever

Although kidney transplantation (KT) is widely used for treating renal amyloidosis secondary to familial Mediterranean fever (FMF), data concerning transplant outcome are limited and inconsistent. The aim of this study was to determine the long‐term outcome of KT in patients with amyloidosis secondary to FMF. Kidney transplantation outcome in 24 patients with FMF was compared to that in 72 controls matched for age, gender of recipient, and type of the donor that underwent KT due to end‐stage renal disease (ESRD) not caused by FMF. Mean follow‐up time was 80.3 ± 55.1 months in the FMF group, vs. 86.5 ± 47.6 months in the control group. Death‐censored graft survival at five and 10 yr in the FMF group was 95.8% and 78.4%, respectively, and was comparable to that in the control group. In the FMF group, five‐ and 10‐yr patient survival (87.5 and 65.6%) was shorter than in the control group, but the difference was not statistically significant. The findings show that long‐term outcome of KT in the patients with amyloidosis secondary to FMF was comparable to that in patients with ESRD not caused by FMF. Recurrence of amyloidosis in the allograft, gastrointestinal intolerance, and fatal infections remain as major complications during the post‐transplant period.

Safety of Percutaneous Ultrasound-Guided Kidney Biopsy in Patients with AA Amyloidosis

Background: Bleeding is the most frequent complication of kidney biopsy. Although bleeding risk in patients with AA amyloidosis after kidney biopsy has not been studied in a large population, AA amyloidosis has long been perceived as a risk factor for bleeding. The aim of the present study was to evaluate post-biopsy bleeding risk in patients with AA amyloidosis. Methods: We retrospectively analyzed bleeding complications in 88 patients with AA amyloidosis and 202 controls after percutaneous kidney biopsy. All the kidney biopsies were performed under the guidance of real-time ultrasound with the use of an automated core biopsy system after a standard pre-biopsy screening protocol. Bleeding events were classified as major when transfusion of blood products or surgical or radiological intervention was required, or if the bleeding caused hypovolemic shock or death. Bleeding events that did not meet these criteria were accepted as minor. Results: The incidence of post-biopsy bleeding was comparable between AA amyloidosis and control groups (5.7 vs. 5.0%, p = 0.796). Major bleeding events were observed in 3 patients from each group (p = 0.372). Selective renal angiography and embolization were applied to 2 patients from the AA amyloidosis group. One of these patients underwent colectomy and died because of infectious complications. Bleeding events were minor in 2.3% of the patients with AA amyloidosis and 3.5% of the controls (p = 0.728). Conclusions: AA amyloidosis was not associated with increased post-biopsy bleeding risk. Kidney biopsy is safe in AA amyloidosis when standard pre-biopsy screening is applied. Further data are needed to confirm these findings.

Congenital megacalycosis with IgA nephropathy: a case report and review of the literature.

Congenital megacalycosis is a rare renal disease characterized by calyceal dilatation without pelvic or ureteral obstruction. If not accompanied by nephrolithiasis and urinary tract infection, this disease is completely benign and does not cause renal dysfunction. We present a case of congenital megacalycosis that was diagnosed at the age of 41 (oldest case in the literature) after admitting with hematuria and acute renal dysfunction. IgA nephropathy was also diagnosed in this patient. Since renal dysfunction is not likely in these patients, if encountered; renal biopsy should be performed although technically difficult to diagnose the cause of this dysfunction.