Feridun Kavuncuoglu

Loss of Bone Mineral Density in Renal Transplantation Recipients

AIM This study investigated the prevalence and contributing factors of loss of bone mineral density after renal transplantation among Turkish patients. PATIENTS AND METHODS The study included 70 subjects, namely 50 males and 20 females of overall mean age of 36.94 ± 10.09 years. We measured femoral neck mineral density by dual-energy X-ray absorptiometry (DEXA). A T score above -1 was defined as a normal bone mineral density compared with T scores of -1.0 to -2.5 or below -2.5 which were defined as either osteopenia or osteoporosis, respectively. RESULTS At a median duration of 23 months after renal transplantation, osteopenia or osteoporosis was observed among 30 (42.9%) or 30 (42.9%) of the 70 patients, respectively. The mean body mass index (BMI) value was significantly higher among the normal than the osteoporotic group: 27.59 ± 4.66 kg/m(2) vs 24.18 ± 3.57 kg/m(2), respectively. However, no significant differences occurred in terms of BMI among the other groups. The amount of proteinuria was significantly lower in the normal than the osteopenic or osteoporotic group: (12.5 (range, 10.0-20.0); 105.0 (10.0-2800.0) or 215.5 (10.0-1880.0) mg/d (P = .001 and .004, respectively). In contrast, there was no significant difference between the amounts of proteinuria displayed by the osteopenic group and the osteoporotic group (P < .05)]. These patient groups showed no difference in age, gender, donor source, cause of end-stage renal disease (ESRD), pretransplant dialysis modality, duration of dialysis, use of a vitamin D preparation, immunosuppressive regimen, posttransplantation period, levels of iPTH or 25 hydroxy vitamin D3 (25OH vit D), exposure to tacrolimus or cyclosporine (CyA), calcium × phosphate product, serum albumin and hemoglobin content, creatinine clearance, or serum bicarbonate concentrations (P > .05). The T scores of the femoral neck correlated with BMI (r: 0.415; P = .001), 25OH vit D level (r: 0.268, P = .026), creatinine clearance (r: 0.273, P = .022), and serum glucose level (r: 0.349, P = .003). It inversely correlated with the amount of proteinuria (r: -0.263, P = .028), serum alkaline phosphatase level (r: -0.329, P = .005), and serum magnesium concentration (r: -0.252, P = .035). Upon multivariate analysis, BMI and 25OH vit D level were observed to be independent risk factors for loss of femoral mineral density. CONCLUSION Loss of bone mineral density is a common complication that correlates with low BMI values and decreased 25OH vit D levels as major risk factors for this problem.

The Lack of Benefit of a Combination of an Angiotensin Receptor Blocker and Calcium Channel Blocker on Contrast-Induced Nephropathy in Patients with Chronic Kidney Disease

Aim: Contrast-induced nephropathy (CIN) is a relatively common and serious complication, which occurs after the administration of contrast materials to patients. Although the pathophysiology of CIN is not exactly understood, ischemia of the medulla, oxidative stress, and direct toxicity of the contrast material are some of the factors that are implicated for the pathogenesis of CIN. To date, the only therapy that reduces the risk of CIN is volume expansion. There are conflicting results about the roles of angiotensin receptor blockers (ARB) and calcium channel blockers (CCB) in studies on CIN. For this reason the aim of this study was to compare the efficiency of the prophylactic use of amlodipine/valsartan plus hydration versus hydration only for the prevention of CIN in patients undergoing coronary angiography (CAG). Patients and methods: We prospectively enrolled 90 patients whose baseline serum creatinine levels were under 2.1 mg/dL and who were scheduled for CAG. Patients were divided into two groups. Group I (n = 45), consisted of patients who received amlodipine/valsartan plus hydration, group II (n = 45) consisted of patients who received only hydration. The patients in group I were given amlodipine/valsartan 5/160 mg once a day for a total of 3 days, starting one day before CAG and continuing on the day of and the day after the procedure. A 1 mL/kg/h sodium chloride infusion was administered for a total of 24 h, starting 12 h before the procedure and 12 h after, in all patients. The baseline serum creatinine (Scre) level was obtained before the procedure and repeated 48 h after. CIN was defined as an increase of ≥0.5 mg/dL or an increase of >25% in baseline Scre on the second day after CAG. Results: The baseline clinical characteristics of the treatment groups were similar. Baseline Scre was 1.13 ± 0.33 in group I and 1.07 ± 0.23 mg/dL in group II (p = 0.31). There was a significant difference between the Scre levels 48 h after CAG between the two groups (1.18 ± 0.33–1.05 ± 0.23) (p = 0.03). The reason for this was the increase of Scre in group I. CIN occurred in 17.8% (8/45) of patients in group I and in 6.7% (3/45) of patients in group II (p = 0.197). In the diabetic subgroup, CIN occurred in 10.5% (2/19) of patients taking amlodipine/valsartan and in none of the patients in group II (p = 0.486). The Mehran scores of the patients who developed CIN were significantly higher than those patients who did not develop CIN. Conclusion: Amlodipine/valsartan therapy plus hydration did not reduce the risk of CIN in chronic kidney disease (CKD) Stage 2 patients who underwent elective CAG using a low-osmolar nonionic contrast medium. This is because there was a decrease in the glomerular filtration rate (GFR) using the Levey Modification of Diet in Renal Disease (MDRD) formula in the amlodipine/valsartan group and CIN occurred at a higher frequency in this group; ARBs and CCBs may be withheld before CAG in high-risk patients.

Renal tubular acidosis in renal transplantation recipients.

Aim: We aimed to investigate the prevalence, type, and possible risk factors of renal tubular acidosis (RTA) in Turkish patients with renal transplantation. Patients and method: The study included 66 adult renal transplantation recipients. We recorded the parameters of venous blood gas analysis including serum pH value, serum bicarbonate (HCO3) concentration, presence of metabolic acidosis, which was defined as low HCO3 (<22 mEq/L), and serum pH value (<7.35) together, and base excess and urine pH at the last follow-up. Creatinine clearance was determined from 24-hour collected urine samples. RTA was defined to be metabolic acidosis with normal serum anion gap and positive urine anion gap. Results: Mean age of 66 patients was 37.0 ± 10.4 years; 48 of 66 patients were male. RTA was found in 14 (21.2%) patients. Considering for differential diagnosis of RTA, 4 patients had type 2 RTA and 10 had type 1 RTA. On the contrary, type 4 RTA was observed in no patients. Creatinine clearance was meaningfully lower in acidosis group than in those of the nonacidosis group (55.16 ± 23.27 vs. 71.06 ± 28.14 mL/min; p = 0.028). HCO3 was correlated with hemoglobin level (r = 0.423, p = 0.001) and creatinine clearance (r = 0.262, p = 0.034). It was inversely correlated with cyclosporine A (CsA) level (r = −0.499, p = 0.035). Conclusion: RTA is a common complication after kidney transplantation. It is related with low creatinine clearance, low hemoglobin level, and high CsA level. Particularly, the value of creatinine clearance is lower and the possibility of RTA is higher.

Tenckhoff catheter obstruction without peritonitis caused by Curvularia species

Peritonitis remains the most common complication of peritoneal dialysis (PD). Staphylococci are responsible for the majority of all PD-related peritonitis episodes (Piraino B et al., Perit Dial Int 2005; 25: 107–31). While fungal peritonitis is relatively uncommon, Candida albicans accounts for the majority of fungal peritonitis episodes (Wang AY et al., Am J Kidney Dis 2000; 36: 1183–92). Fungal peritonitis caused by Curvularia species is extremely rare and has been reported in only a few cases (Pimentel JD et al., J Clin Microbiol 2005; 43: 4288–92; Ujhelyi MR et al., Rev Infect Dis 1990; 12: 621–7). Herein we report a case with continuous ambulatory peritoneal dialysis (CAPD) catheter obstruction caused by Curvularia species in the absence of any signs or symptoms of peritonitis.

Inflammation is associated to volume status in peritoneal dialysis patients.

Abstract 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.

Post-Transplant Hypomagnesemia in Turkish Renal Transplant Recipients: The Frequency and Related Factors

Aim: Hypomagnesemia is a frequent complication in RTRs, particularly in the early post-transplant period. Hypomagnesemia is usually associated with the use of calcineurin inhibitors. The relationship between cyclosporine use and hypomagnesemia is well known. However, it has been reported in several studies that hypomagnesemia was seen more in RTRs treated with tacrolimus compared to those treated with cyclosporine. In this study, we aimed to investigate the frequency and risk factors of post-transplant hypomagnesemia and effects of calcineurin inhibitors on hypomagnesemia among Turkish patients. Patients and method: The study included 68 adult renal transplantation recipients. Hypomagnesemia was defined as serum magnesium level <1.4 mEq/L. Result: Hypomagnesemia were found in 26 (38.2%) of the 68 patients. Levels of serum calcium and glucose were significantly higher in hypomagnesemic group compared to normomagnesemic group (9.7 ± 0.5 mg/dL vs. 8.4 ± 0.5, p: 0.029 and 107.3 ± 19.1 mg/dL vs. 95.8 ± 16.1, p: 0.010, respectively). Post-transplant duration was meaningfully longer in normomagnesemic group (9.5 months vs. 46.5, p: 0.001). Serum magnesium level was meaningfully higher in patients with cyclosporine compared to patients treated with tacrolimus (1.44 ± 0.5 mEq/L vs. 1.52 ± 0.2, p: 0.002, respectively). Post-transplant duration was significantly longer in cyclosporine group (12 months vs. 98.5, p: 0.001). Frequency of hypomagnesemia was significantly higher tacrolimus group (58% vs. 10%, p: 0.001). Conclusion: The frequency of hypomagnesemia was high among Turkish renal transplant recipients, especially those treated with tacrolimus. Increased concentrations of serum calcium and glucose and the shorter post-transplant duration were risk factors for post-transplant hypomagnesemia.

Unusual Clinic Presentation of Polyarteritis Nodosa: Involvement of Axillary and Brachial Artery

Polyarteritis nodosa (PAN) is a necrotizing inflammatory vasculitis of small- and medium-sized muscular arteries. Multiple organs, especially the kidney, skin, peripheric nerves, striated muscles, and intestine, are affected. In this case report, a patient with renal and hepatic involvement and axillary and brachial artery aneurysm resulting in shoulder hematoma and pain due to underlying PAN is presented.