The Relationship Between Serum Level of 25-hydroxy Vitamin D and Cytomegalovirus Infection in Kidney Transplant Recipients.

INTRODUCTION: Kidney transplant recipients are at risk of opportunisticinfections; previous studies demonstrated the association betweenlow level of vitamin D and the risk of viral infections. This studywas designed to evaluate the relationship between serum 25-hydroxyvitamin D level and active Cytomegalovirus infection / disease inkidney transplant recipients. METHODS: A total number of 83 kidney transplant recipients enrolledin this case-control study from June 2013 to January 2014. 38patients had active CMV infection / disease and 45 patients hadno evidence of active CMV infection. Serum level of 25-hydroxyvitamin D was measured in these two groups and classified asdifferent levels of sufficient (more than 30ng/mL), insufficient (15-30ng/mL), and deficient (less than 15 ng/mL). Data were analyzedin SPSS 21 statistical software by using statistical tests of Pearsoncorrelation coefficient, chi-square and t-test. RESULTS: Mean serum 25-hydroxy vitamin D level was 14.42 ng/mL in case group and 17.52 ng/mL in control group. There wasno significant difference between the groups in terms of patients'characteristics (P > .05). No significant statistical difference wasfound between mean 25-hydroxy vitamin D level in case and controlgroups (P > .05) but Vitamin D deficiency (serum 25-hydroxy vitaminD less than 15 ng/mL) was noticed in 63.1% of CMV infected groupversus 42.2% of control group. Thus vitamin D deficiency was seenmore prevalent in the CMV infected group (P > .05). CONCLUSION: Although we did not find a statistically significantrelationship between vitamin D levels and the CMV infection, CMVinfected patients had lower vitamin D level compared with noninfectedrecipients, hence vitamin D deficiency can be consideredas a risk factor for CMV reactivation after renal transplantation.

The relationship between total mass and blood supply of parathyroid glands and their secretion of parathyroid hormone in hemodialysis patients with secondary hyperparathyroidism.

Characteristics of parathyroid glands usually determined by ultrasonography such as its total weight or volume might be a good indicator for the induction or suppression of parathyroid hormone (PTH) secretion from these glands. In the present study, we investigated the relationship between the volume and blood supply grade of the parathyroid glands, and its PTH secretion. Study subjects included 52 consecutive patients with the secondary hyperparathyroidism undergoing maintenance hemodialysis therapy referred to dialysis wards of the Imam Khomeini and Amiralam University Hospitals in Tehran. Serum intact PTH (i-PTH) was measured by an ELISA assay. The parathyroid glands characteristics were identified by ultrasonography that was performed simultaneously with blood collection. Parathyroid blood flows were evaluated by power-Doppler color imaging. There was no significant correlation between the total mass of the glands and serum concentration of i-PTH. No significant correlations were also observed between both total central and peripheral parathyroid glands blood flow and serum i-PTH level. Dialysis duration and serum alkaline phosphatase were significantly correlated in a positive manner with i-PTH level. Furthermore, serum level of i-PTH was not correlated with the total signals of glands blood flow in a multivariable linear regression analysis. Serum secreted i-PTH level might not be predictable by a total mass of parathyroid glands as well as their blood supply.

Association of low vitamin D levels with metabolic syndrome in hemodialysis patients.

Low vitamin D levels have been linked to metabolic syndrome in the general population. In the present study, the relationship between inadequate serum concentrations of vitamin D and metabolic syndrome in patients with end-stage renal disease undergoing hemodialysis was explored. In a cross-sectional setting, 145 patients undergoing maintenance hemodialysis were enrolled. Metabolic syndrome was defined using the International Diabetes Federation criteria. Serum concentration of 25(OH) vitamin D was determined by a commercially available enzyme immunosorbent assay method. The prevalence of metabolic syndrome was 53.1%. The prevalence rate of severe vitamin D deficiency (<5 ng/mL) was 3.4%, mild vitamin D deficiency (5-15 ng/mL) 31.0%, vitamin D insufficiency (16-30 ng/mL) 36.6%, and vitamin D sufficiency (>30 ng/mL) 29.0%. With the increasing number of metabolic abnormalities, vitamin D levels significantly decreased (P for trend = 0.028). Among the components of metabolic syndrome, vitamin D deficiency was significantly associated with central obesity (odds ratio [OR], 95% confident interval [CI] = 2.80, 1.11-7.04, P = 0.028). A positive, but nonsignificant association between vitamin D deficiency and raised fasting plasma glucose was noted (OR, 95% CI = 2.40, 0.94-6.11, P = 0.067). Both vitamin D deficiency and insufficiency were significantly associated with an increased likelihood of having metabolic syndrome (P < 0.05). In a final model controlling for age, sex, and parathyroid hormone levels, vitamin D deficiency increased the odds of having metabolic syndrome by more than threefold (OR, 95% CI = 3.26, 1.30-8.20, P = 0.012). Low levels of vitamin D are frequent among hemodialysis patients and are associated with the metabolic syndrome.

Occult hepatitis C virus infection in Iranian hemodialysis patients.

BACKGROUND: Occult hepatitis C virus (HCV) infection is defined as the presence of HCV-RNA in liver or peripheral blood mononuclear cells (PBMCs) in the absence of detectable hepatitis C antibody (anti-HCV) or HCV-RNA in the serum. Low concentrations of HCV-RNA may be detected in PBMCs of hemodialysis (HD) patients and this could have a great impact on the management of HD patients. OBJECTIVES: The aim of this study was to detect the occult HCV infection in Iranian HD patients. PATIENTS AND METHODS: A total of 70 anti-HCV negative HD patients from three dialysis units in Tehran, Iran were included in this study. In these cases, presence of HCV-RNA in plasma samples was tested by reverse transcriptase-nested polymerase chain reaction (RT-nested PCR). In cases with negative anti-HCV and plasma HCV-RNA, genomic HCV-RNA was checked in PBMC specimens by RT-nested PCR. RESULTS: Seventy anti-HCV negative HD patients were enrolled in the study. 32.85% and 1.43% of cases had elevated levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) respectively. 7.14% of patients had elevated levels of both ALT and AST. HCV-RNA was negative in plasma samples of all anti-HCV negative HD subjects. The genomic HCV-RNA was not detected in any PBMC samples of HD cases with negative anti-HCV and plasma HCV-RNA. CONCLUSIONS: Occult HCV infection was not detected in our HD patients despite of elevated levels of liver enzymes in some participants. Further studies involving larger number of HD patients are required to elucidate the rate of occult HCV infection in HD cases.

Renal Sympathetic Denervation by CT-scan-Guided Periarterial Ethanol Injection in Sheep.

BACKGROUND: Renal nerves are a recent target in the treatment of hypertension. Renal sympathetic denervation (RSD) is currently performed using catheter-based radiofrequency ablation (RFA) and because this method has limitations, percutaneous magnetic resonance (MR)-guided periarterial ethanol injection is a suggested alternative. However, few studies have been conducted on the effectiveness of percutaneous ethanol injection for RSD. AIM: To evaluate the feasibility, efficacy, and complications of computed tomography (CT)-guided periarterial ethanol injection. METHODS: Ethanol (10 ml, 99.6%) was injected around the right renal artery in six sheep under CT guidance with the left kidney serving as a control. Before and after the intervention, the sheep underwent MR imaging studies and the serum creatinine level was measured. One month after the intervention, the sheep were euthanized and norepinephrine (NE) concentration in the renal parenchyma was measured to evaluate the efficacy of the procedure. The treated tissues were also examined histopathologically to evaluate vascular, parenchymal, and neural injury. RESULTS: The right kidney parenchymal NE concentration decreased significantly compared with the left kidney after intervention (average reduction: 40%, P = 0.0016). Histologic examination revealed apparent denervation with no other vascular or parenchymal injuries observed in the histological and imaging studies. CONCLUSION: Effective and feasible RSD was achieved using CT-guided periarterial ethanol injection. This technique may be a potential alternative to catheter-based RFA in the treatment of hypertension.

Isolated anti-hbc and occult HBV infection in dialysis patients.

BACKGROUND: Occult Hepatitis B virus (HBV) infection (OBI) is defined as the presence of HBV-DNA in the liver or serum with undetectable hepatitis B surface antigen (HBsAg). Hemodialysis (HD) patients are at risk of acquiring parenterally transmitted infections. OBJECTIVES: The aim of this study was to assess the prevalence of OBI in HD patients. PATIENTS AND METHODS: A hundred HBsAg negative HD patients were included in this study from main dialysis units in Tehran, Iran. HBsAg, hepatitis B surface antibody (anti-HBs), hepatitis B core antibody (anti-HBc) and liver enzymes levels were examined in all subjects. The presence of HBV-DNA was determined in plasma samples using real-time PCR. RESULTS: A hundredpatients with a mean age of 58.5 ± 16.1 years were enrolled in this study. In total, 56.7% were male and 43.3% female. Anti-HBs, anti-HBc, anti-HCV and anti-HIV were detected in 56.7%, 2%, 5.2% and 1% of patients, respectively. Isolated anti-HBc was detected in 2% of cases. HBV-DNA was detected in 1% of HBsAg negative patients. CONCLUSIONS: This study showed a low rate of isolated anti-HBc and occult HBV infection in HD patients. It can be due to improvement of people's knowledge about HBV transmission routes, HBV vaccination of HD patients and regular surveillance of HBV infection.

Utility of cystatin C-derived equations for evaluation of residual renal function in peritoneal dialysis patients.

BACKGROUND: Residual renal function (RRF) plays a key role in the follow-up of the patients undergoing chronic ambulatory peritoneal dialysis (CAPD). Available methods for measurement of RRF are cumbersome and rarely used, and alternatively, cystatin C-derived equations have been proposed. METHODS: Seventy-six adult CAPD patients were recruited. RRF was measured using the 24-hour urea-creatinine clearance method. Serum concentrations of cystatin C were determined. Glomerular filtration rate (GFR) was estimated using the two published equations of Hoek and colleagues, and Yang and colleagues. GFR was also estimated from serum creatinine using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula. RESULTS: Patients (age range 18-86 years) were on CAPD for a median of 24 months. Average serum concentrations of cystatin C was 5 ± 1.2 mg/L. Average RRF was 0.7 ± 1.6 mL/min/1.73 m(2). All three methods significantly overestimated the measured RRF values (Hoek: 4 ± 1.4; Yang: 4.5 ± 1.5; 7.4 ± 4 mL/min/1.73 m(2)). Based on Bland-Altman plots, all three methods yielded poor agreement with RRF (p < 0.001 for all tests), with Hoek's equation providing the narrowest limits of agreement [mean difference (limits of agreement): 3.4 (2.9-3.9)] and CKD-EPI the widest [6.7 (5.9-7.5)]. Although the Hoek's method outperformed CKD-EPI, the within 30 and 50% accuracy rates were unsatisfactory (10.5 and19.7 %, respectively). CONCLUSIONS: Cystatin C-derived equations outperform the CKD-EPI formula in approximating the RRF values. Yet, these methods still significantly overestimate the measured RRF and their routine application in clinical practice is not advised.

Contribution of stone size to chronic kidney disease in kidney stone formers.

OBJECTIVES: To determine whether stone burden correlates with the degree of chronic kidney disease in kidney stone formers. METHODS: A total of 97 extracorporeal shockwave lithotripsy candidates aged 18 years and older were included. Size, number and location of the kidney stones, along with cumulative stone size, defined as the sum of diameters of all stones) were determined. Estimated glomerular filtration rate was determined using the Chronic Kidney Disease Epidemiology Collaboration cystatin C/creatinine equation, and chronic kidney disease was defined as estimated glomerular filtration rate <60 mL/min/1.73 m(2). RESULTS: In individuals with cumulative stone size <20 mm, estimated glomerular filtration rate significantly decreased when moving from the first (estimated glomerular filtration rate 75.5 ± 17.8 mL/min/1.73 m(2)) to the fourth (estimated glomerular filtration rate 56.4 ± 20.44 mL/min/1.73 m(2) ) quartile (P = 0.004). When patients with a cumulative stone size ≥ 20 mm were included, the observed association was rendered non-significant. In individuals with a cumulative stone size < 20 mm, each 1-mm increase in cumulative stone size was associated with a 20% increased risk of having chronic kidney disease. The relationship persisted even after adjustment for age, sex, body mass index, C-reactive protein, fasting plasma glucose, thyroid stimulating hormone, presence of microalbuminuria, history of renal calculi, history of extracorporeal shockwave lithotripsy, number and location of the stones (odds ratio 1.24, 95% confidence interval 1.02-1.52). The same was not observed for individuals with a cumulative stone size ≥ 20 mm. CONCLUSIONS: In kidney stone formers with a cumulative stone size up to 20 mm, estimated glomerular filtration rate linearly declines with increasing cumulative stone size. Additionally, cumulative stone size is an independent predictor of chronic kidney disease in this group of patients.

Cardiac troponins in patients with chronic kidney disease and kidney transplant recipients without acute cardiac symptoms.

INTRODUCTION: Cardiovascular diseases are the most common causes of death in chronic kidney disease (CKD) and kidney transplant patients. This study aimed to evaluate cardiac troponins in transplant recipients and CKD patients without cardiac symptoms. MATERIALS AND METHODS: Two groups of patients (CKD and kidney transplant recipients) were evaluated for troponins T and I levels. These values were associated with renal replacement therapy and demographic and clinical characteristics of the patients. RESULTS: Eighty CKD patients and 80 kidney transplant recipients were studied. There was a significant difference in Troponins T and I levels were significantly higher in the CKD group than in the transplant recipients. In the CKD group, 14 patients (17.5%) had an elevated troponin T level and 8 (10.0%) had an elevated troponin I, all of whom were in stage 4 of CKD. None of the kidney transplant patients had a positive troponin. Among CKD patients, decreased glomerular filtration rate was associated with elevated troponin I level. Elevated troponin T level was significantly associated with age and decreased glomerular filtration rate. In multivariable analysis, significant associations were found between troponin T level and age, serum creatinine, and glomerular filtration rate. A significant relationship was also found between troponin I and cholesterol and glomerular filtration rate. CONCLUSIONS: The assessment of troponin T and I in CKD and kidney transplant patients shows that in patients with CKD and without any symptoms of acute coronary syndrome, serum level of cardiac troponins increase and it is linked to serum creatinine and GFR.

Chronic kidney disease progression in elderly Iranian patients: a cohort study.

BACKGROUND: In the past few decades, Chronic Kidney Disease (CKD) - a disease with progressive decline in renal function - has become an important problem of global public health, not only in developed countries, but also in developing countries with less economic power. OBJECTIVES: In this study, CKD progression to death or End Stage Renal Disease (ESRD) in elderly Iranian patients was compared with younger counterparts. PATIENTS AND METHODS: This retrospective cohort study was conducted on CKD patients with estimated Glomerular Filtration Rate (eGFR) < 60 mL/min, in a nephrology clinic in Tehran from December of 2006 until December of 2012. eGFR trend, death and need to renal replacement therapy (RRT) were evaluated as outcomes and compared between patients younger and older than 60 years. Data were analyzed using SPSS version 13. RESULTS: Five-hundred and two patients were enrolled and followed up for an average of 37.6 months. Two thirds of the patients were older than 60 years. The incidence density of ESRD in patients younger and older than 60 years were 6.3 and 3.6 for 100 persons per year, respectively. Younger ones showed more rapid decline in their eGFR, while older patients had more stable renal function. CONCLUSIONS: It seems necessary to conduct more researches in order to redefine CKD and identify its prognostic markers in elderly population.

Frequency and Genotype of Hepatitis D Virus Infection in Patients Infected with HIV and Those Undergoing Hemodialysis.

BACKGROUND: Hepatitis D virus (HDV) is a defective virus dependent on hepatitis B virus (HBV) for its replication. Due to HDV transmission routes, patients undergoing hemodialysis and those with HIV infection are at risk of acquiring HDV. OBJECTIVES: This study was aimed to determine the frequency and genotype of HDV infection among patients with HIV infection and those undergoing hemodialysis. PATIENTS AND METHODS: 720 cases including 120 patients undergoing hemodialysis, and 600 patients with HIV infection were studied. All cases with positive results for HBsAg were evaluated for the presence of anti-HDV antibodies. Samples with Anti-HDV positive results were subjected to nested PCR for HDV-RNA confirmation, and sequenced for HDV genotype determination. RESULTS: HBsAg was found in 9 (7.5%) of 120 patients undergoing hemodialysis, and 9 (1.5%) of 600 patients with HIV infection. 3 (33.3%) of patients undergoing hemodialysis with positive results for HBsAg, and 5 (55.5%) of cases with HIV infection and positive results for HBsAg, had positive findings for anti-HDV which were then subjected to nested PCR. The amplification results confirmed that in 3 (37.5%) samples HDV-RNA was detected. Overall 2.5% of patients undergoing hemodialysis, and 0.8% of cases infected with HIV had positive results for anti-HDV and 1.7% and 0.2% of cases undergoing hemodialysis and patients infected with HIV had positive findings for HDV-RNA respectively. All of the HDV isolates were clustered in clade 1. CONCLUSIONS: The survey showed that overall HDV frequency was not high in our high risk cases. Therefore, practitioners and health care managers should become aware of the risk of dual infection with HBV and HDV especially in high risk patients.

Comparison of efficacy of the phosphate binders nicotinic acid and sevelamer hydrochloride in hemodialysis patients.

Hyperphosphatemia is a significant risk factor for the development of ectopic calcification and coronary artery diseases in patients on hemodialysis (HD), and must be controlled with the use of phosphate binders. Studies comparing the effects of sevelamer and nicotinic acid, both similar non-calcium and non-aluminum phosphate binders, are not available. In this study, 40 patients on HD with a serum phosphorus level of more than 6 mg/dL were enrolled. After a two week washout period without phosphate binders, the patients were randomly divided into two equal groups (n = 20) and were started on nicotinic acid or sevelamer for a period of four weeks. The dose of nicotinic acid used was 500 mg and that of sevelamer was 1600 mg daily. Blood samples were drawn for the measurement of the total calcium (Ca), phosphorus (P), alkaline phosphatase (ALP), triglyceride (TG), total cholesterol (Chol), high-density lipoprotein (HDL), low-density lipoprotein (LDL), uric acid and parathyroid hormone (PTH). Patients receiving sevelamer showed a significant reduction in serum P level (2.2 ± 0.69 mg/dL; P <0.0001) in comparison with the nicotinic acid group (1.7 ± 1.06 mg/dL; P = 0.004). Reduction in the Ca-P product was significantly different in the two groups; in the sevelamer group, it was 21 ± 7; (P <0.0001) while in the nicotinic acid group, it was 16 ± 11 (P = 0.007). Also, patients on sevelamer showed greater reduction in the mean TG level (38.9 ± 92 mg/dL; P = 0.005). No significant changes were observed in the mean serum Ca, total Chol, HDL, LDL, ALP and iPTH levels in the two study groups. Our short-term study suggests that although nicotinic acid reduced hyperphosphatemia, sevelamer showed higher efficacy in controlling hyperphosphatemia as well as the Ca-P product.

Occult hepatitis B virus infection in hemodialysis patients with isolated hepatitis B core antibody: a multicenter study.

Occult hepatitis B virus (HBV) infection is characterized by presence of HBV infection with undetectable hepatitis B surface antigen (HBsAg). Occult HBV infection harbors potential risk of HBV transmission through hemodialysis (HD). The aim of this study was to assess the occult HBV infection in hemodialysis patients with isolated hepatitis B core antibody (anti-HBc). A total of 289 HD patients from five dialysis units in Tehran, Iran, were included in this study. Hepatitis B surface antigen (HBsAg), Hepatitis B surface antibody (anti-HBs), anti-HBc, Hepatitis C antibody (anti-HCV), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were tested in all subjects. The presence of HBV-DNA was determined quantitatively in plasma samples of HD patients with isolated anti-HBc (HBsAg negative, anti-HBs negative and anti-HBc positive) by real-time PCR using the artus HBV RG PCR kit on the Rotor-Gene 3000 real-time thermal cycler. Of 289 patients enrolled in this study, 18 subjects (6.2%, 95% confidence interval (CI), 3.5%-8.9%) had isolated anti-HBc. HBV-DNA was detectable in 9 of 18 patients (50%, 95% CI, 27%-73%) who had isolated anti-HBc. Plasma HBV-DNA load was less than 50 IU/ml in all of these patients. Our study showed that detection of isolated anti-HBc could reflect unrecognized occult HBV infection in HD patients. The majority of these infections are associated with low viral loads.