Iranian Journal of Kidney Diseases
Volume:4 Issue: 2, Apr 2010

Dietary phosphorus control is often a main strategy in the management of patients with chronic kidney disease. Dietary protein is a major source of phosphorus intake. Recent data indicate that imposed dietary phosphorus restriction may compromise the need for adequate protein intake, leading to protein-energy wasting and possibly to increased mortality. The two main sources of dietary phosphorus are organic, including animal and vegetarian proteins, and inorganic, mostly food preservatives. Animal-based foods and plant are abundant in organic phosphorus. Usually 40% to 60% of animal-based phosphorus is absorbed; this varies by degree of gastrointestinal vitamin-D-receptor activation, whereas plant phosphorus, mostly associated with phytates, is less absorbable by human gastrointestinal tract. Up to 100% of inorganic phosphorus in processed foods may be absorbed; ie, phosphorus in processed cheese and some soda (cola) drinks. A recent study suggests that a higher dietary phosphorus-protein intake ratio is associated with incremental death risk in patients on long-term hemodialysis. Hence, for phosphorus management in chronic kidney disease, in addition to absolute dietary phosphorus content, the chemical structure (inorganic versus organic), type (animal versus plant), and phosphorus-protein ratio should be considered. We recommend foods and supplements with no or lowest quantity of inorganic phosphorus additives, more plant-based proteins, and a dietary phosphorus-protein ratio of less than 10 mg/g. Fresh (nonprocessed) egg white (phosphorus-protein ratio less than 2 mg/g) is a good example of desirable food, which contains a high proportion of essential amino acids with low amounts of fat, cholesterol, and phosphorus.

Introduction. Hepatitis B virus (HBV)-associated nephropathy is one of the manifestations of HBV infection. However, since it is not common, the patient populations of reports are usually limited. In order to have a more perfect understanding of the disease, we conducted this analysis of data published in articles of the English literature on HBV-associated nephropathy.Materials and Methods. We conducted a comprehensive search for the available publications on HBV-associated nephropathy through the PubMed. The patients were defined as pediatric when they were 18 years old or younger. The definition criteria for complete remission were in part different between studies, but a generalized definition was taken as a significant decrease in the proteinuria to levels around normal with no relapse episodes in 1 year after remission.Results. Overall, 119 patients from 10 reports were included into this analysis. All of the patients using lamivudine experienced remissions compared to those receiving other treatment modalities (P =. 001), of whom 72.7% (16 of 22) had complete remission (P =. 08). None of lamivudine recipients lost their kidneys (P =. 04). Pediatric patients were more frequently positive for hepatitis B envelop antigen (P =. 001). Immunoglobulin A nephropathy was more frequent among adult patients (P =. 01), and membranous nephropathy in children (P =. 01). Children represented significantly higher levels for aspartate aminotransferase (P =. 004) and alanine aminotransferase (P =. 002).Conclusions. Lamivudine therapy can effectively be used to stop progression of HBV-associated nephropathy. Pediatric patients represent different serological and laboratorial test results compared to their adult counterparts. Future studies with larger patient population are needed to confirm our findings.

Abu Bakr Mohammad Ibn Zakariya Razi, known in the west as Rhazes (865 to 925 AD), was born in the ancient city of Rayy, near Tehran, Iran. He was a renowned physician in medical history and not only followed Hippocrates and Galen, but also greatly extended the analytical approach of his predecessors. Based on the existing documents, he was known as the most distinguished character in the world of medicine up to the 17th century. A great number of innovations and pioneering works in the medical science have been recorded in the name of Rhazes. His fundamental works in urology as part of his research in the realm of medicine have remained unknown. Pathophysiology of the urinary tract, venereal diseases, and kidney and bladder calculi are among his main interests in this field. He also purposed and developed methods for diagnosis and treatment of kidney calculi for the first time in medical history. He also presented a very exact and precise description of neuropathic bladder followed by vertebral fracture. He advanced urine analysis and studied function and diseases of the kidneys. Rhazes recommendations for the prevention of calculi are quite scientific and practical and in accordance with current recommendations to avoid hypercalciuria and increased saturation of urine. Rhazes was not only one of the most important Persian physician-philosophers of his era, but for centuries, his writings became fundamental teaching texts in European medical schools. Some important aspects of his contributions to medicine are reviewed.

Introduction. The purpose of this study was to determine normal reference values for urine calcium-creatinine (Ca/C) ratio in Iranian children of Jahrom, in south-east of Iran.Materials and Methods. A total of 1068 school-age children were included by stratified clustered random sampling from primary schools of Jahrom, Iran, between March 2008 and May 2008. Nonfasting random urine specimens from each subject were analyzed for calcium and creatinine concentrations.Results. The mean ratio of urine Ca/C in all children was 0.123 ± 0.106 (range, 0.01 to 2.25), and the 95th percentile value was 0.25. Nonfasting Ca/C ratios were not significantly different between the boys and the girls. The Ca/C ratio was highest in 9-year-old children (mean, 0.132 ± 0.11). Based on the 95 percentile value of urine Ca/C (> 0.25) in the present study, 5.1% of the children in Jahrom were hypercalciuric. The prevalence of hypercalciuria differed with age (P =. 06), and the most prevalent rate was observed in 9-year-old group (9.3%).Conclusions. We provided a reference value for urine Ca/C ratio in south-east Iranian children. A child''s age and ethnicity should be taken into consideration when assessing the urinary solute-creatinine ratios.

Introduction. Although a series of risk factors for contrast-induced nephropathy are known, data on significance of some of the risk factors such as age, sex, hypercholesterolemia, hyperuricemia, and dose of contrast medium are inconsistent. Our aim was to identify risk factors for contrast-related acute kidney injury (AKI).Materials and Methods. In this prospective study, 290 consecutive patients with a serum creatinine level lower than 3 mg/dL undergoing percutaneous angiography were analyzed. Contrast-related AKI was evaluated using the risk, injury, failure, loss, and end-stage (RIFLE) criteria, and its correlation with clinical and laboratory data of the patients was analyzed.Results. Contrast-related AKI was found in 15.5% of the patients, with a maximum RIFLE category (risk in 13.8%, injury in 1.4%, and failure in 0.3%). Serum creatinine level, contrast volume, safe contrast volume factor, diabetes mellitus, and dehydration were significantly associated with contrast-related AKI. Age, sex, and serum uric acid level did not differ significantly between those with and without contrast-related AKI. Multiple logistic regression analysis disclosed diabetes mellitus to be the strongest predictor for being at risk of contrast-related AKI (odds ratio, 5.1; 95% confidence interval, 1.9 to 11.0; P =. 001), followed by hypercholesterolemia (odds ratio, 4.6; 95% confidence interval, 1.1 to 8.3; P =. 03), and an estimated glomerular filtration rate lower than 90 mL/min/1.73 m2 (odds ratio, 3.0; 95% confidence interval, 1.8 to 5.7; P =. 003).Conclusions. Our results indicate that diabetes mellitus, hypercholesterolemia, and underlying chronic kidney disease are the major factors of contrast-related AKI.

Introduction. Hepatitis C virus (HCV) infection is a hepatotropic virus causing a variety of extrahepatic immunological manifestations and is a risk factor of a variety of extrahepatic diseases, such as mixed cryoglobulinemia and membranoproliferative glomerulonephritis (MPGN), which is the most common glomerulonephritis. The aim of this study was to evaluate renal involvement in HCV-infected patients.Materials and Methods. A total of 300 randomly-selected HCV antibody-positive outpatients at the HCV clinic of Shariati hospital were enrolled. Serum creatinine was measured and glomerular filtration rate was estimated accordingly. Urine proteinuria was measured in 24-hour urine samples.Results. The patients were 249 men (83.2%) and 51 women (16.8%) with a mean age of 37.8 ± 11.7 years (range, 18 to 70 years). Proteinuria was found in 12 HCV antibody-positive adults (4%), 1 of whom underwent biopsy. He was a 55- year-old man with a 4-month history of facial and lower extremities edema and 3-g proteinuria with a normal kidney function (glomerular filtration rate, 85 mL/min) and normocomplementemia. Kidney biopsy specimens showed MPGN. The frequency of low glomerular filtration rate was 0.7% (2 patients) in the HCV antibody-positive adults. There was no significant relationship between HCV seropositivity and low glomerular filtration rate.Conclusions. Our observations showed renal involvement in HCV antibody-positive patients. Among immune complex glomerular kidney diseases, MPGN without cryoglobulins is thought to be the most common in these patients.

Introduction. Diabetic nephropathy is the most prevalent cause of end-stage renal disease. Besides factors such as angiotensin II, cytokines, and vascular endothelial growth factor, uric acid may play a role as the underlying cause of diabetic nephropathy. We evaluated allopurinol effects on proteinuria in diabetic patients with nephropathy.Materials and Methods. In a double-blinded randomized controlled trial on 40 patients with type 2 diabetes mellitus and diabetic nephropathy (proteinuria, at least 500 mg/24 h and a serum creatinine level less than 3 mg/dL), allopurinol (100 mg/d) was compared with placebo. Administration of antihypertensive and renoprotective drugs (angiotensin-converting enzyme inhibitors and angiotensin receptor blockers continued for both groups, without changes in dosage. Proteinuria was compared at baseline and 2 and 4 months between the two groups.Results. Each group consisted of 9 men and 11 women. There were no difference between two groups regarding age, body mass index, duration of diabetes mellitus, systolic and diastolic blood pressure, fasting blood glucose, blood urea nitrogen, serum creatinine, serum potassium, and urine volume. Serum levels of uric acid (P =. 02) and 24-hour urine protein (P =. 049) were significantly lower in the patients on allopurinol, after 4 months of receiving allopurinol, compared with the control group.Conclusions. Low-dose allopurinol can reduce severity of proteinuria after 4 months of drug administration, which is probably due to decreasing the serum level of uric acid. Thus, allopurinol can be administered as an adjuvant cost-effective therapy for patients with diabetic nephropathy.

Introduction. Our information about renal involvement in beta-thalassemia major is limited. Recently, few studies have reported proteinuria, hypercalcuria, phosphaturia, and oversecretion of tubular damage markers; however, hematuria has not yet been meticulously studied in these patients. We investigated hematuria in patients with beta-thalassemia major.Materials and Methods. Urinalysis was performed in 500 patients with beta-thalassemia major under a regular blood transfusion program. In those with hematuria (at least 3 to 5 erythrocytes per high-power field) a second urinalysis was done at the next transfusion time.Results. The patients ranged in age from 6 months to 32 years. The male-female ratio was 1.05:1. Hematuria was detected in 55 (10.6%), including 9.8% of those younger than 20 years and 20.0% of those older than 20 years. Hematuria was persistent in 79.2% of the second urinalyses. Sixty-four percent of the patients with hematuria were females. A blood transfusion program had been started during the first year of life in 81% percent of the patients with hematuria. Sterile pyuria was detected in 4% and proteinuria in 16% of the patients with hematuria, while these figures in patients without hematuria were 2.1% (P =. 56) and 1.4% (P =. 002), respectively.Conclusions. We found that in patients with beta-thalassemia major, the risk of hematuria rises with age. Moreover, proteinuria seems to be more common in those with hematuria. Further studies are needed to ascertain the importance of these findings.

Introduction. Pruritus is one of the common problems in patients on hemodialysis. There are several causes for pruritus, and different treatment modalities are applied to control it. The aim of this study was to evaluate the therapeutic effect of capsaicin on pruritus, compared with placebo, in patients on hemodialysis.Materials and Methods. This randomized double-blinded cross-over clinical trial was performed on 34 patients on hemodialysis with uremic pruritus. The patients were divided into 2 groups, one group received capsaicin 0.03% and the other, placebo, for 4 weeks. Treatment was stopped for 2 weeks as washout period and continued as a cross-over technique. Pruritus scores were analyzed and compared.Results. Thirty-four patients on long-term hemodialysis, 14 men and 20 women with a mean age of 57.0 ± 18.6 years were studied. The mean of pruritus score before capsaicin treatment was 15.9 ± 6.3, which was reduced to 6.4 ± 3.9, 4.7 ± 3.1, 3.2 ± 2.9, and 2.5 ± 2.5 on weeks 1 to 4, respectively (P <. 001). In the placebo group, pruritus score before treatment was 15.0 ± 6.0 on average, and it was 11.7 ± 5.8, 9.4 ± 5.9, 7.9 ± 5.5, and 7.2 ± 5.5, respectively, on weeks 1 to 4 (P <. 001). There was no significant difference in pruritus scores before the treatment between the two groups, but after each week, the difference was significant (P <. 001). Repeated measurement test showed that decreasing in pruritus severity in the capsaicin group was more than that in the placebo group during treatment period (P <. 001).Conclusions. Capsaicin is a new safe and effective topical treatment for hemodialysis-induced pruritus in patients with end-stage renal disease.

Introduction. Single nucleotide polymorphisms within promoter or other regulatory sequences of cytokine genes mainly influence the level of production and secretion of proteins. A large amount of evidence has shown that cytokine gene variations alter graft survival length after kidney transplantation. We studied the association of gene polymorphisms in the interlekin-10 gene (IL10; -1082 G/A), interferon-gamma gene (IFNG; +874 T/A), transforming growth factor-beta gene (TGFB; +869 T/C), and tumor necrosis factor-alpha gene (TNFA; -308 A/G) with kidney allograft survival.Materials and Methods. The IL10 (-1082 G/A), IFNG (+874 T/A), TGFB (+869 T/C), and TNFA (-308 A/G) genotypes were determined in 32 kidney allograft recipients with graft rejection during the 1st posttransplant year and 52 without rejection in 5 posttransplant years, using allele-specific oligonucleotides-polymerase chain reaction method.Results. The IFNG +874 A/T genotype showed a significantly higher frequency among kidney recipients of the rejection group than the control group (odds ratio, 2.64, 95% confidence interval, 1.03 to 6.74; P =. 04). Comparisons between the rejection and control groups in IL10 (-1082 G/A), IFNG (+874 T/A), TGFB (+869 T/C), and TNFA (-308 A/G) single nucleotide polymorphisms showed no significant difference.Conclusions. Based on the finding of this study, it seems polymorphisms in the genes that regulate IL-10, IFN-gamma, TGF-beta, and TNF-alpha cytokines do not play a major role in kidney allograft survival, and other potential factors in this regard should be considered.

Introduction. Hyperglycemia is common and a contributing factor to the undesirable outcomes in kidney transplant recipients. This study investigates the relationship of pretransplant blood glucose levels and the occurrence of delayed graft function among kidney transplant recipients without a diagnosis diabetes mellitus before transplantation.Materials and Methods. Eighty-one patients on long-term hemodialysis with no history of clinically diagnosed diabetes mellitus were enrolled in this study. Correlation of the occurrence of delayed graft function with age, gender, donor source, underlying cause of kidney failure, insulin resistance, and blood glucose levels before transplantation was evaluated.Results. There was a significant correlation between abnormal glucose metabolism categories and occurrence of delayed graft function (P =. 004). Logistic regression analysis showed that fasting blood glucose before kidney transplantation is an independent predictor of delayed graft function immediately after transplantation (odds ratio = 1.042, P =. 04).Conclusions. Hyperglycemic patients have an increased risk for delayed graft function and should be treated by more potent immune therapy and further restriction of blood glucose regulation in peritransplantation period.

Introduction. Cyclosporine is the backbone of immunosuppression in kidney transplantation. However, it is associated with side effects, some of which are dose-dependent. We evaluated association between cyclosporine trough level and its side effects.Materials and Methods. In 50 kidney transplant recipients, serum cyclosporine level, fasting blood glucose, and serum creatinine were measured 7 times during first 6 months after transplantation. The participants were also assessed for blood pressure, hand tremor, and headache at each visit. The relationship between cyclosporine trough level and hypertension, hyperglycemia, hand tremor, and headache were evaluated.Results. There were no significant relationship between cyclosporine levels and allograft function. Except at the second week and sixth month, there were no significant differences between drug doses in various serum cyclosporine trough level groups. At the second week, the mean drug dose in patients with cyclosporine trough levels less than the target therapeutic level was 279.16 ± 56.23 mg/d, while in the patients with cyclosporine levels higher than the therapeutic level, its dose was 302.08 ± 66.61 mg/d (P <. 05). At the sixth month, the mean drug dose was 137.50 ± 17.67 mg/d in the patients with lower than target cyclosporine levels, and it was 242.18 ± 58.25 mg/d in those with cyclosporine levels higher than the therapeutic level (P <. 05). There was no significant relationship between serum cyclosporine level and its side effects.Conclusions. We demonstrated cyclosporine trough level had no direct relation with drug side effects and it is not a suitable measure for assessment of drug side effects.

Introduction. Viral infections are a real threat in kidney transplant recipients because of their immunocompromised condition. This study aimed to evaluate herpes simplex virus-2 (HSV-2) seropositivity among kidney transplant recipients.Materials and Methods. Serum samples of 91 kidney transplant recipients from Urmia, Iran, were examined serologically for antibodies against HSV-2 using an enzyme-linked immunosorbent assay.Results. The mean time from transplantation at HSV-2 testing was 5.04 ± 4.45 years. The anti-HSV-2 immunoglobulin G antibody was positive in 5.4% of the kidney transplant recipients. Seropositive patients did not present any clinical manifestations of genital herpes infection. There was no association between HSV-2 seropositivity and age, gender, history of hemodialysis and transplantation, blood transfusion, or immunosuppressive regimen.Conclusions. Seroprevalence of HSV-2 is not high among our kidney transplant recipients. However, it remains a source of concern, considering the compromised immune system in this specific population.

Kidney failure is the principal cause of death in scleroderma and accounts for at least 50% of deaths in this disease. Management of scleroderma-related end-stage renal disease requires some form of renal replacement therapy. Survival up to 18 months has been reported in one patient on continuous ambulatory peritoneal dialysis. Surviving for more than 1 year on automated peritoneal dialysis has not been reported. We report a patient with scleroderma-related end-stage renal disease treated with automated peritoneal dialysis with steady state control of uremia and hypertension at 18 months of follow-up.