Iranian Journal of Kidney Diseases
Year:2011 | Volume:5 | Issue:6|Papers Count:13

Oxidative stress is a major mediator of adverse outcomes throughout the course of transplantation. Transplanted kidneys are prone to oxidative stress-mediated injury by pre-transplant and post-transplant conditions that cause reperfusion injury or imbalance between oxidants and antioxidants. Besides adversely affecting the allograft, oxidative stress and its constant companion, inflammation, cause cardiovascular disease, cancer, metabolic syndrome, and other disorders in transplant recipients. Presence and severity of oxidative stress can be assessed by various biomarkers produced from interaction of reactive oxygen species with lipids, proteins, nucleic acids, nitric oxide, glutathione, etc. In addition, expression and activities of redox-sensitive molecules such as antioxidant enzymes can serve as biomarkers of oxidative stress. Via activation of nuclear factor kappa B, oxidative stress promotes inflammation which, in turn, amplifies oxidative stress through reactive oxygen species generation by activated immune cells. Therefore, inflammation markers are indirect indicators of oxidative stress. Many treatment options have been evaluated in studies conducted at different stages of transplantation in humans and animals. These studies have provided useful strategies for use in donors or in organ preservation solutions. However, strategies tested for use in post-transplant phase have been largely inconclusive and controversial. A number of therapeutic options have been exclusively examined in animal models and only a few have been tested in humans. Most of the clinical investigations have been of short duration and have provided no insight into their impact on the long-term survival of transplant patients. Effective treatment of oxidative stress in transplant population remains elusive and awaits future explorations.

A 40-year-old man presented with complaints of left-sided lower back discomfort for 2 to 3 months.There was no other significant history. Physical examination was unremarkable except for a palpable mass in the left flank. Ultrasonography showed a hypoechoic mass. Biphasic contrast-enhanced computerized tomogram revealed a large, heterogenous, infiltrating, necrotic mass lesion arising from the left kidney with blood supply from the left renal artery. Fine needle aspiration cytology showed sheaths, bundles and whorls of cells with indistinct cell margin, moderate amount of eosinophilic cytoplasm, elongated wavy nuclei and moderate anisocytosis suggestive of malignant peripheral nerve sheath tumor (× 100, hematoxylin-eosin). He underwent a radical tumor excision.

Introduction: Chronic kidney disease (CKD) is becoming a major public health problem worldwide. A remarkable part of health budget is designated annually to control end-stage renal disease in most countries. The aim of this study was to screen for CKD among the general population of the rural area of Shahreza, in the central region of Iran.Materials and Methods: In a study of rural area around Shahreza, Iran, in 2009, a total of 1400 participants aged over 30 years old were selected by systematic randomized sampling. Glomerular filtration rate (GFR) was used as an index of kidney function and albuminuria, as an index of kidney damage. The simplified Modification of Diet in Renal Disease Study equation was used for estimation of GFR.Results: A GFR less than 60 mL/min/m2 was found in 4.7% of the study population (1.8% in men and 6.1% in women).Microalbuminuria and macroalbuminuria were present in 16.2% of the participants (15% of men and 16.8% of women). Pyuria and hematuria rates were 12.3% and 12.6%. The prevalence of a GFR less than 60 mL/min/1.73 m2 was significantly increasing by age groups in both genders.Conclusions: Considering its high prevalence, CKD needs measures to identify the disease sooner and requires an active national screening program to identify patients in earlier stages. It seems reasonable to integrate such programs in the primary healthcare system.

Introduction: Atypical hemolytic uremic syndrome (HUS) is accompanied by a poor prognosis and high mortality rate. We investigated the predictive value of severity of renal involvement, as evaluated by pathologic examination, for long-term outcome of atypical HUS.Materials and Methods: Kidney biopsies of 29 children diagnosed with atypical HUS between 1992 and 2005 were reviewed. The severity of glomerular, vascular (arteriolar and arterial), interstitial, and tubular involvement were determined. Scores of renal involvement were determined by re-evaluating kidney specimens. The outcome measures were death, chronic kidney disease (CKD), hypertension, and proteinuria.Results: After a mean of 3.7 years of follow-up, 24.1% of the patients had normal kidney function and blood pressure, 24.1% showed proteinuria, and 41.4% had CKD, and 10.3% had unknown prognosis. Overall, 24.1% of the patients died due to emergent hypertension with or without CKD. The existence of arteriolar and arterial thrombosis attributed to severe CKD (risk ratio, 3.67, 95% confidence interval, 1.63 to 8.2). Presence of thrombosis in the vessels, and thickening of the arterial medial and intimal layers had brought about a significantly higher mortality rate. Chronic kidney disease was more frequent in the children with vascular scores higher than 0.14 and a final score of more than 0.2.Conclusions: The severity of renal pathological involvement, especially the degree of vascular damage, is a good predictor of long-term outcome of patient with atypical HUS.

Introduction: The aim of this study was to investigate power Doppler ultrasonography for diagnosis and prediction of scarring compared with technetium Tc 99m dimercaptosuccinic acid scintigraphy in acute pyelonephritis.Materials and Methods: Sixty-six children, aged 2 months to 6 years old, admitted with clinical and biological signs of their first febrile urinary tract infection were studied. All of the children underwent PDU and technetium Tc 99m dimercaptosuccinic acid scintigraphy within 7 days after diagnosis and repeat scintigraphy at least 6 months later, if results of the first study were abnormal.Scintigraphic and Doppler studies were interpreted and compared.Results: Dimercaptosuccinic acid scintigraphy demonstrated scar in 7.6% of renal units, 3.1% of patients without reflux and 66.7% of those with high-grade reflux. Kidneys with permanent kidney damage had a mean resistive index (RI) of 0.71±0.06, while the RI value for nonscarred kidneys was 0.66±0.06 (P=0.02). The best cutoff point of RI value was 0.715, with a sensitivity of 70%, a specificity of 87.7%, and positive and negative predictive values of 32% and 97%, respectively. These values significantly increased when grey-scale ultrasonography findings were brought into account. Reflux was observed in 19.7% of renal units, which were associated with significantly higher RI values (P=0.05).Conclusions: Power Doppler ultrasonography with a cutoff value of 0.715 has a reasonable sensitivity and specificity for prediction of renal scarring in young children with febrile urinary tract infection.

Introduction: The production of tumor necrosis factor (TNF) -a has been deeply deregulated in systemic lupus erythematosus. We evaluated the association of -863C>A and -1031T>C polymorphisms of the TNF gene with susceptibility to and clinical manifestations of juvenile systemic lupus erythematosus.Materials and Methods: This study was performed on 70 juvenile patients with systemic lupus erythematosus (mean age, 13.0±4.2 years). Ninety age- and sex-matched children served as a controls.All participants were genotyped for the TNF-863C>A and -1031T>C polymorphisms by polymerase chain reaction-restriction fragment length polymorphism method. Analysis of serum TNF-a was done by solid-phase sandwich enzyme immunoassay.Results: The mean serum TNF-α was significantly higher in the SLE patients compared to controls (P<0.001). Regarding all participants, the mean serum TNF-a was significantly higher in children with-863AA genotype compared to carriers of -863C allele (P         <0.001).The TNF -863AA genotype frequencies were significantly higher in the patients group compared with the controls (P=0.005) and were associated with increased risk for SLE development (odds ratio, 4.05, 95% confidence interval, 1.38 to 13.13, P=0.005). The -863AA variant was associated with nephritis (P<0.001) and Raynaud phenomenon (P=0.001).Conclusions: The -863A allele of the TNF gene can be used as a genetic marker for SLE susceptibility and was associated with high TNF-a production, Raynaud phenomenon, and nephritis in juvenile SLE Egyptian patients.

Introduction: Pre-eclampsia is one of the leading causes of maternal and fetal mortality and morbidity. It occurs in 7% of all the pregnancies and accounts for 80% of the cases of pregnancyinduced hypertension. Diagnosis of pre-eclampsia in patients with pre-existing chronic kidney disease, proteinuria, and hypertension is a dilemma. The fractional excretion of urea has been described as a marker for renal perfusion. Since pre-eclampsia is associated with a marked decline in renal perfusion, we explored the utility of the fractional excretion of urea as a marker for pre-eclampsia.Materials and Methods: Urine and serum chemistries were evaluated in 6 pregnant women with pre-eclampsia on their first visit, immediately prior to delivery, and postpartum. For each of these three measurements, the fractional excretion of urea was calculated and proteinuria was assessed by random urine proteincreatinine ratio or 24-hour urine protein studies.Results: In patients diagnosed with pre-eclampsia, the fractional excretion of urea decreased substantially from higher values obtained during the 3rd trimester to values consistent with renal hypoperfusion (<35%) just prior to delivery, and it rapidly normalized immediately after delivery.Conclusions: Alterations in fractional excretion of urea, which suggest a decreased renal perfusion, may be a useful tool in supporting the diagnosis of preeclampsia.

Introduction: Poor sleep quality is very common among maintenance hemodialysis patients and has negative impacts on patients’ quality of life. Benzodiazepines have traditionally been used in this population, however, they may induce physical dependence and sleep apnea. Nonbenzodiazepine hypnotic medications with less side effects are introduced as alternatives. This study was designed to compare the effect of zolpidem and clonazepam on sleep quality of hemodialysis patients.Materials and Methods: In a randomized crossover study on 23 hemodialysis patients, sleep quality was assessed using the Pittsburgh Sleep Quality Index at baseline, at the initiation of a 1-week washout period after a 2-week treatment with zolpidem (1 mg) and clonazepam (5 mg to 10 mg), and after the second 2 weeks of treatment. Patients who suffer from any concurrent situations that may affect sleep quality or psychiatric disorders and those on medications affecting sleep quality were excluded.Results: The prevalence of poor sleep quality was 87.8% of the 88 hemodialysis patients who were initially approached. There was a significant negative correlation between iron deficiency and poor sleep quality. Both clonazepam and zolpidem significantly improved sleep quality, however, clonazepam was more effective in decreasing the Pittsburgh Sleep Quality Index scores (P=0.03).Zolpidem was better tolerated in the hemodialysis patients.Conclusions: Clonazepam was more effective than zolpidem in the improvement of sleep quality of hemodialysis patients, while zolpidem was better tolerated in these patients.

Introduction: In end-stage renal disease, there is a high incidence of secondary hyperparathyroidism. It is proposed that increasing vitamin C levels by dietary supplementation results in a decrease of parathyroid hormone (PTH) in vitamin C-deficient hemodialysis patients with secondary hyperparathyroidism. The aim of this study was the evaluation of vitamin C administration for reduction of serum PTH level in hemodialysis patients.Materials and Methods: Twenty-one hemodialysis patients with serum PTH levels less than 550 pg/mL (but more than 200 pg/ mL) were administered intravenous vitamin C, 200 mg, 3 times per week for 3 months. Blood samples for measurement of PTH were obtained at the beginning of the hemodialysis session every month for three months.Results: The mean level of serum biointact PTH was 333.3±141.3 pg/mL (reference range, 7 pg/mL to 82 pg/mL) at baseline, and it decreased to 256.5±137.2 pg/mL at 1 month (P=0.03). The mean PTH level was also lower than the baseline value at 2 months (260.1±123.2 pg/mL, P=0.03), while it increased to 328.9±176.0 pg/mL at 3 months, which was still slightly lower than the baseline level (P=0.13). In 15 patients (71.4%), serum levels of PTH were lower than the baseline at months 1 to 2, while in the remaining 6 (28.6%), it was higher than the baseline value. At 3 months, 5 of the 15 patients with lower PTH levels up to the 3rd month experienced an increase in these levels again.Conclusions: Administration of intravenous vitamin C in hemodialysis patients noticeably decreased level of PTH, but its effect gradually diminished.

Introduction: Urinary tract infection (UTI) is common after pediatric kidney transplantation. The purpose of this study was to evaluate the prevalence of UTI and its risk factors in children and adolescents with kidney transplantation in Shiraz Transplant Center.Materials and Methods: All children with kidney transplantation from 1990 to 2008 who were under regular follow-up were included in this retrospective study. Confirmed episodes of UTI after the 1st month of kidney transplantation were reviewed.Results: Of the 216 patients younger than 19 years at the time of transplantation, 138 were included. The mean age at the time of kidney transplantation was 13.6±3.5 years. Urinary tract infection was documented in 24 patients (15 girls and 9 boys), of whom 12 experienced 1 episode, 4 had 2 episodes, and 8 had more than 2 episodes, during a median follow-up period of 54 months. Of the patients with UTI, 14 (58%) had urinary reflux-obstruction disorders as the primary kidney diseases, 6 (25%) had suffered hereditary diseases, 3 (12.5%) had glomerular disease, and 1 (4.5%) had a urinary calculus. Occurrence of UTI was not significantly different among children with different primary kidney diseases (P=0.22).Despite using prophylactic antibiotics after the 1st month of kidney transplantation in all 5 patients with neurogenic bladder, they all experienced recurrent UTI.Conclusions: Despite discontinuation of antibiotic therapy, UTI was uncommon in children after the first month of transplantation. Two significant risk factors for UTI were female gender and neurogenic bladder in this transplant population.

Introduction: Osteoporosis develops and progresses in a considerable number of kidney transplant patients. Bisphosphonates, which are used for prevention and treatment of osteoporosis, may accentuate gasterointestinal complications and lead to more nonadherence to treatment. This randomized clinical trial was conducted to compare the effect of pamidronate versus alendronate on early bone mineral density changes in kidney transplant patients.Materials and Methods: Forty patients (27 men and 13 women), aged from 20 to 58 years, with low bone mineral density (T score<-2) in the spine, total hip, or femur neck were enrolled. Participants were randomly allocated into 2 groups to receive pamidronate or alendronate. The pamidronate group received intravenous pamidronate, 90 mg, starting from the 3rd week of transplantation for 3 months. The alendronate group started to receive oral alendronate, 70 mg per week for the same period. At baseline and 6 months, bone mineral density was measured by dual-energy x-ray absorptiometry. Gastrointestinal side effects were monitored every month.Results: No significant difference was found in bone density changes of the lumber area between the two groups, however, significantly less reduction in bone mineral density of the femur neck and femur occurred in the pamidronate group. Kidney function and parathyroid hormone levels were similar in the two groups before and after the study. Gastrointestinal side effects were seen in 3 patients of the alendronate group only.Conclusions: Pamidronate was comparable to alendronate in prevention of early bone loss after kidney transplantation.

Secondary hypertension is responsible for less than 10% of cases of hypertension. If associated with hypokalemia, it may be due to primary or secondary hyperaldostronism, the latter being rarely caused by renin-secreting tumors. We present a 22-year-old woman with a history of hypertension and repeated hypokalemia, who was finally diagnosed with a small renin-secreting tumor after extensive paraclinical workup and imaging studies.

Primary hyperoxaluria is a genetic disorder in glyoxylate metabolism that leads to systemic overproduction of oxalate. Functional deficiency of alanine-glyoxylate aminotransferase in this disease leads to recurrent nephrolithiasis, nephrocalcinosis, systemic oxalosis, and kidney failure. We present a young woman with end-stage renal disease who received a kidney allograft and experienced early graft failure presumed to be an acute rejection. There was no improvement in kidney function, and she was required hemodialysis. Ultimately, biopsy revealed birefringent calcium oxalate crystals, which raised suspicion of primary hyperoxaluria. Further evaluations including genetic study and metabolic assay confirmed the diagnosis of primary hyperoxaluria type 1. This suggests a screening method for ruling out primary hyperoxaluria in suspected cases, especially before planning for kidney transplantation in patients with end-stage renal disease who have nephrocalcinosis, calcium oxalate calculi, or a family history of primary hyperoxaluria.