Iranian Journal of Kidney Diseases
Year:2012 | Volume:6 | Issue:3|Papers Count:16

Most of patients with a well-functioning kidney allograft ask their physicians whether it is safe to preserve the dialysis vascular access or not, as it becomes useless after successful kidney transplantation. They certainly do not want to have a second fistula placed if that were the case. Arteriovenous fistula (AVF) for hemodialysis has its risks and can be expensive as well as being associated with considerable morbidity. There are several important complications for AVF including bleeding, infections, nerve injury, early AVF or graft failure, venous stenosis, steal syndrome, thrombosis, and aneurysmal formation.

The intima-media thickness, also called intimal medial thickness, is a measurement of the thickness of the artery walls, used in ultrasonography studies, to detect the presence and to follow up progression of atherosclerotic plaques.

Since 1976, when Fernstorm and Johansson reported the first percutaneous nephrolithtomy Its goal is removal of kidney and upper ureteral calculi with low complication, shorter hospital stay, and minimal morbidity. In the standard technique described by the authors, placement of a ureteral catheter before getting access to the kidney and insertion of nephrostomy tube after calculus removal is recommended, because it provides sufficient pyelocaliceal drainage, prevents urinary leakage from the kidney, provides an access pathway for a second look if needed, and stops bleeding due to tamponade of the access tract.

Kaposi sarcoma (KS) is the most common cancer after kidney transplantation in the Middle East countries. The prevalence of KS in comparison with other tumors is also quite higher in Iranian recipients.  However, squamous cell carcinoma of the skin is the most common posttransplant malignancy in other reports.  Its incidence following kidney transplantation has steadily increased due to the long-term use of potent immunosuppressive drugs for prevention of allograft rejection.

Glomerular filtration rate is low in fetal and neonatal life. It increases after birth and reaches approximately 20 mL/min/1.73 m2 at 1 month of age in term and preterm neonates. Various methods have been used to measure glomerular filtration rate in neonates such as inulin clearance, creatinine clearance, and serum cystatin C. Serum creatinine concentrations are influenced by many factors. It is suggested to use other markers which are stable over time and are not affected by muscle mass or tubular reabsorption and secretion. Cystatin C incorporates these characteristics; however, there are some other limitations in the use of cystatin C as a marker of kidney function in neonates. Additionally, the numbers of studies focused on the use of cystatin C in neonates is limited. There is a need for further studies to determine cystatin C’s normal range levels and investigate whether cystatin C can replace other tests such as serum creatinine as marker of kidney function in newborn babies. Assessment of newer kidney function tests is also warranted in newborn infants.

Introduction: Glomerulonephritis is the third most common cause of end-stage renal disease. Epidemiological data of kidney disease is population-based and has great geographic variability. The aim of this study was to assess the results of all kidney biopsies in a 5-year period in the Guilan province.Materials and Methods: In a retrospective study of 336 kidney biopsies recorded in the Department of Nephrology in Razi Hospital of Rasht, capital city of Guilan province, from August 2001 to September 2006, data consisting of age, gender, indication of kidney biopsy, and histopathological diagnosis were collected and analyzed.Results: A total of 336 kidney biopsies were reviewed (73.8% males; mean age, 40.12±16.78 years). Nephritic syndrome (42.5%) and nephrotic syndrome (38.7%) were the most frequent indications of biopsy. Overall, pathologic examinations were indicative of glomerulonephritis in 272 (81.0%) biopsies and nonglomerular diseases in 64 (19.0%). The most common cause of secondary glomerulonephritis was lupus nephritis (82.6%). Focal and segmental glomerusclerosis (20.5%) was the most common pathologic diagnosis, followed by membranous glomerulonephritis (14.9%), minimal change disease (11.6%), tubulointerstitial nephritis (8.9%), and IgA nephropathy (3.6%). The most common pathologic finding among glomerular diseases was focal segmental glomerusclerosis (25.4%), while tubulointerstitial nephritis (46.9%) was the most common among nonglomerular diseases, followed by diffuse glomerulosclerosis, interstitial fibrosis, and tubular atrophy indicative of end-stage renal disease (23.4%).Conclusions: In our study, FSGS was the most common pathologic finding in kidney biopsies, and the frequency of IgA nephropathy was much lower than that in other studies.

Introduction: The aim of the present study was to evaluate the association of maternal UTI during pregnancy with neonatal UTI.Materials and Methods: One hundred and fourteen neonates admitted to hospital were enrolled in the present study, of whom 40 were admitted for management of UTI and 74 for management of jaundice. Urinalysis and urine culture were carried out for all of the neonates. Data regarding gestational age, history of UTI in the mother during pregnancy, and urinary symptoms of neonates were collected.Results: The mean gestational age of the neonates was 38.4±1.4 weeks (range, 30 to 40 weeks) and their mean age at admission was 6.2±3.8 days old (range, 1 to 25 days). The mean gestational age and birth weight of the two groups with and without UTI were 38.38±1.32 weeks versus 38.41±1.62 weeks and 2930.43±492.15 g versus 2930±447.33 g, respectively. No abnormal findings were detected on physical examinations, and none of the neonate had abnormal renal ultrasonography findings. There was a significant relationship between maternal prenatal UTI and neonatal infection; 30.0% of the neonates with UTI versus 6.8% of those without UTI had mothers with a history of UTI (odds ratio, 5.9; 95% confidence interval, 1.9 to 18.3; P = .001).Conclusions: Our study showed an association between maternal and neonatal UTI. This indicates a possible benefit of evaluation of neonates of mothers who had UTI during pregnancy.

Introduction: Human paraoxonase 1 (PON1) is an enzyme related with high-density lipoprotein cholesterol. The link between genetic polymorphisms of PON1 and hyperlipidemia and increased lipid oxidation may explain these complications in the course of glomerular diseases. In this study, we aimed to investigate PON1 192 and PON1 55 polymorphisms in patients with primary glomerulonephritis and healthy individuals.Materials and Methods: Eighty-six patients with biopsy-proven primary glomerulonephritis and 50 healthy controls were included in the study. Clinical characteristics, lipid profile, paraoxonase activity, and PON1 genotypes (PON1 192 and PON1 55) of all of the participants were studied.Results: Histopathological diagnoses of the patients were membranoproliferative glomerulonephritis (53.5%), focal segmental glomerulosclerosis (33.7%), and membranous nephropathy (12.8%). The patients had lower PON1 activity levels than the healthy controls. No differences were observed in PON1 192 genotypes between the two groups. However, the controls were more likely to carry PON1 55 LM genotype (odds ratio, 4.10; 95% confidence interval, 1.96 to 8.61; P<.001) and M allele (odds ratio, 3.0; 95% confidence interval, 1.45 to 6.19; P = .003) compared to the patients with primary glomerulonephritis. There was a marked elevation in the frequency of PON1 55 LL genotype in the patients compared to the controls (odds ratio, 0.33; 95% confidence interval, 0.16 to 0.68; P = .003).Conclusions: This preliminary study shows that the LL genotype might be a risk factor for the development of primaryglomerulonephritis and the M allele might be a protective factor against its progression.

Introduction: The pathophysiology of urolithiasis in infancy is not well known. The aim of this study was to investigate whether infants with urolithiasis have higher serum levels of vitamin D, as a possible risk factor for urolithiasis, compared to infants without urinary calculi.Materials and Methods: In this case-control study, 36 infants with urolithiasis (age range, 2.5 to 24 months) were enrolled as well as 36 age- and sex-matched infants without urolithiasis. Random urine samples were tested for calcium, phosphorous, oxalate, citrate, uric acid, sodium, potassium, magnesium, and creatinine levels, and also nitroprusside test was done on the samples. Serum levels of potassium, urea nitrogen, creatinine, 25-hydroxyvitamin D3, parathyroid hormone, calcium, phosphorous, and uric acid were measured in all of the infants with urolithiasis. Serum levels of 25-hydroxyvitamin D3 were also measured in the control group.Results: Serum levels of 25-hydroxyvitamin D3 were significantly higher in the infants with urolithiasis than in the controls (33.85±14.78 ng/mL versus 18.26±7.43 ng/mL, P<.001). Nine infants in the urolithiasis group (25%) were found to have hypercalcemia; 3 of these cases also had hypervitaminosis D. Hypercalciuria was detected in 10 infants with urolithiasis (27.8%), hypocitraturia in 6 (16.7%), hypomagnesiuria in 3 (8.3%), and hyperoxaluria in 1 (2.8%). Nineteen infants with urolithiasis had at least one metabolic disorder.Conclusions: High serum levels of vitamin D may play an important role in the pathogenesis of urolithiasis in infants with hypercalcemia. We recommend evaluation of vitamin D levels in these infants.

Introduction: Exercise-induced proteinuria is predominantly caused by alterations in renal hemodynamics. The present study was conducted to determine the effect of aerobic exercise in hypoxia on proteinuria and hematuria.Materials and Methods: The study population consisted of 17physically trained healthy young men. They were asked to attend in 4 sets of 30-minute running sessions, separated by 72-hour resting intervals, to attain 70% of maximal heart rate in normoxia (fraction of inspired oxygen of 0.21) and 3 different levels of hypoxia (lower fraction of inspired oxygen equivalent to the heights of 2750 m, 3250 m, and 3750 m above the sea level). Urine samples were collected before exercise and immediately and 1 hour after each session to measure total protein, albumin, b2-microglobulin, and erythrocyte count.Results: Postexercise urinary total protein, albumin, and b2-microglobulin showed significant increases compared to basline values, while no significant difference was found in urinary total protein between hypoxia and normoxia conditions. However, there was a significant positive correlation between the amount of albuminuria and the height (P=.01), and a significant difference in b2-microglobulinuria between normoxia and the simulated 2750-m altitude (P=.007), which disappeared at higher elevations. None of the participants developed hematuria.Conclusions: Aerobic exercise with moderate intensity in trained men might induce mixed proteinuria with glomerular predominance correlated with height, while tubular component loses this relation at altitudes above 2750 m. Further research on the influence of exercise on urinary abnormalities, particularly in different environmental conditions, is recommended.

Introduction: The cardiovascular impact of a patent arteriovenous fistula (AVF) following kidney transplantation has not been clearly described. This study aimed to evaluate the natural history of AVFs in kidney transplant recipients and the effect of spontaneous AVF closure after kidney transplantation on cardiac status.Materials and methods: Data on vascular access for dialysis were collected from medical charts of kidney transplant recipients between July 2009 and November 2010 at a single center. Echocardiographic re-assessment of the AVF flow and cardiac status was done in selected patients with functioning and nonfunctioning AVFs.Results: Of 180 kidney transplant recipients, 142 had AVFs before transplantation and 99 (69.7%) had a functioning fistula at the time of study after kidney transplantation. Twenty-three patients with a functioning AVF were compared with 17 with spontaneously closed AVFs. The left ventricular ejection fraction improved in both groups posttransplant. In the group with patent fistulas, there was a trend towards lower value of left ventricular endsystolic and end-diastolic diameters, but it did not reach statistical significance. The mean fistula flow was 560±405 mL/min in this group. A significant reduction was observed in the interventricular septum and left ventricular posterior wall diameters in the group with closed AVFs.Conclusions: Spontaneous AVF closure did not offer a significant cardiac beneficial effect. There are insufficient data to promote systematic closure of AVF after successful kidney transplantation.

Introduction: Carotid intima-media thickness (CIMT) could be used as a surrogate marker of atherosclerosis in hemodialysis patients. Since different mechanisms are involved in the atheroma formation and arterial wall thickness, we assessed the relationship between the maximum and the mean CIMT with different cardiovascular risk factors in dialysis patients.Materials and Methods: The mean and the maximum CIMT were measured using a B-mode ultrasonography in 75 hemodialysis patients, and the correlation between CIMT and cardiovascular risk factors were assessed.Results: The mean and maximum CIMT measurements were 0.5 mm (range, 0.2 mm to 1 mm) and 3.4 mm (1.4 mm to 5.6 mm), respectively. Among all the studied variables, age (P=.04, r=0.238), HS-CRP (P=.01, r=0.284), mean arterial blood pressure (P=.003, r=0.343), and DM (P=.02) had significant correlations with the mean CIMT, while only age (P=.02, r=0.473) and serum creatinine levels (P=.02, r=-0.493) were significantly associated with the maximum CIMT. A positive nonsignificant correlation was observed between the mean and maximum CIMT values (P=.08, R2 linear=0.214).Conclusions: These findings suggest that in dialysis patients, effects of cardiovascular risk factors on the mean and maximum CIMT might be different. Further studies are recommended to evaluate the prediction impact of each risk factor in end-stage renal disease patients compared with otherwise healthy individuals.

Introduction: Angiogenesis plays a role in the pathogenesis of coronary heart disease (CHD) and diabetes mellitus (DM) pathology, and certain angiogenic factors are increased by inflammation. The aim of this study was to evaluate plasma angiogenin and vascular endothelial factor A (VEGFA) levels in hemodialysis patients, as well as the effect of CHD, DM, and inflammation on these markers.Materials and Methods: Sixty-six hemodialysis patients were enrolled in the study, of whom 22 (33.3%) suffered from CHD, 22 (33.3%) from DM, and 28 (42.4%) from inflammation. They were compared with 24 healthy volunteers. Plasma angiogenin and VEGFA were assessed by means of enzyme-linked immunosorbent assay, and serum C-reactive protein was measured with an immunoturbidimetric method. These markers were compared between hemodialysis patients with and without CHD, DM, and inflammation.Results: Compared to healthy volunteers, plasma angiogenin was significantly higher in hemodialysis patients (263.57±65.95 ng/mL versus 499.15±175.68 ng/mL; P<.001). Similarly, plasma VEGFA was markedly increased in hemodialysis patients (median, 60.50 pg/ mL; range, 280 pg/mL), compared to healthy volunteers (median, 28.84 pg/mL; range, 59.40 pg/mL; P<.001). Neither angiogenin nor VEGFA levels differed significantly between hemodialysis patients with and without CHD, DM, or inflammation.Conclusions: Plasma angiogenin and VEGFA levels are markedly increased in hemodialysis patients, but not associated with CHD, DM, or inflammation among hemodialysis patients.

We evaluated the outcomes of percutaneous nephrolithotomy in patients with chronic renal insufficiency. A total of 60 patients with a creatinine level greater than 1.5 mg/dL who underwent PCNL were included. Serum creatinine level, as a kidney function index, was assessed before and after the operation. The mean calculus size was 31.13±9.38 mm. The mean pre-operative and 2-week postoperative serum creatinine levels were 2.43±0.75 mg/dL and 2.08±0.78 mg/dL, respectively. There was a significant difference between the pre-operative and postoperative creatinine levels in all postoperative days (days 1, 2, and 14). Fifty of the 60 patients (83.3%) were stone free. Ten patients (16.6%) developed postoperative fever. We can conclude that percutaneous nephrolithotomy seems to be a safe and effective therapeutic option for kidney calculi in patients with chronic kidney disease.

Almost all kidney transplant recipients with diabetes mellitus will eventually develop recurrence of diabetic nephropathy in their allograft. Despite this high incidence, there are very few reported cases of diabetic nephropathy of diffuse type, and the nodular sclerosis form is uncommon. Recurrence of diabetic nephropathy of nodular glomerulosclerosis type usually occurs during the second decade of transplantation. We report a rare case of diabetic nodular glomerulosclerosis developing 5 years after transplantation, leading to progressive kidney dysfunction and graft loss.

After the first description of Kaposi sarcoma in 1872, many cases of this tumor were reported worldwide. This tumor is multifocal and laryngeal involvement is considered to be as unusual site. Kaposi sarcoma is almost always are associated with classical skin lesion, and only about 5% of non-acquired immune deficiency syndrome Kaposi sarcomas are reported to be located in the larynx. We report a kidney transplant recipient diagnosed with solitary laryngeal Kaposi sarcoma 21 months after transplantation, who was treated with combined surgery, chemotherapy, and immunosuppressive modification.