Marcela Vergara

Prevention of Serious Bacterial Infections in New-Onset Nephrotic Syndrome: A Survey of Current Practices

are the most serious infections in these patients. The heightened risk of infection is due to abnormalities in circulating immunoglobulin levels, opsonization, cellular immunity, and granulocyte chemotaxis. The secondary effects of treatment with corticosteroids and cytotoxic agents may exacerbate these intrinsic problems.si2 Prophylactic antibiotics and/or pneumococcal vaccines are given to children with nephrotic syndrome in an attempt to prevent infections. However, there are

Is antibiotic prophylaxis indicated for a voiding cystourethrogram

Sirs, Most published data about the association of urinary catheterization and urinary tract infection (UTI) relate to long-term catheterization. In contrast, the risk of UTI from the one-time insertion of a catheter that is subsequently promptly removed appears to be low [1, 2], although at least one sepsis-related fatality is known to have occurred in a 6-week-old male following a voiding cystourethrogram (VCUG) (O. Mehls, personal communication). More recently, in a study of 123 adults who had undergone pressure flow studies, Logadottir et al. [3] reported that 4.1% had a positive urine culture and symptoms of infection 1 week after the procedure, and required antibiotic treatment. The authors concluded that routine antibiotic prophylaxis was not indicated after a study involving a brief catheterization of the bladder. This conclusion was supported by another study of 94 women who had undergone urodynamic testing involving two catheterizations. Those patients were randomly assigned to receive trimethoprim-sulfamethoxazole prophylaxis or a placebo. One week after the urodynamic testing, cleancatch urine samples showed UTI in 5.4% of the treated patients and 6.1% of the placebo patients (P=0.6) [4]. We were able to find only one study of the risk of UTI associated with VCUGs in children. In that retrospective study of 932 children who had undergone VCUGs, 18 patients (1.9%) developed a febrile UTI within 7 days of undergoing a VCUG. The risk was higher in boys, infants, patients with vesicoureteral reflux, and patients with other urinary tract abnormalities, but was not significantly lowered by antibiotic prophylaxis [5]. A few months ago, the occurrence of a UTI a few days after a VCUG in one of our patients prompted us to try to determine whether or not pediatric nephrologists routinely provide antibiotic prophylaxis to their patients who are scheduled to undergo a VCUG. To achieve this, we sent the following email to the subscribers of the PEDNEPH Internet Pediatric Nephrology List: UTI occurs in a small proportion of patients who undergo a VCUG. Do you prescribe prophylactic antibiotic treatment against that risk? Fifty-three responses were received. We included our own answers to the question for a total of 56 responses. Two respondents gave equivocal answers that were not included in the final count. One of those prescribed an antibiotic, after the procedure, only when the catheterization was difficult. The other prescribed prophylaxis for infants but not for older children. Of the remaining 54, 25 (46%) reported that they did not routinely provide prophylaxis and 29 (54%) reported that they did. There was a disparity in the practice of pediatric nephrologists working in the United States and those working in other countries. Of the 35 American respondents, 20 (57%) did not recommend prophylaxis and 15 (43%) did. Of the 19 non-American respondents, only 5 (26%) did not recommend prophylaxis, while 14 (74%) did. The difference between American and non-American nephrologists was statistically significant (chi-squared 4.71, P 0.05). In view of the absence of a clear-cut association between VCUG and post-VCUG UTI, after many years of performing the procedure, we suggest that UTI is an infrequent complication and that antibiotic prophylaxis cannot be considered the “standard of care.” This conclusion is supported by the fact that only slightly more than half of pediatric nephrologists who responded to our question recommended prophylaxis. What little evidence is available does not support antibiotic prophylaxis for VCUGs. B. Gauthier · M. Vergara · R. Frank · S. Vento · H. Trachtman Division of Nephrology, Schneider Children’s Hospital of the North Shore-Long Island Jewish Health System, Long Island Campus for the Albert Einstein College of Medicine, New Hyde Park, New York, USA

URINARY TRACT INFECTIONS, VUR, AND AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY DISEASE

This case series of 16 patients with autosomal dominant polycystic kidney disease (ADPKD) describes 4 girls who presented with a urinary tract infection (UTI). Radiological evaluation revealed that each of these patients had vesicoureteral reflux (VUR). The frequency of VUR was significantly higher in the patients with ADPKD compared with otherwise healthy age-matched children who underwent testing after a UTI (100% versus 15%, P<0.002). These findings suggest VUR is an associated somatic anomaly in children with ADPKD that may contribute to the occurrence of UTI in this patient population.

Outcome after renal transplantation in children: Results of follow‐up by nephrologists in a primary referral center

Abstract:  Pediatric patients who receive a kidney transplant require extended follow‐up to monitor graft function and for management of complications. Because of convenience, most patients are sent back to the nephrologists who referred them for transplantation (the primary nephrologist) for long‐term care. As a consequence, many pediatric nephrologists who provide this extended care are not associated with a transplant center. It is not known if this arrangement yields satisfactory outcomes for children and adolescents who receive a kidney transplant.

Efficacy of losartan in the treatment of erythrocytosis in a young adult with CRF

We report a 25-year-old man who was born with bilateral hydroureteronephrosis. He was referred to the pediatric nephrology service in 1997 at 20 years of age for management of proteinuria and a declining glomerular filtration rate (GFR). At the time of referral, the patient was in good health. His height was 173.5 cm (33%), weight 80.9 kg (81%), and blood pressure (BP) 128/ 71 mmHg. Laboratory testing revealed hemoglobin 16.2 g/dl, creatinine 1.6 mg/dl, calculated GFR 76 ml/ min per 1.73 m2 [1], and a protein/creatinine (Up/c) ratio of 3.7 in an early morning urine specimen. He was started on the angiotensin converting enzyme inhibitor (ACEI) lisinopril 10 mg daily and his Up/c fell to 0.4. Over the next 5 years, he gradually developed erythrocytosis, with a hemoglobin level that rose from 15.8 to 19.6 g/dl. His serum creatinine concentration remained at 1.6 mg/dl, but his Up/c increased to 1.9, and he had systolic hypertension (BP 142/65 mmHg). In June 2003, at the age of 25 years, magnetic resonance imaging showed massive cystic changes in both kidneys, with small areas of remaining normal renal parenchyma. His lisinopril dose had been stable at 15 mg daily for 16 months. After evaluation by a hematologist for erythrocytosis, the patient was placed on losartan in addition to lisinopril. The response to this treatment is summarized in Table 1. In this case report, we show that inhibition of the renin-angiotensin system modulated erythrocytosis prior to kidney transplantation in a young adult with obstructive uropathy. The addition of an angiotensin II type 1 receptor blocker (ARB) was more effective than prior treatment with an ACEI alone. Several studies have documented a benefit of either ACEI or ARB in patients with post-transplant erythrocytosis [2, 3, 4]. We are aware of only one previous study demonstrating the benefit of ACEI in adult polycythemic patients who retained their native kidneys [5]. In a randomized study, Yildiz et al. [4] showed that enalapril caused a greater decrease in hemoglobin levels but a shorter time to relapse after discontinuation of the medication, compared with losartan in patients with posttransplantation erythrocytosis. They concluded that the two medications act through different mechanisms. Our case report is consistent with this proposal. However, since the ACEI was not discontinued, it is possible that the improvement following addition of losartan was secondary to an additive effect of the two medications, as opposed to a distinct pathway. The mechanism by which blockade of the reninangiotensin axis ameliorates erythrocytosis is a subject of debate. Some [2, 3], but not all [5], studies show a sustained decrease in erythropoietin levels in treated patients that parallels the fall in hemoglobin concentration. An alternative mechanism of action for losartan may be blockade of angiotensin II receptors on erythroid precursors [2]. Our data demonstrating a decrease in erythropoietin levels after initiation of losartan are consistent with a direct drug-mediated inhibition of erythropoietin secretion. The patient tolerated the use of both drugs without a decrement in kidney function or hyperkalemia. Moreover, M. L. Stoll · B. G. Gauthier · M. Vergara · R. Frank · H. Trachtman Department of Pediatrics, Division of Nephrology, Schneider Children’s Hospital of the North Shore–Long Island Jewish Health System, New Hyde Park, New York, USA

Diagnostic Yield of Parathyroid Hormone Testing in Children Evaluated for Hypercalciuria

Hypercalciuria is a frequent cause of non-glomerular hematuria in pediatric patients. Because hypercalciuria can be secondary to primary hyperparathyroidism, measurement of serum parathyroid hormone (PTH) levels is often performed in children with this urinary abnormality. A retrospective chart review was performed to determine the diagnostic yield of PTH measurements when performed under these clinical circumstances. Over a 30-month period (January 1, 2001 to September 30, 2003), among 31 children who had a PTH determination, the level was elevated in 1 (3%) patient. Based on these findings and the serious nature of untreated primary hyperparathyroidism, serum PTH level should be measured in pediatric patients with newly diagnosed hypercalciuria.