Biomedical subjects

Carolyn L Abitbol

Publications and source records attributed to Carolyn L Abitbol.

7 recordsLinked to original sources

PubMed2006

Paricalcitol versus calcitriol treatment for hyperparathyroidism in pediatric hemodialysis patients.

Secondary hyperparathyroidism (SHPT) remains a treatment dilemma in pediatric dialysis patients. Recent experience with paricalcitol (P), a vitamin D analogue, in adults with SHPT has shown equal efficacy and improved survival compared to traditional treatment with calcitriol (C). We present our experience with (C) compared to (P) treatment in our pediatric dialysis patients with SHPT. Twenty-one patients (mean age 11.5+/-5 years) with SHPT (intact parathyroid hormone (iPTH) averaging 1,228+/-496 pg/ml) were studied. Seventeen received (C) followed by (P); while an additional four were treated with either (C=1) or (P=3) alone. After 26+/-8 weeks, average percent (%) decrease in iPTH was similar with (C) and (P) (-60.4+/-34% versus -65.4+/-28%, respectively; p=0.6). In the (P) group, the effective dose in children was greater than in adult trials based on kilogram weight. Episodes of hypercalcemia between the treatment groups were not different. However, episodes of elevated calcium x phosphorus product (CaxP)> or =70 mg(2)/dl(2) occurred more frequently in the (C) group (odds ratio=1.5; p=0.01). Paricalcitol appears to be safe and effective in pediatric patients. Data suggest that dosing should be gauged according to degree of SHPT. This should serve as impetus for future pharmacokinetic studies in pediatric dialysis patients.

Adolescent↗

PubMed2006

Profiling proteinuria in pediatric patients.

This study was designed to characterize proteinuria in children with kidney disease. Random urine samples from 250 pediatric patients were examined by quantitative measures of total protein (pr), albumin (Alb), and creatinine (cr). Patient diagnoses were subjectively categorized as "Glomerular" (GD) or "Tubulo-interstitial" disease (TD) in origin. Proteinuria was quantitated by the random urine protein-to-creatinine (Upr/cr) ratio, and glomerular proteinuria was assessed as the albumin-to-creatinine ratio (Ualb/cr) and percentage albuminuria (%Alb=Alb/pr*100). The non-albumin fraction (1-Alb/pr) includes low-molecular-weight proteins and micro- and macroglobulins. Of the 250 patients, 112 (45%) had GD and 138 (55%) had TD. Both proteinuria and albuminuria correlated with a decline in glomerular filtration rate (GFR) (r=-0.4; p<0.0001). Those with GD averaged significantly greater %Alb than those with TD at all levels of proteinuria (p<0.0001). With loss in GFR, %Alb increased significantly in patients with TD (18+/-13 to 47+/-30%; p<0.001) and GD (56+/-26 to 74+/-15%; p<0.01), respectively. The %Alb at all levels of GFR averaged <50% in those with TD and >50% in those with GD. In conclusion, random Ualb/cr, Upr/cr, and %Alb provide a simple and inexpensive assessment of proteinuria and may profile renal disease activity and response to therapy in pediatric patients.

Adolescent↗

PubMed2005

Reversal of oliguric tacrolimus nephrotoxicity in children.

BACKGROUND: Acute tacrolimus toxicity is manifest by oliguria and elevated serum creatinine. Various vasoregulatory molecules have been implicated in calcineurin inhibitor-mediated nephrotoxicity, including calcium, adenosine and endothelin. Theophylline (THEO), a non-specific adenosine-receptor antagonist prevents renal dysfunction from various nephrotoxins which mediate vasoconstriction. In the setting of acute tacrolimus toxicity, we demonstrated that administration of THEO along with a loop diuretic (LD) enhanced diuresis. This randomized, controlled trial was undertaken to confirm these earlier findings under more rigorous conditions. METHODS: Children with non-renal visceral transplant(s) and evidence of tacrolimus nephrotoxicity oliguria with a 25% increase in serum creatinine concentration from baseline, a whole blood tacrolimus concentration >20 ng/dl and oliguria resistant to therapy with a LD were randomized to receive either THEO (n = 10) or normal saline placebo (n = 8). Using pre and post (6 h) timed urine collections and coincident plasma concentrations the following were measured or calculated: urine flow rate, net fluid balance, creatinine clearance, fractional excretion of chloride, free water clearance and distal delivery of chloride. RESULTS: These patients had markedly impaired creatinine clearance at the onset of tacrolimus toxicity. Urine flow increased in the LD + THEO group by 110% over baseline, but was unchanged in the LD + NS group. An increase in creatinine clearance did not reach statistical significance (P = 0.09). Fractional excretion of chloride and distal solute delivery increased after THEO treatment. CONCLUSIONS: THEO induced a solute diuresis during furosemide-resistant oliguric tacrolimus toxicity in paediatric patients with a trend towards improved renal function.

Adolescent↗

PubMed2005

Renal manifestations of sexually transmitted diseases: sexually transmitted diseases and the kidney.

The adolescent population is particularly vulnerable to STDs. Those that cause significant kidney disease are of viral origin. The primary VVD are HIV-1, HBV, and HCV. Screening of high-risk populations should include quantitation of proteinuria, including total protein and microalbumin, to assess severity of renal damage and potential for progression. Renal biopsy is indicated for diagnosis and for planning important treatment interventions if there is significant proteinuria or decreased renal function. Causes of acute renal failure are frequently reversible and should be treated aggressively. These include HUS, vaso-motor or ischemic acute tubular necrosis, and drug toxicities. The spectrum of chronic kidney disease associated with VVD is broad and may include systemic manifestations of vasculitis. HIV-associated nephropathy is the prototype, with the most prevalent lesion remaining FSGS. Progression occurs in up to 15% of the patients, who are overwhelmingly of African lineage. Significant advances in management include ongoing development of HAART, angiotensin antagonists to control proteinuria, and novel immune-modulating drugs such as MMF, CsA, and rituximab. Dialysis therapies have offered improved survival, especially in pediatric patients. Moreover, transplantation is no longer considered experimental and should be offered to select patients.

Adolescent↗

PubMed2004

A functional immature model of chronic partial ureteral obstruction.

BACKGROUND: The most common nonlethal congenital anomaly of the urinary tract is ureteral obstruction without dysplasia. Although rarely progressive, the morbidity associated with metabolic and surgical management is considerable. Our study was designed to measure local and systemic pathophysiologic mechanisms in an immature model of chronic partial unilateral ureteral obstruction (UUO) after completion of glomerulogenesis. METHODS: A partial UUO was created by the method of "psoas wrap" in young male weanling rats. Control animals were sham operated. Three groups were divided as follows: sham (N= 15), UUO (N= 18), and UUO + angiotensin-converting enzyme (ACE) (N= 16) inhibitor, enalapril. Renal glomerular and tubular functions were determined by creatinine and uric acid clearances. Diuresis was assessed by urine volume, osmolality, and fractional solute excretions from samples above and below the obstruction. Proteinuria was determined by the urine protein/creatinine ratio (Up/c). RESULTS: Proteinuria was attenuated in UUO + ACE-treated animals. The hyperuricemia of the immature UUO animals was avoided by an increase in the clearance of uric acid in the UUO + ACE-treated group. Fractional solute excretions suggested a diversion of diuresis to the contralateral unobstructed kidney. CONCLUSION: Angiotensin blockade during chronic UUO in young rats affords protection by attenuating proteinuria, promoting uricosuria, and diverting solute diuresis. These data suggest a complex interaction of local and systemic mechanisms unique to the maturing kidney.

Animals↗

PubMed2003

Long-term follow-up of extremely low birth weight infants with neonatal renal failure.

The long-term outcome of 20 preterm infants with extremely low birth weight and acute renal failure in the neonatal period was studied retrospectively over an 18-year period. Those with progressive renal disease are compared with those with normal renal function. Current mean age is 7.5+/-4.6 years (range 3.2-18.5 years). Nine patients showed deterioration in renal function (low GFR group). Increasing proteinuria, as determined by random urine protein/creatinine ratio (Up/c), correlated with deterioration in renal function ( r=0.8, P<0.0001). Prominent risk factors for progression were Up/c >0.6 at 1 year of age [100% sensitivity, 75% positive predictive value (PPV), P<0.01], serum creatinine >0.6 mg/dl at 1 year of age (75% sensitivity, 80% PPV, P<0.01), and a tendency to obesity with body mass index >85th percentile (89% sensitivity, PPV 67%, P=0.03). Loss of renal mass and nephrocalcinosis were not prognostic indicators. This report begins to identify important clinical parameters that should lead to closer surveillance and potential treatment interventions for preservation of renal function in a growing population of surviving low birth weight individuals.

Acute Kidney Injury↗

PubMedDate not supplied

Histomorphometric analysis of postnatal glomerulogenesis in extremely preterm infants.

Until now oligonephropathy to indicate "too few nephrons" has been associated with intrauterine growth restriction and experimentally induced abnormalities of renal development. The purpose of this study was to determine whether there is evidence of abnormal postnatal glomerulogenesis in extremely low birth weight preterm infants. Renal autopsy tissue was studied by computer-assisted morphometry from 56 extremely premature infants (birth weight < or = 1000 g) and 10 fullterm infants as controls. Preterm infants were divided into two groups (short survival < or = 40 days vs. long survival > or = 40 days). Each group was subdivided into those with renal failure (RF) and those with normal renal function. Forty-two of 56 preterm infants (75%) were adequate for gestational age. Glomerulogenesis as measured by radial glomerular counts (RGC) was markedly decreased in all preterm infants as compared to term controls and correlated significantly with gestational age (r = 0.87; P < 0.001). Active glomerulogenesis with "basophilic S-shaped bodies" was absent in longer surviving preterm and all term infants. RGC of preterm infants surviving > or =40 days with RF were significantly less than RGC of those with long survival and no RF (P < 0.001). Only this latter group demonstrated increased glomerular size as measured by mesangial tuft area and Bowman's capsule area compared to all other groups (P < 0.001). The kidney continues to form postnatally in preterm neonates, but glomerulogenesis ceases after 40 days. Moreover, it is further inhibited by RF. Compensatory mechanisms in longer surviving preterm infants include glomerular hypertrophy and mesangial proliferation that could lead to hyperfiltration.

Female↗