A circulating inhibitor of platelet aggregation in Bartter's syndrome.

Aggregation studies were performed on platelets from five patients with Bartter's syndrome. Epinephrine failed to induce aggregation in all five patients. Adenosine 5'-diphosphate (ADP) produced a single reversible phase of aggregation, and there was depressed sensitivity to collagen. Response to ristocetin was normal. There was a dose-related inhibition of ADP-induced platelet aggregation when plasma from the patients was addeded to normal platelet-rich plasma. This inhibition was diminished or absent when patients were receiving aspirin. Washed platelets from two patients who were no longer undergoing aspirin therapy, showed a normal response to epinephrine in normal platelet-poor plasma. Bleeding time was reduced from 23 minutes to 12 minutes in one patient while on aspirin therapy. These studies suggest that a circulating inhibitor of platelet aggregation, probably of prostaglandin origin, is present in the plasma of patients with Bartter's syndrome.     

Association of Bartter's syndrome and empty sella

Bartter's syndrome is characterized by hypochloremia, hypokalemia, metabolic alkalosis associated with renal potassium leakage, and normal blood pressure despite increased plasma renin activity. Although association of empty sella with Gitelman syndrome has been reported, no association has been reported with Bartter's syndrome. Here we report a patient with Bartter's syndrome and empty sella. A 12 month-old male patient presented with a history of nausea, vomiting, abdominal distension, constipation, and edema in the lower extremities that had begun in the early postnatal period. The patient was born at 32 weeks gestation by operative delivery for polyhydramnios. Blood pressure was normal. Serum sodium, potassium, calcium, phosphate, chloride, albumin and alkaline phosphatase levels were 129 mEq/l, 2.5 mEq/l, 9 mg/dl, 3.8 mg/dl, 72 mg/dl, 4.2 g/dl and 1285 IU/l, respectively. Serum magnesium level was normal. Arterial blood gas levels revealed pH 7.55 (normal, 7.35-7.45), PCO2 33.6 mm/Hg (36-46), base excess +7.1 (+/- 2.3), and total CO2 33.6 mmol/l (23-27). Renin and aldosterone levels were elevated. Urine had pH 8.0 and specific gravity 1.010. Urinary calcium excretion was 22.8 kg/day (urine calcium/creatinine ratio 0.46). Urinary potassium and chloride levels were elevated. MRI of the brain was normal except for partially empty sella. We present the first pediatric patient with the association of Bartter's syndrome and empty sella.     

The role of prostaglandins in Bartter's syndrome

In two children with Bartter's syndrome, treatment with indomethacin halved the urinary excretion of prostaglandins E and F within 24 hours and subsequently maintained it within the normal range during follow-up for more than 5 years. Growth rate was improved and plasma renin and aldosterone and the urinary excretions of sodium and calcium fell to normal. Both children continued to lose excessive quantities of potassium in the urine. The results provide further evidence that over-production of prostaglandins is not the primary cause of Bartter's syndrome.     

Bartter's syndrome:clinical findings,genetic causes and therapeutic approach

Backgound Bartter's syndrome(BS)is a rare group of salt losing tubulopathies due to the impairment of transport mecha-nisms at the thick ascending limb of the H...     

Treatment of Bartter's syndrome in early childhood with prostaglandin synthetase inhibitors.

The diagnosis of Bartter's syndrome was made in a 9-month-old boy investigated for poor weight and height gain. Initial treatment with oral potassium supplements and later spironolactone had little or no effect on his growth, although plasma potassium rose to normal after spironolactone. At 33 months indomethacin therapy was started with dramatic results. His symptoms went and his height and weight accelerated into the normal range. In view of the toxicity of indomethacin it was replaced after 12 months by another prostaglandin synthetase inhibitor, ketoprofen, with a satisfactory result. During the change-over period from indomethacin to ketoprofen the expected deterioration in clinical well-being was observed, accompanied by a rise in urinary prostaglandins and plasma renin activity. Prostaglandin synthetase inhibitors provide the best available treatment for Bartter's syndrome.     

Studies on the site of renal tubular defect in Bartter's syndrome

Renal tubular function was studied in an 8-month-old male infant with Bartter's syndrome, which is characterized by hypokalemic metabolic alkalosis, normotensive hyperreninemic hyperaldosteronism, and reduced pressor response to angiotensin II. Chloride transport along the diluting segment (C_H2O/C_H2O + C_Cl) was impaired. Furthermore, furosemide did not elicit normal natriuresis, which suggested impaired chloride reabsorptive capacity at the furosemide-sensitive ascending limb of Henle's loop. Loss of antidiuretic hormone-mediated urinary concentration was in support of this. These findings pointed to the thick ascending limb of Henle's loop as the site of the primary defect in this child.     

Insulin resistant diabetes, acanthosis nigricans and Bartter's syndrome, a fortuitous association?]

The authors have followed during 10 years a girl with Bartter's syndrome who developed severe insulin resistance with acanthosis nigricans. In this rare association, hypokalemia and renal failure did not appear to be relevant factors triggering the onset of diabetes. The therapeutic difficulties in this case have still not been resolved.     

Option of pre-emptive nephrectomy and renal transplantation for Bartter's syndrome

Bartter's syndrome (BS) is an incurable genetic disease, with variable response to supportive therapy relating to fluid and electrolyte management. Poor control or therapy non-compliance may result in frequent life threatening episodes of dehydration, acidosis and hypokalemia, with resultant adverse effects on patient quality of life (QOL). We report, for the first time, pre-emptive bilateral native nephrectomies and successful renal transplantation, prior to the onset of ESRD, for severe, clinically brittle, neonatal BS, resulting in correction of metabolic abnormalities and excellent graft function. We propose that fragile BS should be considered as a possible indication for early native nephrectomies and pre-emptive renal transplantation, procedures that results in a 'cure' for the underlying disease and significant improvements in patient QOL.     

Bartter's syndrome in Arabic children: review of 13 cases

BACKGROUND: Bartter's syndrome (BS) is an inherited disease of renal potassium wasting characterized by hypokalemic alkalosis, normal blood pressure, vascular insensitivity to pressor agents and elevated plasma concentrations of renin and aldosterone. It is caused by generalized hyperplasia of the juxtaglomerular apparatus at the site of renin production caused by mutations in the Na-K-2Cl cotransporter gene, NKCC2. The objective of our study is to establish the prevalence and incidence of BS in Kuwait and to assess treatment modalities for it. METHODS AND RESULTS: Bartter's syndrome was diagnosed in 13 Kuwaiti children over a 14 year period (1981-1995) with the estimated incidence of 1.7/100,000 live births. The mean age at diagnosis was 9.3 months (range 2-32 months). There were five males and eight females (ratio 1:1.6). The mean duration of follow up was 5.6 years (1-14 years). Both consanguinity and familial history among our patients were high (69 and 54%, respectively). All patients had hypokalemia, hypochloremia with metabolic alkalosis, hyperreninemia and were normotensive. Clinical presentation was essentially similar to that in other series. Eleven patients (85%) had growth failure, two had nephrocalcinosis (15%) and one had renal failure. All patients were treated with supplemental potassium, an aldosterone antagonist (spironolactone) and a prostaglandin synthetase inhibitor (indomethacin or aspirin) sequentially. Significant catch-up of growth (four patients) and increases in serum potassium (eight patients) were recorded after administration of indomethacin therapy. One patient died of severe pneumonia with respiratory failure from hypokalemic myopathy. Clinical presentation, inheritance, complications and therapy of BS are briefly discussed. CONCLUSION: Bartter's syndrome is a rare disease, but should be considered in the differential diagnosis of other disorders with growth failure and/or hypokalemia. Early diagnosis, close follow up and compliance with treatment may lead to appropriate growth and development.