Pseudohypoaldosteronism, a proximal tubular sodium wasting disease

Long term observations in a patient with pseudohypoaldosteronism

This paper describes a patient with severe pseudohypoaldosteronism (PHA) for over 12 years. The patient presented at 10 days of age with a serum sodium of 118 mEq/l and potassium of 12 mEq/l. After failing to maintain normal fluid and electrolyte status with standard therapy, including maximal mineralocorticoid stimulation, he was given a special formula containing minimal potassium plus salt supplements which normalized his electrolyte status. However, when he was 4.5 years of age, an acute gastrointestinal illness led to severe volume depletion, hyperkalemia, and cardiopulmonary arrest. This resulted in significant neurological impairment. At 12.5 years of age, the patient continues to require massive sodium supplements and his diet contains less than 0.5 mEq/kg potassium daily; his height and weight are at the 95th percentile, thus demonstrating that normal growth may be achieved with strict dietary manipulation in a patient with persistent, severe PHA. Serial studies to further define the lesion in this patient have demonstrated: (1) normal binding of aldosterone to aldosterone binding globulin (5.1% bound); (2) normal mineralocorticoid "activity"; (2) suppressible renin and aldosterone levels; (4) increased prostaglandin excretion (3.15 micrograms/g creatinine); (5) lack of benefit of prostaglandin inhibition with indomethacin; (6) normal proximal tubule function (CNa + CH2O = 18.0 ml/100 ml glomerular filtration rate; (7) impaired distal tubule function (CH2O/CNa + CH2O = 79.8%) during water diuresis.

Salt losing nephropathy simulating congenital adrenal hyperplasia in infants with obstructive uropathy and/or vesicoureteral reflux--value of ultrasonography in diagnosis

Salt losing nephropathy, occurring predominantly in male infants, has been reported in association with a spectrum of urologic diseases including obstructive uropathy and massive, infected vesicoureteral reflux (VUR). This has been called pseudo-hypoaldosteronism (PHA) or alternatively, pseudo salt-losing congenital adrenal hyperplasia (CAH), and is thought to reflect a tubular unresponsiveness to aldosterone. We report our experience with six cases, discuss one case in detail and review the 39 cases previously reported. A one month old male infant presented with a left upper quadrant mass. Signs and symptoms included vomiting, dehydration, hyponatremia and hyperkalemia. This suggested the diagnosis of CAH for which therapy was instituted. Ultrasonographic examination subsequently revealed the mass to be a urinoma in an infant with posterior urethral valve (PUV) and obstructive hydronephrosis.

Urosepsis in infants with vesicoureteral reflux masquerading as the salt-losing type of congenital adrenal hyperplasia

Three male infants with vomiting, dehydration, hyponatremia, hyperkalemia and metabolic acidosis were found to have vesicoureteral reflux (VUR) and urinary tract infection. Two were initially thought to have the salt-losing form of congenital adrenal hyperplasia. Although prompt diagnosis of this potentially fatal condition is critical, its mimicry by urosepsis in infants with VUR is actually more common. Infection probably causes unresponsiveness of the distal renal tubules to aldosterone.

Familial pseudohypoaldosteronism

The clinical course of two siblings with a severe form of pseudohypoaldosteronism was followed over a period of seven and five years respectively. Both children persistently had a high sodium-potassium excretion ratio in the urine, sweat, saliva, and stools as well as high serum concentrations of aldosterone and renin and an increased urinary excretion of tetrahydroaldosterone. Despite sustained treatment with sodium chloride (10-40 mmol/kg/d) and cation exchange resin (sodium polystyrole sulfonate 0.5-2 g/kg/d) they repeatedly developed episodes of salt wasting and hyperkalemia which occurred mainly during uncomplicated respiratory tract infections. Aldosterone receptor characteristics were studied in the cytosol of the rectal mucosa at ages 2.5 years and 6 months respectively. Compared to age matched controls there was a decreased affinity for aldosterone at the low affinity binding site. Among the members of the family, the father and one of his sisters had high concentrations of sodium in the sweat and an increased urinary excretion of tetrahydroaldosterone.

Acute tubular dysfunction in infants with obstructive uropathy

Eleven patients are described with severe hyponatraemia, hyperkalaemia and metabolic acidosis associated with a urinary tract infection and obstructive uropathy. This clinical entity resembles adrenocortical disorders. Urine culture investigation in combination with abdominal ultrasound examination will reveal urinary tract obstruction. Differential diagnosis, pathogenesis and treatment are discussed. In most patients correction of the metabolic disturbance can be achieved with antibiotic treatment, occasionally in combination with surgical therapy. Some degree of polyuria will generally persist.