Hypertension in a patient with medullary sponge kidney: A case report.

RATIONALE: Medullary sponge kidney (MSK) is a congenital renal disorder characterized by recurrent nephrolithiasis or nephrocalcinosis. Recently, it has been found that MSK can be also combined with other diseases, such as primary aldosteronism and Beckwith-Wiedemann, but whether it is associated with secondary hypertension remains unknown. PATIENT CONCERNS: A 22-year-old hypertensive female presented to our hospital characterized by hypokalemia and hypertension. DIAGNOSIS: The laboratory examination showed secondary aldosteronism. And the common causes for secondary aldosteronism include renal artery stenosis, glomerulonephritis, lupus nephropathy, and diabetic nephropathy, all of which were excluded except MSK. INTERVENTIONS: She was treated with angiotensin-converting enzyme inhibitors. OUTCOMES: Her blood pressure, serum potassium, and plasma renin levels were reversed after treatment with angiotensin-converting enzyme inhibitors. LESSONS: We presumed that MSK may be associated with secondary hypertension, and the mechanism may be the activation of the renin-angiotensin-aldosterone system.

The impact of potassium citrate therapy in the natural course of Medullary Sponge Kidney with associated nephrolithiasis.

OBJECTIVES: The present study was carried out to evaluate the effectiveness of medical therapy with potassium citrate in preventing calculosis complicating Medullary Sponge Kidney (MSK) without renal acidification defects. MATERIALS AND METHODS: In a open, uncontrolled, retrospective analysis, 49 MSK patients with nephrolithiasis without renal tubular acidosis, underwent a complete metabolic evaluation and received potassium citrate therapy 4-6 g/day. The course of stone disease before and after citrate therapy was determined in each patient from a combination of clinical history, past records, radiographs and kidney ultrasound. The rate of new stone formation/pt/yr, of endourological and extracorporeal procedures, of urinary tract infection (UTI) and number of hospitalization before and after medical treatment were calculated. RESULTS: Metabolic anomalies (hypercalciuria, hypocitraturia, hyperuricuria and hyperoxaluria) were present in 83% of the patients. Follow-up before and after alkali citrate therapy was comparable (4.7+/-1.4 and 4.9+/-1.7 years respectively). Medical treatment significantly reduced rates of stone formation from 2.0+/-1.0 to 0.2+/-0.5 pt/yr, ureteroscopy (URS) from 0.9+/0.8 to 0.4+/-0.5 pt/yr, extratracoporeal lithotripsy (ESWL) from 1.1+/-0.8 to 0.4+/-0.6 pt/yr, urinary tract infections (UTIs) from 0.8+/-1.2 to 0.3+/-0.5 pt/yr and hospitalization from 1.1+/-0.6 to 0.2+/-0.3 pt/yr, p < 0.001. This effect was observed also in MSK patients without metabolic anomalies. In 35 patients the asymptomatic disappearance of calcium stones was also observed. CONCLUSIONS: Our study documents the effectiveness of potassium citrate therapy in preventing neprolithiasis in MSK patients also in the absence of distal tubular acidosis. It suggests that in MSK patients alkali citrate may promote calcium stone dissolution by oral administration.

Medullary sponge kidney: causes and treatments.

Medullary sponge kidney is a little known and little understood disease. A patient with a medullary sponge kidney may undergo decades of suffering in the form of infections and pain before any diagnosis is even made. When a diagnosis is made, it is more than likely to be an incidental finding from a test for another problem. However, on diagnosis there are a number of options available to treat this condition. These include non-invasive treatments such as drug therapy, diet or extracorporeal shock wave lithotripsy, to invasive therapies such as percutaneous nephrolithotomy, ureteroscopy and more advanced surgery. The aim of this article is to highlight this little known condition, outline the effects, and discuss the treatment options available to patients.

Long-term treatment with potassium citrate and renal stones in medullary sponge kidney.

BACKGROUND AND OBJECTIVES: Medullary sponge kidney (MSK) is a renal malformation typically associated with nephrocalcinosis and recurrent calcium stones. Incomplete distal renal tubular acidosis, hypocitraturia, and hypercalciuria are common. For stone prevention, patients with MSK generally receive the standard "stone clinic" recommendations and often receive potassium citrate (KC). However, the effect on stone recurrence of citrate treatment in these patients has never been studied. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: The issue was retrospectively analyzed on an outpatient basis in 97 patients with a radiologic diagnosis of MSK: 65 had at least one stone risk factor (SRF; hypercalciuria, hypocitraturia, hyperuricosuria, hyperoxaluria) and received KC [29 +/- 8 (SD) mEq/d]; 10 patients with SRF and 22 without received only general stone clinic suggestions. Follow-up was 78 +/- 13, 72 +/- 15, and 83 +/- 14 months, respectively. The 24-hour urinary excretion of calcium, oxalate, uric acid, citrate, and morning urine pH were investigated at baseline and at the end of follow-up. RESULTS: Parallel to a significant rise in urinary citrate and decreased urinary calcium (all P < 0.001), KC led to a dramatic reduction in the stone event rate (from 0.58 to 0.10 stones/yr per patient). The existence of a group of patients with MSK, those without SRF, with a very low stone rate and no SRF was recognized. CONCLUSIONS: Treatment with KC is effective in preventing renal stones in the typical patient with MSK. It seems that two clinical phenotypes among patients showing typical MSK features during radiologic study exist.

Bone disease in medullary sponge kidney and effect of potassium citrate treatment.

BACKGROUND AND OBJECTIVES: In medullary sponge kidney (MSK)-a common malformative renal condition in patients with calcium nephrolithiasis-hypercalciuria, incomplete distal renal tubular acidosis, and hypocitraturia are common. Clinical conditions with concomitant hypercalciuria and/or incomplete distal renal tubular acidosis are almost invariably associated with bone disease, making osteopathy highly likely in MSK, too. Patients with MSK have never been investigated for osteopathy; neither has the potential effect of potassium citrate administration (CA) on their urinary metabolic risk factors and on bone mineralization. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: These issues were retrospectively analyzed in 75 patients with MSK and primary stone risk factor (PSRF; hypercalciuria, hypocitraturia, hyperuricosuria, and/or hyperoxaluria) on an outpatient basis; 65 received CA (2.9 +/- 0.8 g/d), whereas 10 received only general "stone clinic" suggestions. The 24-h urinary excretion of calcium, phosphate, oxalate, uric acid, and citrate; morning urine pH; serum biochemistry; and bone mineral density were investigated at baseline and at the end of follow-up (78 +/- 13 and 72 +/- 15 mo in groups A and B, respectively). RESULTS: CA led to a significant rise in urinary pH and citrate and decreased urinary calcium and phosphate (all P < 0.001). Patients with MSK and PSRF had reduced bone density. Bone density improved significantly in the group that was treated with oral CA. CONCLUSIONS: Bone disease is very frequent in patients with MSK and concomitant PSRF. Long-term CA improves bone density. The concurrent effects of treatment on PSRF suggest that the subtle acidosis plays a pivotal role in bone disease and hypercalciuria in patients with MSK.

A case of normotensive primary aldosteronism with hypopituitarism, epilepsy, and medullary sponge kidney.

A 55-year-old man with normotensive primary aldosteronism, hypopituitarism, epilepsy, and medullary sponge kidney is reported. Seventeen years before admission, he had been noted to have hypokalemia associated with high potassium clearance, suppressed plasma renin activity, metabolic alkalosis, and normal blood pressure as well as low urinary excretion of 17-hydroxycorticosteroids. He kept normotensive in spite of hyperaldosteronism until nine months after the initiation of replacement therapy with glucocorticoid and thyroxine for hypopituitarism, when he became hypertensive. Hypopituitarism seemed to play a role in keeping a normal blood pressure despite long-standing hyperaldosteronism.

Change of urinary excretion of electrolytes after acid, base and furosemide application in sponge kidney.

Sponge kidney is rare clinical and pathological entity, incidentally found in 0.4--1% of all excretory urographies. In the advanced stage of the disease, distal tubules are affected and renal-tubular acidosis, change of urinary laminar flow and Ca2+ wasting syndrome result in frequent formation of Ca-oxalate stones. Alkali therapy is investigated on the excretion of Na+, K+ and Ca2+ and compared to furosemide administration.