A. Fabris

Medullary Sponge Kidney and Hyperparathyroidism -a Puzzling Association

28 adult patients with radiological evidence of medullary sponge kidney (MSK) were studied. Hypercalcemia and increased serum parathyroid hormone (PTH) values were found in 10 patients (36%). In 7 of them, parathyroid surgery was performed: a single adenoma was found in 6 cases and multiple-gland hyperplasia in 1 case. After surgery, 3 patients had normalization of calcium metabolism; 4 patients had persistence of hypercalciuria with progressive increase in serum PTH values (and recurrence of the adenoma in 1 case). Of the remaining patients, 10 (36%) had definite or marginal hypercalciuria, resulting from renal calcium leak in 8 and from intestinal calcium hyperabsorption in 2 of them. In 8 patients (28%), no evidence of disordered calcium metabolism was found. The association of MSK and hyperparathyroidism is not a chance occurrence. MSK might be a renal anatomical complication of primary hyperparathyroidism, or it might be regarded as an anatomic substrate--or rather as a consequence--of prolonged hypercalciuria, regardless of its pathogenesis. The lack of disordered calcium metabolism in a considerable number of patients, however, shows that the enigma of MSK is still far from being solved.

Unusual renal presentation of Fabry disease in a female patient.

Background. A 29-year-old white woman with a family history of Fabry disease was referred to a nephrology clinic with hypertension and nephropathy. Her renal function was below normal (serum creatinine level 141 µmol/l; estimated glomerular filtration rate 41 ml/min/1.73 m2) with no proteinuria or albuminuria.Investigations. Medical history, physical examination, leukocyte α-galactosidase A assay, laboratory tests (for antinuclear antibodies, antineutrophil cytoplasmic antibodies, lupus anticoagulant, anticardiolipin antibodies, complement and cryoglobulin), ophthalmological examination, echocardiography, brain magnetic resonance angiography, renal ultrasonography, renal color echo-Doppler scan, renal magnetic resonance angiography, renal angiography and renal biopsy.Diagnosis. Diffuse sclero-atrophic renal tissue changes and widespread renal arterio-arteriolosclerotic changes secondary to Fabry disease.Treatment. Angiotensin-converting-enzyme inhibitors and maintenance treatment with agalsidase-β, 1 mg/kg body weight, every 2 weeks.

Phosphate-Restricted Diets versus Calcitonin in the Prevention of Osteodystrophy in Experimental Renal Disease

Restriction of dietary phosphate intake is beneficial in preventing the development of secondary hyperparathyroidism and bone disease in experimental renal failure in the dog (l–3). If associated with vitamin D administration, this dietary regimen can prevent both pathologic bone resorption and osteomalacia in the same experimental model (3). In rats with surgically-induced renal failure, the administration of phosphate-deficient diets (0.03% phosphate) is followed by anorexia, hypophosphatemia, growth arrest, stunting, and severe rickets (4,5). On the other hand, growth failure is also commonly observed when the same animals are given high-phosphate diets (1.58 % phosphate) (6).