Polyendocrine syndrome with severe hypoparathyroidism responsible for progressive renal damage in a case of initial diabetic nephropathy

Our patient is a woman affected with insulin-dependent diabetes mellitus (IDDM) from the age of 16 months. Since the time of the diagnosis she presented alopecia areata, and convulsive episodes due to hypoglycemia. At the age of 2 years the appearance of cranic mucocutaneous moniliasis not responsive to therapy. Successively the patient has always bad a poor dialytic control and periodic convulsive crises. During these episodes other than low plasma glucose levels very low levels of calcemia of 1 mmol/l (4.2 mg/dl) with phosphatemia of 3.7 mmol/l (11.7 mg/dl) were found. Plasma PTH level resulted undetectable, serum magnesium concentration of 0.61 mmol/l (1.5 mEq/l) and urinary excretion of calcium of 0.45 mmol/day (18.2 mg/day), corresponded to 0.0125 mmol/kg/day (0.50 mg/kg/day). Serum alkaline phosphatase was 387 U/L, glomerular filtration rate of 75 ml/min (1.73 m²). Dual-energy X-ray absorptiometry (DEXA) appeared normal. The clinical and metabolic features: alopecia areata, calcification of the lens with cataract formation, chronic mucocutaneous moniliasis acid convulsive episodes led a diagnosis of hypoparathyroidism included in an autoimmune polyendocrine syndrome type I with candidiasisectodermal dystrophy (APECED). The patient has been treated with vitamin D 1,25(OH)₂D₃ 75 μg/day with a fairly good control of calcium and phosphate metabolism. Now at the age of 23, appearance of clinically detectable proteinuria of 0.250 mg/day probably signifying an initial diabetic nephropathy. At the same time, an important reduction of glomerular filtration rate 26 ml/min. We think that in this case hypoparathyroidism and chronic hyperphosphatemia may have been responsible for chronic progression of renal failure. The progressive renal damage seems only partially due to initial diabetic nephropathy.