Serum calcium as an early indicator for surgical treatment of hyperparathyroidism after renal transplantation

In an attempt to find out if a particular group of patients with hyperparathyroidism after renal transplantation (HRT) are at risk of developing complications, 14 patients with overt untreated HRT who had at least 1 serum calcium determination ≥ 12 mg/100 ml were evaluated and compared retrospectively with 11 normocalcemic transplant recipients at 6 and 30± 8 months after successful renal allografting. Serum calcium was ≥ 12 mg/100 ml within 6 months of transplantation in 13 of the 14 HRT patients. At 6 months significant differences were found between HRT and controls in mean serum calcium (11.6 versus 9.2 mg/100 ml) and alkaline phosphatase (228 versus 120 U/l). At 30±8 months differences were found in serum calcium (10.2 versus 9.4 mg/100 ml), phosphate (2.8 versus 4.8 mg/100 ml), and alkaline phosphatase (180 versus 88 U/l). Serum creatinine levels were similar in the 2 groups. A significant correlation was found between early and late determinations of alkaline phosphatase when all 25 patients were studied as a single group (r=0.72, p<0.001). Bone pain and/or radiological evidence of hyperparathyroid bone disease were significantly associated with HRT (8 versus 1 and 7 versus 0, respectively). A higher but not significant incidence of vascular calcifications (5 versus 1) and acute pancreatitis (2 versus 0) was found in HRT. Patients who develop moderate to severe HRT as defined by at least 1 serum calcium determination ≥ 12 mg/100 ml do so within 6 months of renal transplantation, have increased morbidity, particularly involving the skeleton, and might benefit from early subtotal parathyroidectomy .