High Parathyroid Hormone Level and Osteoporosis Predict Progression of Coronary Artery Calcification in Patients on Dialysis.

Coronary artery calcifications (CACs) are observed in most patients with CKD on dialysis (CKD-5D). CACs frequently progress and are associated with increased risk for cardiovascular events, the major cause of death in these patients. A link between bone and vascular calcification has been shown.

The opposing actions of the two parathyroid hormones, 1-84 PTH and 7-84 PTH: improvement in renal bone and calcium metabolism management.

Bone biopsy, while invasive, is the gold standard for assessing bone status. According to published bone biopsy studies, half of the end-stage renal disease patients have adynamic bone disease. Compared to high-bone-turnover disease, adynamic bone disease has the higher mortality and is associated with arterial calcification.

Intact PTH assay overestimates true 1-84 PTH levels after maxacalcitol therapy in dialysis patients with secondary hyperparathyroidism.

Background: Although the so-called intact parathyroid hormone (iPTH) assay detects not only true 1-84 PTH (1-84PTH) but also large C-terminal PTH fragments, it remains inconclusive whether the 1-84PTH assay is more useful in clinical practice. Previous studies have shown that the results of these two PTH assays in dialysis patients are closely correlated.

Methods: Chronic dialysis patients whose plasma iPTH levels were >400 pg/ml were selected for inclusion in the present study.

Activating antibodies to the calcium-sensing receptor in two patients with autoimmune hypoparathyroidism.

Autoimmune hypoparathyroidism is thought to result from immune-mediated destruction of the parathyroid glands. We encountered two patients with hypoparathyroidism and other autoimmune conditions (Graves' disease and Addison's disease, respectively) in whom autoimmune destruction of the parathyroid glands had not taken place. In the first, a histologically normal parathyroid gland was observed at the time of subtotal thyroidectomy; and in the second, the hypoparathyroidism remitted spontaneously.

Decreased expression of caveolin-1 and altered regulation of mitogen-activated protein kinase in cultured bovine parathyroid cells and human parathyroid adenomas.

Caveolins are key components of caveolae membranes. The calcium-sensing receptor (CaR) resides within caveolin-rich membrane domains in bovine parathyroid (PT) cells. Recent studies reported reduced CaR expression, and abnormal calcium-sensing in PT tumors.

A syndrome of hypocalciuric hypercalcemia caused by autoantibodies directed at the calcium-sensing receptor.

Antibodies to cell surface receptors can cause endocrine dysfunction by mimicking or blocking the actions of their respective hormones. We sought patients with autoantibodies to the extracellular calcium (Ca(2+)(o))-sensing receptor (CaR), which sets the normal level of blood calcium, that mimic the genetic disorder, familial hypocalciuric hypercalcemia, caused by heterozygous inactivating mutations of the CaR. Four individuals from two kindreds were identified with PTH-dependent hypercalcemia, who had other autoimmune manifestations: one with sprue and antigliadin and antiendomyseal antibodies and three with antithyroid antibodies.