PTH immunoassay interference: differential diagnosis with normocalcemic primary hyperparathyroidism?

The main diagnostic dilemma in normocalcemic hyperparathyroidism is differentiating this condition from secondary hyperparathyroidism and other causes of elevated parathyroid hormone (PTH) levels in eucalcemic patients, including potential assay interferences. Despite the analytical sensitivity of immunoassays, they may lack adequate accuracy due to several analytical interferences, such as the presence of heterophilic antibodies. Immunoassays for PTH measurement use the immunometric "sandwich" technique, and only a few cases of interference with this assay have been reported to date.

Planned parathyroidectomy: the new standard in hypercalcemic crisis.

Objective: The study sought to determine the clinical features of hyperparathyroid-induced hypercalcemic crisis (HIHC) along with treatment options and outcomes.

Subjects And Methods: This is a retrospective analysis of our historical cohort of patients with primary hyperparathyroidism (PHPT). Patients were divided in groups according to their calcium levels and clinical presentation.

Levels of bioavailable, and free forms of 25(OH)D after supplementation with vitamin D in primary hyperparathyroidism.

The 25 hydroxyvitamin D [25(OH)D] is the major metabolite for ascertaining vitamin D status, which circulates bound to a specific carrier (vitamin D-binding protein - VDBP). A portion that circulates unbound vary according to the VDBP genotype. This study evaluates the behavior of different forms of 25(OH)D, before and after supplementation with 14,000 IU of vitamin D3, weekly for 12 weeks, in individuals with primary hyperparathyroidism and controls.

Surgery for primary hyperparathyroidism.

Primary hyperparathyroidism (PHPT) is a hypercalcemic disorder that occurs when one or more parathyroid glands produces excessive parathyroid hormone (PTH). PHPT is typically treated with surgery, and it remains the only definitive therapy, whose techniques have evolved over previous decades. Advances in preoperative localization exams and the intraoperative PTH monitoring have become the cornerstones of recent parathyroidectomy techniques, as minimally invasive techniques are appropriate for most patients.

Definition and management of very high fracture risk in women with postmenopausal osteoporosis: a position statement from the Brazilian Society of Endocrinology and Metabolism (SBEM) and the Brazilian Association of Bone Assessment and Metabolism (ABRASSO).

Several drugs are available for the treatment of osteoporosis in postmenopausal women. Over the last decades, most patients requiring pharmacological intervention were offered antiresorptive drugs as first-line therapy, while anabolic agents were considered a last resource for those with therapeutic failure. However, recent randomized trials in patients with severe osteoporosis have shown that anabolic agents reduce fractures to a greater extent than antiresorptive medications.

Trabecular Bone Score (TBS) in Primary Hyperparathyroidism (PHPT): A Useful Tool?

Primary Hyperparathyroidism (PHPT) often leads to bone loss, even in its asymptomatic presentations. Trabecular Bone Score (TBS) is a method to assess the trabecular bone structure of the spine. This study aimed to evaluate TBS measurements combined with Dual X-ray Absorptiometry (DXA) values in the search for more accurate bone fragility risk assessment among PHPT patients.

Prediction of bone mass changes after successful parathyroidectomy using biochemical markers of bone metabolism in primary hyperparathyroidism: is it clinically useful?

Objective: To measure type 1 serum amino-terminal propeptide procollagen (P1NP) and type 1 cross-linked C-terminal telopeptide collagen (CTX) before parathyroidectomy (PTX) in PHPT patients, correlating these measurements with bone mineral density (BMD) changes.

Subjects And Methods: 31 primary hyperparathyroidism (HPTP) were followed from diagnosis up to 12-18 months after surgery. Serum levels of calcium, parathyroid hormone (PTH) vitamin D, CTX, P1NP, and BMD were measured before and 1 year after surgery.

Experience with a third-generation parathyroid hormone assay (BIO-PTH) in the diagnosis of primary hyperparathyroidism in a Brazilian population.

Objective: To evaluate the usefulness of a third-generation PTH assay in the diagnosis of primary hyperparathyroidism (PHPT).

Subjects And Methods: Forty-one PHPT patients (4 men and 37 women) with 61.2 ± 10.

Parathyroid responsiveness during hypocalcemia after total parathyroidectomy and autotransplantation in patients with renal hyperparathyroidism.

Introduction: Hyperparathyroidism is a frequent complication of chronic kidney disease (CKD). Total parathyroidectomy (PTX) with parathyroid tissue autotransplantation (AT) is a treatment option in those individuals that do not respond to clinical management.

Objective: To evaluate grafted parathyroid tissue response during induced hypocalcemia among CKD patients who underwent total PTX with AT.

Autotransplant tissue selection criteria with or without stereomicroscopy in parathyroidectomy for treatment of renal hyperparathyroidism.

Introduction: Several methods have been proposed to improve operative success in renal hyperparathyroidism.

Objective: To evaluate stereomicroscopy in parathyroid tissue selection for total parathyroidectomy with autotransplantation in secondary (SHPT)/tertiary (THPT) hyperparathyroidism.

Methods: 118 renal patients underwent surgery from April of 2000 to October 2009.

Localization of ectopic and supernumerary parathyroid glands in patients with secondary and tertiary hyperparathyroidism: surgical description and correlation with preoperative ultrasonography and Tc99m-Sestamibi scintigraphy.

Introduction: Hyperparathyroidism is an expected metabolic consequence of chronic kidney disease (CKD). Ectopic and/or supernumerary parathyroid glands (PT) may be the cause of surgical failure in patients undergoing total parathyroidectomy (PTX).

Aim: To define the locations of ectopic and supernumerary PT in patients with renal hyperparathyroidism and to correlate intraoperative findings with preoperative tests.

Intraoperative PTH cutoff definition to predict successful parathyroidectomy in secondary and tertiary hyperparathyroidism.

Unlabelled: In order to improve success rates in surgery of renal hyperparathyroidism, we evaluated intraoperative PTH (IOPTH) measurement utility.

Method: 86 patients underwent total parathyroidectomy with intramuscular presternal autotransplantation from 04/2000 to 10/2009 and were followed for 26.5 months on average (prospective cohort).

Parathyroid carcinoma and hungry bone syndrome.

We hereby report two patients with parathyroid carcinoma presenting extremely high calcium and PTH levels, severe bone disease, and palpable neck mass at diagnosis. They both underwent parathyroidectomy, and one of them evolved to lung metastasis. Important hypocalcemia was observed after surgery in both: after parathyroidectomy in one patient, and only after surgical removal of the metastasis in the other.

Parathyroid hormone: an early predictor of symptomatic hypocalcemia after total thyroidectomy.

Objective: The purpose of this study was to evaluate if the measurement of peri-operative parathyroid hormone (PTH) is able to identify patients with increased risk of developing symptoms of hypocalcemia.

Subjects And Methods: Forty patients who underwent total thyroidectomy were studied prospectively. Ionized serum calcium and PTH were measured after induction of anesthesia, one hour (PTH1) and one day after surgery (PTH24).

Heterogeneity of carboxyl-terminal parathyroid hormone circulating forms in patients with hyperparathyroidism due to end stage renal disease.

Objective: To study carboxyl-terminal (COOH) parathyroid hormone (PTH) circulating forms in patients with hyperparathyroidism due to end stage renal disease (ESRD).

Methods: An immunometric assay that recognizes both intact and COOH PTH forms was developed. The assay, in conjunction with an intact assay, was used to measure PTH in serum samples obtained from 25 patients with hyperparathyroidism due to ESRD.

[Usefulness of intraoperative PTH measurement in primary and secondary hyperparathyroidism: experience with 109 patients].

Introduction: Intraoperative parathyroid hormone measurement (IO-PTH) was first described in 1988 and it's potentially useful in predicting cure after parathyroidectomy. The aim of this study was to evaluate IO-PTH decay profile and the utility of this procedure in predicting cure in primary (PHH) and secondary (SHH) hyperparathyroidism due to renal disease.

Patients And Methods: 109 patients were evaluated from 06/2000 to 12/2004.

[Parathyroid carcinoma].

Parathyroid carcinoma is a rare condition, comprising less than 1% of the cases of primary hyperparathyroidism (PHP). Nonetheless, due to its aggressiveness, and having prognosis dependent on the precocity of diagnosis and radical therapeutic approach, it is paramount that the clinical suspicion be made before surgery. Clinical presentation is typical of severe PHP, with a parathyroid tumor >1.

[Parathyroid hormone values obtained with immunometric assays depend on the amino-terminal antibody specificity].

Introduction of 2nd generation immunometric assays for the measurement of serum parathyroid hormone (PTH), turned them more available, simple and rapid. These methods, based on double identification of the PTH molecule, supposedly measure the intact, bioactive molecule, with the sequence 1-84. Recent works showed that they also measure forms with amino-terminal deletions, like the 7-84 form, which are not able to activate the traditional PTH receptor (PTH1R).