[Mandibular fracture in a Lhasa Apso with secondary renal hyperparathyroidism]

A Lhassa Apso is presented in emergency after having been injured by another dog. It was suffering from a mandibular fracture. The clinical exam revealed generalized and excessive mobility of the whole dentition. Radiographs showed generalized jaw bone demineralisation. A blood sample was analysed and revealed chronic renal disease. We came to the conclusion that this dog was suffering from secondary renal hyperparathyroidism. The hypocalcified bone was so thin that a slight trauma induced the mandibular fracture.

Effect of cinacalcet cessation in renal transplant recipients with persistent hyperparathyroidism

BACKGROUND: Persistent hyperparathyroidism after renal transplantation affects bone and allografts. Cinacalcet, a calcimimetic, reduces serum calcium and PTH in renal transplant recipients with persistent hyperparathyroidism. Here, we address the question whether this effect of cinacalcet persists after withdrawal. METHODS: Therefore, cinacalcet was stopped after 12 months treatment in 10 stable renal transplant patients. Serum calcium, phosphate, PTH, creatinine and cystatin C were monitored for 3 months. RESULTS: Serum calcium, normalized in nine patients before cessation of cinacalcet (2.32 +/- 0.05mmol/l, mean +/- SEM), increased after 3 months of discontinuation by 0.17 +/- 0.04mmol/l, P < 0.05, but remained within the normal range in eight patients. Compared with the time point of cessation, PTH remained unchanged or decreased further after 3 months without therapy in six patients. Measurements of cystatin C suggested an improvement of the glomerular filtration rate after cessation in 9 out of 10 patients (1.55 +/- 0.09 vs 1.33 +/- 0.12 mg/l, P < 0.01). CONCLUSION: First, a beneficial effect of cinacalcet beyond the duration of a 12-month therapy appears to be present in some patients and second, the previously suspected influence of cinacalcet therapy on renal function is reversible. Thus, it is reasonable to consider a trial of cinacalcet cessation to identify these patients. The optimal time point for such a discontinuation is unknown. The present observations are preliminary. They clearly require a prospective randomized trial for definitive confirmation.

1,25-(OH)2-16ene-23yne-D3 reduces secondary hyperparathyroidism in uremic rats with little calcemic effect

To compare the effects of vitamin D analogs versus calcitriol on serum levels of Ca, P and parathyroid hormone (PTH). A compound better than calcitriol should increase the Ca x P product less than calcitriol for an equivalent decrease in PTH levels.

Effects of nasal calcitonin on bone mineral density following parathyroidectomy in patients with primary hyperparathyroidism

To investigate whether nasal salmon calcitonin (CT; 200 U/day) given in addition to calcium helps to restore the bone mass after parathyroidectomy (PTX) in patients with primary hyperparathyroidism (PHPT).

Bone mineral density at distal tibia using dual-energy X-ray absorptiometry in normal women and in patients with vertebral osteoporosis or primary hyperparathyroidism

To assess the effect of age and disease on mineral distribution at the distal third of the tibia, bone mineral content (BMC) and bone mineral density (BMD) were measured at lumbar spine (spine), femoral neck (neck), and diaphysis (Dia) and distal epiphysis (Epi) of the tibia in 89 healthy control women of different age groups (20-29, n = 12; 30-39, n = 11; 40-44, n = 12; 45-49, n = 12; 50-54, n = 12; 55-59, n = 10; 60-69, n = 11; 70-79, n = 9), in 25 women with untreated vertebral osteoporosis (VOP), and in 19 women with primary hyperparathyroidism (PHPT) using dual-energy x-ray absorptiometry (DXA; Hologic QDR 1000 and standard spine software). A soft tissue simulator was used to compensate for heterogeneity of soft tissue thickness around the leg. Tibia was scanned over a length of 130 mm from the ankle joint, fibula being excluded from analysis. For BMC and BMD, 10 sections 13 mm each were analyzed separately and then pooled to define the epiphysis (Epi 13-52 mm) and diaphysis area (Dia 91-130 mm). Precision after repositioning was 1.9 and 2.1% for Epi and Dia, respectively. In the control group, at any site there was no significant difference between age groups 20-29 and 30-39, which thus were pooled to define the peak bone mass (PBM).(ABSTRACT TRUNCATED AT 250 WORDS)

Population based case-control study of sick leave in postmenopausal women before diagnosis of hyperparathyroidism

Objective: To analyse sick leave in women at risk of primary hyperparathyroidism before its diagnosis.

Understanding hyperparathyroidism /

Mode of access: Internet.

Genetic testing in familial isolated hyperparathyroidism: unexpected results and their implications

Familial hyperparathyroidism is not uncommon in clinical endocrine practice. It encompasses a spectrum of disorders including multiple endocrine neoplasia types 1 (MEN1) and 2A, hyperparathyroidism-jaw tumour syndrome (HPT-JT), familial hypocalciuric hypercalcaemia (FHH), and familial isolated hyperparathyroidism (FIHP). Distinguishing among the five syndromes is often difficult but has profound implications for the management of patient and family. The availability of specific genetic testing for four of the syndromes has improved diagnostic accuracy and simplified family monitoring in many cases but its current cost and limited accessibility require rationalisation of its use. No gene has yet been associated exclusively with FIHP. FIHP phenotypes have been associated with mutant MEN1 and calcium-sensing receptor ( CASR) genotypes and, very recently, with mutation in the newly identified HRPT2 gene. The relative proportions of these are not yet clear. We report results of MEN1, CASR, and HRPT2 genotyping of 22 unrelated subjects with FIHP phenotypes. We found 5 (23%) with MEN1 mutations, four (18%) with CASR mutations, and none with an HRPT2 mutation. All those with mutations had multiglandular hyperparathyroidism. Of the subjects with CASR mutations, none were of the typical FHH phenotype. These findings strongly favour a recommendation for MEN1 and CASR genotyping of patients with multiglandular FIHP, irrespective of urinary calcium excretion. However, it appears that HRPT2 genotyping should be reserved for cases in which other features of the HPT-JT phenotype have occurred in the kindred. Also apparent is the need for further investigation to identify additional genes associated with FIHP.

Single-cell functional analysis of parathyroid adenomas reveals distinct classes of calcium sensing behaviour in primary hyperparathyroidism.

Primary hyperparathyroidism (PHPT) is a common endocrine neoplastic disorder caused by a failure of calcium sensing secondary to tumour development in one or more of the parathyroid glands. Parathyroid adenomas are comprised of distinct cellular subpopulations of variable clonal status that exhibit differing degrees of calcium responsiveness. To gain a clearer understanding of the relationship among cellular identity, tumour composition and clinical biochemistry in PHPT, we developed a novel single cell platform for quantitative evaluation of calcium sensing behaviour in freshly resected human parathyroid tumour cells. Live-cell intracellular calcium flux was visualized through Fluo-4-AM epifluorescence, followed by in situ immunofluorescence detection of the calcium sensing receptor (CASR), a central component in the extracellular calcium signalling pathway. The reactivity of individual parathyroid tumour cells to extracellular calcium stimulus was highly variable, with discrete kinetic response patterns observed both between and among parathyroid tumour samples. CASR abundance was not an obligate determinant of calcium responsiveness. Calcium EC50 values from a series of parathyroid adenomas revealed that the tumours segregated into two distinct categories. One group manifested a mean EC50 of 2.40 mM (95% CI: 2.37-2.41), closely aligned to the established normal range. The second group was less responsive to calcium stimulus, with a mean EC50 of 3.61 mM (95% CI: 3.45-3.95). This binary distribution indicates the existence of a previously unappreciated biochemical sub-classification of PHPT tumours, possibly reflecting distinct etiological mechanisms. Recognition of quantitative differences in calcium sensing could have important implications for the clinical management of PHPT.

Long-term outcomes following “presumed” total parathyroidectomy for secondary hyperparathyroidism of chronic kidney disease

Aim. The most efficacious surgical treatment for renal hyperparathyroidism is still subject of research. Considering its low incidence rate of long-term relapse, “presumed” total parathyroidectomy without autotrasplantation (TP) may be indicated for secondary hyperparathyroidism (2HPT) in patients with chronic kidney disease (CKD), not eligible for kidney transplantation. The aim of this study was to analyse the TP long-term results in 2HPT haemodialysis (HD) patients. Method. Between January 2004 and October 2009, 25 2HPT HD patients, not eligible for kidney transplantation, underwent TP of at least four parathyroid glands. Clinical status and intact parathyroid hormone (iPTH) serum levels were assessed intraoperatively and during a 36-month follow-up. Results. TP improved the typical clinical symptoms and a significant reduction of iPTH serum levels was achieved in each patient. Aparathyroidism was never observed; in case of severe postoperative hypocalcemia, hypocalcemic seizures were never reported and the long-term recurrence rate was 8%. Only one patient received a kidney transplantation. Postoperative cardiovascular events (hypertension, peripheral artery disease, arrhythmia, coronary or cerebrovascular disease) were observed in 32% of cases and mortality rate was 16%. Conclusions. Considering its low long-term relapse rate and the absence of postoperative aparathyroidism, TP may still be considered the treatment of choice in patients with aggressive forms of 2HPT or of advanced dialytic vintage, with no access to renal transplantation. In case of postoperative hypoparathyroidism, hypocalcaemia can be effectively managed by medical treatment.

Seizure and Profound Hypokalemia: Unusual Presentation of Primary Hyperparathyroidism

A 68-year-old man was admitted because of tonic–clonic convulsion. He had been receiving 200 mg itraconazole for 10 days. He had hypokalaemia (2.2 mEq/l), hypercalcaemia (Cacorr 11.0 mg/dl) and elevated serum parathyroid hormone (PTH, 95 pg/ml). Ultrasound examination of the neck revealed a low echoic tumour. Cessation of itraconazole and fluid supplementation eradicated clinical symptoms and profound hypokalaemia, but serum potassium remained low normal (3.4 mEq/l) and the mild hypercalcaemia and elevated PTH were unchanged. To conclude, a small amount of itraconazole (200 mg) precipitated profound hypokalaemia and seizure in a patient with mild hyperparathyroidism and low normal serum potassium.