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Faiq S, Lavelle K, Hu T, Shoback D, Ku G. Cinacalcet increases renal calcium excretion in PTHrP-mediated hypercalcemia: a case report. BMC Endocr Disord 2023; 23:133. [PMID: 37328745 PMCID: PMC10273565 DOI: 10.1186/s12902-023-01386-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 06/08/2023] [Indexed: 06/18/2023] Open
Abstract
BACKGROUND In the acute setting, PTH-independent hypercalcemia is typically treated with anti-resorptive agents such as zoledronic acid or denosumab. When these agents are no longer able to control hypercalcemia, several case reports have shown the utility of cinacalcet. However, it is not known if cinacalcet can be effective in patients naïve to anti-resorptive therapy or how cinacalcet ameliorates the hypercalcemia. CASE PRESENTATION A 47-year-old male with a history of alcohol-induced cirrhosis was admitted for left cheek bleeding and swelling from an infiltrative squamous cell carcinoma of the oral cavity. On admission, he was found to have an elevated albumin-corrected serum calcium of 13.6 mg/dL, a serum phosphorus of 2.2 mg/dL and an intact PTH of 6 pg/mL (normal 18-90) with a PTHrP of 8.1 pmol/L (normal < 4.3), consistent with PTHrP-dependent hypercalcemia. Aggressive intravenous saline hydration and subcutaneous salmon calcitonin were initiated, but his serum calcium remained elevated. Given tooth extractions scheduled for the next day and possible irradiation to the jaw in the near future, alternatives to antiresorptive therapy were sought. Cinacalcet was initiated at 30 mg twice daily then increased to 60 mg twice daily the following day. The albumin-corrected serum calcium level decreased from 13.2 to 10.9 mg/dL within 48 h. The fractional excretion of calcium increased from 3.7 to 7.0%. CONCLUSIONS This case demonstrates the utility of cinacalcet for the treatment of PTHrP-mediated hypercalcemia without prior anti-resorptive therapy via increased renal clearance of calcium.
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Affiliation(s)
- Samya Faiq
- School of Medicine, University of California Davis, Davis, USA
| | - Kristen Lavelle
- Department of Medicine, Division of Endocrinology and Metabolism, University of California, San Francisco, 513 Parnassus Ave, HSW 1027, San Francisco, CA, 94143, USA
| | - Tina Hu
- Department of Medicine, Division of Endocrinology and Metabolism, University of California, San Francisco, 513 Parnassus Ave, HSW 1027, San Francisco, CA, 94143, USA
| | - Dolores Shoback
- Department of Medicine, Division of Endocrinology and Metabolism, University of California, San Francisco, 513 Parnassus Ave, HSW 1027, San Francisco, CA, 94143, USA
- Department of Veterans Affairs, Endocrine Research Unit, San Francisco, CA, USA
| | - Gregory Ku
- Department of Medicine, Division of Endocrinology and Metabolism, University of California, San Francisco, 513 Parnassus Ave, HSW 1027, San Francisco, CA, 94143, USA.
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2
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Schmidt GS, Weaver TD, Hoang TD, Shakir MK. Severe Symptomatic Hypocalcemia, complicating cardiac arrhythmia following Cinacalcet (Sensipar TM) administration: A Case Report. Clin Case Rep 2021; 9:e04876. [PMID: 34659755 PMCID: PMC8502441 DOI: 10.1002/ccr3.4876] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 09/02/2021] [Accepted: 09/09/2021] [Indexed: 11/29/2022] Open
Abstract
Clinicians should closely monitor patients on calcimimetics for hypocalcemic symptoms and arrhythmia, even though asymptomatic hypocalcemia typically resolves without intervention.
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Affiliation(s)
- Gregory S. Schmidt
- Department of EndocrinologyWalter Reed National Military Medical CenterBethesdaMDUSA
| | - Travis D. Weaver
- Department of EndocrinologyWalter Reed National Military Medical CenterBethesdaMDUSA
| | - Thanh D. Hoang
- Department of EndocrinologyWalter Reed National Military Medical CenterBethesdaMDUSA
| | - Mohamed K.M. Shakir
- Department of EndocrinologyWalter Reed National Military Medical CenterBethesdaMDUSA
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3
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Hannan FM, Olesen MK, Thakker RV. Calcimimetic and calcilytic therapies for inherited disorders of the calcium-sensing receptor signalling pathway. Br J Pharmacol 2018; 175:4083-4094. [PMID: 29127708 PMCID: PMC6177618 DOI: 10.1111/bph.14086] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 10/24/2017] [Accepted: 10/30/2017] [Indexed: 12/15/2022] Open
Abstract
The calcium-sensing receptor (CaS receptor) plays a pivotal role in extracellular calcium homeostasis, and germline loss-of-function and gain-of-function mutations cause familial hypocalciuric hypercalcaemia (FHH) and autosomal dominant hypocalcaemia (ADH), respectively. CaS receptor signal transduction in the parathyroid glands is probably regulated by G-protein subunit α11 (Gα11 ) and adaptor-related protein complex-2 σ-subunit (AP2σ), and recent studies have identified germline mutations of these proteins as a cause of FHH and/or ADH. Calcimimetics and calcilytics are positive and negative allosteric modulators of the CaS receptor that have potential efficacy for symptomatic forms of FHH and ADH. Cellular studies have demonstrated that these compounds correct signalling and/or trafficking defects caused by mutant CaS receptor, Gα11 or AP2σ proteins. Moreover, mouse model studies indicate that calcilytics can rectify the hypocalcaemia and hypercalciuria associated with ADH, and patient-based studies reveal calcimimetics to ameliorate symptomatic hypercalcaemia caused by FHH. Thus, calcimimetics and calcilytics represent targeted therapies for inherited disorders of the CaS receptor signalling pathway. LINKED ARTICLES This article is part of a themed section on Molecular Pharmacology of GPCRs. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.21/issuetoc.
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Affiliation(s)
- Fadil M Hannan
- Department of Musculoskeletal Biology, Institute of Ageing and Chronic DiseaseUniversity of LiverpoolLiverpoolUK
- Academic Endocrine Unit, Radcliffe Department of MedicineUniversity of OxfordOxfordUK
| | - Mie K Olesen
- Department of Musculoskeletal Biology, Institute of Ageing and Chronic DiseaseUniversity of LiverpoolLiverpoolUK
- Academic Endocrine Unit, Radcliffe Department of MedicineUniversity of OxfordOxfordUK
| | - Rajesh V Thakker
- Academic Endocrine Unit, Radcliffe Department of MedicineUniversity of OxfordOxfordUK
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4
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Nemeth EF, Van Wagenen BC, Balandrin MF. Discovery and Development of Calcimimetic and Calcilytic Compounds. PROGRESS IN MEDICINAL CHEMISTRY 2018; 57:1-86. [PMID: 29680147 DOI: 10.1016/bs.pmch.2017.12.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The extracellular calcium receptor (CaR) is a G protein-coupled receptor (GPCR) and the pivotal molecule regulating systemic Ca2+ homeostasis. The CaR was a challenging target for drug discovery because its physiological ligand is an inorganic ion (Ca2+) rather than a molecule so there was no structural template to guide medicinal chemistry. Nonetheless, small molecules targeting this receptor were discovered. Calcimimetics are agonists or positive allosteric modulators of the CaR, while calcilytics are antagonists and all to date are negative allosteric modulators. The calcimimetic cinacalcet was the first allosteric modulator of a GPCR to achieve regulatory approval and is a first-in-class treatment for secondary hyperparathyroidism in patients on dialysis, and for hypercalcemia in some forms of primary hyperparathyroidism. It is also useful in treating some rare genetic diseases that cause hypercalcemia. Two other calcimimetics are now on the market (etelcalcetide) or under regulatory review (evocalcet). Calcilytics stimulate the secretion of parathyroid hormone and were initially developed as treatments for osteoporosis. Three different calcilytics of two different chemotypes failed in clinical trials due to lack of efficacy. Calcilytics are now being repurposed and might be useful in treating hypoparathyroidism and several rare genetic diseases causing hypocalcemia. The challenges ahead for medicinal chemists are to design compounds that select conformations of the CaR that preferentially target a particular signalling pathway and/or that affect the CaR in a tissue-selective manner.
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5
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Takada D, Tsukamoto T, Fuse M, Kada S, Yanagita M. The use of cinacalcet hinders the diagnosis of parathyroid carcinoma in a chronic dialysis patient: a case report. BMC Nephrol 2017; 18:315. [PMID: 29047366 PMCID: PMC5648519 DOI: 10.1186/s12882-017-0733-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 09/28/2017] [Indexed: 12/15/2022] Open
Abstract
Background Secondary hyperparathyroidism (SHPT) is a common complication in patients receiving chronic dialysis therapy. Although cinacalcet can control parathyroid function and bone turnover, preventing ectopic calcification remains challenging. Cinacalcet can also suppress PTH secretion due to parathyroid carcinoma in the same way as it does for parathyroid hyperplasia in the uremic condition. We present a case of parathyroid carcinoma partially controlled by cinacalcet, in which tumorous calcinosis was successfully resolved by total parathyroidectomy. Case presentation A female patient in her forties who had received dialysis for 12 years was referred to our hospital for painful ectopic calcifications on her right hip joint and both knees. Although she had been treated with alfacalcidol and cinacalcet for 2 years, this therapy had been discontinued 6 months earlier as a result of hypercalcemia. The patient exhibited normocalcemia (2.37 mmol/L) and hyperphosphatemia (2.42 mmol/L) with elevated intact parathyroid hormone (707,000 μg/L). Ultrasonography revealed an enlarged parathyroid gland on the left lower side of the thyroid gland. The otolaryngologist surgeons had to perform an en bloc excision to remove this parathyroid gland because of tight adhesions. Histological examination revealed that parathyroid cells had invaded the surrounding skeletal muscle through fibrous capsules, consistent with parathyroid carcinoma. Her joint pain disappeared 2 weeks after parathyroidectomy, and the tumorous calcinosis had largely resolved after 1 year. Conclusions Parathyroid carcinoma is a rare cause of hyperparathyroidism in end-stage kidney disease. Our case indicates that the use of cinacalcet hinders the diagnosis of parathyroid carcinoma in a chronic dialysis patient. When uncontrolled hypercalcemia and/or hyperphosphathemia develop during cinacalcet administration, parathyroidectomy should be considered to prevent a vicious exacerbation of ectopic calcification.
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Affiliation(s)
- Daisuke Takada
- Department of Nephrology, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo, Kyoto, Japan. .,Department of Nephrology & Dialysis, Kitano Hospital, The Tazuke Kofukai Medical Research Institute, Osaka, Japan.
| | - Tatsuo Tsukamoto
- Department of Nephrology, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo, Kyoto, Japan.,Department of Nephrology & Dialysis, Kitano Hospital, The Tazuke Kofukai Medical Research Institute, Osaka, Japan
| | - Miho Fuse
- Department of Otorhinolaryngology, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan
| | - Shinpei Kada
- Department of Otorhinolaryngology, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan
| | - Motoko Yanagita
- Department of Nephrology, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo, Kyoto, Japan
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6
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Ballhausen BD, Wehner A, Zöllner M, Hartmann K, Unterer S. [Diagnostic approach and management of hypercalcaemia in dogs exemplary of primary hyperparathyroidism]. TIERARZTLICHE PRAXIS. AUSGABE K, KLEINTIERE/HEIMTIERE 2017; 45:122-133. [PMID: 28352923 DOI: 10.15654/tpk-160923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 02/22/2017] [Indexed: 06/06/2023]
Abstract
Hypercalcaemia can be caused by many different diseases. This article summarizes the causes, pathophysiologic mechanisms and diagnostic procedures as well as treatment recommendations. The main focus is on hypercalcaemia in primary hyperparathyroidism (PH), complemented by a case report. An elevated total calcium level should generally be investigated and verified by measurement of ionized calcium concentration. The further diagnostic approach depends on the phosphate level. Tumour screening, measurement of parathormone and parathromone-related protein and sonography of parathyroid glands may be necessary. If the calcium-phosphate-product exceeds 60 mg/dl, there is a risk of tissue mineralisation and a rapid treatment of hypercalcaemia is required. For acute therapy, sodium chloride infusion, furosemide and glucocorticoids can be used. Glucocorticoids should only be given after strict indication and after a definite diagnosis. For long-term management, bisphosphates, particularly alendronate, are increasingly used successfully. Causal therapy of PH can be performed by parathyreoidectomy, heat ablation or ethanol ablation. Thereafter, particularly in cases of severe preoperative hypercalcaemia, hypocalcaemia can occur. Treatment is performed using vitamin D3 (calcitriol), which may also be given preoperatively in cases of severe hypercalcaemia. A concomitant oral calcium supplementation using calcium carbonate as medication of choice is contentious. Due to a potential relapse after successful excision of the affected parathyroid gland in PH, the serum calcium level should be monitored periodically.
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Affiliation(s)
- B Désirée Ballhausen
- Dr. B. Désirée Ballhausen, Tierärztliche Fachklinik für Kleintiere, Keferloher Straße 25, 85540 Haar, E-Mail:
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7
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Leach K, Gregory KJ. Molecular insights into allosteric modulation of Class C G protein-coupled receptors. Pharmacol Res 2017; 116:105-118. [DOI: 10.1016/j.phrs.2016.12.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 11/18/2016] [Accepted: 12/07/2016] [Indexed: 12/23/2022]
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Koh J, Hogue JA, Sosa JA. A Novel Ex Vivo Method for Visualizing Live-Cell Calcium Response Behavior in Intact Human Tumors. PLoS One 2016; 11:e0161134. [PMID: 27537691 PMCID: PMC4990350 DOI: 10.1371/journal.pone.0161134] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 07/29/2016] [Indexed: 01/09/2023] Open
Abstract
The functional impact of intratumoral heterogeneity has been difficult to assess in the absence of a means to interrogate dynamic, live-cell biochemical events in the native tissue context of a human tumor. Conventional histological methods can reveal morphology and static biomarker expression patterns but do not provide a means to probe and evaluate tumor functional behavior and live-cell responsiveness to experimentally controlled stimuli. Here, we describe an approach that couples vibratome-mediated viable tissue sectioning with live-cell confocal microscopy imaging to visualize human parathyroid adenoma tumor cell responsiveness to extracellular calcium challenge. Tumor sections prepared as 300 micron-thick tissue slices retain viability throughout a >24 hour observation period and retain the native architecture of the parental tumor. Live-cell observation of biochemical signaling in response to extracellular calcium challenge in the intact tissue slices reveals discrete, heterogeneous kinetic waveform categories of calcium agonist reactivity within each tumor. Plotting the proportion of maximally responsive tumor cells as a function of calcium concentration yields a sigmoid dose-response curve with a calculated calcium EC50 value significantly elevated above published reference values for wild-type calcium-sensing receptor (CASR) sensitivity. Subsequent fixation and immunofluorescence analysis of the functionally evaluated tissue specimens allows alignment and mapping of the physical characteristics of individual cells within the tumor to specific calcium response behaviors. Evaluation of the relative abundance of intracellular PTH in tissue slices challenged with variable calcium concentrations demonstrates that production of the hormone can be dynamically manipulated ex vivo. The capability of visualizing live human tumor tissue behavior in response to experimentally controlled conditions opens a wide range of possibilities for personalized ex vivo therapeutic testing. This highly adaptable system provides a unique platform for live-cell ex vivo provocative testing of human tumor responsiveness to a range of physiological agonists or candidate therapeutic compounds.
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Affiliation(s)
- James Koh
- Department of Surgery, Duke University Medical Center, Durham, North Carolina, United States of America
- * E-mail:
| | - Joyce A. Hogue
- Department of Surgery, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Julie A. Sosa
- Department of Surgery, Duke University Medical Center, Durham, North Carolina, United States of America
- Duke Cancer Institute and Duke Clinical Research Institute, Duke University Medical Center, Durham, North Carolina, United States of America
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9
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Kim SM, Shu AD, Long J, Montez-Rath ME, Leonard MB, Norton JA, Chertow GM. Declining Rates of Inpatient Parathyroidectomy for Primary Hyperparathyroidism in the US. PLoS One 2016; 11:e0161192. [PMID: 27529699 PMCID: PMC4986953 DOI: 10.1371/journal.pone.0161192] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Accepted: 08/01/2016] [Indexed: 11/19/2022] Open
Abstract
Parathyroidectomy is the only curative therapy for patients with primary hyperparathyroidism. However, the incidence, correlates and consequences of parathyroidectomy for primary hyperparathyroidism across the entire US population are unknown. We evaluated temporal trends in rates of inpatient parathyroidectomy for primary hyperparathyroidism, and associated in-hospital mortality, length of stay, and costs. We used the Healthcare Cost and Utilization Project Nationwide Inpatient Sample (NIS) from 2002–2011. Parathyroidectomies for primary hyperparathyroidism were identified using International Classification of Diseases, Ninth Revision codes. Unadjusted and age- and sex- adjusted rates of inpatient parathyroidectomy for primary hyperparathyroidism were derived from the NIS and the annual US Census. We estimated 109,583 parathyroidectomies for primary hyperparathyroidism between 2002 and 2011. More than half (55.4%) of patients were younger than age 65, and more than three-quarters (76.8%) were female. The overall rate of inpatient parathyroidectomy was 32.3 cases per million person-years. The adjusted rate decreased from 2004 (48.3 cases/million person-years) to 2007 (31.7 cases/million person-years) and was sustained thereafter. Although inpatient parathyroidectomy rates declined over time across all geographic regions, a steeper decline was observed in the South compared to other regions. Overall in-hospital mortality rates were 0.08%: 0.02% in patients younger than 65 years and 0.14% in patients 65 years and older. Inpatient parathyroidectomy rates for primary hyperparathyroidism have declined in recent years.
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Affiliation(s)
- Sun Moon Kim
- Division of Nephrology, Department of Medicine, Stanford University School of Medicine, Stanford, California, United States of America
| | - Aimee D. Shu
- Division of Endocrinology, Gerontology and Metabolism, Stanford University School of Medicine, Stanford, California, United States of America
| | - Jin Long
- Division of Nephrology, Department of Medicine, Stanford University School of Medicine, Stanford, California, United States of America
| | - Maria E. Montez-Rath
- Division of Nephrology, Department of Medicine, Stanford University School of Medicine, Stanford, California, United States of America
| | - Mary B. Leonard
- Division of Nephrology, Department of Medicine, Stanford University School of Medicine, Stanford, California, United States of America
- Division of Pediatric Nephrology, Department of Pediatrics, Stanford University School of Medicine, Stanford, California, United States of America
| | - Jeffrey A. Norton
- Department of Surgery, Stanford University School of Medicine, Stanford, California, United States of America
| | - Glenn M. Chertow
- Division of Nephrology, Department of Medicine, Stanford University School of Medicine, Stanford, California, United States of America
- * E-mail:
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10
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Mayr B, Schnabel D, Dörr HG, Schöfl C. GENETICS IN ENDOCRINOLOGY: Gain and loss of function mutations of the calcium-sensing receptor and associated proteins: current treatment concepts. Eur J Endocrinol 2016; 174:R189-208. [PMID: 26646938 DOI: 10.1530/eje-15-1028] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 12/08/2015] [Indexed: 12/26/2022]
Abstract
The calcium-sensing receptor (CASR) is the main calcium sensor in the maintenance of calcium metabolism. Mutations of the CASR, the G protein alpha 11 (GNA11) and the adaptor-related protein complex 2 sigma 1 subunit (AP2S1) genes can shift the set point for calcium sensing causing hyper- or hypo-calcemic disorders. Therapeutic concepts for these rare diseases range from general therapies of hyper- and hypo-calcemic conditions to more pathophysiology oriented approaches such as parathyroid hormone (PTH) substitution and allosteric CASR modulators. Cinacalcet is a calcimimetic that enhances receptor function and has gained approval for the treatment of hyperparathyroidism. Calcilytics in turn attenuate CASR activity and are currently under investigation for the treatment of various diseases. We conducted a literature search for reports about treatment of patients harboring inactivating or activating CASR, GNA11 or AP2S1 mutants and about in vitro effects of allosteric CASR modulators on mutated CASR. The therapeutic concepts for patients with familial hypocalciuric hypercalcemia (FHH), neonatal hyperparathyroidism (NHPT), neonatal severe hyperparathyroidism (NSHPT) and autosomal dominant hypocalcemia (ADH) are reviewed. FHH is usually benign, but symptomatic patients benefit from cinacalcet. In NSHPT patients pamidronate effectively lowers serum calcium, but most patients require parathyroidectomy. In some patients cinacalcet can obviate the need for surgery, particularly in heterozygous NHPT. Symptomatic ADH patients respond to vitamin D and calcium supplementation but this may increase calciuria and renal complications. PTH treatment can reduce relative hypercalciuria. None of the currently available therapies for ADH, however, prevent tissue calcifications and complications, which may become possible with calcilytics that correct the underlying pathophysiologic defect.
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Affiliation(s)
- Bernhard Mayr
- Division of Endocrinology and DiabetesDepartment of Medicine I, Universitätsklinikum Erlangen, Friedrich-Alexander University Erlangen-Nuremberg, Ulmenweg 18, 91054 Erlangen, GermanyCenter for Chronic Sick ChildrenPediatric Endocrinology and Diabetes, Charité University Medicine Berlin, Berlin, GermanyDivision of Paediatric Endocrinology and DiabetesDepartment of Paediatrics, Universitätsklinikum Erlangen, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany
| | - Dirk Schnabel
- Division of Endocrinology and DiabetesDepartment of Medicine I, Universitätsklinikum Erlangen, Friedrich-Alexander University Erlangen-Nuremberg, Ulmenweg 18, 91054 Erlangen, GermanyCenter for Chronic Sick ChildrenPediatric Endocrinology and Diabetes, Charité University Medicine Berlin, Berlin, GermanyDivision of Paediatric Endocrinology and DiabetesDepartment of Paediatrics, Universitätsklinikum Erlangen, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany
| | - Helmuth-Günther Dörr
- Division of Endocrinology and DiabetesDepartment of Medicine I, Universitätsklinikum Erlangen, Friedrich-Alexander University Erlangen-Nuremberg, Ulmenweg 18, 91054 Erlangen, GermanyCenter for Chronic Sick ChildrenPediatric Endocrinology and Diabetes, Charité University Medicine Berlin, Berlin, GermanyDivision of Paediatric Endocrinology and DiabetesDepartment of Paediatrics, Universitätsklinikum Erlangen, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany
| | - Christof Schöfl
- Division of Endocrinology and DiabetesDepartment of Medicine I, Universitätsklinikum Erlangen, Friedrich-Alexander University Erlangen-Nuremberg, Ulmenweg 18, 91054 Erlangen, GermanyCenter for Chronic Sick ChildrenPediatric Endocrinology and Diabetes, Charité University Medicine Berlin, Berlin, GermanyDivision of Paediatric Endocrinology and DiabetesDepartment of Paediatrics, Universitätsklinikum Erlangen, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany
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Koh J, Hogue JA, Wang Y, DiSalvo M, Allbritton NL, Shi Y, Olson JA, Sosa JA. Single-cell functional analysis of parathyroid adenomas reveals distinct classes of calcium sensing behaviour in primary hyperparathyroidism. J Cell Mol Med 2015; 20:351-9. [PMID: 26638194 PMCID: PMC4727552 DOI: 10.1111/jcmm.12732] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 10/01/2015] [Indexed: 12/13/2022] Open
Abstract
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.
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Affiliation(s)
- James Koh
- Department of Surgery, Duke University Medical Center, Durham, NC, USA
| | - Joyce A Hogue
- Department of Surgery, Duke University Medical Center, Durham, NC, USA
| | - Yuli Wang
- Department of Biomedical Engineering, University of North Carolina, Chapel Hill, NC, USA.,North Carolina State University, Raleigh, NC, USA
| | - Matthew DiSalvo
- Department of Biomedical Engineering, University of North Carolina, Chapel Hill, NC, USA.,North Carolina State University, Raleigh, NC, USA
| | - Nancy L Allbritton
- Department of Biomedical Engineering, University of North Carolina, Chapel Hill, NC, USA.,North Carolina State University, Raleigh, NC, USA
| | - Yuhong Shi
- Departments of Surgery and Biochemistry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - John A Olson
- Departments of Surgery and Biochemistry, University of Maryland School of Medicine, Baltimore, MD, USA.,Departments of Surgery and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Julie A Sosa
- Department of Surgery, Duke University Medical Center, Durham, NC, USA.,Duke Cancer Institute and Duke Clinical Research Institute, Duke University Medical Center, Durham, NC, USA
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12
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Nemeth EF. Allosteric modulators of the extracellular calcium receptor. DRUG DISCOVERY TODAY. TECHNOLOGIES 2014; 10:e277-84. [PMID: 24050279 DOI: 10.1016/j.ddtec.2012.11.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The extracellular calcium receptor (CaR) is a Family C G protein-coupled receptor that controls systemic Ca2+ homeostasis, largely by regulating the secretion of parathyroid hormone (PTH). Ligands that activate the CaR have been termed calcimimetics and are classified as either Type I (agonists) or Type II (allosteric activators) and effectively inhibit the secretion of PTH. CaR antagonists have been termed calcilytics and all act allosterically to stimulate secretion of PTH. The calcimimetic cinacalcet has been approved for treating parathyroid cancer and secondary hyperparathyroidism in patients on renal replacement therapy. Cinacalcet was the first allosteric modulator of a G proteincoupled receptor to achieve regulatory approval. This review will focus on the technologies used to discover and develop allosterically acting calcimimetics and calcilytics as novel therapies for bone and mineral-related disorders.
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Caltabiano S, Dollery CT, Hossain M, Kurtinecz MT, Desjardins JP, Favus MJ, Kumar R, Fitzpatrick LA. Characterization of the effect of chronic administration of a calcium-sensing receptor antagonist, ronacaleret, on renal calcium excretion and serum calcium in postmenopausal women. Bone 2013; 56:154-62. [PMID: 23756230 DOI: 10.1016/j.bone.2013.05.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Revised: 04/25/2013] [Accepted: 05/30/2013] [Indexed: 10/26/2022]
Abstract
Ronacaleret is an orally-active calcium-sensing receptor (CaSR) antagonist that has the potential for therapeutic utility in the stimulation of PTH release, notably as a bone anabolic agent comparable to recombinant human PTH(1-34) (rhPTH(1-34)). A recent study has shown that, despite the ability to increase circulating PTH levels in postmenopausal women in a dose-dependent manner, minimal effects of ronacaleret on bone mineral density have been observed. Therefore, the purpose of this study was to characterize the PTH profile as well as calcium metabolism parameters as a marker of PTH biological activity following the administration of ronacaleret or rhPTH(1-34). Administration of ronacaleret led to lower peak levels of PTH than were observed with rhPTH(1-34), however, greater total PTH exposure was observed. Further, chronic administration of either agent was associated with increases in urinary calcium excretion and serum calcium levels, with the magnitude of the changes following ronacaleret significantly greater than that for rhPTH(1-34). The greater magnitude of effects observed with ronacaleret is likely due to the greater total PTH exposure, and is potentially reflective of a state comparable to mild hyperparathyroidism. It is not clear whether the administration of all calcilytics would lead to a similar result, or is due to characteristics specific to ronacaleret.
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14
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Wu-Wong JR, Nakane M, Chen YW, Mizobuchi M. Mechanistic analysis for time-dependent effects of cinacalcet on serum calcium, phosphorus, and parathyroid hormone levels in 5/6 nephrectomized rats. Physiol Rep 2013; 1:e00046. [PMID: 24303131 PMCID: PMC3835002 DOI: 10.1002/phy2.46] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 07/05/2013] [Accepted: 07/08/2013] [Indexed: 12/21/2022] Open
Abstract
This study investigates the time-dependent effects of cinacalcet on serum calcium, phosphorus, and parathyroid hormone (PTH) levels in 5/6 nephrectomized (NX) rats with experimental chronic renal insufficiency. In this study, 5/6 NX male, Sprague-Dawley rats were treated with vehicle or cinacalcet (10 mg/kg, oral, 1× daily). On Day 0 (before treatment), Day 12 and 13 after treatment (to approximate the clinical practice), and also at 0, 1, 4, 8, 16, and 24 hours after the last dosing, blood was collected for analysis. After 12 or 13 days of cinacalcet treatment, modest changes were observed in serum Ca and phosphorus (Pi), while PTH decreased by >45% to Sham levels (152 ± 15 pg/mL). Detailed mapping found that cinacalcet caused a significant time-dependent decrease in serum Ca following dosing, reaching a lowest point at 8 hours (decrease by 20% to 8.43 ± 0.37 mg/dL), and then returning to normal at 24 hours. Cinacalcet also caused a significant increase in serum Pi levels (by 18%). To investigate the potential mechanism of action, a broad approach was taken by testing cinacalcet in a panel of 77 protein-binding assays. Cinacalcet interacted with several channels, transporters, and neurotransmitter receptors, some of which are involved in brain and heart, and may impact Ca homeostasis. Cinacalcet dose-dependently increased brain natriuretic peptide (BNP) mRNA expression by 48% in cardiomyocytes, but had no significant effects on left ventricular hypertrophy and cardiac function. The results suggest that cinacalcet's hypocalcemic effect may be due to its nonspecific interaction with other receptors in brain and heart.
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Affiliation(s)
- J Ruth Wu-Wong
- Department of Pharmacy Practice, University of Illinois at Chicago Chicago, Illinois
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15
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Hage MP, Salti I, El-Hajj Fuleihan G. Parathyromatosis: a rare yet problematic etiology of recurrent and persistent hyperparathyroidism. Metabolism 2012; 61:762-75. [PMID: 22221828 DOI: 10.1016/j.metabol.2011.11.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Revised: 10/31/2011] [Accepted: 11/02/2011] [Indexed: 11/29/2022]
Abstract
Recurrent or persistent hyperparathyroidism is an uncommon yet challenging clinical problem, and parathyromatosis is one of its very rare causes. In this minireview, we review causes of recurrent hyperparathyroidism and all cases of parathyromatosis available in the literature. The clinical course of a case of parathyromatosis with the longest follow-up (1977-2011) is described. Similar cases reported between 1975 and the present are reviewed and analyzed to characterize the clinical presentation, course, and management of this rare condition. Parathyromatosis, which is benign parathyroid tissue seeding, has been detailed in 35 patients in the English literature. The majority were female subjects, with end-stage renal disease, in their fifth to sixth decade of life. In most cases, the diagnosis was made intraoperatively; and the condition was often refractory to surgery. A calcimimetic agent was used in 5 cases with end-stage renal disease; serum calcium and/or parathyroid hormone levels decreased in 4 subjects, but only one was reported to experience increments in bone density. Medical management combining a calcimimetic with a bisphosphonate may therefore be a preferred alternative.
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Affiliation(s)
- Mirella P Hage
- Department of Internal Medicine, Division of Endocrinology, American University of Beirut-Medical Center, Riad El Solh 1107 2020, Beirut, Lebanon
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16
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Abstract
Parathyroidectomy is currently the only curative treatment for primary hyperparathyroidism (PHPT). There are few alternative treatment options in patients who are ineligible for, or unwilling to undergo, surgery and those in whom parathyroidectomy has failed. Current options include the recently approved drug cinacalcet. Cinacalcet is an allosteric modulator of the calcium-sensing receptor, acting to sensitize this receptor to extracellular calcium. Cinacalcet has been found to be effective in reducing or normalizing serum calcium levels in several groups of PHPT patients, including those with mild-to-moderate PHPT, intractable disease, parathyroid carcinoma and multiple endocrine neoplasia Type 1. Cinacalcet slightly reduces parathyroid hormone levels and has no effect on bone mineral density. Cinacalcet is well tolerated when used at low doses, but side effects are not uncommon when relatively high doses are needed to control hypercalcemia. The current evidence indicates that cinacalcet may be of benefit in a wide spectrum of PHPT severities, offering a novel therapeutic option for the control of hypercalcemia in PHPT patients who are not able to undergo parathyroidectomy. It is presently unknown how much of the biochemical benefit of cinacalcet treatment translates into a clinical benefit, particularly in patients with mild-to-moderate hypercalcemia. Moreover, there are no data as to whether long-term treatment with cinacalcet can prevent the complications of PHPT.
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Affiliation(s)
- Filomena Cetani
- a Department of Endocrinology and Metabolism, University of Pisa, Pisa, Italy
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17
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Tonelli F, Giudici F, Cavalli T, Brandi ML. Surgical approach in patients with hyperparathyroidism in multiple endocrine neoplasia type 1: total versus partial parathyroidectomy. Clinics (Sao Paulo) 2012; 67 Suppl 1:155-60. [PMID: 22584722 PMCID: PMC3328832 DOI: 10.6061/clinics/2012(sup01)26] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Usually, primary hyperparathyroidism is the first endocrinopathy to be diagnosed in patients with multiple endocrine neoplasia type 1, and is also the most common one. The timing of the surgery and strategy in multiple endocrine neoplasia type 1/hyperparathyroidism are still under debate. The aims of surgery are to: 1) correct hypercalcemia, thus preventing persistent or recurrent hyperparathyroidism; 2) avoid persistent hypoparathyroidism; and 3) facilitate the surgical treatment of possible recurrences. Currently, two types of surgical approach are indicated: 1) subtotal parathyroidectomy with removal of at least 3-3 K glands; and 2) total parathyroidectomy with grafting of autologous parathyroid tissue. Transcervical thymectomy must be performed with both of these procedures. Unsuccessful surgical treatment of hyperparathyroidism is more frequently observed in multiple endocrine neoplasia type 1 than in sporadic hyperparathyroidism. The recurrence rate is strongly influenced by: 1) the lack of a pre-operative multiple endocrine neoplasia type 1 diagnosis; 2) the surgeon's experience; 3) the timing of surgery; 4) the possibility of performing intra-operative confirmation (histologic examination, rapid parathyroid hormone assay) of the curative potential of the surgical procedure; and, 5) the surgical strategy. Persistent hyperparathyroidism seems to be more frequent after subtotal parathyroidectomy than after total parathyroidectomy with autologous graft of parathyroid tissue. Conversely, recurrent hyperparathyroidism has a similar frequency in the two surgical strategies. To plan further operations, it is very helpful to know all the available data about previous surgery and to undertake accurate identification of the site of recurrence.
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Affiliation(s)
- Francesco Tonelli
- Surgical Unit, Department of Clinical Physiopathology, University of Florence, Florence, Italy.
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18
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Marcocci C, Cetani F. Update on the use of cinacalcet in the management of primary hyperparathyroidism. J Endocrinol Invest 2012; 35:90-5. [PMID: 22104762 DOI: 10.3275/8112] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Cinacalcet is an allosteric modulator of the calcium sensing receptor acting to sensitize this receptor to the extracellular calcium. Cinacalcet has been shown to be effective in reducing or normalizing serum calcium levels in several groups of patients with primary hyperparathyroidism (PHPT), including patients with mild to moderate PHPT, intractable PHPT, and parathyroid carcinoma, and in PHPT as a part of multiple endocrine neoplasia type 1. Cinacalcet slightly reduces PTH levels and has no effects on bone mineral density. Cinacalcet at low doses is well tolerated, but side effects are more frequent and severe when relatively high doses are needed to control hypercalcemia. Cinacalcet may be of benefit in a wide spectrum of PHPT severity, offering a novel therapeutic option for the control of hypercalcemia in PHPT patients who are not able to undergo parathyroidectomy. To what extent the reduction of serum calcium particularly in patients with mild to moderate hypercalcemia, translates into a clinical benefit is currently unknown. Moreover, there are no data as to whether long-term treatment with cinacalcet can prevent the complications of PHPT. Finally, more data are needed on the long-term safety of cinacalcet, particularly at the renal level.
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Affiliation(s)
- C Marcocci
- Department of Endocrinology and Metabolism, University of Pisa, Pisa, Italy.
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Kimura S, Nakagawa T, Matsuo Y, Ishida Y, Okamoto Y, Hayashi M. JTT-305, an orally active calcium-sensing receptor antagonist, stimulates transient parathyroid hormone release and bone formation in ovariectomized rats. Eur J Pharmacol 2011; 668:331-6. [PMID: 21810422 DOI: 10.1016/j.ejphar.2011.07.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Revised: 06/23/2011] [Accepted: 07/07/2011] [Indexed: 10/17/2022]
Abstract
Intermittent administration of parathyroid hormone (PTH) has a potent anabolic effect on bone in humans and animals. Calcium-sensing receptor (CaSR) antagonists stimulate endogenous PTH secretion through CaSR on the surface of parathyroid cells and thereby may be anabolic agents for osteoporosis. JTT-305 is a potent oral short-acting CaSR antagonist and transiently stimulates endogenous PTH secretion. The objective of the present study was to investigate the effects of JTT-305 on PTH secretion and bone in ovariectomized rats. Female rats, immediately after ovariectomy (OVX), were orally administered vehicle or JTT-305 (0.3, 1, or 3 mg/kg) for 12 weeks. The serum PTH concentrations were transiently elevated with increasing doses of JTT-305. In the proximal tibia, JTT-305 prevented OVX-induced decreases in both the cancellous and total bone mineral density (BMD) except for the 0.3mg/kg dose. At the 3mg/kg dose, JTT-305 increased the mineralizing surface and bone formation rate in histomorphometry. The efficacy of JTT-305 at the 3mg/kg dose on the BMD corresponded to that of exogenous rat PTH1-84 injection at doses between 3 and 10 μg/kg. In conclusion, JTT-305 stimulated endogenous transient PTH secretion and bone formation, and consequently prevented bone loss in OVX rats. These results suggest that JTT-305 is orally active and has the potential to be an anabolic agent for the treatment of osteoporosis.
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Affiliation(s)
- Shuichi Kimura
- Biological/Pharmaceutical Research Laboratories, Central Pharmaceutical Research Institute, Japan Tobacco Inc., Osaka, Japan.
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20
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Kiefer L, Leiris S, Dodd RH. Novel calcium sensing receptor ligands: a patent survey. Expert Opin Ther Pat 2011; 21:681-98. [PMID: 21406038 DOI: 10.1517/13543776.2011.568479] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION In the parathyroid gland, the calcium sensing receptor responds to small changes in circulating levels of Ca(2+), and consequently stimulates or inhibits the secretion of parathyroid hormone (PTH). Thus, ligands potentiating the action of calcium (calcimimetics) lead to decreased PTH secretion and can thus be useful for the treatment of hyperparathyroidism. On the other hand, ligands which antagonize the action of calcium (calcilytics) stimulate PTH secretion, favoring bone tissue regeneration. AREAS COVERED This review first discusses the rapid development of calcimimetics (only one of which has been approved for the treatment of hyperparathyroidism) followed by that of calcilytics (none of which has as yet been approved for the treatment of osteoporosis). Peer-reviewed articles generated by these patents are also surveyed. EXPERT OPINION The rapid progress in developing a clinically approved calcimimetic has not been matched by an identical success in finding an orally available calcilytic useful for the treatment of osteoporosis. However, the growing importance of osteoporosis as a debilitating disease is a stimulating factor in discovering such compounds.
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Affiliation(s)
- Lionel Kiefer
- Institut de Chimie des Substances Naturelles, UPR 2301, CNRS, Avenue de la Terrasse, 91198 Gif-sur-Yvette, France.
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21
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Urwyler S. Allosteric modulation of family C G-protein-coupled receptors: from molecular insights to therapeutic perspectives. Pharmacol Rev 2011; 63:59-126. [PMID: 21228259 DOI: 10.1124/pr.109.002501] [Citation(s) in RCA: 164] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Allosteric receptor modulation is an attractive concept in drug targeting because it offers important potential advantages over conventional orthosteric agonism or antagonism. Allosteric ligands modulate receptor function by binding to a site distinct from the recognition site for the endogenous agonist. They often have no effect on their own and therefore act only in conjunction with physiological receptor activation. This article reviews the current status of allosteric modulation at family C G-protein coupled receptors in the light of their specific structural features on the one hand and current concepts in receptor theory on the other hand. Family C G-protein-coupled receptors are characterized by a large extracellular domain containing the orthosteric agonist binding site known as the "venus flytrap module" because of its bilobal structure and the dynamics of its activation mechanism. Mutational analysis and chimeric constructs have revealed that allosteric modulators of the calcium-sensing, metabotropic glutamate and GABA(B) receptors bind to the seven transmembrane domain, through which they modify signal transduction after receptor activation. This is in contrast to taste-enhancing molecules, which bind to different parts of sweet and umami receptors. The complexity of interactions between orthosteric and allosteric ligands is revealed by a number of adequate biochemical and electrophysiological assay systems. Many allosteric family C GPCR modulators show in vivo efficacy in behavioral models for a variety of clinical indications. The positive allosteric calcium sensing receptor modulator cinacalcet is the first drug of this type to enter the market and therefore provides proof of principle in humans.
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Affiliation(s)
- Stephan Urwyler
- Department of Chemistry and Biochemistry, University of Berne, P/A Weissensteinweg 3, CH-3303 Jegenstorf, Berne, Switzerland.
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22
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Rothe HM, Liangos O, Biggar P, Petermann A, Ketteler M. Cinacalcet treatment of primary hyperparathyroidism. Int J Endocrinol 2011; 2011:415719. [PMID: 21461394 PMCID: PMC3065008 DOI: 10.1155/2011/415719] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Accepted: 01/04/2011] [Indexed: 02/07/2023] Open
Abstract
Although parathyroidectomy remains the only curative approach to most primary hyperparathyroidism cases, medical treatment with cinacalcet HCl has been proven to be a reasonable alternative for several patient subgroups. Cinacalcet almost always controls hypercalcemia and hypophosphatemia sufficiently. PTH levels are lowered, and cognitive parameters improve. While an increase in bone mineral density DEXA scan scores was not demonstrated in cinacalcet trials, the same applies to more than half of patients after parathyroidectomy. Medical therapy should be first choice in patients with hyperplasia in all glands rather than an isolated adenoma (10-15%), patients with persisting HPT following unsuccessful surgery or inoperable cases due to comorbidities, and patients detected in lab screens for hypercalcemia before developing symptoms who should be treated early but are usually reluctant to undergo surgery. Nephrolithiasis was not found to occur more frequently in cinacalcet trial groups, but urine calcium excretion as one major risk factor of this complication of primary HPT may increase on cinacalcet. Patients carrying the rs1042636 polymorphism of the calcium-sensing receptor gene respond more sensitively to cinacalcet and have a higher risk of calcium stone formation. Cinacalcet is usually administered twice daily but three or four doses per day should be discussed to mimic the beneficial pulsatile PTH-pattern.
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Affiliation(s)
- H. M. Rothe
- Division of Nephrology and Hypertension, Medical Department, Klinikum Coburg III, D-96450 Coburg, Germany
- *H. M. Rothe:
| | - O. Liangos
- Division of Nephrology and Hypertension, Medical Department, Klinikum Coburg III, D-96450 Coburg, Germany
| | - P. Biggar
- Division of Nephrology and Hypertension, Medical Department, Klinikum Coburg III, D-96450 Coburg, Germany
| | - A. Petermann
- Division of Nephrology and Hypertension, Medical Department, Klinikum Coburg III, D-96450 Coburg, Germany
| | - M. Ketteler
- Division of Nephrology and Hypertension, Medical Department, Klinikum Coburg III, D-96450 Coburg, Germany
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Banerjee S, Smith B, Hitchcock SR. A dimethylzinc/diphenylphosphinoylimine approach to the asymmetric synthesis of the calcimimetic agent NPS R-568. Appl Organomet Chem 2010. [DOI: 10.1002/aoc.1723] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Abstract
PURPOSE OF REVIEW At all stages of chronic kidney disease (CKD) cardiovascular death is the most prominent cause of mortality. Current treatment options are still not completely satisfactory in this group of high cardiovascular risk patients. Experimental data and clinical observations suggest a role of secondary hyperparathyroidism, hyperphosphatemia, and hypercalcemia in the genesis of cardiovascular complications of CKD. The ubiquitous expression of the calcium-sensing receptor, which is targeted by calcimimetics and the pleiotropic effects of calcimimetics, make this class of drugs potential candidates for cardiovascular intervention. RECENT FINDINGS Recent experimental studies suggest that calcimimetics interfere with the development of vascular abnormalities in CKD and to some extent even reverse them. The effects of calcimimetics on the vasculature are, at least partially, independent of their effects on calcemia, phosphatemia, and parathyroid hormone concentration. The beneficial effects of calcimimetics on vascular calcification, arteriolar thickening, atherogenesis, and myocardial capillarization are well documented. In addition they have hypotensive and renoprotective actions. SUMMARY Experimental models suggest beneficial effects of calcimimetics on cardiovascular disease. Although prospective clinical data are still lacking, retrospective data suggest cardiovascular benefit of calcimimetics even in humans. Clinical trials with calcimimetics evaluating hard cardiovascular end-points would be desirable.
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Fernández I, Valdivia V, Alcudia A, Chelouan A, Khiar N. Enantiodivergent Approach to Trifluoromethylated Amines: A Concise Route to Both Enantiomeric Analogues of Calcimimetic NPS R-568. European J Org Chem 2010. [DOI: 10.1002/ejoc.200901158] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Marie PJ. The calcium-sensing receptor in bone cells: a potential therapeutic target in osteoporosis. Bone 2010; 46:571-6. [PMID: 19660583 DOI: 10.1016/j.bone.2009.07.082] [Citation(s) in RCA: 171] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2009] [Revised: 07/27/2009] [Accepted: 07/29/2009] [Indexed: 12/16/2022]
Abstract
Recent progress has been made in our understanding of the functional role of the seven-transmembrane-spanning extracellular calcium-sensing receptor (CaSR) in bone cells. Both in vitro and in vivo data indicate that the CaSR is a physiological regulator of bone cell metabolism. The CaSR regulates the recruitment, differentiation and survival of osteoblasts and osteoclasts through activation of multiple CaSR-mediated intracellular signaling pathways in bone cells. This raises the possibility that the bone CaSR could potentially be targeted by allosteric modulators, either agonists (calcimimetics) or antagonists (calcilytics) to control bone remodeling. The therapeutic potential of CaSR agonists or antagonists in bone cells is however hampered by their effects on the CaSR in nonskeletal tissues. Rather, direct targeting of the bone CaSR may be of potential interest for the treatment of bone diseases. Targeting the bone CaSR using a bone-seeking CaSR agonist offers a potential mean to modulate bone cell metabolism. The development of drugs that preferentially target the CaSR and possibly other cation-sensing receptors in bone cells may thus be helpful for the treatment of osteoporosis.
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27
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Horie I, Ando T, Inokuchi N, Mihara Y, Miura S, Imaizumi M, Usa T, Kinoshita N, Sekine I, Kamihara S, Eguchi K. First Japanese patient treated with parathyroid hormone peptide immunization for refractory hypercalcemia caused by metastatic parathyroid carcinoma. Endocr J 2010; 57:287-92. [PMID: 20051648 DOI: 10.1507/endocrj.k09e-283] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Patients with unresectable parathyroid carcinoma develop severe hypercalcemia, bone fractures and renal failure, and become unresponsive to conventional treatments. It has been shown that successful induction of anti-parathyroid hormone (PTH) antibodies, using PTH peptide fragments for immunisation, normalized serum levels of calcium as well as improved clinical symptoms. Here, we report our experience of PTH immunization in a Japanese female suffering from refractory hypercalcemia and renal failure caused by unresectable metastatic parathyroid carcinoma. Upon immunization, there were apparent clinical responses including reduction of serum levels of Ca along with anti-PTH antibodies induction. Therefore, we concluded that PTH immunization was an effective treatment against hypercalcemia caused by metastatic parathyroid carcinomas that are unresponsive to conventional treatments.
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Affiliation(s)
- Ichiro Horie
- First Department of Medicine, Nagasaki University School of Medicine, Nagasaki, Japan.
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28
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Yano S, Suzuki K, Sumi M, Tokumoto A, Shigeno K, Himeno Y, Sugimoto T. Bone metabolism after cinacalcet administration in patients with secondary hyperparathyroidism. J Bone Miner Metab 2010; 28:49-54. [PMID: 19548062 DOI: 10.1007/s00774-009-0102-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2009] [Accepted: 05/07/2009] [Indexed: 11/26/2022]
Abstract
Cinacalcet, an allosteric modulator of a calcium (Ca)-sensing receptor, significantly suppresses parathyroid hormone (PTH) secretion and bone turnover rate in chronic hemodialysis (HD) patients with secondary hyperparathyroidism (SHPT). In this study, bone metabolism after cinacalcet treatment was examined, because hungry bone syndrome is sometimes experienced after parathyroidectomy in severe SHPT. We conducted a prospective observational study in 17 HD patients with SHPT. Cinacalcet was started at 25 mg/day, and the dose was increased step by step based on serum calcium level. A significant decrease in serum Ca and intact PTH concentration was found within 2 weeks. Tartrate-resistant acid phosphatase 5b, a good bone resorption marker, was significantly decreased at week 2 of the study. Serum bone alkaline phosphatase, a marker of bone formation, was increased at week 2 compared with the basal level. It became, however, gradually decreased until week 14. Only one patient whose bone turnover was considerably high had a mild numbness feeling. These results suggest that cinacalcet treatment might transiently accelerate bone formation with rapid suppression of bone resorption. This uncoupling could be involved in a mechanism by which cinacalcet decreases serum Ca level.
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Affiliation(s)
- Shozo Yano
- Department of Internal Medicine 1, Shimane University Faculty of Medicine, Izumo, Japan.
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29
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Saidak Z, Brazier M, Kamel S, Mentaverri R. Agonists and allosteric modulators of the calcium-sensing receptor and their therapeutic applications. Mol Pharmacol 2009; 76:1131-44. [PMID: 19779033 DOI: 10.1124/mol.109.058784] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The calcium-sensing receptor (CaR) belongs to the G protein-coupled receptor superfamily, with a characteristic structure consisting of seven transmembrane helices, an intracellular C-terminal and an extracellular N terminal domain. The primary physiological function of the CaR is the maintenance of constant blood Ca2+ levels, as a result of its ability to sense very small changes in extracellular Ca2+ (Ca2+(o)). Nevertheless, in addition to being expressed in tissues involved in Ca2+(o) homeostasis, the CaR is also expressed in tissues not involved in mineral homeostasis, suggestive of additional physiological functions. Numerous agonists and modulators of the CaR are now known in addition to Ca2+(o), including various divalent and trivalent cations, aromatic l-amino acids, polyamines, and aminoglycoside antibiotics. The signaling of the CaR is also regulated by extracellular pH and ionic strength. The activated CaR couples mainly to the phospholipase Cbeta and extracellular signal-regulated kinase 1/2 signaling pathways, and it decreases intracellular cAMP levels, leading to various physiological effects. The recent identification of synthetic allosteric modulators of the CaR has opened up a new field of research possibilities. Calcimimetics and calcilytics, which increase and decrease agonist signaling via the CaR, respectively, may facilitate the manipulation of the CaR and thus aid in further investigations of its precise signaling. These allosteric modulators, as well as strontium, have been demonstrated to have therapeutic potential for the treatment of disorders involving the CaR. This review discusses the various agonists and modulators of the CaR, differences in their binding and signaling, and their roles as therapeutics in various diseases.
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Affiliation(s)
- Zuzana Saidak
- INSERM ERI-12, 1, rue des Louvels, Amiens 80037, France.
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30
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Parathyroid carcinoma in a child: an unusual case of an ectopically located malignant parathyroid gland with tumor invading the thymus. J Pediatr Surg 2009; 44:1649-52. [PMID: 19635322 DOI: 10.1016/j.jpedsurg.2009.04.024] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2009] [Revised: 04/15/2009] [Accepted: 04/15/2009] [Indexed: 11/20/2022]
Abstract
Parathyroid carcinoma is exceptionally rare in children. Parathyroid carcinoma in the pediatric population most typically presents with significant hypercalcemia and a palpable neck mass. The authors report the seventh case of parathyroid carcinoma diagnosed in a child younger than 16 years. To our knowledge, this case is the first documented case, in the pediatric population, of parathyroid carcinoma in an ectopically located parathyroid gland with tumor invading the thymus.
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Carrasco F, Pérez-Flores I, Calvo N, Ridao N, Sánchez A, Barrientos. Treatment of Persistent Hyperparathyroidism in Renal Transplant Patients With Cinacalcet Improves Control of Blood Pressure. Transplant Proc 2009; 41:2385-7. [DOI: 10.1016/j.transproceed.2009.06.167] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Chakravarti B, Dwivedi SKD, Mithal A, Chattopadhyay N. Calcium-sensing receptor in cancer: good cop or bad cop? Endocrine 2009; 35:271-84. [PMID: 19011996 DOI: 10.1007/s12020-008-9131-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2008] [Revised: 09/30/2008] [Accepted: 10/21/2008] [Indexed: 12/28/2022]
Abstract
The extracellular calcium-sensing receptor (CaR) is a versatile 'sensor' for di- and polycationic molecules in the body. CaR plays a key role in the defense against hypercalcemia by "sensing" extracellular calcium levels in the parathyroid and kidney, the key organs maintaining systemic calcium homeostasis. Although mutation of CaR gene has so far not been associated with any malignancy, aberrant functions of CaR have implications in malignant progression. One situation is loss of CaR expression, resulting in loss of growth suppressing effects of elevated extracellular Ca(2+) by CaR, reported in parathyroid adenoma and in colon carcinoma. Another situation is activation of CaR, resulting in increased production of parathyroid hormone-related peptide (PTHrP), a primary causal factor in hypercalcemia of malignancy and a contributor to metastatic processes involving bone. CaR signaling and effects have been studied in several cancers including ovarian cancers, gastrinomas, and gliomas in addition to comparatively detailed studies in breast, prostate, and colon cancers. Studies on H-500 rat Leydig cells, a xenotransplantable model of humoral hypercalcemia of malignancy has shed much light on the mechanisms of CaR-induced cancer cell growth and survival. Pharmacological agonists and antagonists of CaR hold therapeutic promise depending on whether activation of CaR is required such as in case of colon cancer or inactivating the receptor is required as in the case of breast- and prostate tumors.
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Affiliation(s)
- Bandana Chakravarti
- Division of Endocrinology, Central Drug Research Institute, Chattar Manzil, Lucknow, India.
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Quesada Charneco M. [Primary hyperparathyroidism in special situations: multiple endocrine neoplasia syndromes and parathyroid cancer]. ENDOCRINOLOGIA Y NUTRICION : ORGANO DE LA SOCIEDAD ESPANOLA DE ENDOCRINOLOGIA Y NUTRICION 2009; 56 Suppl 1:35-40. [PMID: 19627759 DOI: 10.1016/s1575-0922(09)70854-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Primary hyperparathyroidism (PHP) is a known endocrine disorder. Many years ago, the most frequent forms of clinical presentation were symptomatic renal or skeletal disease with moderate or severe hypercalcemia; however, currently, most patients have few symptoms and mild hypercalcemia. The last NIH Workshop on Asymptomatic PHP developed criteria for the management of this disease. Multiple endocrine neoplasia (MEN) types 1 and 2 are two genetic syndromes caused by different types of molecular abnormalities. PHP is the most common manifestation of MEN-1 and is the last feature to appear in MEN 2A. Parathyroid carcinoma (PC) is a rare neoplasm and an uncommon cause of parathyroid hormone (PTH)-dependent hypercalcemia. In this report, the treatment of PHP in MEN syndrome and PC are reviewed. Special attention is paid to a new class of drugs called "calcimimetics", which are powerful compounds that may be highly useful in the treatment of both conditions.
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Muñoz Torres M, García Martín A. [Medical treatment of primary hyperparathyroidism: role of calcimimetics]. ENDOCRINOLOGIA Y NUTRICION : ORGANO DE LA SOCIEDAD ESPANOLA DE ENDOCRINOLOGIA Y NUTRICION 2009; 56 Suppl 1:29-34. [PMID: 19627758 DOI: 10.1016/s1575-0922(09)70853-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Primary hyperparathyroidism (PHPT) is a common endocrinological process, characterized by chronic elevation of serum concentrations of calcium and parathyroid hormone (PTH). The only intervention able to cure the disease is parathyroidectomy. However, there are few valid medical alternatives for patients whose PHPT is unresolved by surgery, or in those with contraindications for surgery or who refuse the procedure. The discovery of calcium-sensing receptors (CaSRs), which regulate PTH secretion according to extracellular calcium concentrations, has allowed specific anti-parathyroid drugs called calcimimetics to be designed. Cinacalcet is an allosteric modulator of CaSR that has demonstrated safety and efficacy in controlling serum calcium values and in reducing PTH levels in patients with PHPT. The exact role of calcimimetics in the overall management of PHPT is promising and should be considered in future clinical practice guidelines.
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Affiliation(s)
- Manuel Muñoz Torres
- Unidad de Metabolismo Oseo, Servicio de Endocrinología y Nutrición, RETICEF, Hospital Universitario San Cecilio, Granada, España.
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Hiperparatiroidismo primario. Una alternativa a la cirugía. ACTA ACUST UNITED AC 2009; 56:132-5. [DOI: 10.1016/s1575-0922(09)70843-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2008] [Accepted: 01/14/2009] [Indexed: 11/22/2022]
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Khan A, Grey A, Shoback D. Medical management of asymptomatic primary hyperparathyroidism: proceedings of the third international workshop. J Clin Endocrinol Metab 2009; 94:373-81. [PMID: 19193912 DOI: 10.1210/jc.2008-1762] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Primary hyperparathyroidism (PHPT) is a common endocrine disorder that is frequently asymptomatic. The 2002 International Workshop on Asymptomatic PHPT addressed medical management of asymptomatic PHPT and summarized the data on nonsurgical approaches to this disease. At the Third International Workshop on Asymptomatic PHPT held in May 2008, this subject was reviewed again in light of data that have since become available. We present the results of a literature review of advances in the medical management of PHPT. METHODS A series of questions was developed by the International Task Force on PHPT. A comprehensive literature search for relevant studies evaluating the management of PHPT with bisphosphonates, hormone replacement therapy, raloxifene, and calcimimetics was conducted. Existing guidelines and recent unpublished data were also reviewed. All selected relevant articles were reviewed, and the questions developed by the International Task Force were addressed by the Consensus Panel. RESULTS Bisphosphonates and hormone replacement therapy are effective in decreasing bone turnover in patients with PHPT and improving bone mineral density (BMD). Fracture data are not available with either treatment. Raloxifene also lowers bone turnover in patients with PHPT. None of these agents, however, significantly lowers serum calcium or PTH levels. The calcimimetic cinacalcet reduces both serum calcium and PTH levels and raises serum phosphorus. Cinacalcet does not, however, reduce bone turnover or improve BMD. CONCLUSIONS Bisphosphonates and hormone replacement therapy provide skeletal protection in patients with PHPT. Limited data are available regarding skeletal protection in patients with PHPT treated with raloxifene. Calcimimetics favorably alter serum calcium and PTH in PHPT but do not significantly affect either bone turnover or BMD. Medical management of asymptomatic PHPT is a promising option for those who are not candidates for parathyroidectomy.
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Affiliation(s)
- Aliya Khan
- McMaster University, Hamilton, Ontario, Canada.
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Ceglia L, Harris SS, Rasmussen HM, Dawson-Hughes B. Activation of the calcium sensing receptor stimulates gastrin and gastric acid secretion in healthy participants. Osteoporos Int 2009; 20:71-8. [PMID: 18536954 PMCID: PMC2716662 DOI: 10.1007/s00198-008-0637-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2008] [Accepted: 03/11/2008] [Indexed: 11/29/2022]
Abstract
UNLABELLED In 17 adults on a fixed metabolic diet, an 11-day course of cinacalcet increased serum gastrin and basal gastric acid output, but not maximal gastric acid output, compared with a placebo. These findings indicate that the calcium sensor receptor plays a role in the regulation of gastric acid. INTRODUCTION Gastric acid secretion is a complex process regulated by neuronal and hormonal pathways. Ex vivo studies in human gastric tissues indicate that the calcium sensing receptor (CaR), expressed on the surface of G and parietal cells, may be involved in this regulation. We sought to determine whether cinacalcet, a CaR allosteric agonist, increases serum gastrin and gastric acid secretion. METHODS Seventeen healthy adults with normal gastric acid output were placed on an 18-day metabolic diet. On day 8 (baseline), participants were given cinacalcet (15 then 30 mg/day) or placebo for 11 days. Changes in gastric acid output, serum gastrin, and other measures were compared in the two groups. RESULTS Changes in serum gastrin and basal acid output (adjusted for baseline body weight) were significantly more positive in the cinacalcet group compared with placebo (P = 0.004 and P = 0.039 respectively). Change in maximal acid output was similar in the two groups (P = 0.995). As expected, cinacalcet produced significant decreases in serum PTH (P < 0.001) and ionized calcium levels (P = 0.032), and increases in serum phosphorus levels (P = 0.001) and urinary calcium (P = 0.023). CONCLUSIONS This study provides in vivo evidence that activation of the CaR increases serum gastrin levels and basal gastric acid secretion in healthy adults.
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Affiliation(s)
- L Ceglia
- Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, 711 Washington Street, Boston, MA, 02111, USA,
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Tonelli F, Marcucci T, Giudici F, Falchetti A, Brandi ML. Surgical approach in hereditary hyperparathyroidism. Endocr J 2009; 56:827-41. [PMID: 19797826 DOI: 10.1507/endocrj.k09e-204] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Affiliation(s)
- Francesco Tonelli
- Surgical Unit, Department of Clinical Physiopathology, and Regional Center for Hereditary Endocrine Tumors, University of Florence, Florence, Italy
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Tfelt-Hansen J, Brown EM. THE CALCIUM-SENSING RECEPTOR IN NORMAL PHYSIOLOGY AND PATHOPHYSIOLOGY: A Review. Crit Rev Clin Lab Sci 2008; 42:35-70. [PMID: 15697170 DOI: 10.1080/10408360590886606] [Citation(s) in RCA: 173] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The discovery of a G protein-coupled, calcium-sensing receptor (CaR) a decade ago and of diseases caused by CaR mutations provided unquestionable evidence of the CaR's critical role in the maintenance of systemic calcium homeostasis. On the cell membrane of the chief cells of the parathyroid glands, the CaR "senses" the extracellular calcium concentration and, subsequently, alters the release of parathyroid hormone (PTH). The CaR is likewise functionally expressed in bone, kidney, and gut--the three major calcium-translocating organs involved in calcium homeostasis. Intracellular signal pathways to which the CaR couples via its associated G proteins include phospholipase C (PLC), protein kinase B (AKT); and mitogen-activated protein kinases (MAPKs). The receptor is widely expressed in various tissues and regulates important cellular functions in addition to its role in maintaining systemic calcium homeostasis, i.e., protection against apoptosis, cellular proliferation, and membrane voltage. Functionally significant mutations in the receptor have been shown to induce diseases of calcium homeostasis owing to changes in the set point for calcium-regulated PTH release as well as alterations in the renal handling of calcium. Gain-of-function mutations cause hypocalcemia, whereas loss-of-function mutations produce hypercalcemia. Recent studies have shown that the latter clinical presentation can also be caused by inactivating autoantibodies directed against the CaR Newly discovered type II allosteric activators of the CaR have been found to be effective as a medical treatment for renal secondary hyperparathyroidism.
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Affiliation(s)
- Jacob Tfelt-Hansen
- Laboratory of Molecular Cardiology, Medical Department B, H:S Rigshospitalet, University of Copenhagen, Copenhagen O, Denmark.
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41
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Stratigis S, Stylianou K, Mamalaki E, Perakis K, Vardaki E, Tzenakis N, Katsipi I, Papavasiliou S, Yarmenitis S, Kyriazis J, Daphnis E. Percutaneous ethanol injection therapy: a surgery-sparing treatment for primary hyperparathyroidism. Clin Endocrinol (Oxf) 2008; 69:542-8. [PMID: 18331604 DOI: 10.1111/j.1365-2265.2008.03238.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To describe our 3-year experience in the long-term efficacy and safety of percutaneous ethanol injection therapy (PEIT), as an alternative to surgery for the management of patients with primary hyperparathyroidism (p-HPT). DESIGN Prospective study with a mean follow-up of 19.6 +/- 10.6 months. PATIENTS Our study population included 19 consecutive high risk patients with p-HPT, who met the criteria for surgery. MEASUREMENTS Under ultrasonic guidance, ethanol (95%) was injected into parathyroid glands with a volume of >or= 0.15 cm(3). With the aim of normalizing intact parathormone (iPTH) values, repeated ethanol injections were carried out, in an interval of 2 weeks, until normalization of iPTH was reached or until no residual blood supply was detected by ultrasound in the gland. Biochemical parameters were monitored throughout the study. RESULTS At 6-month follow-up, normalization of iPTH levels (10-65 ng/l) was achieved in 11 (58%) patients (responders). Of the eight remaining patients (nonresponders), six patients had reduced (but not normalized) iPTH levels and two patients required parathyroid surgery. Seventeen (11 responders and 6 nonresponders) of the 19 patients (89.5%) became normocalcaemic (serum Ca <or= 2.57 mmol/l) and remained so for a mean follow-up of 21 months (8-39 months). The odds ratio (P < 0.05) of response vs. no response to PEIT was 16.7-fold for pretreatment iPTH < 200 vs. > 200 ng/l. The only complication was a transient dysphonia noticed in three patients. CONCLUSIONS PEIT is a safe and effective nonsurgical treatment for patients with p-HPT, who are unsuitable for surgical intervention.
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Affiliation(s)
- Spyros Stratigis
- Departments of Nephrology, University Hospital of Heraklion, Crete, Greece
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42
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Lewis CE, Yeh MW. Inherited endocrinopathies: an update. Mol Genet Metab 2008; 94:271-82. [PMID: 18434223 DOI: 10.1016/j.ymgme.2008.03.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2007] [Revised: 03/10/2008] [Accepted: 03/10/2008] [Indexed: 12/15/2022]
Abstract
Inherited endocrinopathies, including multiple endocrine neoplasia type 1 (MEN-1), multiple endocrine neoplasia type 2 syndromes (MEN-2A, MEN-2B, familial medullary thyroid carcinoma), and inherited syndromes with pheochromocytoma (von Hippel-Lindau disease, neurofibromatosis type 1, others), comprise a heterogeneous group of cancer susceptibility syndromes that affect one or more components of the endocrine system. During the past several years, novel findings regarding genotype-phenotype correlation have highlighted the importance of establishing a genetic diagnosis in the treatment of these diseases. Here, we present a case-based review of recent advances in the genetics, diagnosis and management of inherited endocrinopathies.
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Affiliation(s)
- Catherine E Lewis
- Department of General Surgery, David Geffen School of Medicine, University of California, 10833 Le Conte Avenue, Los Angeles, CA 90095-6904, USA
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43
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Iglesias P, José Díez J. [Not Available]. ENDOCRINOLOGIA Y NUTRICION : ORGANO DE LA SOCIEDAD ESPANOLA DE ENDOCRINOLOGIA Y NUTRICION 2008; 55:193-195. [PMID: 22967912 DOI: 10.1016/s1575-0922(08)70667-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2007] [Accepted: 11/05/2007] [Indexed: 06/01/2023]
Affiliation(s)
- Pedro Iglesias
- Servicio de Endocrinología y Nutrición. Hospital General. Segovia. España
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Piecha G, Kokeny G, Nakagawa K, Koleganova N, Geldyyev A, Berger I, Ritz E, Schmitt CP, Gross ML. Calcimimetic R-568 or calcitriol: equally beneficial on progression of renal damage in subtotally nephrectomized rats. Am J Physiol Renal Physiol 2008; 294:F748-57. [PMID: 18199601 DOI: 10.1152/ajprenal.00220.2007] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Patients with renal insufficiency develop secondary hyperparathyroidism. Monotherapy with active vitamin D or calcimimetics ameliorates secondary hyperparathyroidism. We compared kidney damage in subtotally nephrectomized (SNX) rats treated with active vitamin D (calcitriol) or the calcimimetic R-568. Male Sprague-Dawley SNX and sham-operated (sham-op) rats were randomized into the following treatment groups: SNX + R-568, SNX + calcitriol, SNX + vehicle, sham-op + R-568, sham-op + calcitriol, and sham-op + vehicle. Albuminuria and blood pressure were monitored and kidneys were examined using morphometry, immunohistochemistry, quantitative RT-PCR, and in situ hybridization. Parathyroid hormone concentrations were lowered to the same extent by the two interventions, although phosphorus and the calcium-phosphorus product were reduced only by R-568 treatment. SNX rats developed marked albuminuria, which was significantly reduced in ad libitum- and pair-fed animals treated with R-568 and animals treated with calcitriol. Mean glomerular volume (6.05 +/- 1.46 vs. 2.70 +/- 0.91 mm(3)), podocyte volume (831 +/- 127 vs. 397 +/- 67 microm(3)), the degree of foot process fusion (mean width of foot processes = 958 +/- 364 vs. 272 +/- 35 nm), and glomerular basement membrane thickness (244 +/- 6 vs. 267 +/- 23 nm), as well as desmin staining, were significantly higher in vehicle-treated SNX than sham-operated animals. These changes were ameliorated with R-568 and calcitriol. In SNX, as well as sham-operated, animals, expression of the calcium-sensing receptor (protein and mRNA) was upregulated by treatment with the calcimimetic, but not calcitriol. Calcitriol and R-568 were similarly effective in ameliorating kidney damage.
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Affiliation(s)
- Grzegorz Piecha
- Institute of Pathology, Univ. of Heidelberg, Im Neuenheimer Feld 220/221, D-69120 Heidelberg, Germany.
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Ing SW, Pelliteri PK. Diagnostic Fine-Needle Aspiration Biopsy of an Intrathyroidal Parathyroid Gland and Subsequent Eucalcemia in a Patient with Primary Hyperparathyroidism. Endocr Pract 2008; 14:80-6. [PMID: 18238745 DOI: 10.4158/ep.14.1.80] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Steven W Ing
- Division of Endocrinology, Diabetes, and Metabolism, Ohio State University, Columbus, Ohio 43210, USA
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46
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N-Isopropylsulfinylimines as Useful Intermediates in the Synthesis of Chiral Amines: Expeditive Asymmetric Synthesis of the Calcimimetic (+)-NPS R-568. J Org Chem 2007; 73:745-8. [DOI: 10.1021/jo7018703] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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47
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Chertow GM, Martin KJ. Current and Future Therapies for the Medical Management of Secondary Hyperparathyroidism. Semin Dial 2007. [DOI: 10.1111/j.1525-139x.1998.tb00363.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Fryer RM, Segreti JA, Widomski DL, Franklin PH, Banfor PN, Koch KA, Nakane M, Wu-Wong JR, Cox BF, Reinhart GA. Systemic activation of the calcium sensing receptor produces acute effects on vascular tone and circulatory function in uremic and normal rats: focus on central versus peripheral control of vascular tone and blood pressure by cinacalcet. J Pharmacol Exp Ther 2007; 323:217-26. [PMID: 17636005 DOI: 10.1124/jpet.107.123901] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Calcium-sensing receptor (CaR) activation decreases serum parathyroid hormone (PTH) and Ca2+ and, despite long-term reductions in mean arterial blood pressure (MAP), may produce acute hypertension in rats, an effect we hypothesized was mediated by constriction of multiple vascular beds. Rats were subjected to 5/6 nephrectomy (NX) or no surgery (Normal); at 7 to 8 weeks, uremia animals were anesthetized and instrumented to record MAP and regional blood flow (carotid, mesenteric, and hindlimb). Cinacalcet [N-(1-naphthalen-1-ylethyl)-3-[3-(trifluoromethyl)phenyl]-propan-1-amine; 1, 3, and 10 mg/kg; 30 min/dose] was infused over 90 min. In NX rats, cinacalcet dose-dependently decreased ionized calcium (iCa2+), elicited a 90% reduction in PTH, and produced dose-dependent self-limiting increases in MAP (from 119 +/- 6 to 129 +/- 5, 142 +/- 4, and 145 +/- 3 mm Hg at the end of each infusion). At 1 mg/kg, carotid vascular resistance (CVR) and mesenteric vascular resistance (MVR) increased to 16 +/- 6 and 18 +/- 6% above baseline, respectively. Hindlimb vascular resistance (HVR) also trended upward (13 +/- 8%). At 3 mg/kg, increases in CVR (38 +/- 10%), MVR (40 +/- 8%), and HVR (39 +/- 14%) were exacerbated; at 10 mg/kg, values remained at or near these levels. The effects of cinacalcet in Normal rats were similar to NX and were attenuated by ganglionic blockade with hexamethonium at low doses but remained significantly elevated at higher doses. Thus, CaR activation acutely increases MAP in uremic and nonuremic rats, responses that occur in parallel to vasoconstriction in multiple vascular beds through both a central and peripheral mechanism of action. Moreover, subsequent mechanistic studies suggest that increases in MAP produced by cinacalcet may be mediated by reduced tonic NO synthase-dependent NO production subsequent to reductions in blood iCa2+.
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Affiliation(s)
- Ryan M Fryer
- Integrative Pharmacology, Global Pharmaceutical Research and Development, Abbott Laboratories, 100 Abbott Park Road, Abbott Park, IL 60064-6119, USA.
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Abstract
Multiple endocrine neoplasia (MEN) type 1 and type 2 exhibit an autosomal dominant pattern of inheritance. In the past two decades the germline mutations that cause these inherited syndromes have been identified. The large majority of patients with MEN1 have mutations in the menin gene. Mutations in the REarranged during Transfection (RET) gene cause MEN2A, MEN2B, and familial medullary thyroid carcinoma (FMTC). Specific codon mutations within RET correlate with disease phenotype and severity. Also, children from families with MEN2A, MEN2B, or FMTC, who are found to have inherited a mutated RET allele, can be managed by prophylactic thyroidectomy, thus preventing the development of medullary thyroid carcinoma (MTC), the dominant endocrinopathy in patients with these hereditary syndromes. New insights into the molecular pathway of RET signal transduction are leading to novel targeted therapies in patients with locally advanced or metastatic hereditary MTC.
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Affiliation(s)
- Vipul T Lakhani
- Department of Medicine, Division of Endocrinology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA
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Meissner K, Distel H, Mitzdorf U. Evidence for placebo effects on physical but not on biochemical outcome parameters: a review of clinical trials. BMC Med 2007; 5:3. [PMID: 17371590 PMCID: PMC1847831 DOI: 10.1186/1741-7015-5-3] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2006] [Accepted: 03/19/2007] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Recent reviews on placebo effects in clinical trials suggest that objective changes following placebo treatments may not exist or, at least, have been considerably overestimated. However, the possibility that yet unidentified subsets of parameters are responsive to placebo treatments has not been taken into account. Therefore, the aim of the present study is to examine the effects of placebo treatments on objectively measured outcome parameters by specifically focusing on peripheral disease processes. METHODS An initial dataset was collected from a MEDLINE search for placebo-controlled, randomized clinical trials. Trials with stable disease conditions were identified, and the effects of placebo treatments on peripheral outcome parameters were estimated by the changes from baseline in the placebo groups. An explorative data analysis was conducted in order to identify parameter classes with differential responsiveness to placebo treatments. A subgroup meta-analysis of a second dataset was performed to test whether the preliminary classification would also apply to placebo effects derived from the comparison of placebo groups with untreated control groups. RESULTS The explorative analysis of outcome parameters and strength of placebo effects yielded a classification into responsive "physical" versus non-responsive "biochemical" parameters. In total, 50% of trials measuring physical parameters showed significant placebo effects, compared with 6% of trials measuring biochemical parameters. A subgroup meta-analysis substantiated the differential response (physical parameters: n = 14, Hedges' pooled effect size g = 0.34, 95% CI 0.22 to 0.46; biochemical parameters: n = 15, g = 0.03, 95% CI -0.04 to 0.10). The subanalysis of the second dataset supported the classification and revealed a significant improvement for physical parameters (n = 20, g = 0.22, 95% CI 0.07 to 0.36) and a deterioration for biochemical parameters (n = 6, g = -0.17, 95% CI -0.31 to -0.02). CONCLUSION The results suggest that placebo interventions can improve physical disease processes of peripheral organs more easily and effectively than biochemical processes. This differential response offers a good starting point for theoretical considerations on possible mediating mechanisms, and for future investigations in this field.
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Affiliation(s)
- Karin Meissner
- Institute of Medical Psychology, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Hans Distel
- Institute of Medical Psychology, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Ulla Mitzdorf
- Institute of Medical Psychology, Ludwig-Maximilians-University Munich, Munich, Germany
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