Nephrocalcinosis and kidney function in children and adults with X-linked hypophosphatemia: baseline results from a large longitudinal study.

BACKGROUND: In patients with X-linked hypophosphatemia (XLH), conventional therapy with oral phosphate salts and active vitamin D has been associated with nephrocalcinosis. However, the nature of the relationships among XLH, its treatment, nephrocalcinosis, and kidney function remain poorly understood. METHODS: Renal ultrasounds were performed and glomerular filtration rates were estimated (eGFR) at baseline in burosumab-naïve patients with XLH who participated in burosumab clinical trials (NCT02181764, NCT02526160, NCT02537431, NCT02163577, NCT02750618, NCT02915705) or enrolled in the XLH Disease Monitoring Program (XLH-DMP; NCT03651505). In this cross-sectional analysis, patient, disease, and treatment characteristics were described among patients with and without nephrocalcinosis. RESULTS: The analysis included 196 children (mean [SD] age 7.6 [4.0] yr) and 318 adults (40.3 [13.1] yr). Mean (SD) height z-score was -1.9 (1.2) for children and -2.3 (1.7) for adults. Nearly all children (97%) and adults (94%) had previously received conventional therapy. Nephrocalcinosis was detected in 22% of children and 38% of adults. In children, reduced eGFR <90 mL/min/1.73 m2 was more prevalent in those with nephrocalcinosis (25%) than in those without (11%), a finding that was not observed in adults. Children with nephrocalcinosis had lower mean values of TmP/GFR (p<.05), serum 1,25(OH)2D (p<.05), and eGFR (p<.001) and higher mean serum calcium concentrations (p<.05) than did those without nephrocalcinosis. Adults with nephrocalcinosis had lower mean serum phosphorus (p<.01) and 1,25(OH)2D (p<.05) concentrations than those without. Exploratory logistic regression analyses revealed no significant associations between the presence of nephrocalcinosis and other described patient or disease characteristics. CONCLUSIONS: Nephrocalcinosis was observed in nearly one-quarter of children and more than one-third of adults with XLH. Further study is needed to better understand the predictors and long-term consequences of nephrocalcinosis, with surveillance for nephrocalcinosis remaining important in the management of XLH.

Conventionally, patients with X-linked hypophosphatemia (XLH) were treated with phosphate and vitamin D taken by mouth. However, this therapy might lead to a buildup of calcium in the kidney, called nephrocalcinosis. Here, we tried to better understand how XLH, conventional therapy, nephrocalcinosis, and kidney function are related. Nephrocalcinosis was detected with kidney ultrasounds. Kidney function, called the estimated glomerular filtration rate (eGFR), was determined using blood levels of creatinine. Patients had been part of burosumab clinical trials or part of the XLH Disease Monitoring Program. Data were collected from patients before they received burosumab. The study included 196 children and 318 adults. Almost all children and adults had received conventional therapy. 22% of children and 38% of adults had nephrocalcinosis. Some lab values were different among patients with vs without nephrocalcinosis. Children with nephrocalcinosis had significantly greater loss of phosphate by the kidneys, lower blood levels of the active form of vitamin D (1,25(OH)2D), lower eGFR, and higher blood levels of calcium than those without nephrocalcinosis. Adults with nephrocalcinosis had significantly lower blood levels of phosphorus and 1,25(OH)2D concentrations than those without. It remains important to monitor patients with XLH for nephrocalcinosis. Further study is needed to better understand nephrocalcinosis.

Palopegteriparatide Treatment Improves Renal Function in Adults with Chronic Hypoparathyroidism: 1-Year Results from the Phase 3 PaTHway Trial.

INTRODUCTION: Individuals with chronic hypoparathyroidism managed with conventional therapy (active vitamin D and calcium) have an increased risk for renal dysfunction versus age- and sex-matched controls. Treatments that replace the physiologic effects of parathyroid hormone (PTH) while reducing the need for conventional therapy may help prevent a decline in renal function in this population. This post hoc analysis examined the impact of palopegteriparatide treatment on renal function in adults with chronic hypoparathyroidism. METHODS: PaTHway is a phase 3 trial of palopegteriparatide in adults with chronic hypoparathyroidism that included a randomized, double-blind, placebo-controlled 26-week period followed by an ongoing 156-week open-label extension (OLE) period. Changes in renal function over 52 weeks (26 weeks blinded + 26 weeks OLE) were assessed using estimated glomerular filtration rate (eGFR). A subgroup analysis was performed with participants stratified by baseline eGFR < 60 or ≥ 60 mL/min/1.73 m2. RESULTS: At week 52, over 95% (78/82) of participants remained enrolled in the OLE and of those, 86% maintained normocalcemia and 95% achieved independence from conventional therapy (no active vitamin D and ≤ 600 mg/day of calcium), with none requiring active vitamin D. Treatment with palopegteriparatide over 52 weeks resulted in a mean (SD) increase in eGFR of 9.3 (11.7) mL/min/1.73 m2 from baseline (P < 0.0001) and 43% of participants had an increase ≥ 10 mL/min/1.73 m2. In participants with baseline eGFR < 60 mL/min/1.73 m2, 52 weeks of treatment with palopegteriparatide resulted in a mean (SD) increase of 11.5 (11.3) mL/min/1.73 m2 (P < 0.001). One case of nephrolithiasis was reported for a participant in the placebo group during blinded treatment; none were reported through week 52 with palopegteriparatide. CONCLUSION: In this post hoc analysis of the PaTHway trial, palopegteriparatide treatment was associated with significantly improved eGFR at week 52 in addition to previously reported maintenance and normalization of serum and urine biochemistries. Further investigation of palopegteriparatide for the preservation of renal function in hypoparathyroidism is warranted. TRIAL REGISTRATION: ClinicalTrials.gov NCT04701203.

Chronic hypoparathyroidism is caused by inadequate parathyroid hormone (PTH) levels. Hypoparathyroidism is managed with conventional therapy (active vitamin D and calcium), but over time the disease itself and conventional therapy can increase the risk of medical complications including kidney problems. This study looked at how a new treatment for chronic hypoparathyroidism, palopegteriparatide (approved in the European Union under the brand name YORVIPATH^®), affects kidney function in adults in the PaTHway clinical trial. Participants were randomly assigned to receive palopegteriparatide or a placebo injection once daily along with conventional therapy. For both groups, clinicians used a protocol to eliminate conventional therapy while maintaining normal blood calcium levels. After 26 weeks, participants on placebo switched to palopegteriparatide. Ninety-five percent of participants were still enrolled in the PaTHway trial after 52 weeks. Of those, 86% had normal blood calcium levels and 95% did not need conventional therapy (not taking vitamin D and not taking therapeutic doses of calcium [> 600 mg/day]). After 52 weeks of treatment with palopegteriparatide, significant improvements were seen in a measure of kidney function called estimated glomerular filtration rate (eGFR). Improvements in eGFR from the beginning of the trial to week 52 were considered clinically meaningful for over 57% of participants. In participants with impaired kidney function at the beginning of the trial, eGFR improvements were even greater, and 74% of participants had a clinically meaningful improvement. These results suggest that palopegteriparatide treatment may be beneficial for kidney function in adults with chronic hypoparathyroidism, especially those with impaired kidney function.

Proposed diagnostic criteria for the diagnosis of hypophosphatasia in children and adolescents: results from the HPP International Working Group.

Hypophosphatasia (HPP) is a rare inborn error of metabolism that presents variably in both age of onset and severity. HPP is caused by pathogenic variants in the ALPL gene, resulting in low activity of tissue nonspecific alkaline phosphatase (TNSALP). Patients with HPP tend have a similar pattern of elevation of natural substrates that can be used to aid in diagnosis. No formal diagnostic guidelines currently exist for the diagnosis of this condition in children, adolescents, or adults. The International HPP Working Group is a comprised of a multidisciplinary team of experts from Europe and North America who have expertise in the diagnosis and management of patients with HPP. This group reviewed 93 papers through a Medline, Medline In-Process, and Embase search for the terms "HPP" and "hypophosphatasia" between 2005 and 2020 and that explicitly address either the diagnosis of HPP in children, clinical manifestations of HPP in children, or both. Two reviewers independently evaluated each full-text publication for eligibility and studies were included if they were narrative reviews or case series/reports that concerned diagnosis of pediatric HPP or included clinical aspects of patients diagnosed with HPP. This review focused on 15 initial clinical manifestations that were selected by a group of clinical experts.The highest agreement in included literature was for pathogenic or likely pathogenic ALPL variant, elevation of natural substrates, and early loss of primary teeth. The highest prevalence was similar, including these same three parameters and including decreased bone mineral density. Additional parameters had less agreement and were less prevalent. These were organized into three major and six minor criteria, with diagnosis of HPP being made when two major or one major and two minor criteria are present.

Global guidance for the recognition, diagnosis, and management of tumor-induced osteomalacia.

Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome caused by mesenchymal tumors that secrete fibroblast growth factor 23 (FGF23). Patients present with progressive bone pain, muscle weakness, and fragility fractures. TIO is characterized by hypophosphatemia, excess renal phosphate excretion, and low/inappropriately normal 1,25-dihydroxyvitamin D (1,25(OH)2 D) levels. Rarity and enigmatic clinical presentation of TIO contribute to limited awareness among the medical community. Accordingly, appropriate diagnostic tests may not be requested, leading to delayed diagnosis and poorer patient outcomes. We have developed a global guidance document to improve the knowledge of TIO in the medical community, enabling the recognition of patients with TIO and appropriate referral. We provide recommendations aiding diagnosis, referral, and treatment, helping promote a global standard of patient management. We reviewed the literature and conducted a three-round Delphi survey of TIO experts. Statements were drafted based on published evidence and expert opinions (≥70% consensus required for final recommendations). Serum phosphate should be measured in patients presenting with chronic muscle pain or weakness, fragility fractures, or bone pain. Physical examination should establish features of myopathy and identify masses that could be causative tumors. Priority laboratory evaluations should include urine/serum phosphate and creatinine to assess renal tubular reabsorption of phosphate and TmP/GFR, alkaline phosphatase, parathyroid hormone, 25-hydroxyvitamin D, 1,25(OH)2 D, and FGF23. Patients with the clinical/biochemical suspicion of TIO should be referred to a specialist for diagnosis confirmation, and functional imaging should be used to localize causative tumor(s). Recommended treatment is tumor resection or, with unresectable/unidentifiable tumors, phosphate salts plus active vitamin D, or burosumab.

Prevalence and Outcomes of COVID-19 among Hematology/Oncology Patients and Providers of a Community-Facing Health System during the B1.1.529 ("Omicron") SARS-CoV-2 Variant Wave.

(1) Background: the SARS-CoV-2 (COVID-19) pandemic continues, and patients actively receiving chemotherapy are known to be at enhanced risk for developing symptomatic disease with poorer outcomes. Our study evaluated the prevalence of COVID-19 among patients and providers of our community-facing county health system during the B1.1.529 ("Omicron") COVID-19 variant wave. (2) Methods: We retrospectively analyzed patients that received care and clinical providers whom worked at the Jackson Memorial Hospital Hematology/Oncology clinic in Miami, Florida, USA, from 1 December 2021 through 30 April 2022. We assessed demographic variables and quality outcomes among patients. (3) Results: 1031 patients and 18 providers were retrospectively analyzed. 90 patients tested positive for COVID-19 (8.73%), while 6 providers tested positive (33.3%) (p = 0.038). There were 4 (10.3%) COVID-19-related deaths (and another outside our study timeframe) and 39 non-COVID-19-related deaths (89.7%) in the patient population (p = 0.77). COVID-19 accounted for 4.44% of our clinic's total mortality, and delayed care in 64.4% of patients. (4) Conclusions: The prevalence of COVID-19 positivity in our patient cohort mirrored local, state, and national trends, however a statistically significant greater proportion of our providers tested positive. Almost two-thirds of patients experienced a cancer treatment delay, significantly impacting oncologic care.

The Efficacy and Safety of Medical and Surgical Therapy in Patients With Primary Hyperparathyroidism: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Both medical and surgical therapy represent potential management options for patients with asymptomatic primary hyperparathyroidism (PHPT). Because uncertainty remains regarding both medical and surgical therapy, this systematic review addresses the efficacy and safety of medical therapy in asymptomatic patients or symptomatic patients who decline surgery and surgery in asymptomatic patients. We searched Medline, Embase, Cochrane Central Register of Controlled Trials, and PubMed from inception to December 2020, and included randomized controlled trials in patients with PHPT that compared nonsurgical management with medical therapy versus without medical therapy and surgery versus no surgery in patients with asymptomatic PHPT. For surgical complications we included observational studies. Paired reviewers addressed eligibility, assessed risk of bias, and abstracted data for patient-important outcomes. We conducted random-effects meta-analyses to pool relative risks and mean differences with 95% confidence intervals and used Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) to assess quality of evidence for each outcome. For medical therapy, 11 trials reported in 12 publications including 438 patients proved eligible: three addressed alendronate, one denosumab, three cinacalcet, two vitamin D, and two estrogen therapy. Alendronate, denosumab, vitamin D, and estrogen therapy all increased bone density. Cinacalcet probably reduced serum calcium and parathyroid hormone (PTH) levels. Cinacalcet and vitamin D may have a small or no increase in overall adverse events. Very-low-quality evidence raised the possibility of an increase in serious adverse events with alendronate and denosumab. The trials also provided low-quality evidence for increased bleeding and mastalgia with estrogen therapy. For surgery, six trials presented in 12 reports including 441 patients proved eligible. Surgery achieved biochemical cure in 96.1% (high quality). We found no convincing evidence supporting an impact of surgery on fracture, quality of life, occurrence of kidney stones, and renal function, but the evidence proved low or very low quality. Surgery was associated with an increase in bone mineral density. For patients with symptomatic and asymptomatic PHPT, who are not candidates for parathyroid surgery, cinacalcet probably reduced serum calcium and PTH levels; anti-resorptives increased bone density. For patients with asymptomatic PHPT, surgery usually achieves biochemical cure. These results can help to inform patients and clinicians regarding use of medical therapy and surgery in PHPT. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Evaluation and Management of Hypoparathyroidism Summary Statement and Guidelines from the Second International Workshop.

This clinical practice guideline addresses the prevention, diagnosis, and management of hypoparathyroidism (HypoPT) and provides evidence-based recommendations. The HypoPT task forces included four teams with a total of 50 international experts including representatives from the sponsoring societies. A methodologist (GG) and his team supported the taskforces and conducted the systematic reviews. A formal process following the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology and the systematic reviews provided the structure for seven of the guideline recommendations. The task force used a less structured approach based on narrative reviews for 20 non-GRADEd recommendations. Clinicians may consider postsurgical HypoPT permanent if it persists for >12 months after surgery. To predict which patients will not develop permanent postsurgical HypoPT, we recommend evaluating serum PTH within 12 to 24 hours post total thyroidectomy (strong recommendation, moderate quality evidence). PTH > 10 pg/mL (1.05 pmol/L) virtually excludes long-term HypoPT. In individuals with nonsurgical HypoPT, genetic testing may be helpful in the presence of a positive family history of nonsurgical HypoPT, in the presence of syndromic features, or in individuals younger than 40 years. HypoPT can be associated with complications, including nephrocalcinosis, nephrolithiasis, renal insufficiency, cataracts, seizures, cardiac arrhythmias, ischemic heart disease, depression, and an increased risk of infection. Minimizing complications of HypoPT requires careful evaluation and close monitoring of laboratory indices. In patients with chronic HypoPT, the panel suggests conventional therapy with calcium and active vitamin D metabolites as first-line therapy (weak recommendation, low-quality evidence). When conventional therapy is deemed unsatisfactory, the panel considers the use of PTH. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Management of Hypoparathyroidism.

Hypoparathyroidism (HypoPT) is a rare disorder characterized by hypocalcemia in the presence of a low or inappropriately normal parathyroid hormone level. HypoPT is most commonly seen after neck surgery, which accounts for approximately 75% of cases, whereas approximately 25% have HypoPT due to nonsurgical causes. In both groups of patients, conventional therapy includes calcium and active vitamin D analogue therapy aiming to maintain serum calcium concentration in the low normal or just below the normal reference range and normalize serum phosphorus, magnesium concentrations, and urine calcium levels. The limitations of conventional therapy include wide fluctuations in serum calcium, high pill burden, poor quality of life, and renal complications. Parathyroid hormone (PTH) replacement therapy may improve the biochemical profile in those in whom conventional therapy proves unsatisfactory. Based on a systematic review and meta-analysis of the literature, the panel made a graded recommendation suggesting conventional therapy as first line therapy rather than administration of PTH (weak recommendation, low quality evidence). When conventional therapy is deemed unsatisfactory, the panel considers use of PTH. Because pregnancy and lactation are associated with changes in calcium homeostasis, close monitoring is required during these periods with appropriate adjustment of calcium and active vitamin D analogue therapy to ensure that serum calcium remains in the mid to low normal reference range in order to avoid maternal and fetal complications. Emerging therapies include molecules with prolonged PTH action as well as different mechanisms of action that may significantly enhance drug efficacy and safety. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

ALCAM: A Novel Surface Marker on EpCAMlow Circulating Tumor Cells.

Background: Current strategies in circulating tumor cell (CTC) isolation in pancreatic cancer heavily rely on the EpCAM and cytokeratin cell status. EpCAM is generally not considered a good marker given its transitory change during Epithelial to Mesenchymal Transition (EMT) or reverse EMT. There is a need to identify other surface markers to capture the complete repertoire of PDAC CTCs. The primary objective of the study is to characterize alternate surface biomarkers to EpCAM on CTCs that express low or negligible levels of surface EpCAM in pancreatic cancer patients. Methods: Flow cytometry and surface mass spectrometry were used to identify proteins expressed on the surface of PDAC CTCs in culture. CTCs were grown under conditions of attachment and in co-culture with naïve neutrophils. Putative biomarkers were then validated in GEMMs and patient samples. Results: Surface proteomic profiling of CTCs identified several novel protein biomarkers. ALCAM was identified as a novel robust marker in GEMM models and in patient samples. Conclusions: We identified several novel surface biomarkers on CTCs expressed under differing conditions of culture. ALCAM was validated and identified as a novel alternate surface marker on EpCAMlow CTCs.

Osteonecrosis of the Jaw and Antiresorptive Agents in Benign and Malignant Diseases: A Critical Review Organized by the ECTS.

CONTEXT: Antiresorptive therapy significantly reduces fracture risk in patients with benign bone disease and skeletal-related events (SREs) in patients with bone metastases (BM). Osteonecrosis of the jaw (ONJ) is a rare but severe condition manifested as necrotic bone lesion or lesions of the jaws. ONJ has been linked to the use of potent antiresorptive agents, termed medication-related ONJ (MRONJ). OBJECTIVE: We aimed to identify the differences various aspects of MRONJ among distinct patient categories and provide recommendations on how to mitigate the risk and optimally manage MRONJ in each of them. METHODS: A working group of the European Calcified Tissue Society (ECTS) and 2 experts performed an updated detailed review of existing literature on MRONJ incidence, characteristics, and treatment applied in bone diseases with variable severity of skeletal insult, ranging from osteoporosis to prevention of cancer treatment-induced bone loss and SREs in cancer patients with BM. RESULTS: The risk for MRONJ is much higher in patients with advanced malignancies compared to those with benign bone diseases because of the higher doses and more frequent administration of antiresorptive agents in individuals with compromised general health, along with coadministration of other medications that predispose to MRONJ. The overall risk for MRONJ is considerably lower than the benefits in all categories of patients. CONCLUSION: The risk for MRONJ largely depends on the underlying bone disease and the relevant antiresorptive regimen applied. Physicians and dentists should keep in mind that the benefits of antiresorptive therapy far outweigh the risk for MRONJ development.

Primary Hyperparathyroidism in Pregnancy: Literature Review of the Diagnosis and Management.

BACKGROUND: Parathyroid disease is uncommon in pregnancy. During pregnancy, multiple changes occur in the calcium regulating hormones which may make the diagnosis of primary hyperparathyroidism more challenging. Close monitoring of serum calcium during pregnancy is necessary in order to optimize maternal and fetal outcomes. In this review, we will describe the diagnosis and management of primary hyperparathyroidism during pregnancy. METHODS: We searched MEDLINE, CINAHL, EMBASE and Google scholar bases from 1 January 1990 to 31 December 2020. Case reports, case series, book chapters and clinical guidelines were included in this review. CONCLUSIONS: Medical management options for primary hyperparathyroidism during pregnancy are severely limited due to inadequate safety data with the various potential therapies available, and surgery is advised during the 2nd trimester of pregnancy in the presence of severe hypercalcemia (calcium adjusted for albumin greater than 3.0 mmol/L (12.0 mg/dL)). Hypercalcemia should be avoided during pregnancy in order to minimize maternal and fetal complications.

Primary Hyperparathyroidism: A Narrative Review of Diagnosis and Medical Management.

Primary hyperparathyroidism (PHPT) is the most common cause of hypercalcemia in the outpatient setting. Symptomatic presentation includes non-specific signs and symptoms of hypercalcemia, skeletal fragility, nephrolithiasis and nephrocalcinosis. The majority of individuals present at an asymptomatic stage following routine biochemical screening, without any signs or symptoms of calcium or parathyroid hormone (PTH) excess or target organ damage. Indications for surgery have recently been revised as published in recent guidelines and consensus statements. Parathyroidectomy is advised in patients younger than 50 years old and in the presence of either significant hypercalcemia, impaired renal function, renal stones or osteoporosis. Surgery is always appropriate in suitable surgical candidates, however, medical management may be considered in those with mild asymptomatic disease, contraindications to surgery or failed previous surgical intervention. We summarized the optimal medical interventions available in the care of PHPT patients not undergoing parathyroidectomy. Calcium and vitamin D intake should be optimized. Antiresorptive therapy may be used for skeletal protection in patients with an increased fracture risk. Cinacalcet, a calcimimetic agent, has been shown to effectively lower serum calcium and PTH levels. The effect of medical treatment on the reduction in fracture risk is unknown and should be the focus of future research.

Determining the National Cataract Surgical Rate in Pakistan.

PURPOSE: Cataract surgical rate (CSR) (cataract surgeries performed per million population) is an eye health indicator that helps assess the state of eye care services. A survey in 2002 revealed a CSR of 2254. The current survey aimed to establish a new and sustainable development goal compliant baseline for the volume of cataract surgery performed by different service providers in Pakistan at district, provincial, and national levels. METHODS: The survey was commissioned by the National Committee for Eye Health under the Ministry of National Health Services, Regulations and Coordination. The methodology used for the survey included identification and mapping of all service providers by district and category and data collection from all districts in the country. RESULTS: There were more cataract surgeries performed in women than men with a male-to-female ratio of 0.95. About 98.9% of all cataract surgeries were performed with intraocular lenses, while 63.9% were performed by phacoemulsification. About 17.7% of cataract surgical services were provided in the government sector (including Forces), while nongovernmental organizations and the private sector contributed to 82.3%. Pakistan achieved a national CSR of 5307 which is almost double the CSR determined in 2002. CONCLUSION: In order to achieve a CSR of 7500+ by 2030, there is a need for at least 1,840,000 cataract surgeries to be performed annually. If there is no change in the current annual cataract surgical output, the CSR will drop to 4628 by 2030.

Medication-Related Osteonecrosis of the Jaw: MASCC/ISOO/ASCO Clinical Practice Guideline.

PURPOSE: To provide guidance regarding best practices in the prevention and management of medication-related osteonecrosis of the jaw (MRONJ) in patients with cancer. METHODS: Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISOO) and ASCO convened a multidisciplinary Expert Panel to evaluate the evidence and formulate recommendations. Guideline development involved a systematic review of the literature and a formal consensus process. PubMed and EMBASE were searched for studies of the prevention and management of MRONJ related to bone-modifying agents (BMAs) for oncologic indications published between January 2009 and December 2017. Results from an earlier systematic review (2003 to 2008) were also included. RESULTS: The systematic review identified 132 publications, only 10 of which were randomized controlled trials. Recommendations underwent two rounds of consensus voting. RECOMMENDATIONS: Currently, MRONJ is defined by (1) current or previous treatment with a BMA or angiogenic inhibitor, (2) exposed bone or bone that can be probed through an intraoral or extraoral fistula in the maxillofacial region and that has persisted for longer than 8 weeks, and (3) no history of radiation therapy to the jaws or metastatic disease to the jaws. In patients who initiate a BMA, preventive care includes comprehensive dental assessments, discussion of modifiable risk factors, and avoidance of elective dentoalveolar surgery (ie, surgery that involves the teeth or contiguous alveolar bone) during BMA treatment. It remains uncertain whether BMAs should be discontinued before dentoalveolar surgery. Staging of MRONJ should be performed by a clinician with experience in the management of MRONJ. Conservative measures comprise the initial approach to MRONJ treatment. Ongoing collaboration among the dentist, dental specialist, and oncologist is essential to optimal patient care.

Hypoparathyroidism.

The regulation of plasma calcium levels is essential for the normal physiologic function of every cell. Parathyroid hormone (PTH) is the principal regulator of serum calcium and phosphate homeostasis. PTH is synthesized and secreted by the parathyroid chief cells in the parathyroid glands primarily in response to a decline in serum calcium levels. The causes of hypocalcemia can be broadly classified as inadequate PTH or vitamin D production, PTH resistance, or miscellaneous causes. The term "hypoparathyroidism" refers to a metabolic disorder in which hypocalcemia and hyperphosphatemia occur either from a failure of the parathyroid glands to secrete sufficient amounts of biologically active PTH, or from an inability of PTH to appropriately induce a biological response in its target tissues. The most common cause of acquired hypoparathyroidism is surgery, accounting for 75% of all cases. Nonsurgical causes of hypoparathyroidism include autoimmune, genetic variants, infiltrative, metastatic, radiation, mineral deposition, magnesium deficiency or excess or idiopathic. The objective of this chapter is to provide a comprehensive review of the physiology of calcium homeostasis, the causes of hypocalcemia, and the epidemiology of hypoparathyroidism. It is very important to determine the underlying cause of the hypoparathyroidism in order to effectively treat our patients and improve quality of life.

Medical Hypoparathyroidism.

Hypoparathyroidism is a metabolic disorder characterized by hypocalcemia, hyperphosphatemia, and inadequate levels of or function of parathyroid hormone (PTH). The authors review the nonsurgical or medical causes of hypoparathyroidism. The most common of the nonsurgical causes is autoimmune destruction of the parathyroid. Magnesium deficiency or excess can cause a functional hypoparathyroidism. Genetic conditions result in hypoparathyroidism as part of a syndrome or in isolation. Pseudohypoparathyroidism reflects a resistance to PTH. Infiltrative, metastatic, radiation destruction, mineral deposition, or idiopathic are uncommon causes of hypoparathyroidism. This article reviews the causes of hypoparathyroidism and an approach to the evaluation of this condition.

Hyperparathyroidism.

Primary hyperparathyroidism is a common endocrine disorder of calcium metabolism characterised by hypercalcaemia and elevated or inappropriately normal concentrations of parathyroid hormone. Almost always, primary hyperparathyroidism is due to a benign overgrowth of parathyroid tissue either as a single gland (80% of cases) or as a multiple gland disorder (15-20% of cases). Primary hyperparathyroidism is generally discovered when asymptomatic but the disease always has the potential to become symptomatic, resulting in bone loss and kidney stones. In countries where biochemical screening tests are not common, symptomatic primary hyperparathyroidism tends to predominate. Another variant of primary hyperparathyroidism has been described in which the serum calcium concentration is within normal range but parathyroid hormone is elevated in the absence of any obvious cause. Primary hyperparathyroidism can be cured by removal of the parathyroid gland or glands but identification of patients who are best advised to have surgery requires consideration of the guidelines that are regularly updated. Recommendations for patients who do not undergo parathyroid surgery include monitoring of serum calcium concentrations and bone density.

A weekly 35,000 IU vitamin D supplementation improves bone turnover markers in vitamin D deficient Saudi adolescent females.

This study examined the effects of weekly 35,000 IU vitamin D supplementation for 4 weeks on bone turnover markers (BTMs). There was improvement in the levels of parathyroid hormone (PTH), osteocalcin, and carboxy-terminal telopeptides of crosslinks of type 1 collagen (ßCTX) which paralleled the increase in vitamin D levels. PURPOSE: The effects of vitamin D supplementation on bone turnover markers (BTMs) have been inconsistent. This study examined the effects of weekly 35,000 IU vitamin D supplementation for 1 month on BTMs. METHODS: Sixty-eight vitamin D deficient adolescent females were given 35,000 IU of vitamin D3 for 4 weeks. Pre and post intervention blood samples were taken for 25(OH) D, PTH, osteocalcin and ßCTX. RESULTS: There was a significant increase in serum 25 (OH) D in the post intervention period which was accompanied by a significant decrease in PTH, osteocalcin and ßCTX (P < 0.001). CONCLUSIONS: We concluded that weekly 35,000 IU vitamin D supplementation for 4 weeks results in significant improvement of BTMs.

Drug-Related Adverse Events of Osteoporosis Therapy.

Postmenopausal osteoporosis is associated with microarchitectural deterioration and increased risk of fracture. Osteoporosis therapy effectively reduces the risk of vertebral, nonvertebral, and hip fracture and has been associated with increased survival. Currently approved treatments for osteoporosis include bisphosphonates, denosumab, selective estrogen receptor modulators, and teriparatide. This article reviews the adverse events of therapy associated with these medical interventions. Hormone replacement therapy is not included, because it is no longer indicated for the treatment of osteoporosis in all countries. Calcitonin and strontium ranelate are also not included, because their indication for osteoporosis has recently been limited or withdrawn.