Diagnosis and treatment of Paget’s disease of bone: A clinical practice guideline

Assessing bone formation in patients with chronic kidney disease using procollagen type I N-terminal propeptide (PINP): The choice of assay makes a difference

BACKGROUND

Measurement of procollagen type I N-terminal propeptide (PINP) concentration in serum reflects the rate of type I collagen synthesis and can therefore be used as a bone formation marker. There are two methods of PINP quantification; the first measures the trimeric propeptide (intact PINP) and the second measures both the trimeric and monomeric propeptides (total PINP). Trimeric PINP is excreted via hepatic endothelial cells, whereas monomeric PINP is cleared renally. Therefore, in renal failure, the total assay has a positive bias with respect to the intact assay, due to monomeric PINP accumulation. The aim of this study was to compare the performance of both assays across all stages of chronic kidney disease.

METHODS

Serum was taken from male (n = 111) and female (n = 105) patients attending a metabolic bone clinic, and these were partitioned into stages of chronic kidney disease 1-5. Each serum sample was analysed using the Roche electrochemiluminescence immunoassay for total PINP and the Immunodiagnostic Systems chemiluminescence immunoassay for intact PINP.

RESULTS

Passing-Bablok regression analysis comparing both methods showed that with advancing chronic kidney disease there was a proportional positive bias affecting the total assay when compared with the intact assay. This proportional positive bias was statistically significant for chronic kidney disease stages 3b, 4 and 5.

CONCLUSIONS

Based on this method comparison study, usage of the total PINP assay should be avoided in chronic kidney disease stages 3b, 4 and 5 (eGFR ≤44 mL/min/1.73 m²) and instead an intact assay used as the total assay overestimates PINP concentrations due to monomeric PINP accumulation.

Bilateral Cemented Custom-Made Total Hip Arthroplasty in Paget's Disease with Femoral Cortical Thickening and Canal Narrowing

In this report, we present a case of a 57-year-old man complaining of pain in both his hips. Clinically, the patient reported lameness and reduction in the range of motion of the hips. Radiographic imaging showed a very narrow medullary femoral canal, confirmed by a computed tomography scan. In consideration of the narrowness of the femoral canal and cortex thickening, and due to the rarity of the clinical case, we opted to use a custom-made prosthesis. We performed total hip arthroplasty, initially on the right side. One year later, we repeated the procedure on the left side. One year after the last surgery, the patient reported well-being and continuous improvement in walking, with no complications. This case report highlights the features and the critical issues related to this kind of surgery in patients affected by Paget's disease of the bone and the importance of custom-made implants in challenging cases.

Clinical features, diagnosis and treatment of Paget's disease of bone in mainland China: A systematic review

Paget's disease of bone (PDB) is a metabolic bone disease with distinct geographical and ethnic differences in its pathogenesis. In this study, we aimed to retrospectively analyze the clinical features and the status of diagnosis and treatment of PDB in mainland China to improve the clinician's understanding of this disease. For this purpose, we conducted a systematic review of 118 articles, including a total of 332 patients with PDB. The results showed that the onset age of PDB in mainland China was 46-60 years. The number of male patients in most age groups was slightly higher than that of female patients, but there was no statistical difference (p > 0.05). The gender ratio (male to female) of PDB in mainland China was significantly different from that in Japan (p < 0.05), but not from that in the USA (p > 0.05). The clinical manifestations of PDB patients in mainland China mainly included ostealgia, bone malformation, hearing loss, and fracture, and bisphosphonate was used as the main treatment drug. These findings were similar to those in Japan, UK, and USA. Total alkaline phosphatase (TALP) level was elevated in about 89.7% of patients, and no correlation between TALP level and ostealgia was observed (p > 0.05). In addition, no difference in TALP level between males and females in each group was observed (p > 0.05).

Paget's disease of bone: updates for clinicians

PURPOSE OF REVIEW

To provide clinicians an overview to the diagnosis, treatment, and management of Paget's disease, including recent guideline recommendations, with comparison of the Endocrine Society Clinical Practice Guideline (JCEM 2014) with the new Clinical Guideline review endorsed by the International Osteoporosis Foundation, the American Society of Bone and Mineral Research, the European Calcified Tissues Society, and the United Kingdom Bone Research Society (JBMR 2019).

RECENT FINDINGS

Radionuclide bone scans are recommended for assessing the extent of Paget's disease. Bisphosphonates remain the mainstay for therapy with evidence of reducing symptomatic bone pain. One 5 mg intravenous dose of zoledronic acid is the current standard therapy for Paget's disease.

SUMMARY

Paget's disease of the bone is characterized by focal increased bone remodeling activity, resulting in sclerotic or lytic lesions and poor bone quality at one or more sites. Patients may be symptomatic with bone pain, or may be asymptomatic, and identified through unexplained elevations in serum alkaline phosphatase. Diagnosis is through plain film imaging, with radionuclide bone scan to determine the extent. A single dose of IV zoledronic acid typically results in extended suppression of bone turnover and amelioration of bone pain. There remains a lack of evidence regarding efficacy of this treatment with regards to other complications of Paget's, but in general, bisphosphonate treatment is recommended.

Bisphosphonates-much more than only drugs for bone diseases

α,α-Bisphosphonates (BPs) are well established in the treatment of bone diseases such as osteoporosis and Paget's disease. Their successful application originates from their high affinity to hydroxyapatite. While the initially appreciated features of BPs are already beneficial to many patients, recent developments have further expanded their pleiotropic applications. This review describes the background of the interactions of BPs with bone cells that form the basis of the classical treatment. A better understanding of the mechanism behind their interactions allows for the parallel application of BPs against bone cancer and metastases followed by palliative pain relief. Targeted therapy with bone-seeking BPs coupled with a diagnostic agent in one particle resulted in theranostics which is also described here. For example, in such a system, BP moieties are bound to contrast agents used in magnetic resonance imaging or radionuclides used in positron emission tomography. In addition, another example of the pleiotropic function of BPs which involves targeting the imaging agents to bone tissues accompanied by pain reduction is presented in this work.

[Differential diagnoses of osteoporosis]

The differential diagnoses of osteoporosis in geriatric and trauma patients are very important as they may induce different therapies. On average approximately 20% of women and 50% of men have secondary causes of osteoporosis. The foundation of the diagnostics is a basic osteological laboratory investigation with which the most important secondary causes can be identified. From a geriatric and traumatological point of view vitamin D deficiency with secondary hyperparathyroidism, primary hyperparathyroidism, male hypogonadism, multiple myeloma and monoclonal gammopathy of unclear significance (MGUS) are of particular importance.

Chronic Non-bacterial Osteomyelitis: A Review

Chronic non-bacterial osteomyelitis (CNO) is a rare auto-inflammatory bone disorder, with a prevalence of around one in a million patients. In the more severe form, it is referred to as chronic recurrent multifocal osteomyelitis (CRMO). We present the current knowledge on epidemiology, pathophysiology as well as diagnostic options and treatment regimens. CNO/CRMO most commonly affects children and lesions are often seen in the metaphyseal plates of the long bones, but cases have been described affecting all age groups as well as lesions in almost every bone. It is, therefore, a disease that clinicians can encounter in many different settings. Diagnosis is mainly a matter of exclusion from differential diagnoses such as bacterial osteomyelitis and cancer. Magnetic resonance imaging is the best radiological method for diagnosis coupled with a low-grade inflammation and a history of recurring episodes. Treatment is based on case reports and consists of alleviating symptoms with non-steroidal anti-inflammatory drugs since the disease is often self-limiting. Recently, more active treatments using either bisphosphonates or biological treatment are becoming more common, to prevent long term bone damage. In general, due to its rarity, much remains unclear regarding CNO/CRMO. We review the known literature on CNO/CRMO and propose areas of interest as well as possible ways to make current diagnostic criteria more detailed. We also find unifocal cases of the jaw to be a possible sub-type that may need its own set of criteria.

Long-term control of Paget's disease of bone with low-dose, once-weekly, oral bisphosphonate preparations, in a "real world" setting

PURPOSE

Bisphosphonates are the mainstay of the treatment of Paget's disease of bone (PDB). Clinical practice guidelines recommend treatment with intravenous zoledronic acid or high-dose oral nitrogen bisphosphonates (N-BPs). We present our long-term experience treating PDB patients with lower than recommended oral doses of N-BPs, equivalent to once-weekly doses used for treating osteoporosis.

METHODS

PDB patients were seen, between 1990 and 2015 at the endocrine clinic of an academic medical center. Diagnosis was established according to accepted criteria. Patients were initially treated with alendronate 70 mg/week or risedronate 35 mg/week. Whenever the initial dose failed to produce remission, the dosage was increased to twice a week the respective dose.

RESULTS

Patients were followed for a mean of 11.9 years (range: 1.7-24.8). Out of 96 treatment courses with N-BPs, 89% were with alendronate and 11% with risedronate. Remission was achieved in 84% of the courses with alendronate 70 mg/week. 90% of those who did not achieve remission subsequently responded to 140 mg/week. Out of the 8 treatment courses with risedronate 35 mg/week, 87% achieved remission, and the 2 patients who did not achieve remission subsequently responded to 70 mg/week. The median duration of remissions following 3-4 months courses of alendronate 70 mg/week or risedronate 35 mg/week was 8.8 months (IQR: 5.5, 14.8).

CONCLUSION

In a large proportion of "real world" PDB patients, remission can be achieved with once-weekly, "osteoporosis doses" of alendronate or risedronate.

Low-dose zoledronate for the treatment of bone metastasis secondary to prostate cancer

Background

Bisphosphonates (BPs) including zoledronate (zol) have become standard care for bone metastases as they effectively inhibit tumor-induced osteolysis and associated pain. Several studies have also suggested that zol has direct anti-tumor activity. Systemic administration at high doses is the current approach to deliver zol, yet it has been associated with debilitating side effects. Local therapeutic delivery offers the ability to administer much lower total dosage, while at the same time maintaining sustained high-local drug concentration directly at the target treatment site. Here, we aimed to assess effects of lower doses of zol on bone metastases over a longer time.

Methods

Prostate cancer cell line LAPC4 and prostate-induced bone metastasis cells were treated with zol at 1, 3 and 10 µM for 7 days. Following treatment, cell proliferation was assessed using Almarblue^®, Vybrant MTT^®, and Live/Dead^® viability/cytotoxicity assays. Additionally, cell migration and invasion were carried out using Falcon™ cell culture inserts and Cultrex^® 3D spheroid cell invasion assays respectively.

Results

We show that treatment with 3–10 µM zol over 7-days significantly decreased cell proliferation in both the prostate cancer cell line LAPC4 and cells from spine metastases secondary to prostate cancer. Using the same low-dose and longer time course for treatment, we demonstrate that 10 µM zol also significantly inhibits tumor cell migration and 3D-cell growth/invasion.

Conclusions

This project harnesses the potential of using zol at low doses for longer treatment periods, which may be a viable treatment modality when coupled with biomaterials or biodevices for local delivery.

Electronic supplementary material

The online version of this article (10.1186/s12935-019-0745-x) contains supplementary material, which is available to authorized users.