Paget's disease of bone: a review of 889 patients

Long-term effectiveness of zoledronic acid in patients with Paget's disease of bone - a retrospective cohort study

PURPOSE

The aims of the current study were to describe clinical and biochemical features of patients with Paget disease of bone (PDB) followed at our medical center, and to examine the long-term effectiveness of zoledronate.

METHODS

Retrospective cohort study included consecutive patients≥18 years with a diagnosis of PDB, followed in the Rabin Medical Center (RMC) Institute of Endocrinology from 1973 to 2023. The cohort comprised two groups: patients treated/not treated with zoledronic acid (ZOL/NZOL). The primary outcome was the percentage of patients who achieved a biochemical therapeutic response.

RESULTS

Overall, 101 patients with PDB were included, 68 in the ZOL group and 33 in the NZOL group. The mean age was 65.2 ± 10.0 years, and 47% were female. Notably, 77% exhibited monostotic involvement, and only 3% had experienced fractures attributed to PDB. Mean ALP level at diagnosis was 160 ± 70.6 U/L. The median follow-up duration was 17 years since PDB diagnosis, comparable between the groups. Primary outcome was more prevalent in the ZOL compared to the NZOL group [42 patients (88%) VS 11 patients (52%) respectively, P = 0.004]. At the end of follow-up, mean ALP levels in the NZOL group were significantly higher than the levels in the ZOL group irrespective of the number of infusions received.

CONCLUSION

The majority of patients with PDB experience a mild disease course, marked by monostotic involvement and a low prevalence of fractures. Zoledronic acid effectively manages PDB, providing sustained biochemical response. The necessity for multiple zoledronic acid injections remains questionable, often implemented due to osteoporosis.

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).

Management of Paget's disease of bone

Paget's disease is a progressive focal bone condition which can result in pain, low quality of life, deformity and other complications. Disease progression can be halted with potent bisphosphonates, resulting in improvement in both quality of life and pain, and normalisation of scintigraphy, plain radiographs and bone histology. Zoledronate has transformed the treatment of Paget's disease, producing sustained remissions in almost all patients. Thus, it is now possible to normalise bone cell activity and prevent disease progression at low cost, with one or two intravenous injections of zoledronate, greatly reducing follow-up costs. Patients with Paget's disease who are symptomatic or at risk of complications should have the opportunity to reap these therapeutic benefits. Potent bisphosphonates are highly effective in halting disease progression in Paget's disease, but guidelines disagree about treatment indications. The efficacy, safety and low cost of zoledronate recommend its use in any patient who is symptomatic or judged to be at risk of complications from Paget's disease.

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.

Diagnosis and Management of Paget's Disease of Bone in Adults: A Clinical Guideline

An evidence-based clinical guideline for the diagnosis and management of Paget's disease of bone (PDB) was developed using GRADE methodology, by a Guideline Development Group (GDG) led by the Paget's Association (UK). A systematic review of diagnostic tests and pharmacological and nonpharmacological treatment options was conducted that sought to address several key questions of clinical relevance. Twelve recommendations and five conditional recommendations were made, but there was insufficient evidence to address eight of the questions posed. The following recommendations were identified as the most important: 1) Radionuclide bone scans, in addition to targeted radiographs, are recommended as a means of fully and accurately defining the extent of metabolically active disease in patients with PDB. 2) Serum total alkaline phosphatase (ALP) is recommended as a first-line biochemical screening test in combination with liver function tests in screening for the presence of metabolically active PDB. 3) Bisphosphonates are recommended for the treatment of bone pain associated with PDB. Zoledronic acid is recommended as the bisphosphonate most likely to give a favorable pain response. 4) Treatment aimed at improving symptoms is recommended over a treat-to-target strategy aimed at normalizing total ALP in PDB. 5) Total hip or knee replacements are recommended for patients with PDB who develop osteoarthritis in whom medical treatment is inadequate. There is insufficient information to recommend one type of surgical approach over another. The guideline was endorsed by the European Calcified Tissues Society, the International Osteoporosis Foundation, the American Society of Bone and Mineral Research, the Bone Research Society (UK), and the British Geriatric Society. The GDG noted that there had been a lack of research on patient-focused clinical outcomes in PDB and identified several areas where further research was needed. © 2019 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc.

A case of Paget from a Northern Italy medieval necropolis

An excavation conducted in 2002 by the Lombardy Archaeological Heritage in the St. Giulio Church (Cassano Magnago-Northern Italy) revealed an adult skeleton with an important alteration of the left femur. The femur, longer than the contralateral, exhibited an expansion of the full diaphysis; the surface was coarsened and porous. In cross section, it appeared that almost all the cortical bone had been converted into cancellous bone. Macroscopic and radiological alterations are suggestive of the monostotic form of Paget's disease, a chronic disorder, characterized by focal areas of excessive osteoclastic bone resorption followed by a secondary increase in osteoblastic bone formation. Differential diagnosis is complex for Paget's disease, requiring histological analysis, which revealed a thickened and disorganized trabecular pattern with thick cement lines. Such features, resembling to a mosaic pattern, are typical of Paget's disease.

Clinical and Microstructural Findings in Paget Disease of the Entire Mandible

Paget disease of bone (PDB) is a chronic progressive bone disorder characterized by localized increased bone turnover and focal areas of woven bone formation. Although skull involvement is common, PDB very rarely affects the mandible. This report describes the clinical and histologic findings in a 75-year-old patient with PDB involving the mandible. Microstructural analyses showed an altered quality of the bone microstructure and calcium depletion of the affected bone. Differential diagnosis of PDB affecting the mandible is discussed.

Renal Cell Carcinoma Metastasized to Pagetic Bone

Paget's disease of the bone, historically known as osteitis deformans, is an uncommon disease typically affecting individuals of European descent. Patients with Paget's disease of the bone are at increased risk for primary bone neoplasms, particularly osteosarcoma. Many cases of metastatic disease to pagetic bone have been reported. However, renal cell carcinoma metastasized to pagetic bone is extremely rare. A 94-year-old male presented to the emergency department complaining of abdominal pain. A computed tomography scan of the abdomen demonstrated a large mass in the right kidney compatible with renal cell carcinoma. The patient was also noted to have Paget's disease of the pelvic bones and sacrum. Within the pagetic bone of the sacrum, there was an enhancing mass compatible with renal cell carcinoma. A subsequent biopsy of the renal lesion confirmed renal cell carcinoma. Paget's disease of the bone places the patient at an increased risk for bone neoplasms. The most commonly reported sites for malignant transformation are the femur, pelvis, and humerus. In cases of malignant transformation, osteosarcoma is the most common diagnosis. Breast, lung, and prostate carcinomas are the most common to metastasize to pagetic bone. Renal cell carcinoma associated with Paget's disease of the bone is very rare, with only one prior reported case. Malignancy in Paget's disease of the bone is uncommon with metastatic disease to pagetic bone being extremely rare. We report a patient diagnosed with concomitant renal cell carcinoma and metastatic disease within Paget's disease of the sacrum. Further research is needed to assess the true incidence of renal cell carcinoma associated with pagetic bone.

The fracture mechanics of human bone: influence of disease and treatment

Aging and bone diseases are associated with increased fracture risk. It is therefore pertinent to seek an understanding of the origins of such disease-related deterioration in bone's mechanical properties. The mechanical integrity of bone derives from its hierarchical structure, which in healthy tissue is able to resist complex physiological loading patterns and tolerate damage. Indeed, the mechanisms through which bone derives its mechanical properties make fracture mechanics an ideal framework to study bone's mechanical resistance, where crack-growth resistance curves give a measure of the intrinsic resistance to the initiation of cracks and the extrinsic resistance to the growth of cracks. Recent research on healthy cortical bone has demonstrated how this hierarchical structure can develop intrinsic toughness at the collagen fibril scale mainly through sliding and sacrificial bonding mechanisms that promote plasticity. Furthermore, the bone-matrix structure develops extrinsic toughness at much larger micrometer length-scales, where the structural features are large enough to resist crack growth through crack-tip shielding mechanisms. Although healthy bone tissue can generally resist physiological loading environments, certain conditions such as aging and disease can significantly increase fracture risk. In simple terms, the reduced mechanical integrity originates from alterations to the hierarchical structure. Here, we review how human cortical bone resists fracture in healthy bone and how changes to the bone structure due to aging, osteoporosis, vitamin D deficiency and Paget's disease can affect the mechanical integrity of bone tissue.

Bone as a Structural Material

As one of the most important natural materials, cortical bone is a composite material comprising assemblies of tropocollagen molecules and nanoscale hydroxyapatite mineral crystals, forming an extremely tough, yet lightweight, adaptive and multi-functional material. Bone has evolved to provide structural support to organisms, and therefore its mechanical properties are vital physiologically. Like many mineralized tissues, bone can resist deformation and fracture from the nature of its hierarchical structure, which spans molecular to macroscopic length-scales. In fact, bone derives its fracture resistance with a multitude of deformation and toughening mechanisms that are active at most of these dimensions. It is shown that bone's strength and ductility originate primarily at the scale of the nano to submicrometer structure of its mineralized collagen fibrils and fibers, whereas bone toughness is additionally generated at much larger, micro- to near-millimeter, scales from crack-tip shielding associated with interactions between the crack path and the microstructure. It is further shown how the effectiveness with which bone's structural features can resist fracture at small to large length-scales can become degraded by biological factors such as aging and disease, which affect such features as the collagen cross-linking environment, the homogeneity of mineralization, and the density of the osteonal structures.

Modifications to nano- and microstructural quality and the effects on mechanical integrity in Paget's disease of bone

Paget's disease of bone (PDB) is the second most common bone disease mostly developing after 50 years of age at one or more localized skeletal sites; it is associated with severely high bone turnover, bone enlargement, bowing/deformity, cracking, and pain. Here, to specifically address the origins of the deteriorated mechanical integrity, we use a cohort of control and PDB human biopsies to investigate multiscale architectural and compositional modifications to the bone structure (ie, bone quality) and relate these changes to mechanical property measurements to provide further insight into the clinical manifestations (ie, deformities and bowing) and fracture risk caused by PDB. Here, at the level of the collagen and mineral (ie, nanometer-length scale), we find a 19% lower mineral content and lower carbonate-to-phosphate ratio in PDB, which accounts for the 14% lower stiffness and 19% lower hardness promoting plastic deformation in pathological bone. At the microstructural scale, trabecular regions are known to become densified, whereas cortical bone loses its characteristic parallel-aligned osteonal pattern, which is replaced with a mosaic of lamellar and woven bone. Although we find this loss of anisotropic alignment produces a straighter crack path in mechanically-loaded PDB cases, cortical fracture toughness appears to be maintained due to increased plastic deformation. Clearly, the altered quality of the bone structure in PDB affects the mechanical integrity leading to complications such as bowing, deformities, and stable cracks called fissure fractures associated with this disease. Although the lower mineralization and loss of aligned Haversian structures do produce a lower modulus tissue, which is susceptible to deformities, our results indicate that the higher levels of plasticity may compensate for the lost microstructural features and maintain the resistance to crack growth.

Current perspectives on bisphosphonate treatment in Paget's disease of bone

Paget's disease of bone is a chronic metabolic bone disease with focal increase in bone turnover. The exact etiology of the disease is uncertain, although genetic and environmental factors are believed to be important. Bisphosphonate is the main class of medication being used to control disease activity via its antiresorptive effect. This review discusses the controversies concerning the use of bisphosphonates in the treatment of Paget's disease of bone, the efficacy of different bisphosphonates in controlling disease activity, and the possible rare side effects of bisphosphonates. Symptoms are the main indication for treatment in Paget's disease of bone. As treatment benefits in asymptomatic individuals remain controversial and nonevidence based, the decision to treat these patients should be individualized to their risk and benefit profiles. There are several trials conducted to evaluate and compare the efficacy of different regimes of bisphosphonates for treating Paget's disease of bone. Most trials used biochemical markers rather than clinical symptoms or outcomes as parameters for comparison. Zoledronate is an attractive option as it can achieve high rates of biochemical remission and sustain long duration of suppression by a single dose. Atypical femoral fracture and osteonecrosis of the jaw are two rare and severe side effects reported, possibly related to the use of bisphosphonates in patients with osteoporosis and malignancy-induced hypercalcemia. As the regimes of bisphosphonates used for treating Paget's disease of bone are different from those two diseases, the risks of developing these two possible side effects are expected to be very low, although this remains unknown. Vitamin D and calcium supplement should be given to patients at risk of vitamin D insufficiency when given zoledronate, as symptomatic hypocalcemia may develop. For those intolerant of bisphosphonates, subcutaneous calcitonin can be used for a limited period due to its associated risk of malignancy.

Clinical presentation of Paget's disease: evaluation of a contemporary cohort and systematic review

Paget's disease of bone (PDB) has become less common over recent decades but it is unclear if this has impacted on clinical presentation. Here we evaluated the presenting features of PDB in a contemporary cohort of UK patients and conducted a systematic review of studies in which the presenting features had been reported. The case series comprised 88 patients referred to a specialist clinic between 2005 and 2013. Bone pain was the most common presenting feature occurring in 73.8% of patients. Others included bone deformity (18.1%), deafness (7.9%) and pathological fracture (5.7%). The disease was asymptomatic in 22% of cases. Antiresorptive treatment was given for pain in 34 cases and 61.7% of patients responded. Patients with a shorter disease duration were more likely to respond (p = 0.047). In the systematic review, bone pain was the most common presenting feature (52.2% of cases) followed by deformity (21.5%), deafness (8.9%) and fracture (8.5%). Time trend analysis in subjects of European descent showed that fracture was less common in studies performed during the past 25 years as compared with older studies (5.5 vs. 10.8% p < 0.001) whereas pain was more common (54.3 vs. 48.3%, p = 0.003). While changes in the mode of presentation of PDB have occurred over recent years, many patients present with complications such as fracture and deformity. Further research is required to determine if early detection and therapeutic intervention might be of value in preventing the morbidity associated with this common disease.

New insights into the role of sequestosome 1/p62 mutant proteins in the pathogenesis of Paget's disease of bone

Paget's disease of bone (PDB) is characterized by focal areas of aberrant and excessive bone turnover, specifically increased bone resorption and disorganized bone formation. Germline mutations in the sequestosome 1/p62 (SQSTM1/p62) gene are common in PDB patients, with most mutations affecting the ubiquitin-associated domain of the protein. In vitro, osteoclast precursor cells expressing PDB-mutant SQSTM1/p62 protein are associated with increases in nuclear factor κB activation, osteoclast differentiation, and bone resorption. Although the precise mechanisms by which SQSTM1/p62 mutations contribute to disease pathogenesis and progression are not well defined, it is apparent that as well as affecting nuclear factor κB signaling, SQSTM1/p62 is a master regulator of ubiquitinated protein turnover via autophagy and the ubiquitin-proteasome system. Additional roles for SQSTM1/p62 in the oxidative stress-induced Keap1/Nrf2 pathway and in caspase-mediated apoptosis that were recently reported are potentially relevant to the pathogenesis of PDB. Thus, SQSTM1/p62 may serve as a molecular link or switch between autophagy, apoptosis, and cell survival signaling. The purpose of this review is to outline recent advances in understanding of the multiple pathophysiological roles of SQSTM1/p62 protein, with particular emphasis on their relationship to PDB, including challenges associated with translating SQSTM1/p62 research into clinical diagnosis and treatment.

Thirteen Chinese patients with sporadic Paget's disease of bone: clinical features, SQSTM1 mutation identification, and functional analysis

To increase awareness of the rarity of Paget's disease of bone (PDB) in the Chinese population, we characterized the clinical manifestations and features of 13 Chinese sporadic PDB patients. The clinical features of our Chinese PDB patients show similarities with cases reported in Western countries. The most common lesion sites were the pelvis, femur, and tibia; the next most common lesion sites were the spine and skull. Most patients had a higher serum alkaline phosphatase (ALP) level. Treatment with bisphosphonates was effective. In addition, we screened for PDB-causing mutations and performed a functional analysis in an attempt to elucidate the molecular pathogenesis of PDB. A total of 216 persons, including 13 sporadic PDB patients, three unaffected relatives of 1 patient, and 200 healthy donors, were recruited. All eight exons and exon-intron boundaries of the SQSTM1 gene were amplified by polymerase chain reaction (PCR) and directly sequenced. We identified a 53-year-old man who harbored a heterozygous T-to-C transversion at position 1250 in exon 8 (1250T > C), which resulted in a methionine-to-threonine (ATG > ACG) substitution at codon 404 (M404T). The M404T mutant SQSTM1 protein exhibited increased NF-κB activation and drove a significantly increased number of osteoclast-like cells (OLCs) that formed in response to RANKL and an increased number of OLC nuclei. This is the first report of an SQSTM1 genetic mutation that contributes to the pathogenesis of PDB in Chinese patients. These results may partially explain the mechanism by which this SQSTM1 mutation contributes to the pathogenesis of sporadic PDB in Chinese patients.

Asymptomatic Paget's bone disease in ethnic Thais: a series of four case reports and a review of the literature

Paget's bone disease is quite common in some parts of Europe and countries inhabited by European emigrants, but it is rare in Asia. There have been only 13 reported cases in Southeast Asia, including one reported case from Thailand. Half of the previously reported cases had bone symptoms and the other half were asymptomatic, but were incidentally discovered when patients were being investigated for other medical problems. Here are reported cases of four asymptomatic patients who presented elevation of serum alkaline phosphatase during routine annual medical checkups. All patients were of Chinese descent and all cases were proven by biopsy. Based on this experience, we are of the opinion that a substantial number of unrecognized cases of Paget's disease exist among ethnic Thais. We feel that they would be revealed if clinicians were alerted of its presence and if they included it as a possible diagnosis together with metastasis and osteoporosis when examining bone lesions or when results for elevated serum alkaline phosphatase are detected during routine checkups. We also anticipate that a higher prevalence of this disease may occur in future Thai generations due to the addition of offspring from Asian-European intermarriages to offspring of Chinese descent in the ethnic Thai population.

Paget disease of the spine: an evaluation of 101 patients with a histomorphometric analysis of 29 cases

INTRODUCTION

Paget's disease of bone (PDB) is the second most frequent metabolic bone disease with the spine being a common site of manifestation. Still, neither the disease's etiology nor reasons for its manifestation at preferred skeletal sites are understood. The aim of the current study was therefore to perform a histologic and histomorphometric analysis of PBD biopsies of the spine to achieve a more detailed understanding concerning PDB activity and characteristics.

MATERIALS AND METHODS

Out of 754 cases with histologically proven PDB, 101 cases were identified to have involvement of the spine. A total of 29 individual vertebral body biopsies were available for histologic and histomorphometric analysis and were compared to age- and sex-matched spinal bone specimens obtained from skeletal-intact individuals at autopsy. Histomorphometric results were correlated with vertebral body height, disease location and iliac crest biopsies.

RESULTS

In the majority of patients, PDB was located in the lumbar spine (62.2%). The cervical spine was affected in 8.2% of all cases with involvement of the second vertebral body (C2) in every other case. In comparison to age-matched individuals, histomorphometric analysis of vertebral body biopsies revealed a significant increase both in trabecular bone volume as well as osteoid parameters. In comparison to histomorphometric data obtained for extra-spinal skeletal locations affected by PDB (iliac crest), no differences in bone micro-architecture or disease activity were observed.

CONCLUSION

Disease activity in terms of osteoblast and osteoclast number does not appear to be significantly associated with disease location when spinal and iliac bone biopsies are compared. However, a positive correlation between vertebral body height and density in skeletal-intact individuals and disease incidence was observed leading to the conclusion that vertebral body height and possibly at least the spine bone volume together with bone density might play an important role in the incidence of PDB.

A single infusion of zoledronic acid produces sustained remissions in Paget disease: data to 6.5 years

Two trials have shown that a single 5-mg infusion of zoledronic acid achieves much higher response rates in Paget disease of bone than risedronate. The duration of this effect is unknown. We have conducted an open follow-up of responders from the two trials (152 originally treated with zoledronic acid, 115 with risedronate) out to 6.5 years without further intervention. Endpoints were times to relapse (ie, return of serum total alkaline phosphatase activity to within 20% of the pretreatment value) or loss of response (response = normalization of alkaline phosphatase or 75% or greater reduction in its excess). Bone turnover markers were lower in the zoledronic acid group throughout follow-up, with mean alkaline phosphatase (ALP) remaining within the reference range in these patients, whereas the mean in the risedronate group was above normal from 1 year. Relapse rates were substantially greater in the risedronate group (23 of 115, 20%) than in those treated with zoledronic acid (1 of 152, 0.7%, p < .001), and loss of response occurred in 19 (12.5%) zoledronic acid patients compared with 71 (62%) risedronate patients (p < .0001). Risk ratios for relapse and loss of response in zoledronic acid patients were 0.02 [95% confidence interval (CI) 0.00-0.18] and 0.12 (95% CI 0.07-0.19), respectively. Changes from baseline in quality of life, assessed using SF-36 scores, were more positive in the zoledronic acid group across the follow-up period (p = .01). Bone markers at 6 months were predictive of response duration. These data demonstrate an unprecedented duration of remission of Paget disease following treatment with zoledronic acid, accompanied by an improved quality of life.

Bisphosphonates in Paget's disease

Paget's disease is the best example of a common high turnover bone disease. A review of the early use of bisphosphonates in the treatment of this condition shows that many of the fundamental therapeutic issues were identified using drugs which by today's standards were far from ideal. Over the succeeding decades there has been a steady increase in potency culminating in the introduction of intravenous zoledronic acid which is capable of inducing long term remissions which were unthinkable when bisphosphonates were first introduced.

Epidemiological, clinical, and genetic characteristics of Paget's disease of bone in a rural area of Calabria, Southern Italy

BACKGROUND

The prevalence of Paget's disease of bone (PDB) is unknown in peninsular Southern Italy, although an elevated clinical severity of the disease was reported in patients from Campania.

AIM

This study was performed to evaluate the epidemiological and genetic characteristics of PDB in a rural area of Calabria, the southernmost region in the Italian peninsula.

SUBJECTS AND METHODS

We examined 1068 consecutive pelvic radiographs of patients older than 40 yr referred for any reason to the "Spinelli" Hospital, Belvedere Marittimo, from January 1st 2004 to December 31st 2006. In subjects with radiological findings of pelvic PDB, a 99m Technetium methylene diphosphonate bone scan and the sequence analysis of the sequestosome 1 (SQSTM1) gene were subsequently performed.

RESULTS

In the examined geographic area, the crude radiographic prevalence of pelvic PDB was 0.74% (8/1068; male:female 5:3, mean age 71.6 ± 13.1 yr) whereas the estimated overall prevalence of PDB between 0.82% and 1.21%. PDB patients from Calabria showed clinical characteristics similar to those reported in patients from Campania. The disease was also frequently complicated by osteoarthritis and the right side of the body was more affected than the left. The SQSTM1 gene analysis revealed the presence of a novel missense mutation (M401V) in exon 8 in one subject with a familial and aggressive form of PDB.

CONCLUSION

The study results confirmed that patients with PDB from rural districts of Southern Italy show an earlier onset and an increased clinical severity of the disease that appears mostly independent from the presence of germinal SQSTM1 mutations.

Archaeological skeletons support a northwest European origin for Paget's disease of bone

The strong genetic component in the etiology of Paget's disease of bone (PDB), together with marked geographic variation in its prevalence, with high frequencies in British populations, has led some to suggest that the disease originated in Britain and spread around the world in recent times by the migration and admixture of British populations. This study aims to investigate this hypothesis by studying the world geographic distribution of PDB cases identified in ancient skeletons excavated from archaeological sites. The methodology is a review of PDB cases described in the literature. There were 109 cases that met modern diagnostic criteria. All came from Western Europe, 94% from England. These data support the hypothesis that PDB originated in this geographic region.

Demographic and Clinical Features Related to a Symptomatic Onset of Paget’s Disease of Bone

Objective.

Paget’s disease of bone (PDB) is a focal disorder of skeletal remodeling that can lead to bone pain, deformity, and fractures, but it can often be asymptomatic for a long time. This study investigated which factors may distinguish patients with clinical manifestations from asymptomatic patients.

Methods.

The study group consisted of 224 patients with PDB referred to our Bone Disease Unit. For all patients, data were collected about clinical and demographic variables and diagnostic procedures. Logistic regression analyses were used to assess the role of recorded variables on the odds of being diagnosed clinically rather than by chance.

Results.

Among the 124 patients with clinical manifestations leading to the diagnosis (55.4%), 36 subjects complained of bone pain, 32 articular pain, 42 back pain, 2 headache; 9 had fractures in Paget bone, and 3 had bone deformity. In 100 patients (44.6%) PDB was diagnosed by chance. At the multivariate analysis, only the number of bones involved (OR for 1 site increment = 1.18, 95% CI: 1.007–1.402; p = 0.04) acted as an independent predictor for a clinical diagnosis. Some skeletal localizations were associated with a clinical diagnosis: the involvement of lumbar spine (OR = 2.085, 95% CI: 1.024–4.224; p = 0.043) was more likely in symptomatic patients; pelvis and tibia showed a borderline statistical significance. The skull was predictive for asymptomatic PDB.

Conclusion.

A systematic laboratory screening including serum alkaline phosphatase of an older subject complaining of bone pain, articular pain, or back pain is the sole strategy to improve the diagnostic sensitivity for PDB.

Paget's disease of bone: histologic analysis of 754 patients

Although Paget's disease of bone (PDB) is the second most common metabolic bone disease, to our knowledge, there is only one quantitative analysis on the histological and especially on the histomorphometric level. Therefore, the aim of this study was to analyze, on the basis of the Hamburg Bone Register, PBD in terms of incidence, skeletal distribution, malignant transformation, and histological and histomorphometric characteristics. Bone biopsies and patient files of 754 cases with histologically proven PDB were reviewed in a retrospective study. Quantitative static histomorphometry was performed on a representative subgroup of 247 biopsies derived from patients with manifestation of PDB at the iliac crest and compared with an age- and sex-matched control group. The peak incidence of PDB was between 70 and 80 yr of age. The majority of monostotic skeletal manifestation was localized at the os ilium, followed by the spine and femur. Histomorphometric results showed a high bone turnover with a significant increase in bone resorption and bone formation indices leading to an increased bone volume. Paget sarcoma was diagnosed in 6 of 754 patients, indicating a malignant transformation in 0.8% of the affected patients. Taken together, our study characterizes PDB in Germany on the basis of one of the largest cohorts of patients with histologically proven PDB. Moreover, for the first time, a quantitative histomorphometric approach was taken for >200 cases, where we could show local high bone mass lesions as a result of an increase of both osteoclast and osteoblast indices.

Prevalence of Paget's disease of bone in Spain

INTRODUCTION

Epidemiological studies in Europe have revealed that the prevalence of Paget's disease of bone (PDB) has marked geographic variations. At present, the prevalence of PDB in Spain is unknown, limited to data from isolated towns or centers. We conducted a radiological national-based survey, to estimate the age and sex prevalence of PDB and its geographic variation within the country. In addition, we tested the patients' awareness of their disease.

METHODS

Stratified samples throughout Spain of abdominal radiographs, of subjects aged >or=55 years, from stored consecutive digitalized films in selected hospitals were obtained, over the period of 2006-2007. Radiographs including all lumbar vertebrae, pelvis, sacrum and femoral heads were examined for the diagnosis of PDB, according to standardized criteria. Age, sex and information regarding patient's awareness of the illness were obtained from the hospital files.

RESULTS

A total of 4528 radiographs from 13 centers were evaluated. The crude prevalence of PDB was 1% (95%CI: 0.7-1.3) in individuals older than 55, and the estimated prevalence ranged from 1.1% (95%CI: 0.8-1.4) to 1.6% (95%CI: 1.1-2.1) when a reported pelvic involvement in 60-90% of PDB patients was considered. The prevalence was slightly higher in men than in women, and significantly higher in individuals older than 75. A significant geographic variation in prevalence was observed within the country (p=0.004). 73% of PDB patients were unaware of their illness at the time of the radiological survey.

CONCLUSIONS

Prevalence of PDB in Spain is at least 1% in individuals older than 55, with remarkable geographical variations and age related differences. Most patients were unaware of their disease.

Vitamin D receptor gene polymorphisms predict acquired resistance to clodronate treatment in patients with Paget's disease of bone

Bisphosphonates are first-choice drugs for treatment of Paget's disease of bone (PDB); nevertheless, acquired resistance to bisphosphonate therapy has been described in PDB patients. The 1,25(OH)(2)D(3)/vitamin D receptor (VDR) system influences the effectiveness of antiresorptive treatments in metabolic bone disorders. This study evaluated the relationship between acquired resistance to clodronate treatment and BsmI, TaqI, and FokI VDR polymorphisms in Caucasian patients with polyostotic PDB (n = 84). We also evaluated the influence of mutations in exons 7 and 8 of the sequestosome 1 (SQSTM1) gene on the occurrence of this phenomenon. All patients were treated from diagnosis for several cycles with intravenous clodronate infusion (1500 mg/cycle). Acquired resistance to clodronate treatment was defined as the failure of total alkaline phosphatase serum levels to be suppressed to at least 50% of the patient's previous highest levels during a subsequent treatment course with the same compound, which produced a >50% response after the first exposure. During an observation period of 10.6 +/- 2.7 years, 31 PDB patients (36.9%) showed acquired resistance to clodronate. It was observed that the bb and TT VDR genotypes as well as a lower persistence of the biochemical response to the first treatment course were significantly and independently associated with the risk of developing resistance to clodronate treatment. SQSTM1 gene mutations, considered altogether, did not influence the occurrence of this phenomenon. Our results indicate that 3'VDR allelic variants and duration of biochemical response to the first treatment course are independent predictors of acquired resistance to clodronate treatment in patients with polyostotic PDB.

Detection of hearing impairment and handicap in Paget's disease of bone using a simple scoring system: a case control study

Paget's disease of bone is known to be associated with hearing loss but there are limited data on the prevalence of hearing impairment and handicap in people with Paget's disease. Previous published population studies have used patient-completed questionnaires or review of GP records, none have included audiometry. 80 Paget's subjects were selected at random from a hospital database, 75 (94%) entered the study and were matched by age and gender with 76 controls. All participants completed a screening questionnaire for hearing handicap, the HHIE-S; a questionnaire on perception of hearing-related handicap, noise exposure, hearing aids and GP consultations regarding hearing; and audiometry. The results show significant problems from hearing loss in people with Paget's disease of bone. Paget's patients were significantly more likely to perceive hearing handicap (P=0.0001), 41% Paget's patients rated themselves moderate-severe compared to none of the controls. Paget's patients were significantly more likely to report difficulties such as hearing normal speech, watching TV or hearing over background noise (all P=0.0001). They were more likely to consult their GP due to hearing problems (P=0.004) or tinnitus (P=0.0001), or use a hearing aid (P=0.0001). Audiometry confirmed higher rates of deafness in Paget's patients. 41/75 Paget's patients compared to 19/76 controls had at least 40 decibels hearing loss (dBHL) (P=0.0001). The HHIE-S proved to be an effective screening tool. A score of greater than 8 increased the odds ratio of detecting moderate hearing impairment (>40 dBHL) in people with Paget's disease by 5.1. The specificity of HHIE-S >8 as a screening tool to select for audiometry appears good, 1/46 (2%) of Paget's patients would have proved to have normal hearing thresholds. The sensitivity is better with worse hearing loss, 7/16 Paget's patients with moderate loss (>40 dBHL) and 2/25 with severe-profound loss (>60 dBHL) would have been missed. In conclusion, 55% unselected Paget's patients have at least moderate levels of hearing loss, compared to 25% of age and gender matched controls. Paget's patients and controls under-reported hearing problems, many of which can be ameliorated. Screening for hearing problems in Paget's disease of bone can be done using the HHIE-S.

Monostotic Paget's disease of the patella

Paget's disease is a common skeletal disorder in the elderly; however, monostotic Paget's disease of the patella is very rare and only a few cases have been reported. We present the clinical, radiographic, surgical and histological findings in a patient with monostotic Paget's disease of the patella, presenting with knee pain.

Evidence for increased clinical severity of familial and sporadic Paget's disease of bone in Campania, southern Italy

The analysis of 236 Italian patients with Paget's bone disease showed higher clinical severity and greater frequency of neoplastic degeneration among patients who live or descend from individuals living in the Campania region (southern Italy). A prevalent involvement of the spine and the skull, the sites preferentially involved in giant cell tumors complicating Paget's disease, was also shown in familial cases from this geographical region.

INTRODUCTION

The Campania region in southern Italy has been recently indicated as a high prevalence area for Paget's disease of bone (PDB), and most pagetic families with multiple occurrence of neoplasms in affected members were from this geographical region.

MATERIALS AND METHODS

We evaluated the PDB epidemiological characteristics in 125 patients from Campania in comparison with 111 patients from other Italian regions. Twenty-three patients from Campania and 26 patients from other Italian areas had at least one first-degree relative affected by PDB (familial cases). The remaining patients made up the sporadic cases.

RESULTS

Among subjects from Campania, the patients in the familial group tended to come from larger families and showed at diagnosis higher serum total alkaline phosphatase, larger extension of disease, and earlier mean age with respect to patients with PDB of the sporadic group. The skull, spine, and humerus were the sites preferentially involved in the familial cases. In contrast, no such differences were observed between familial and sporadic PDB cases among patients from the other geographical areas, except for a lower age at diagnosis. An increased PDB clinical severity was finally observed in the PDB cohort from Campania in comparison with patients from other Italian regions. Neoplastic degeneration of pagetic bones (osteosarcoma and giant cell tumor) was exclusively observed in patients with polyostotic PDB from Campania.

CONCLUSIONS

We showed a higher clinical severity of PDB with occurrence of neoplastic degeneration in the high prevalence area of Campania, with its maximum expression in cases with familial disease. This peculiar pattern might be traced to genetic predisposition and/or to the abnormal impact of a still undefined environmental trigger.

Prevalence and clinical features of Paget's disease of bone in Japan

The present study aimed to evaluate the prevalence and clinical presentation of Paget's disease of bone (PDB) in Japan. As PDB is a very rare disease in Japan, a nationwide mail survey was conducted targeting doctors in the specialty most frequently diagnosing and treating PDB patients in Japan. First, the literature for all case reports in Japan published between January 1990 and December 2002 was reviewed to determine who was diagnosing and treating PDB in Japan. This literature review for all case reports in Japan revealed that 72.1% of cases in Japan were reported from departments of orthopedic surgery. A nationwide two-phase mail survey was conducted for the departments of orthopedic surgery of 2,320 general hospitals accredited by the Japanese Orthopaedic Association. Phase 1 involved determining how many patients with PDB were followed at each hospital. If the answer was one or more, phase 2 of the survey gathered information on the clinical presentation of current patients. The mail survey yielded a final response rate of 75.4% for phase 1 and 87.6% for phase 2. Phase 1 indicated that the prevalence of PDB in Japan is about 2.8 cases per million capita. Phase 2 revealed a slight female predominance, lower frequency of familial clustering, higher frequency of femoral fracture in the affected femur, and a higher ratio of symptomatic PDB in Japan compared with findings in countries displaying a higher prevalence of PDB. The present epidemiological study revealed that the disorder is extremely rare in Japanese individuals, and that some differences exist with regard to the clinical features of PDB between Japanese patients and patients from high-prevalence countries.

Paget's disease of bone in a Chinese patient: A case report and review of the literature

Although it is fairly common in the Western countries, Paget's disease of bone is very rare in Chinese individuals. Through an extensive literature search, only 8 Chinese Paget's disease cases were found in the English language literature and all were reported in local medical journals of Asia that may not be accessible to international readers. To enhance the awareness of the rarity of Paget's disease in Chinese individuals to pathologists worldwide, we present a case of Paget's disease in a 54-year-old Chinese male. We also compare the clinical features of Paget's disease reported in Chinese patients to Paget's disease reported in the Western countries. No familial cases and no malignant transformation are found in the reported cases of Paget's disease in Chinese patients. In addition, more often skull involvement, higher frequency of monostotic cases, and symptomatic cases are observed in this limited number of Paget's disease cases reported in Chinese individuals.

Interleukin-6 and osteoprotegerin systems in Paget's disease of bone: relationship to risedronate treatment

Serum concentrations of interleukin-6 (IL-6), IL-6-soluble receptor (sIL-6R), IL-6 gp130-soluble receptor (sgp130), ligand of receptor activator of nuclear factor (NF)-kappaB (RANKL), and osteoprotegerin (OPG) were determined in 42 patients with polyostotic Paget's disease of bone (PDB) and acquired resistance to clodronate (M/F ratio 23:19; mean age 58.5 +/- 9.4 years) in acute phase of disease and after oral risedronate treatment (30 mg/day for 8 weeks). At baseline, pagetic patients showed higher levels of OPG, sIL-6R, and IL-6 with lower levels of sgp130 compared to 24 age- and sex-matched controls (respectively, 4.69 +/- 1.27 vs. 2.87 +/- 0.54 pmol/L; 40.89 +/- 8.61 vs. 30.98 +/- 4.24 ng/ml; 3.59 +/- 0.97 vs. 1.8 +/- 0.9 pg/ml; 327.34 +/- 43.41 vs. 411.7 +/- 79.5 ng/ml). Response to treatment is related to a significant increase of OPG levels in all patients (from 4.69 +/- 1.27 to 5.48 +/- 1.31 pmol/L). The disease remission, that is, total alkaline phosphatase (tALP) levels within the normal range after therapy, was associated with a simultaneous increase in OPG and sgp130 levels. In patients with tALP higher than the normal range after therapy, the OPG increase was associated with a parallel increase in RANKL levels. Our data suggest that serum levels of components of RANKL/OPG and IL-6 systems, before and after treatment, may be used to better define a therapeutical strategy in pagetic patients.

Risedronate and pamidronate treatment in the clinical management of patients with severe Paget's disease of bone and acquired resistance to bisphosphonates

The aim of this study was to evaluate the efficacy and safety of risedronate and pamidronate in 30 patients (mean age = 57.86 +/- 8.90 years) with severe Paget's disease of bone (PDB), showing acquired resistance to intravenous (IV) clodronate treatment. Fifteen patients were treated with oral risedronate (30 mg/day for 8 weeks). Treatment was repeated in patients without evidence of PDB remission [total alkaline phosphatase (tALP) serum levels in the normal range] at day 120. Fifteen patients were treated with IV pamidronate (30 mg/day for 3 days). Pamidronate treatment (60 mg/day for 3 days) was repeated in patients without evidence of PDB remission at day 120. At day 60, a significant decrease in tALP serum levels was obtained in all pagetic patients. At day 360, 13 (86.6%) patients treated with risedronate achieved PDB remission, 9 patients during the initial treatment and 4 after retreatment. Two patients showed a significant decrease in tALP serum levels without clinical remission after two risedronate treatments. At the same time, 12 (80%) patients treated with pamidronate achieved PDB remission, 6 patients during the first treatment and 6 after retreatment. Three patients showed a significant decrease in tALP serum levels but no clinical remission after two pamidronate courses. Two of these patients showed a relapse during the study. The incidence of minor side effects and transient hyperparathyroidism related to bisphosphonate treatment was significantly lower after risedronate therapy. In patients with resistant PDB, oral risedronate therapy has comparable efficacy to IV pamidronate with a lower incidence of treatment-related side effects.

Symptomatic and Scintigraphic Improvement after Intravenous Pamidronate Treatment of Paget’s Disease of Bone in Patients with Normal Serum Alkaline Phosphatase Levels

OBJECTIVE

To describe three patients with symptomatic Paget's disease of bone who presented with normal levels of serum alkaline phosphatase.

METHODS

We present three cases of Paget's disease of bone and chronicle the laboratory, scintigraphic, and clinical findings relative to treatment with intravenously administered pamidronate.

RESULTS

Although measurement of serum total alkaline phosphatase usually provides a general indication of bone turnover in Paget's disease, about 15% of patients present with normal serum alkaline phosphatase levels. Nonetheless, these patients may have active Paget's disease when assessed with bone scintigraphy or urinary markers of bone resorption. All three study patients had xray findings characteristic of Paget's disease of bone, increased uptake of radiotracer material on bone scans, and elevated levels of urinary markers of bone resorption but normal alkaline phosphatase levels. They were treated with intravenously administered pamidronate, 60 mg once weekly for 2 to 3 consecutive weeks. After treatment, the serum alkaline phosphatase level decreased by 19 to 36%, markers of bone resorption normalized, bone scans showed improvement, and bone pain resolved.

CONCLUSION

Pagetic activity in bone and related clinical manifestations may be present in the setting of a normal serum alkaline phosphatase level. Appropriate therapy should not be withheld because of the normal alkaline phosphatase.

Osteosarcoma arising in Paget's disease of the mandible

Although osteosarcoma is a well-known complication of Paget's disease of bone, it uncommonly develops in the jaw bones. We present an osteosarcoma arising in Paget's disease of the mandible with unique features of a normal serum alkaline phosphatase level, and histologic features of telangiectatic change in the osteosarcoma and association with cemento-osseous dysplasia. Sixteen reported cases of osteosarcoma arising in Paget's disease of the jaw bones (OPJ) are also reviewed and compared to osteosarcoma arising in Paget's disease occurring in the entire skeleton (OPS) and osteosarcoma arising de novo in the jaw bones (OJ). Females are more commonly involved in OPJ in contrast to a male predominance in OPS and OJ. OPJ also has a distinctively higher percentage involving blacks compared to OPS. The prognosis of OPJ is poor, with 69% of patients dying within two years after diagnosis. Early recognition, early and aggressive treatment are important to improve the prognosis and are hence emphasized.

[Paget's disease of bone: study of 314 patients]

BACKGROUND

To describe the clinical and laboratory features of Paget's disease of bone at the time of diagnosis.

PATIENTS AND METHOD

This multicenter and retrospective study included 314 patients. Diagnosis was performed by means of characteristic radiological findings and typical bone scintigraphy. The variables analyzed included: epidemiological variables, cause of diagnosis, bone involvement, disease extension (Coutris index), complications, alkaline phosphate (AP) levels and disease activity (Renier index).

RESULTS

There were 159 (50.5%) males and the mean age was 64.9 years (SD 12.6). Diagnosis was casual in 228 (72.6%) patients. Polyostotic involvement was detected in 201 (63.9%) patients. More common locations were pelvis, skull and lumbar spine. Sacrum was more frequently involved in men than in women (p < 0.05), whereas skull involvement was more common in women (p < 0.05). The number of bones involved was 3.1 SD 3 and the percentage of skeletal involvement was 8.7 % (SD 6.5). One hundred ninety eigth (63%) patients had complications. The disease was active in 242 (77%) patients with a mean AP value of 377 IU/L (SD 493); the activity of the disease measured by the Renier index was 34 (SD 46); the activity was greater in the skull and the humerus.

CONCLUSIONS

Paget's disease of bone is usually asymptomatic. Polyostotic involvement and activity are common at the time of diagnosis. Knowledge of the extension and activity by means of a mathematical model may aid to make therapeutical decisions.

From the archives of the AFIP. Radiologic spectrum of Paget disease of bone and its complications with pathologic correlation

Paget disease of bone is a common disorder affecting approximately 3%-4% of the population over 40 years of age. The pathologic abnormality in Paget disease is excessive and abnormal remodeling of bone. Three pathologic phases have been described: the lytic phase (incipient-active), in which osteoclasts predominate; the mixed phase (active), in which osteoblasts cause repair superimposed on the resorption; and the blastic phase (late-inactive) in which osteoblasts predominate. Radiographic appearance of Paget disease reflects these pathologic changes and is often characteristic. Initially, there is osteolysis, particularly affecting the skull (osteoporosis circumscripta) and subchondral long bones, with subsequent development of trabecular and cortical thickening and enlargement of bone in the mixed phase of the disease. Finally, areas of sclerosis may develop in the blastic phase. Frequent sites of involvement include the skull (25%-65% of cases), spine (30%-75%), pelvis (30%-75%), and proximal long bones (25%-30%). Bone scintigraphy typically demonstrates marked increased uptake of radionuclide in all phases of Paget disease. Computed tomography and magnetic resonance imaging often show changes similar to those seen radiographically in noncomplicated Paget disease with maintenance of yellow marrow. Complications of Paget disease include the effects of osseous weakening (deformity and fracture), arthritis, neurologic symptoms, and neoplastic involvement. Sarcomatous transformation is the most feared complication, occurring in approximately 1% of cases, and is seen on images as focal bone destruction extending through the cortex with an associated soft-tissue mass. Recognition of the radiologic spectrum of the appearances of Paget disease usually allows prospective diagnosis and differentiation of its associated complications, which helps guide therapy and improve patient management.

Paget's disease in an archeological population

The aim of this investigation was to study the prevalence and distribution of Paget's disease in an archeological population. Paget's disease, first described over 100 years ago, is a well-recognized chronic disorder involving abnormal bone turnover with established radiological features. Prevalence within modern populations varies both within individual countries and between them. Paleopathological examples are uncommon and sporadically reported both from Europe and the Americas and from many periods of history. A large skeletal assemblage (2,770 individuals) from Barton on Humber, UK, provided an opportunity to examine the prevalence of Paget's disease in one area of the northern England over the period 900-1,850 AD. All bones were examined visually for evidence of Paget's disease of the bone (PDB) and all abnormal bones were examined further by plain radiography. Fifteen cases of probable Paget's disease were found. The overall prevalence was 2.1% in those aged >40 years. The prevalence before 1500 AD was 1.7% and post-1500 AD was 3.1%. The distribution of disease mirrored modern disease, with the lumbar spine, pelvis, and proximal femur being the commonest sites. The prevalence of Paget's disease in the United Kingdom over the last 1,000 years has been assessed. Although there is a trend of increasing prevalence, this did not reach statistical significance. This is likely caused by the small sample size, but this is by far the greatest number of cases of PDB described in a single skeletal assemblage to date. The distribution of lesions within the skeleton is unchanged.