Prevalence of pelvic Paget's disease of bone in France

Epidemiology and characteristics of Paget's disease of bone in a French nationwide HIV cohort

Paget's disease of bone (PDB) has rarely been reported in people with HIV (PWH). We describe the prevalence and characteristics of patients with PDB in the French multicenter Dat'AIDS cohort. Among 49 698 PWH actively followed in 2022, 9 had a diagnosis of PDB. The overall prevalence of PDB was 0.02% [95% confidence interval (CI) 0.01-0.03]. The prevalence of PDB in PWH is very low and does not appear to differ from the non-HIV population.

Prevalence and incidence of Paget's disease of bone: Temporal trend over 20 years in the province of Quebec, Canada

BACKGROUND

Paget's disease of bone (PDB) is a focal bone disorder characterized by an increased bone remodeling and an anarchic bone structure. A decline of prevalence and incidence of PDB has been observed in some countries. No epidemiological data are available on PDB in Canada.

AIMS

We aimed at examining the evolution of the prevalence and incidence of PDB in Quebec (Canada) by analyzing health administrative databases.

METHODS

PDB case definition relied on one or more hospitalizations, or one or more physician-billing claims with a diagnosis code of PDB. To identify incident cases, a 'run-in' period of four years (1996-1999) was used to exclude prevalent cases. For each fiscal year from 2000 to 2001 to 2019-2020 (population size 2,914,480), crude age and sex-specific prevalence and incidence rates of PDB among individuals aged ≥55 years were determined, and sex-specific rates were also standardized to the 2011 age structure of the Quebec population. Generalized linear regressions were used to test for linear changes in standardized prevalence and incidence rates.

RESULTS

Over the study period, standardized prevalence of PDB has remained stable in Quebec, from 0.44 % in 2000/2001 to 0.43 % in 2019/2020 (mean change -0.002, p-value = 0.0935). For the 2019-2020 fiscal year, 13,165 men and women had been diagnosed with PDB and prevalence of PDB increased with age. Standardized incidence of PDB has decreased over time from 0.77/1000 in 2000/2001 to 0.28/1000 in 2019-2020 (mean change -0.228/year, p-value<0.0001), the incidence decreasing from 0.82/1000 to 0.37/1000 in men and from 0.76/1000 to 0.22/1000 in women, respectively. This decrease was observed in all age categories.

CONCLUSION

With the exception of a slight increase in PDB prevalence up to 0.55 % in years 2005 to 2007, the prevalence of PDB has remained stable in Quebec over the past 20 years, 13,160 men and women being currently diagnosed with PDB. The incidence has decreased over time. Our results support the epidemiological changes of PDB reported in other countries.

Update on the pathogenesis and genetics of Paget’s disease of bone

Studies over the past two decades have led to major advances in the pathogenesis of Paget’s disease of bone (PDB) and particularly on the role of genetic factors. Germline mutations of different genes have been identified, as a possible cause of this disorder, and most of the underlying pathways are implicated in the regulation of osteoclast differentiation and function, whereas other are involved in cell autophagy mechanisms. In particular, about 30 different germline mutations of the Sequestosome 1 gene (SQSTM1) have been described in a significant proportion of familial and sporadic PDB cases. The majority of SQSTM1 mutations affect the ubiquitin-binding domain of the protein and are associated to a more severe clinical expression of the disease. Also, germline mutations in the ZNF687 and PFN1 genes have been associated to severe, early onset, polyostotic PDB with increased susceptibly to neoplastic degeneration, particularly giant cell tumor. Mutations in the VCP (Valosin Containing Protein) gene cause the autosomal dominant syndrome “Inclusion Body Myopathy, PDB, Fronto-temporal Dementia,” characterized by pagetic manifestations, associated with myopathy, amyotrophic lateral sclerosis and fronto-temporal dementia. Moreover, germline mutations in the TNFRSF11A gene, which encodes for RANK, were associated with rare syndromes showing some histopathological, radiological, and clinical overlap with PDB and in two cases of early onset PDB-like disease. Likewise, genome wide association studies performed in unrelated PDB cases identified other potential predisposition genes and/or susceptibility loci. Thus, it is likely that polygenic factors are involved in the PDB pathogenesis in many individuals and that modifying genes may contribute in refining the clinical phenotype. Moreover, the contribution of somatic mutations of SQSTM1 gene and/or epigenetic mechanisms in the pathogenesis of skeletal pagetic abnormalities and eventually neoplastic degeneration, cannot be excluded. Indeed, clinical and experimental observations indicate that genetic susceptibility might not be a sufficient condition for the clinical development of PDB without the concomitant intervention of viral infection, in primis paramixoviruses, and/or other environmental factors (e.g., pesticides, heavy metals or tobacco exposure), at least in a subset of cases. This review summarizes the most important advances that have been made in the field of cellular and molecular biology PDB over the past decades.