SAPHO syndrome (Synovitis, Acne, Pustulosis, Hyperostosis and Osteitis) is a chronic inflammatory rheumatism associating bone or joint lesions and dermatological manifestations dominated by severe acne and palmar and palmoplantar pustulosis. Prevalence of SAPHO syndrome is estimated at 1/50000 in France, but this figure is probably underestimated due to frequent misdiagnosis. Osteoarticular manifestations form a rheumatic picture very similar to that of other forms of spondyloarthritis (SpA). The latest French recommendations do not distinguish SAPHO syndrome from other forms of SpA. As a result, the management of SAPHO remains fairly heterogeneous, essentially based on the local experience of rheumatologists. Delays in diagnosis and difficulties in finding effective treatment can result in significant disability and reduced quality of life, particularly detrimental in a young population (age at diagnosis is usually between 30 and 40). The wide spectrum of clinical presentations of SAPHO syndrome explains the complexity of managing this condition. Understanding the pathophysiological mechanisms underlying these different forms of the disease is a major challenge for personalized medicine. SAPHO syndrome is a multifactorial disease that is a result of interaction of genetic, environmental, immunological and infectious factors. In the classification of immune-mediated inflammatory diseases, SAPHO syndrome lies midway between autoinflammatory diseases involving the innate immune response and spondyloarthritis associated with abnormalities in the adaptive immune response. Indeed, while the clinical phenotype may resemble spondyloarthritis in certain aspects, the identification of genetic forms of chronic relapsing osteitis, such as DIRA syndrome or Majeed syndrome, argues in favor of an autoinflammatory origin of SAPHO syndrome. Although osteitis is reputed to be sterile, an infectious initiating factor has long been suspected in this disease. Among the bacterial agents, antigens antigens from Cutibacterium acnes were detected in bone biopsies from patients with SAPHO syndrome. It has been suggested that this bacterium may play a role in triggering a systemic inflammatory response systemic inflammatory response mediated in particular by IL-1β.
Patient aged ≥ 18 years
Patient diagnosed with SAPHO syndrome
Weight > 35 kg
Patient affiliated with a health insurance plan
Patient under guardianship or curatorship
Patient deprived of liberty
Patient under legal protection
Pregnant or breastfeeding patient
patient diagnosed with SAPHO syndrome
Case-only
Prospective
biological sampling
Other interventionDNA and Cells will be sampled
Investigating a Genetic Predisposition to SAPHO Syndrome
Comparison of allelic frequencies in patients with SAPHO syndrome versus the general population
Estimating the Degree of Genetic Component Overlap Between SAPHO Syndrome and Axial SpA
Comparison of allelic frequencies in patients with SAPHO syndrome versus patients with severe and non-severe axial SpA
Studying the Genetic Component Based on Different Phenotypes of SAPHO Syndrome
comparison of allelic frequencies among patients: With pure osteitis form of SAPHO syndrome vs. those with axial form of the disease With cutaneous involvement vs. without cutaneous involvement
Studying the Functional Consequences of Variants Associated with SAPHO Syndrom, on the protein level
comparison of Expression level of protein of the different variants in sorted cells and plasma
Studying the Functional Consequences of Variants Associated with SAPHO Syndrom, on the transciptom level
comparison of Expression level of mRNA of the different variants in sorted cells and plasma
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