FRI0495 The Combined Prevalence of Rare Diseases in Rheumatology Demonstrates A Sum More than Double To That of Ankylosing Spondylitis

Abstract

BackgroundRare diseases (RD) in rheumatology are heterogeneous and thus lack a systemic classification. By definition, prevalences of RD range up to 5/10 000 in Europe. Clinical courses comprise a vast variety of musculoskeletal symptoms such as arthritis, myositis, vasculitis, autoimmune organ involvement and bone diseases. The impact of RD for health care systems is widely unknown and individual patients are prone to unsatisfactory diagnoses and/or treatments.ObjectivesThe objective of this study was to identify and classify RD in rheumatology and estimate their combined prevalence. The data may give a better understanding for this area of rheumatology, may aid specified centers for RD, and perhaps sharpen the overall perception of health care systems.MethodsDatabases (pubmed.org, abstract archives of the European League Against Rheumatism and the American College of Rheumatology, and Orpha.net) were searched for the following terms: rare in combination with arthritis, arteritis, connective tissue disease, rheumatic and vasculitis. Furthermore, terms were used in various combinations including arthralgia, autoimmune, fever, inflammation, joint pain, muscle pain, myalgia and swollen joint. Identified syndromes were then classified according to the following terms and data: differential diagnosis, etiology, genetics, prevalence, principal symptom, prognosis, and therapy. The overall total point prevalence for all RD in rheumatology was estimated by adding up all single point prevalences available.ResultsA total of 82 syndromes and diseases were identified. Classification was as follows: arthritis (n=17) and vasculitis (n=18), fever syndromes (n=13), collagen diseases (n=10), myositis (n=9), and overlaps/others (n=15). Fifty-two diseases showed a chronic progressive course. The mortality was variable in many diseases and thus could not be determined precisely. Point prevalence data were available for 49 syndromes and diseases, and added up to a total point prevalence of 49/ 10 000. Forty-nine of these in part pathophysiologically quite distinct RD are treated with corticosteroids.ConclusionsRare diseases in rheumatology are most often chronic or progressive. Symptoms are variable, they include arthritis, organ and skin involvement. The estimated combined prevalence of all RD in rheumatology is significant with 49/10 000: it is double or more than that of ankylosing spondylitis with 18/10 000 (1). Treatment options are often restricted to corticosteroids presumably because of the scarcity of randomized controlled trials. Health care systems should assign RD the same importance as any other common disease in rheumatology.ReferencesExarchou S, Lindström U, Askling J, Eriksson JK, Forsblad-d'Elia H, Neovius M, Turesson C, Kristensen LE, Jacobsson LT. The prevalence of clinically diagnosed ankylosing spondylitis and its clinical manifestations: a nationwide register study. Arthritis Res Ther 2015; 201; 17(1):118.Disclosure of InterestNone declared

Therapeutic options for patients with rare rheumatic diseases: a systematic review and meta-analysis

“…Studies with less than 10 participants per study arm in the final analysis were excluded. We considered only rheumatic and musculoskeletal diseases as defined by EULAR and the Orphanet classification of rare rheumatic diseases as ORPHA: 182231 (compare Leyens et al [ 1 ] and Orphanet).…”

“…Rare diseases (RDs) in rheumatology present a heterogeneous group of diverse syndromes, and differ in their etiology, clinical symptoms, prognosis, and outcome in clinical trials. Recently, we identified a set of various RDs in rheumatology [ 1 ], and found that they are highly prevalent when considered as a group. Most of these diseases and syndromes have a prevalence of less than one individual in 100,000, and all of them fall under the European Commission’s definition that specifies RDs as “Any disease affecting fewer than five people in 10,000” [ 2 ].…”

“…Of note, this is more than double the prevalence of ankylosing spondylitis (AS) with 18/10,000 [ 3 ], which is one of the more common diseases in the field of rheumatology. The syndromes we have previously identified as RDs in rheumatology [ 1 ] include genetic disorders, e.g., cryopyrin associated periodic syndromes (CAPS) [ 4 ], reactive arthritis [ 5 ], and diseases with unknown etiologies such as systemic sclerosis [ 6 ]. Randomized controlled trials (RCTs) and thus evidence-based pharmacotherapies are unavailable for a magnitude of these conditions.…”