Dear John, there appear to be a wide range of numbers reported for the prevalence of AS and the prevalence of spondyloarthropathy [SpA] in various studies from various centers. Note that AS is a subcategory of spondyloarthropathy, so the prevalence of AS would be expected to be lower than the prevalence of spondyloarthropathy.
Here is what Robert Inman published in reviewing this subject for Cecil Textbook of Medicine published in 2004:
http://www.merckmedicus.com/ppdocs/us/common/cecils/chapters/279_002.htm
http://www.merckmedicus.com/ppdocs/us/common/cecils/chapters/279_003.htm
CECIL TEXT BOOK of MEDICINE
Copyright 2004
Quote:
"PART XXII RHEUMATIC DISEASES
279 THE SPONDYLOARTHROPATHIES
Robert D. Inman ยท
... MRI studies in asymptomatic B27-positive individuals indicate that there is a much higher prevalence of sacroiliitis than previously recognized, and studies are continuing to define that prevalence and indeed the prevalence of SpA [spondyloarthropathy] in the general population. Some investigators have concluded that SpAs are as common as RA in the population...
ANKYLOSING SPONDYLITIS
AS is the most common inflammatory disorder of the axial skeleton. Although prevalence is under study in several centers, the following is a useful rule of thumb: AS occurs in 0.2% of the general population, in 2% of the B27-positive population, and in 20% of B27-positive individuals with an affected family member..."
Dougados is a coauthor on the following recent [2004] study that cites the prevalence of spondyloarthropathy at 0.3% in the Caucasion populations from western Europe. Again, noting that AS is a subcategory of spondyloarthropathy, the prevalence of AS would be expected to be lower.
pubmed abstract:
http://www.ncbi.nlm.nih.gov/entrez/query...t_uids=15234954
Miceli-Richard C, Zouali H, Said-Nahal R, Lesage S, Merlin F, De Toma C,
Blanche H, Sahbatou M, Dougados M, Thomas G, Breban M, Hugot JP; Groupe Francais
d'Etude Genetique des Spondylarthropathies.
Significant linkage to spondyloarthropathy on 9q31-34.
Hum Mol Genet. 2004 Aug 1;13(15):1641-8.
PMID: 15234954
full text:
http://hmg.oxfordjournals.org/cgi/content/full/13/15/1641
Quote:
"Spondyloarthropathy (SpA) is one of the commonest chronic rheumatic diseases. Its prevalence has been set recently in western Europe as 0.3%.."
THis is in accord with the following study published in the Annals of Rheumatic Diseases in October of 2005, which put the prevalence of spondyloarthopathy at 0.3% in France (as of 2001):
http://www.ncbi.nlm.nih.gov/entrez/query...t_uids=15817661
Saraux A, Guillemin F, Guggenbuhl P, Roux CH, Fardellone P, Le Bihan E,
Cantagrel A, Chary-Valckenaere I, Euller-Ziegler L, Flipo RM, Juvin R, Behier JM, Fautrel B, Masson C, Coste J.
Prevalence of spondyloarthropathies in France: 2001.
Ann Rheum Dis. 2005 Oct;64(10):1431-5.
Epub 2005 Apr 7.
PMID: 15817661
Quote:
... CONCLUSION: Prevalence of SpA in France was 0.30% in 2001, with no difference between women and men. Ankylosing spondylitis and psoriatic arthritis were the most common SpA subsets.
