CARD15 gene polymorphisms in patients with spondyloarthropathies identify a specific phenotype previously related to Crohn's disease.
BACKGROUND
The association between spondyloarthropathy and Crohn's disease is well known. A risk for evolution to Crohn's disease has already been shown in the subgroup of patients with spondyloarthropathy associated with chronic gut inflammation.


OBJECTIVE
To investigate whether the reported polymorphisms in the CARD15 gene, a susceptibility gene for Crohn's disease, are associated with the presence of preclinical intestinal inflammation observed in spondyloarthropathies.


METHODS
104 patients with spondyloarthropathies were studied. All underwent ileocolonoscopy with biopsies between 1983 and 2004. The prevalence of three single nucleotide polymorphisms in the CARD15 gene (R702W, G908R, and 1007fs) was assessed using restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR); the patients were compared with an ethnically matched Crohn's disease population and a control population.


RESULTS
The carrier frequency of R702W, G908R, or 1007fs variants in the spondyloarthropathy populations (20%) was similar to the control population (17%), but increased to 38% in the spondyloarthropathy subgroup with chronic gut inflammation. This frequency was significantly higher than in the other spondyloarthropathy subgroups (p = 0.001) or the control group (p = 0.006), but not different from the Crohn's disease group (49%) (NS). This indicates that CARD15 polymorphisms are associated with a higher risk for development of chronic gut inflammation.


CONCLUSIONS
CARD15 gene polymorphisms clearly identify a subgroup of patients with spondyloarthropathies associated with chronic intestinal inflammation.
Laukens
D
D
Department of Gastroenterology, Ghent University Hospital, De Pintelaan 185, B-9000 Ghent, Belgium.
Peeters
H
H
Marichal
D
D
Vander Cruyssen
B
B
Mielants
H
H
Elewaut
D
D
Demetter
P
P
Cuvelier
C
C
Van Den Berghe
M
M
Rottiers
P
P
Veys
E M
EM
Remaut
E
E
Steidler
L
L
De Keyser
F
F
De Vos
M
M
D000293:Adolescent; D000328:Adult; D003424:Crohn Disease / Q000150:complications / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D015796:HLA-B27 Antigen / Q000032:analysis; D006579:Heterozygote; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D053473:Nod2 Signaling Adaptor Protein; D012150:Polymorphism, Restriction Fragment Length; D020641:Polymorphism, Single Nucleotide; D025242:Spondylarthropathies / Q000150:complications / Q000235:genetics*
D015796:HLA-B27 Antigen; D047908:Intracellular Signaling Peptides and Proteins; C429018:NOD2 protein, human; D053473:Nod2 Signaling Adaptor Protein