IL-4 VNTR gene polymorphism in chronic polyarthritis. The rare allele is associated with protection against destruction.
OBJECTIVE
To evaluate the occurrence of variants of the interleukin 4 (IL-4) and IL-4 receptor (IL-4R) genes in patients with rheumatoid arthritis (RA) and their possible contribution to joint destruction.


METHODS
Allelic frequencies for polymorphisms in the IL-4 [variable number of tandem repeat (VNTR) polymorphism in intron 3] and IL-4 receptor alpha chain (transition at nucleotide 1902) genes were assessed in 335 RA patients and 104 controls. Clinical indices of disease activity, disability and joint destruction and plasma levels of IL-1beta, IL-1Ra and sCD23 were assessed to evaluate a possible functional effect.


RESULTS
Carriage of the rare IL-4(2) allele was higher in patients with non-destructive RA (40%) than in those with destructive RA (22.3%; odds ratio = 1.9, 95% confidence interval 1. 1-3.5, P = 0.0006) and in controls (26%, P = 0.002). Patients positive for this rare allele had significantly less joint destruction, assessed by the Larsen wrist index (P = 0.004) and a lower erythrocyte sedimentation rate (P = 0.04). A significantly higher carriage rate of IL-4(2) was seen in HLA-DR4/DR1(-) patients with non-destructive RA than in those with destructive RA. The IL-4 receptor polymorphism was not over-represented. Plasma levels of IL-1beta, IL-1Ra and sCD23, known to be modified by IL-4, were not different in individuals having different alleles.


CONCLUSIONS
This IL-4 VNTR gene polymorphism may be a protective factor for severe joint destruction in RA that could be used as a prognostic marker early in the course of the disease.
Buchs
N
N
Departments of Immunology and Rheumatology, Hôpital Edouard Herriot, Lyon, France, Division of Molecular and Genetic Medicine, University of Sheffield, Royal Hallamshire Hospital, Sheffield, UK and. Department of Medicine, Tufts University.
Silvestri
T
T
di Giovine
F S
FS
Chabaud
M
M
Vannier
E
E
Duff
G W
GW
Miossec
P
P
D000483:Alleles; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000000981:diagnostic imaging / Q000235:genetics*; D015415:Biomarkers; D002908:Chronic Disease; D005260:Female; D005787:Gene Frequency; D008040:Genetic Linkage; D006684:HLA-DR Antigens / Q000235:genetics; D006801:Humans; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1 / Q000097:blood; D015847:Interleukin-4 / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D011859:Radiography; D017455:Receptors, IgE / Q000097:blood; D019948:Receptors, Interleukin-4 / Q000235:genetics; D012016:Reference Values; D012795:Sialoglycoproteins / Q000097:blood; D012995:Solubility; D020080:Tandem Repeat Sequences / Q000235:genetics*
D015415:Biomarkers; D006684:HLA-DR Antigens; C507763:IL1RN protein, human; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1; D017455:Receptors, IgE; D019948:Receptors, Interleukin-4; D012795:Sialoglycoproteins; D015847:Interleukin-4