Interferon-gamma and interleukin-4 gene polymorphisms in Caucasian idiopathic inflammatory myopathy patients in UK.
OBJECTIVE
To determine whether interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) genes confer susceptibility for the idiopathic inflammatory myopathies (IIMs).


METHODS
A large cross-sectional study of UK caucasian adults with polymyositis (PM, n = 101), dermatomyositis (DM, n = 94) and myositis overlapping with a connective tissue disease (myositis/CTD-overlap, n = 70) was completed. 177 ethnically matched controls were available for comparison. Single-nucleotide polymorphisms (SNPs) within intronic regions coding for IL-4, IFN-gamma and a microsatellite marker within intron 1 of the IFN-gamma gene were typed.


RESULTS
Strong linkage disequilibrium was present between SNPs in each gene. In the IFN-gamma gene, a weak allelic association was observed in PM versus controls at rs1861493 (odds ratio (OR) 1.6, 95% confidence interval (CI) 1.03 to 2.4). The microsatellite IFN-gamma CA(14) allele was associated with risk for IIMs overall (OR 3.3, 95% CI 1.4 to 7.8), the strongest association being observed within the anti-U1-ribonucleoprotein (RNP) group (OR 6.0, 95% CI 1.5 to 23.1), and persisting after adjustment for known myositis human leucocyte antigen (HLA) class II associations.


CONCLUSIONS
Genetic markers in the IFN-gamma gene demonstrate significant allelic associations with the IIMs in a UK Caucasian population. The SNPs tested in this study within the region coding for IL-4 fail to show significant associations with susceptibility to IIM disease.
Chinoy
Hector
H
The University of Manchester Rheumatic Diseases Centre, Salford M6 8HD, UK.
Salway
Fiona
F
John
Sally
S
Fertig
Noreen
N
Tait
Brian D
BD
Oddis
Chester V
CV
Ollier
William E R
WE
Cooper
Robert G
RG
D000328:Adult; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D003882:Dermatomyositis / Q000453:epidemiology / Q000208:ethnology / Q000235:genetics; D005787:Gene Frequency; D005819:Genetic Markers / Q000235:genetics; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006680:HLA Antigens / Q000235:genetics; D006801:Humans; D007371:Interferon-gamma / Q000235:genetics*; D015847:Interleukin-4 / Q000235:genetics*; D015810:Linkage Disequilibrium / Q000235:genetics; D018895:Microsatellite Repeats / Q000235:genetics; D009220:Myositis / Q000453:epidemiology / Q000208:ethnology / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D017285:Polymyositis / Q000453:epidemiology / Q000208:ethnology / Q000235:genetics; D006113:United Kingdom / Q000453:epidemiology; D044465:White People / Q000235:genetics*
D005819:Genetic Markers; D006680:HLA Antigens; D015847:Interleukin-4; D007371:Interferon-gamma