Structural polymorphisms in the mannose-binding lectin gene are associated with juvenile idiopathic arthritis.
OBJECTIVE
To investigate the possible association between polymorphisms of the mannose-binding lectin gene (MBL2) and susceptibility to juvenile idiopathic arthritis (JIA).


METHODS
We performed a case-control association study including 118 Hungarian patients with JIA and 118 sex-matched healthy controls. MBL genotyping for the 3 mutant structural alleles at codons 54 (B), 57 (C), and 52 (D) in exon 1 and the promoter polymorphisms at position -550 (HL) and -221 (YX) were carried out by real-time PCR allelic discrimination. Serum level of MBL was determined by ELISA.


RESULTS
Variant allele frequencies of both codon 52 and 57 polymorphisms in the MBL2 gene were significantly overrepresented in JIA (p=0.001 and p=0.004, respectively). The frequency of low MBL genotypes (XA/XA, YA/YO, XA/YO, and YO/YO) in JIA was higher than that in healthy controls (p=0.001). Serum MBL concentrations were found to be significantly lower in JIA patients versus control subjects (p=0.001). The 2 promoter polymorphisms and codon 54 SNP of the MBL2 gene were not associated with JIA.


CONCLUSIONS
Our findings suggest that genetically determined low MBL levels may predispose children to JIA in a Hungarian population. These data warrant further research to investigate the role of the lectin-dependent complement system in the pathogenesis of JIA.
Gergely
Péter
P
1st Department of Rheumatology, National Institute of Rheumatology and Physiotherapy, Frankel Leó u. 25-29, Budapest, H-1023 Hungary.
Pazár
Borbála
B
Nagy
Zsolt B
ZB
Gombos
Tímea
T
Rajczy
Katalin
K
Balogh
Zsolt
Z
Orbán
Ilona
I
Sevcic
Krisztina
K
Poór
Gyula
G
D000293:Adolescent; D000328:Adult; D001171:Arthritis, Juvenile / Q000235:genetics*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D006814:Hungary; D007223:Infant; D008297:Male; D037601:Mannose-Binding Lectin / Q000235:genetics*; D008875:Middle Aged; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic / Q000235:genetics; D055815:Young Adult
C445619:MBL2 protein, human; D037601:Mannose-Binding Lectin