Association of mannose-binding lectin 2 gene polymorphic variants with susceptibility and clinical progression in systemic lupus erythematosus.
OBJECTIVE
This study investigates the role of mannose-binding lectin (MBL) in susceptibility and clinical expression of systemic lupus erythematosus (SLE), through the analysis of promoter region and exon 1 polymorphisms of the MBL2 gene.


METHODS
We analysed 325 SLE patients from the Hospital de Clínicas de Porto Alegre and 344 controls. All individuals were grouped according to ethnic origin. Genotyping of the promoter and exon 1 variants were performed by PCR-SSP and PCR-RFLP, respectively. Polymorphisms frequencies between patients and controls were compared by Chi-square or Fisher's exact tests.


RESULTS
A statistically significant difference was observed among the frequencies of both promoter haplotypes (p=0.005) and haplotypic combinations (p=0.004) in African-derived patients, with a higher incidence of HY haplotype and LY/HY combination in SLE patients when compared to controls. These results showed a tendency to higher frequencies of genotypes related to high MBL levels in African-derived patients. A joint analysis of data from the promoter and exon 1 polymorphisms showed an increased frequency of genotypes conferring a deficient of MBL levels in European-derived patients (p<0.001).


CONCLUSIONS
Our data suggest a possible influence of MBL deficiency in SLE European-derived although we did not observe any involvement of MBL2 variants in SLE clinical progression. The conflicting results shown by the analysis of patients grouped by ethnicity emphasise the need for studies considering this variable.
Department of Genetics, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil. nadineglesse@hotmail.com
Nadine
N
Glesse
Odirlei A
OA
Monticielo
Vanessa S
VS
Mattevi
Joao C T
JC
Brenol
Ricardo M
RM
Xavier
Gabriela K
GK
da Silva
Bruno P
BP
Dos Santos
Guilherme G
GG
Rucatti
José A B
JA
Chies
D000328:Adult; D001938:Brazil / Q000208:ethnology; D018450:Disease Progression; D005006:Ethnicity; D005260:Female; D020022:Genetic Predisposition to Disease / Q000208:ethnology / Q000235:genetics*; D006239:Haplotypes; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000175:diagnosis / Q000208:ethnology / Q000235:genetics*; 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