Association of mannose binding lectin (MBL) gene polymorphism and serum MBL concentration with characteristics and progression of systemic lupus erythematosus.
OBJECTIVE
To determine whether occurrence, characteristics, and progression of systemic lupus erythematosus (SLE) are associated with polymorphism of the mannose binding lectin (MBL) gene and with serum MBL concentration.


METHODS
Codon 54 MBL gene polymorphism of 147 patients with SLE and 160 healthy controls was determined by polymerase chain reaction-restriction fragment length polymorphism. Serum concentration of MBL was measured by enzyme immunoassay. Fluctuations of serum MBL were analysed with respect to disease characteristics and activity.


RESULTS
Frequency of homozygosity for codon 54 minority allele was 6% (9/147) in patients with SLE, and significantly higher than in controls (p = 0.0294, Fisher's exact test). MBL polymorphism in patients with SLE was not significantly associated with disease characteristics or immunological phenotypes. Patients homozygous for the B allele tended to have a higher risk of infection during treatment. Levels of C3 and CH(50) were slightly, but significantly, associated with serum MBL concentration in patients with SLE homozygous for the majority allele. During the course of SLE, serum MBL concentration increased in 6/14 patients, and decreased in 7 after initiation of immunosuppressive treatment.


CONCLUSIONS
MBL gene polymorphism influences susceptibility to SLE, but has no direct effect on disease characteristics. Serum MBL levels fluctuate during the course of SLE in individual patients. MBL genotyping may be useful in assessing the risk of infection during treatment of SLE.
Takahashi
R
R
Division of Rheumatology, Department of General Medicine, Institute of Clinical Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba-city, Ibaraki 305-8575, Japan.
Tsutsumi
A
A
Ohtani
K
K
Muraki
Y
Y
Goto
D
D
Matsumoto
I
I
Wakamiya
N
N
Sumida
T
T
D000293:Adolescent; D000328:Adult; D018450:Disease Progression; D020022:Genetic Predisposition to Disease; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000188:drug therapy / Q000235:genetics*; D037601:Mannose-Binding Lectin / Q000097:blood / Q000235:genetics*; D008775:Methylprednisolone / Q000627:therapeutic use; D008875:Middle Aged; D009894:Opportunistic Infections / Q000097:blood / Q000235:genetics; D011110:Polymorphism, Genetic
D007166:Immunosuppressive Agents; D037601:Mannose-Binding Lectin; D008775:Methylprednisolone