Mannose-binding lectin polymorphisms and susceptibility to infection in systemic lupus erythematosus.
OBJECTIVE
To determine whether variant alleles in the coding portion of the mannose-binding lectin (MBL) gene are associated with increased susceptibility to systemic lupus erythematosus (SLE) and concomitant infections.


METHODS
MBL alleles and serum concentrations were determined by polymerase chain reaction and enzyme-linked immunosorbent assay, respectively, in 91 Danish patients with SLE and in 250 controls.


RESULTS
Homozygosity for MBL variant alleles was observed in 7.7% of the SLE patients compared with 2.8% of the controls (P = 0.06), while no difference was seen for heterozygosity (33.0% versus 34.4%). Homozygotes had an increased risk of acquiring serious infections compared with patients who were heterozygous or homozygous for the normal allele (odds ratio 8.6, 95% confidence interval 1.5-47.6, P = 0.01). The time interval from the diagnosis of SLE to the first infectious event was shorter (P = 0.017), and the annual number of infectious events was 4 times higher, among homozygotes (P = 0.00002). They were especially prone to acquire pneumonia (P = 0.00004). CONCLUSION; Homozygosity for MBL variant alleles may explain much of the increased risk of complicating infections seen in SLE patients. Additionally, it is a minor risk factor for acquiring SLE.
Garred
P
P
Tissue Typing Laboratory 7631, Rigshospitalet, Copenhagen, Denmark.
Madsen
H O
HO
Halberg
P
P
Petersen
J
J
Kronborg
G
G
Svejgaard
A
A
Andersen
V
V
Jacobsen
S
S
D000293:Adolescent; D000328:Adult; D002352:Carrier Proteins / Q000235:genetics*; D037222:Collectins; D003141:Communicable Diseases / Q000209:etiology* / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000150:complications* / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D012189:Retrospective Studies
D002352:Carrier Proteins; D037222:Collectins