Mannose-binding lectin concentrations, MBL2 polymorphisms, and susceptibility to respiratory tract infections in young men.
BACKGROUND
Mannose-binding lectin (MBL) is an important component of innate immunity, and its deficiency is associated with susceptibility to recurrent infections.


METHODS
This exploratory study investigated the association of serum MBL concentrations and MBL2 gene polymorphisms with respiratory tract infections in young men. We genotyped 6 single-nucleotide polymorphisms (SNPs) in the promoter region (alleles H/L, X/Y, and P/Q) and exon 1 (variant alleles B, C, and D and wild-type allele A) of the MBL2 gene by real-time polymerase chain reaction and measured serum MBL concentrations in 111 Finnish military recruits with asthma and 362 without.


RESULTS
An MBL level below the median concentration was a significant risk factor for infections (asthma status-adjusted odds ratio [OR], 2.5 [95% confidence interval {CI}, 1.4-4.5]). Among the 6 SNPs, there was a significant association between the promoter Y/Y genotype and infections (OR, 2.3 [95% CI, 1.2-4.4]) and a borderline significant association between exon 1 variant alleles and infections (OR, 1.7 [95% CI, 0.9-3.1]), after adjustment for asthma status.


CONCLUSIONS
These preliminary results suggest, for the first time, an association between MBL level and respiratory tract infections in young men and a possible association between infections and MBL2 polymorphisms.
Rantala
Aino
A
National Public Health Institute, Oulu, Finland. aino.rantala@ktl.fi
Lajunen
Taina
T
Juvonen
Raija
R
Bloigu
Aini
A
Silvennoinen-Kassinen
Sylvi
S
Peitso
Ari
A
Saikku
Pekka
P
Vainio
Olli
O
Leinonen
Maija
M
D000293:Adolescent; D000328:Adult; D001249:Asthma / Q000150:complications / Q000235:genetics; D005091:Exons / Q000235:genetics; D005387:Finland; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D037601:Mannose-Binding Lectin / Q000097:blood* / Q000235:genetics; D008889:Military Personnel; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic / Q000235:genetics; D012141:Respiratory Tract Infections / Q000235:genetics* / Q000276:immunology
C445619:MBL2 protein, human; D037601:Mannose-Binding Lectin