Leprosy association with low MASP-2 levels generated by MASP2 haplotypes and polymorphisms flanking MAp19 exon 5.
BACKGROUND
The gene MASP2 (mannan-binding lectin (MBL)-associated serine protease 2) encodes two proteins, MASP-2 and MAp19 (MBL-associated protein of 19 kDa), bound in plasma to MBL and ficolins. The binding of MBL/MASP-2 and ficolin/MASP-2 complexes to microorganisms activates the lectin pathway of complement and may increase the ingestion of intracellular pathogens such as Mycobacterium leprae.


METHODS
We haplotyped 11 MASP2 polymorphisms with multiplex sequence-specific PCR in 219 Brazilian leprosy patients (131 lepromatous, 29 borderline, 21 tuberculoid, 14 undetermined, 24 unspecified), 405 healthy Brazilians and 291 Danish blood donors with previously determined MASP-2 and MAp19 levels. We also evaluated MASP-2 levels in further 46 leprosy patients and 69 Brazilian controls.


RESULTS
Two polymorphisms flanking exon 5 of MASP2 were associated with a dominant effect on high MASP-2 levels and an additive effect on low MAp19 levels. Patients presented lower MASP-2 levels (P = 0.0012) than controls. The frequency of the p.126L variant, associated with low MASP-2 levels (below 200 ng/mL), was higher in the patients (P = 0.0002, OR = 4.92), as was the frequency of genotypes with p.126L (P = 0.00006, OR = 5.96). The *1C2-l [AG] haplotype, which harbors p.126L and the deficiency-causing p.439H variant, has a dominant effect on the susceptibility to the disease (P = 0.007, OR = 4.15). Genotypes composed of the *2B1-i and/or *2B2A-i haplotypes, both associated with intermediate MASP-2 levels (200-600 ng/mL), were found to be protective against the disease (P = 0.0014, OR = 0.6). Low MASP-2 levels (P = 0.022), as well as corresponding genotypes with *1C2-l and/or *2A2-l but without *1B1-h or *1B2-h, were more frequent in the lepromatous than in other patients (P = 0.008, OR = 8.8).


CONCLUSIONS
In contrast with MBL, low MASP-2 levels increase the susceptibility to leprosy in general and to lepromatous leprosy in particular. MASP2 genotypes and MASP-2 levels might thus be of prognostic value for leprosy progression.
Laboratório de Imunopatologia Molecular - Hospital de Clínicas, Universidade Federal do Paraná, Curitiba, BR. iarareason@hc.ufpr.br
Angelica Beate Winter
AB
Boldt
Isabela
I
Goeldner
Ewalda R S
ER
Stahlke
Steffen
S
Thiel
Jens Christian
JC
Jensenius
Iara José Taborda
IJ
de Messias-Reason
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D001938:Brazil; D018450:Disease Progression; D005091:Exons; D005260:Female; D005787:Gene Frequency; D023061:Gene Order; D020022:Genetic Predisposition to Disease; D006239:Haplotypes; D006801:Humans; D007918:Leprosy / Q000235:genetics* / Q000378:metabolism*; D008297:Male; D050606:Mannose-Binding Protein-Associated Serine Proteases / Q000235:genetics* / Q000378:metabolism*; D008875:Middle Aged; D011110:Polymorphism, Genetic; D055815:Young Adult
C105296:MASP2 protein, human; D050606:Mannose-Binding Protein-Associated Serine Proteases