03353nas a2200457   4500000000100000008004100001260000900042653001500051653001000066653000900076653002200085653001200107653001100119653002400130653001000154653001100164653001900175653001500194653003800209653001500247653001100262653001200273653000900285653005600294653001600350653002600366653001600392100001200408700001500420700001400435700001200449700001700461700002300478245011800501856007700619300001100696490000600707050001500713520215300728022001402881       2013                            d  c201310aAdolescent10aAdult10aAged10aAged, 80 and over10aAlleles10aBrazil10aDisease Progression10aExons10aFemale10aGene Frequency10aGene Order10aGenetic Predisposition to Disease10aHaplotypes10aHumans10aleprosy10aMale10aMannose-Binding Protein-Associated Serine Proteases10aMiddle Aged10aPolymorphism, Genetic10aYoung Adult1 aBoldt A1 aGoeldner I1 aStahlke E1 aThiel S1 aJensenius JC1 aMessias-Reason LJT00aLeprosy association with low MASP-2 levels generated by MASP2 haplotypes and polymorphisms flanking MAp19 exon 5.  uhttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC3728295/pdf/pone.0069054.pdf  ae690540 v8  aBOLDT 20133 a<p><b>BACKGROUND: </b>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.</p><p><b>METHODS: </b>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.</p><p><b>RESULTS: </b>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).</p><p><b>CONCLUSIONS: </b>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.</p>  a1932-6203