Abstract: Su Ying, Guo Shulan, Yu Xiaojing, Li Chunyang, Sun Qing. Department of Dermatology, Qilu Hospital of Shandong University, Jinan 250012, China Corresponding author: Sun Qing, Email: sywxlwjz@163.com 【Abstract】 Objective To determine the gene polymorphism and serum concentration of mannose-binding lectin （MBL） in patients with psoriasis, and to analyze the relationship between MBL and psoriasis. Methods Totally, 67 patients with psoriasis vulgaris and 69 healthy human controls were enrolled in this study. Venous blood samples were obtained from all the subjects. Genomic DNA was extracted, and PCR-restriction fragment length polymorphism（PCR-RELP） analysis was conducted to determine the polymorphism at codon 54 of the MBL gene. Enzyme-linked immunosorbent assay was performed to measure the serum level of MBL. A chi-square goodness-of-fit test was carried out to evaluate Hardy-Weinberg equilibrium, t test to compare the serum concentration of MBL, and chi-square test to compare the frequency of genotypes and alleles of MBL gene codon 54. Results The patients with psoriasis showed higher frequency of GGC/GAC heterozygote but lower frequency of GGC/GGC homozygote （χ2 = 10.36, P ＜ 0.05）, together with increased frequency of GAC allele but decreased frequency of GGC allele （χ2 = 8.31, P ＜ 0.05）, at codon 54 of the MBL gene compared with the healthy controls. The variant allele GAC at codon 54 of the MBL gene was markedly associated with psoriasis （OR = 3.383，95％ CI 1.585 － 7.211, P ＜ 0.05）. The serum concentration of MBL was （2.193 7 ± 0.816 3） mg/L in patients with psoriasis, significantly lower than that in the healthy controls （（3.269 5±1.205 8） mg/L, t = 6.11, P ＜ 0.05）. Conclusion MBL might be associated with the pathogenesis of psoriasis to some degree.

Key words: Psoriasis, Mannose-binding lectins, Polymorphism, restriction fragment length