Abstract: Objective To evaluate the relationship between polymorphisms in surfactant protein (SP) genes and susceptibility to chronic obstructive pulmonary disease (COPD). Methods An extensive literature search for relevant studies was conducted in databases of Wanfang Data, VIP, Google Scholar, PubMed, CNKI, CBM, EMBASE and Web of Science and so on from inception to Sep., 2013. A meta-analysis was then performed using Stata 12.0 software. Results 7 case-control studies were included with a total of 1,279 COPD cases and 1,482 healthy controls. This meta-analysis revealed that polymorphisms of the SP-A gene might be associated with an increased risk of COPD (allele model: OR=1.53, 95%CI: 1.14~2.05, P=0.005; dominant model: OR=1.65, 95%CI: 1.02~2.69, P=0.043; recessive model: OR=1.66,95%CI: 1.17~2.35, P=0.005: homozygous model: OR=2.06, 95%CI: 1.24~3.41, P=0.005; eterozygous model: OR =1.59, 95%CI: 1.13~2.22, P=0.007; respectively). However, there was no evidence for any association between polymorphisms of the SP-B and SP-D genes and COPD risk (all P>0.05). Further subgroup analysis by ethnicity suggested that SP-A genetic polymorphisms were associated with an increased risk of COPD among Asians, but not among Caucasians. Conclusion SP-A genetic polymorphisms may contribute to increasing susceptibility to COPD, especially among Asians.

Key words: surfactant protein, polymorphism, chronic obstructive pulmonary disease, Meta-analysis