髓过氧化物酶和过氧化氢酶基因多态性及其酶活力与燃煤污染型地方性砷中毒关系的探讨

目的 了解燃煤污染型地方性砷中毒患者体内髓过氧化物酶(MPO)基因和过氧化氢酶(CAT)基因的多态性及其酶活力,分析其与砷中毒发生的关系.方法 以贵州省兴仁县交乐村燃煤污染型地方性砷中毒病区的130例砷中毒患者为病例(砷中毒)组,以居住在距病区约13 km非砷污染大果垛村的140例健康居民为对照组.采集两组人群静脉血,采用PCR-限制性片段长度多态性(PCR-RFLP)方法检测MPO基因-463 G/A位点和CAT基因-262C/T位点的多态性;采用紫外分光光度法检测MPO活力;采用比色法检测CAT活力.结果 砷中毒组MPO-463G/A位点GG、GA和AA基因型分布频率为47.24%(60/127)、44.09%(56/127)和8.67%(11/127),对照组为42.34%(58/137)、48.17%(66/137)和9.49%(13/137),两组比较差异无统计学意义(χ2=0.642,P>0.05).砷中毒组CAT-262C/T位点CC、CT和TT基因型分布频率为65.60%(82/125)、28.80%(36/125)和5.60%(7/125),对照组为76.51%(101/132)、18.94%(25/132)和4.55%(6/132),两组比较差异无统计学意义(χ2=3.845,P>0.05).未发现MPO-463G/A位点和CAT-262C/T位点多态性与砷中毒发病风险(比值比,OR)的关联度有统计学意义(MPO:Oradj=1.36,95%CI:0.74～2.50;CAT:Oradj=1.35,95%CI:0.69～2.63).砷中毒组MPO和CAT活力分别为(25.30±8.70)U/L和(2.80±1.09)×103U/L,对照组分别为(22.76±7.59)U/L和(3.90±1.01)×103U/L,两组比较差异有统计学意义(F值分别为0.760、0.855,P均<0.05).MPO-463G/A和CAT-262C/T不同基因型个体MPO和CAT酶活力比较,差异无统计学意义(F值分别为1.312、2.822,0.151、0.036,P均>0.05).结论 未发现MPO基因-463G/A位点和CAT基因-262C/T位点多态性与燃煤污染型地方性砷中毒的发病风险有关;砷可致MPO和CAT酶活力改变,此改变可能不受MPO-463G/A和CAT-262C/T多态性的影响.

Relationship between myeloperoxidase and catalase genetic polymorphism and their activities with arsenic poisoning caused by coal-burning

Objective To detect genetic polymorphism of myeloperoxidase (MPO) gene and catalase (CAT) gene and their activities, and to analyze their relationship with arsenic poisoning caused by coal-burning. Methods One hundred and thirty arsenic poisoning patients were chosen as case group in Jiaole Village, Xingren County, Guizhou Province(an endemic area). One hundred and forty healthy residents living in 13 km away were chosen as control group. Their blood was collected. Polymerase chain reaction-restriction fragment length polymorphism technique(PCR-RFLP) was used to detect polymorphism of MPO-463G/A and CAT-262C/T. Ultraviolet spectmphotometer method was used to detect myeloperoxidase activity. Chromatometry method was used to detect catalase activity. Results The genotype frequency of MPO-463G/A at GG, GA, AA site was 47.24%(60/127), 44.09%(56/127),8.67% (11/127) in case group and 42.34% (58/137),48.17% (66/137)1,9.49% (13/137) in control group, respectively. The difference between the two groups was not significant(χ2 = 0.642, P > 0.05). The genotype frequency of CAT-262C/T, at CC, CT, TT site was 65.60%(82/125),28.80%(36/125),5.60%(7/125) in case group and 76.51%(101/132), 18.94% (25/132) ,4.55% (6/132) in control group, respectively, without significant difference (χ2 =3.845, P>0.05). The relationship between polymorphism of MPO-463G/A and CAT-262C/T and the risk of arsenic poisoning was not found in this study(ORadj= 1.36, 95%CI: 0.74-2.50 for MPO; ORadj=1.35, 95%CI: 0.69-2.63 for CAT). The activities of MPO and CAT were (25.30±8.70)U/L and (2.80± 1.09)×103 U/L in case group, while (22.76±7.59)U/L and (3.90±1.01)×103U/L in control group with a significant difference(F=0.760 for MPO, F=0.855 for CAT, all P < 0.05). The genotype of MPO-463G/A and CAT-262C/T was not found to have relationship with the activities of MPO, CAT(F=1.312,2.822 for MPO; F= 0.151,0.036 for CAT, P>0.05). Conclusions Genetic polymorphism of MPO-463G/A and CAT-262C/T is not found to have relationship with arsenic poisoning. Arsenic can lead to the change of MPO and CAT activity, which, however, may not be affected by MPO-463G/A and CAT-262C/T polymorphism.