個體IL-6基因多形性／表現量與輸血後產生紅血球異體抗體之相關性探討

The Relationship between IL-6 Gene Promoter Polymorphism /Expression in Serum and Occurrence of Allo-immunization after Blood Transfusion

紅血球抗體可因輸血產生，在臨床工作中，當病人產生抗體，找尋相合的血品，對於血庫工作同仁來說是個挑戰。根據文獻資料，我們推測人類介白素-6（IL-6）與紅血球的異體免疫存在高度相關性。故本研究以IL-6表現量及IL-6基因-174G/C與-572C/G單核苷酸多型性(SNP)，探討其與輸血後發生異體免疫的相關性，未來將可以藉此做為標記區別輸血會產生與不產生抗體者，給與易產生抗體者紅血球次要抗原相同的血，將能有效預防輸血後產生抗體，保障輸血安全。

Transfusion may result in a production of RBC alloantibodies in recipient. Although genetic background plays an important role in RBC alloimmunization, murine studies with identical genetic background suggested other factors resulting a host as responders (who make alloantibodies) or non-responders (who do not make alloantibodies) after transfusion remained to be identified. According to previous studies, we propose IL-6 is highly associated with the RBC alloimmunization. In this study, we focus on the gene expression level and -174G/C and -572 C/G SNP of IL-6 between responders and non-responders. We collected the blood samples from 50 healthy volunteers,45 cases receiving frequent blood transfusion (more than 20 times of transfusion within 3 years) without alloantibodies production and 54 cases with heavy blood exposure and alloantibodies production. DNA from blood samples were extracted and analyzed –174G/C and -572 C/G SNP of IL-6 with RFLP. The serum level of IL-6 were also measured by ELISA kit. Our study revealed that there’s only (-174G/G) single genotype of IL-6 SNP in our population and increasing proportion of higher level IL-6 expression and the dominant G (GG and CG) genotypes of IL-6 SNP (-572 C/G) in alloantibodies production group. This novel finding indicates IL-6 level or certain SNP genotype may be the risky factors of alloimmunization after transfusion. Establishing a method to identify responders before transfusion and giving them phenotyped-matched units could avoid recipients from producing antibodies to enhance the safety of blood transfusion.