中国上海汉族人群IgA缺乏症的研究

Study on immunoglobulin A Deficiency(IgAD) in Chinese Shanghai Blood Donors

目的:通过对中国汉族人群(上海地区献血人群n=61624)Ig AD大规模的调查,一方面筛选出Ig AD者,将他们作为供者建立上海Ig AD稀有血型资料库,为相同稀有血型患者提供配合安全的血液制品,预防和规避免疫性输血过敏反应的发生。同时调查中国汉族人群Ig AD发生频率,研究比较这些Ig AD者的疾病相关风险基因与白种人Ig AD者、与中国汉族正常献血者的遗传差异。方法:筛选61 624名中国汉族献血者,调查Ig AD者、统计Ig AD发生率,观察其免疫球蛋白Ig M及Ig G亚型的表达量,HLA-DR/DQ基因定型并比较中华造血干细胞捐献者资料库相关基因频率。结果:中国汉族人群Ig AD发生频率约为1∶2 000(31/61 624)。Ig AD者血清Ig G水平高于正常值,无Ig G亚型缺失,3人有抗Ig A抗体。2/3 Ig AD献血者携带有白种人Ig AD者的遗传单倍体DRB1*0301-DQB1*0201,DRB1*0701-DQB1*0202和DRB1*0102-DQB1*0501,其频率显著高于中华造血干细胞捐献者资料库数据。结论:中国汉族人群Ig AD频率显著低于白种人。三分之二的Ig AD献血者携带白种人Ig AD相关风险基因,疾病相关的风险基因的低表达可能是中国汉族人群Ig AD发病率低的原因。

Objective:To calculate the prevalence of IgAD in a replicate cohort of the Chinese Han population in Shanghai area by screening blood donors and to study the genetic difference of IgAD individuals in the Mongoloid population.Methods:The prevalence of IgAD in a large number of Chinese blood donors(n =61624) in Shanghai area was investigated.The immunoglobulin class,IgG subclass and anti-IgA serum levels were measured among the IgAD donors.These donors were subsequently tissue typed and the allele frequency was compared with the Shanghai bone marrow donor HLA registry.Results:Thirty-one IgAD blood donors were identified,giving a prevalence of 1:2 000(31/61624).Most IgAD donors had serum IgG levels above the normal range with no major IgG subclass deficiency and 3 donors was positive for anti-IgA.Two-thirds of the IgAD donors carried Caucasian IgAD associated risk haplotypes,including DRB1* 0301-DQB1* 0201,DRB1* 0701-DQB1* 020 and DRB1* 0102-DQB1* 0501,giving a significantly higher frequency of these haplotypes as compared to the Shanghai bone marrow donor HLA registry.Conclusion:The prevalence of IgAD in Chinese Han population is markedly lower than that in Caucasians.The low prevalence of IgAD can potentially be due to the low frequency of the disease associated risk haplotypes in China.However,potential risks exist in performing blood transfusion to IgAD persons,and measures should be taken to reduce IgA anaphylaxis.Meanwhile,it is necessary to set up a Shanghai rare blood bank of IgAD donor for patients to meet the needs of IgA-poor transfusion.