IgG4相关性疾病（IgG4 related disease，IgG4-RD）是以血清IgG4升高、组织中大量淋巴细胞和IgG4+浆细胞浸润、受累脏器增生和肿大为特点的自身免疫病。我们前期研究证实，IgG4-RD患者B细胞表达和功能异常，特别是CD19+CD24-CD38hi B细胞亚群在患者外周血中比例明显升高，并与血清IgG4水平呈显著正相关。为探讨CD19+CD24-CD38hiB细胞亚群在IgG4-RD发病中的作用，我们将进行以下研究：1）明确IgG4-RD患者外周血CD19+CD24-CD38hiB细胞的特性、功能及与其它B细胞亚群基因表达谱的差异；2）该细胞亚群分泌IgG4的情况及在IgG4-RD患者免疫球蛋白类别转换中的作用；3）CD19+CD24-CD38hi细胞在组织受累中的作用。上述研究最终将确定CD19+CD24-CD38hiB细胞是否为IgG4-RD的重要生物标志。

IgG4 related disease (IgG4-RD) is a newly recognized systemic inflammatory condition characterized by elevated serum IgG4 levels, and organ enlargement with massive lymphocytes especially IgG4+ plasma cell infiltration. Our previous study demostrated that both B cell expression and function were abnormal in IgG4-RD patients, CD19+CD24-CD38hi B cell subset was predominantly highly expressed, and correlated with serum IgG4 levels. Thus, the purpose of this study is to reveal the role of CD19+CD24-CD38hi B cells in IgG4-RD patients. The contents includes, 1) Understanding the characteristics, function and the gene expression difference among B cell subsets;2) To investigate IgG4 secreting of CD19+CD24-CD38hi B cells, as well as the role of CD19+CD24-CD38hi B cells in immunoglobulin class switch; 3) To study the role of CD19+CD24-CD38hi B cells in tissue damage. The results will confirm whether CD19+CD24-CD38hi B cells will be one of the most important biomarkers for IgG4-RD.