β_2-微球蛋白(β_2M)是一种低分子蛋白。少量的存在于正常人体尿、血清及其它体液中,其生物学作用尚未明了。所有有核细胞均可合成β_2M。有报告,尽管肾功能正常,血清中β_2M水平升高见于恶性淋巴网状系统疾病(如多发性骨髓瘤)和各种自身免疫或慢性炎症疾病包括类风湿性关节炎。最近的研究表明某些炎性疾病产生β_2M结合蛋白。类风湿因子结 β_2-microglobulin (β_2M) is a low-molecular protein. A small amount exists in normal human urine, serum and other body fluids, its biological role is not yet clear. All nucleated cells can synthesize β_2M. It has been reported that elevated levels of β_2M in serum are found in malignant lymphatic system diseases (such as multiple myeloma) and various autoimmune or chronic inflammatory diseases including rheumatoid arthritis despite normal renal function. Recent studies have shown that certain inflammatory diseases produce β 2 M binding proteins. Rheumatoid factor knot