参考答案：E

解析：多发性骨髓瘤患者血清中有大量的M蛋白；巨琼蛋白血症患者血清中单克隆IgM增高；重链病患者血清和尿中存在着无免疫功能的Ig重链；轻链病患者血清中异常Ig轻链升高；良性单克隆丙种球蛋白白血病患者血清和尿中无游离的轻链和重链。