单克隆丙种球蛋白的特征是血清单克隆成分(MC)加上完整的免疫球蛋白和游离轻链(FLC),或两者的组合。用Freelite®测量FLC是国际骨髓瘤工作组指南推荐的标准做法。最近,引入Hevylite®重链/轻链(HLC)测定以特异性靶向完整免疫球蛋白的重链和轻链之间的连接表位,允许对涉及的(MC)和未涉及的(多克隆免疫球蛋白背景)HLC同种型进行独立定量。在2012年1月至2014年3月期间,共检查了90例患者:49例多发性骨髓瘤(MM),6个闷烧的MM(SMM)和35个意义不明的单克隆丙种球蛋白病(MGUS)。在这90名患者中,在不同时间收集300个样品。在所有90名接受检查的患者中评估了HevyliteA和G测定的诊断和监测贡献。此外,选择3例代表性病例。对于血清蛋白电泳和血清免疫固定,Hevylite绝对值和比率显示出高灵敏度和特异性。HevyliteA和G与Freelite的组合使用在具有一个以上MC或共同迁移成分的可疑情况下特别有用,以及在监测过程中评估FLC和HLC的独立变化,可能反映了队列中克隆异质性的存在。从这项研究中,可以得出结论,FLC和HLC是独立的,有用的标志物来监测MC,并以更高的特异性和敏感性评估治疗的效果,从而提供临床支持。需要进一步的研究来评估Hevylite在MGUS和SMM中的预后潜力。
Monoclonal gammopathies are characterized by serum monoclonal component (MC) plus an intact immunoglobulin and a free light chain (FLC), or a combination of both. The measurement of FLC with Freelite® is the standard practice recommended by International Myeloma Working Group guidelines. Recently, Hevylite® heavy/light chains (HLC) assays were introduced to specifically target junctional epitopes between the heavy and light chains of intact immunoglobulins, allowing the independent quantification of the involved (MC) and uninvolved (polyclonal immunoglobulin background) HLC isotype. Between January 2012 and March 2014, 90 patients were examined: 49 multiple myeloma (MM), 6 smoldering MM (SMM) and 35 monoclonal gammopathy of undetermined significance (MGUS). Of these 90 patients, 300 samples were collected at different times. The diagnostic and monitoring contribution of Hevylite A and G assays was assessed in all 90 patients examined. Additionally, 3 representative cases were selected. The Hevylite absolute values and ratio demonstrated high sensitivity and specificity with respect to serum protein electrophoresis and serum immunofixation. The combined use of Hevylite A and G with Freelite was particularly useful in dubious cases with more than one MC or with co-migrating components, as well as in the course of monitoring to assess the independent change of FLC and HLC, possibly reflecting the presence of clonal heterogeneity in the cohort. From this study, it can be concluded that FLC and HLC are independent, useful markers to monitor the MC and to assess with greater specificity and sensitivity the effect of therapy, thereby providing clinical support. Further studies are required to assess the prognostic potential of Hevylite in MGUS and SMM.