Prokaeva Tatiana, Spencer Brian, Sun Fangui, O'Hara Richard M, Seldin David C, Connors Lawreen H, Sanchorawala Vaishali
a Amyloidosis Center , Boston University School of Medicine , Boston , MA , USA.
b Boston University School of Public Health , Boston , MA , USA.
Amyloid. 2016 Dec;23(4):214-220. doi: 10.1080/13506129.2016.1219715. Epub 2016 Sep 28.
Serum and urine immunofixation electrophoreses (SIFE/UIFE) are used for clonal detection in plasma cell dyscrasias, while serum free light chain (sFLC) testing provides quantitation of clonal disease. Up to 20% of patients with light chain (AL) amyloidosis may present with normal FLC ratio (FLCr).
We assessed the diagnostic, quantitative and prognostic potential of serum heavy light chain ratio (HLCr) in 199 untreated patients at initial evaluation.
An abnormal HLCr was found in 37.2%, abnormal FLCr in 81.9% and positivity by SIFE/UIFE in 94% of patients. HLCr together with SIFE/UIFE identified clonality in 94% patients; the combination with FLCr yielded 100% sensitivity. An HLCr abnormality was significantly over-represented in normal compared to abnormal FLCr group (63.9% versus 31.3%). HLCr did not predict overall survival (OS) (log rank, p = 0.09), while an abnormal FLCr was associated with decreased OS (log rank, p = 0.03). The combined use of both ratios trended toward increased OS in the abnormal HLCr/normal FLCr group (log rank, p = 0.11; Wilcoxon, p = 0.04). On multivariate analysis, HLCr was not predictive of OS, whereas an abnormal FLCr was associated with shorter OS (HR = 1.7, p = 0.04).
The HLC assay has potential as a supplemental test to quantify monoclonal protein in patients with normal FLCr results.
血清和尿液免疫固定电泳（SIFE/UIFE）用于浆细胞异常增殖性疾病的克隆检测，而血清游离轻链（sFLC）检测可对克隆性疾病进行定量分析。高达20%的轻链（AL）淀粉样变性患者可能表现为游离轻链比值（FLCr）正常。
我们在199例未经治疗的患者初诊时评估了血清重轻链比值（HLCr）的诊断、定量和预后潜力。
37.2%的患者HLCr异常，81.9%的患者FLCr异常，94%的患者SIFE/UIFE呈阳性。HLCr与SIFE/UIFE联合可识别94%患者的克隆性；与FLCr联合的敏感性为100%。与FLCr异常组相比，HLCr异常在FLCr正常组中显著多见（63.9%对31.3%）。HLCr不能预测总生存期（OS）（对数秩检验，p = 0.09），而FLCr异常与OS降低相关（对数秩检验，p = 0.03）。在异常HLCr/正常FLCr组中，两种比值联合使用有使OS增加的趋势（对数秩检验，p = 0.11；Wilcoxon检验，p = 0.04）。多因素分析显示，HLCr不能预测OS，而FLCr异常与较短的OS相关（风险比=1.7，p = 0.04）。
HLC检测有潜力作为一项补充检测，用于对FLCr结果正常的患者的单克隆蛋白进行定量分析。
