The study aimed to investigate free light chain (FLC) monoclonality in patients with an abnormal free kappa/lambda ratio (FLC ratio). Seventy serum samples with abnormal FLC ratio were examined using an immunoturbidimetry (Binding Site, SPA) and the two different enzyme-linked immunosorbent assays (1. Sebia diagnostic kit; 2. in house methods), the monoclonal or oligoclonal bands of (FLC) by immunofixation electrophoresis (IE) and isoelectric focusing followed by affinity immunoblotting (IEF/AIB). The reference interval was calculated by non-parametric percentile method. 5.7% of samples examined by IE were suspected of monoclonal character of FLCs, but subsequently monoclonality was refuted by more sensitive IEF/AIB method; 7%, resp. 2.9% of samples showed FLC kappa, resp. FLC lambda oligoclonal character of bands. A statistically significant dependence was found between FLC ratio (Sebia) and FLC ratio (SPA), r_s = 0.510, p = .001. Kappa statistic evaluated a fair conformity between the FLC ratio (Sebia) and IEF/AIB (kappa = 0.468) and between FLC ratio (in house) and IEF/AIB (kappa = 0.300). The verified reference interval for FLC ratio (Binding Site) is between 0.35 and 2.18. The IEF/AIB is the most sensitive method to discriminate between monoclonal and oligoclonal bands of FLC. The Binding Site and Sebia diagnostic kits do not give consistent results. The Binding Site diagnostic kit provides more results above reference interval of FLC ratios. For routine decision on monoclonality of the FLC ratio (SPA) it is advisable to use a verified reference interval.

这项研究旨在研究具有异常κ/λ比率（FLC比率）的患者的游离轻链（FLC）单克隆抗体。使用免疫比浊法（结合位点，SPA）和两种不同的酶联免疫吸附测定法（1. Sebia诊断试剂盒； 2。内部方法），（FLC）的单克隆或寡克隆条带检查了70个FLC比异常的血清样品。通过免疫固定电泳（IE）和等电聚焦，然后进行亲和免疫印迹（IEF / AIB）。参考区间是通过非参数百分位数法计算的。通过IE检验的样本中有5.7％被怀疑具有FLC的单克隆特性，但随后通过更灵敏的IEF / AIB方法推翻了单克隆性；7％，分别。2.9％的样品显示出FLCκ。带的FLC lambda寡克隆特征。_s＝ 0.510，p  ＝ 0.001。Kappa统计量评估了FLC比率（塞尔维亚）和IEF / AIB（kappa = 0.468）之间以及FLC比率（内部）和IEF / AIB（kappa = 0.300）之间的公平一致性。经验证的FLC比（结合位点）参考区间为0.35至2.18。IEF / AIB是区分FLC单克隆和寡克隆带的最灵敏方法。结合位点和Sebia诊断试剂盒的结果不一致。结合位点诊断试剂盒在FLC比值的参考间隔以上提供了更多结果。对于FLC比（SPA）单克隆性的常规决定，建议使用经过验证的参考间隔。