Division of Hematology, Mayo Clinic, Rochester, MN 55905, USA.
Mayo Clin Proc. 2012 Jun;87(6):517-23. doi: 10.1016/j.mayocp.2012.03.009.
To determine whether the free light chain (FLC) assay provides prognostic information relevant to the general population.
After excluding persons with a known plasma cell disorder, we studied 15,859 Olmsted County, Minnesota, residents 50 years or older in whom unmasked data and samples for FLC testing were available. Baseline information was obtained between March 13, 1995, and November 21, 2003, and follow-up status and cause of death were identified through June 30, 2009. The κ and λ FLC sum (Σ FLC) was evaluated for its ability to predict overall survival. Specific causes of death were also investigated.
In 158,003 person-years of follow-up, 4348 individuals died. A high Σ FLC was significantly predictive of worse overall survival; the risk ratio for death for those with the highest decile of Σ FLC (ie, ≥ 4.72 mg/dL) was 4.4 (95% confidence interval, 4.1-4.7) relative to the remaining study participants. Multivariate analyses demonstrated that this excess risk of death was independent of age, sex, and renal insufficiency, with a corrected risk ratio of 2.1 (95% confidence interval, 1.9-2.2). The increased mortality was not restricted to any particular cause of death because the observed-to-expected risk of death from most causes was significantly higher among those individuals with an antecedent Σ FLC of 4.72 mg/dL or higher, which is near the upper limit of normal for the test.
A nonclonal elevation of Σ FLC is a significant predictor of worse overall survival in the general population of persons without plasma cell disorders.
确定游离轻链（FLC）检测是否提供与普通人群相关的预后信息。
排除已知浆细胞疾病患者后，我们研究了明尼苏达州奥姆斯特德县 15859 名年龄在 50 岁及以上、可获得未加掩饰数据和 FLC 检测样本的居民。基线信息于 1995 年 3 月 13 日至 2003 年 11 月 21 日之间获得，随访状态和死亡原因通过 2009 年 6 月 30 日确定。评估κ和λ FLC 总和（Σ FLC）预测总生存率的能力。还研究了具体的死亡原因。
在 158003 人年的随访中，有 4348 人死亡。高Σ FLC 显著预示总体生存率较差；Σ FLC 最高十分位数（即≥4.72mg/dL）个体的死亡风险比为 4.4（95%置信区间，4.1-4.7），相对于其余研究参与者。多变量分析表明，这种死亡风险的增加独立于年龄、性别和肾功能不全，校正后的风险比为 2.1（95%置信区间，1.9-2.2）。死亡的增加不限于任何特定的死亡原因，因为在那些Σ FLC 为 4.72mg/dL 或更高的个体中，观察到的与预期的大多数原因导致的死亡风险显著更高，这接近该检测的正常上限。
Σ FLC 的非克隆性升高是无浆细胞疾病普通人群总体生存率较差的重要预测指标。
