血清轻链κ/λ比值在诊断多发性骨髓瘤和原发性肾病中的临床价值

The significance of serum light chain ratio in the diagnosis of multiple myeloma and primary nephritic

目的 探讨血清轻链κ/λ比值在鉴别诊断多发性骨髓瘤（MM）和原发性肾病的临床价值以及κ/λ比值与MM其他实验室指标的关系.方法 依据血清免疫固定电泳进行分型,选取MM组患者88例,并根据免疫固定电泳时“M”蛋白成分的不同将88例MM患者分为IgGκ组、IgGλ组、IgAκ组、IgAλ组;原发性肾病组109例;选取同期45例健康体检者作为对照组.采用速率散射免疫比浊法测定各组研究对象血清免疫球蛋白IgG、IgA、IgM、轻链κ及轻链λ含量并计算κ/λ比值,同步检测血清β2-微球蛋白（β2-MG）、白蛋白（ALB）、尿素氮（BUN）、肌酐（CRE）水平及M蛋白百分比,并比较其差异.结果 （1）MM组中,各型间性别及国际分期系统（ISS）临床分期差异无统计学意义（P＞0.05）,而年龄分布差异有统计学意义（P =0.011）.（2）与对照组比较,MM组各类κ型骨髓瘤患者血清κ轻链、κ/λ比值及相应的免疫球蛋白显著升高,而血清λ轻链及其他免疫球蛋白含量则显著降低（P＜0.01）,各类λ型骨髓瘤患者血清λ轻链显著升高而κ轻链及κ/λ比值显著降低（P＜0.01）;原发性肾病组患者轻链κ、轻链λ及血IgG含量均降低,与对照组比较差异有统计学意义（P＜0.01）,但κ/λ比值与对照组差异无统计学意义（P＞0.05）.同时各型MM患者与原发性肾病组比较,除轻链及血免疫球蛋白差异有统计学意义外,BUN、CRE差异亦有统计学意义（P＜0.05）.（3）MM组患者血清κ/λ比值与肿瘤负荷指标血清ALB呈负相关（r=-0.264,P=0.013）,与β2-MG呈正相关（r=0.235,P=0.040）.结论 血清κ轻链、λ轻链及κ/λ比值分析对于鉴别诊断MM和原发性肾病具有重要的临床参考价值.κ/λ比值在MM患者疾病进程中与一些肿瘤负荷指标有一定的相关性,可为临床MM患者诊疗、预后监测提供更为有效简便的检测手段.

Objective To explore the clinical value of serum κ/λ ratio in the differential diagnosis of multiple myeloma （MM） and primary nephritic,and to explore its relationship with MM other laboratory markers.Methods We obtained 88 cases of MM patients with serotyping by immunofixation and 109 cases of primary nephritic patients.In accordance with the composition of protein ＆quot;M＆quot; in immunofixation electrophoersis （IFE）,88 patients were divided into 4 groups：IgGκ,IgGλ,IgAκ and IgAλ.In addition,45 serum samples of health examination were collected as control samples.The levels of serum IgG,IgA,IgM,light chain κ and λ in each group were tested by immune turbidimetry,and κ/λ ratio was calculated.The levels of serum β2-microglobin （β2-MG）,albumin （ALB）,serum urea （BUN）,creatinine （CRE）,and M protein percentage were also detected.Results （1） In MM group,there was no significant difference of sex and International Staging System （ISS） stages between each type（P 〉 0.05）,while there was significant difference in age distribution between each type （P 〈 0.05）.（2） Compared to control,the levels of se-rum light chain κ,κ/λ ratio,and matched Ig were significantly higher and the level of light chain λ and other Ig were significantly lower in κ typed MM patients,while the levels of serum light chain λ were significantly higher and the levels of serum light chain κ,and κ/λ ratio were significantly lower in λ typed MM patients（P 〈0.01）.The levels of light chain κ,λ,and IgG in primary nephritic patients were significantly lower than control（P 〈0.01）,while there was no significant difference in κ/λ ratio between two group （P 〉 0.05）.There were also significant difference of light chain,Ig,BUN and CRE levels between MM patients and primary nephritic patients （P 〈 0.05）.（3） The κ/λ ratio correlated with serum ALB （r =-0.264,P =0.013） and β2-MG （r =0.235,P =0.040） levels in MM.Conclusions Serum levels of light chain κ,λ,and κ/λ ratio have great significance in the differential diagnosis of multiple myeloma and primary nephritic.The κ/λ ratio correlated with several tumor markers in MM progresses,rendering it as a promising method for diagnosis and prognosis monitoring of MM.