The significance of serum light chain ratio in the diagnosis of multiple myeloma and primary nephritic / 中国医师杂志

ABSTRACT

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 M in immunofixation electrophoersis (IFE),88 patients were divided into 4 groupsIgGκ,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.