Investigation of the Diagnostic Value of sFLC and Other Indicators in the Detection of M Protein in LCMM.

Abstract

The aim was to explore the diagnostic value of serum free light chain (sFLC) and other laboratory indicators for the patients with light chain multiple myeloma (LCMM). We performed a retrospective study including 82 LCMM cases and 43 healthy subjects as the observation and control groups, respectively. The observation group was further divided into two subgroups: κ- and λ-type LCMM. Sixteen quantitative indicators were collected and the difference among groups was compared. We also evaluated the positive detection rate (PDR) of four qualitative indicators for M protein detection. The receiver operating characteristic (ROC) curve was used to analyze the diagnostic value of sixteen indicators. Fourteen indicators showed statistical differences between the control group and κ- or λ-type LCMM subgroup. The κ and λ sFLC ratio (rFLC) and the difference between κ and λ FLC (dFLC) showed differences among the three groups. Among the four qualitative indicators of M protein detection, rFLC showed the highest PDR for both κ- and λ-type LCMM. Among the three combinations with rFLC or uIFE did not show statistical differences. ROC curve analysis indicated a relatively high diagnostic value of dFLC for both κ- and λ-type LCMM. We should be vigilant about the missed diagnosis by observing the changes of MM-related indicators, particularly dFLC and the six other indicators with high diagnostic value. rFLC can improve the diagnostic ability of LCMM.