血清游离轻链检测在轻链型心肌淀粉样变性中的预后价值

OBJECTIVE: To analyze the prognostic value of baseline serum free light chain (sFLC) in immunoglobulin light-chain cardiac amyloidosis (AL-CA). METHODS: Thirty patients diagnosed with AL-CA from January 2012 to December 2016 at Beijing Chaoyang Hospital were included in this study to retrospectively evaluate the clinical data. The cut-off value of dFLC (involved sFLC minus uninvolved sFLC) was determined according to the receiver operator characteristic curve (ROC) and grouped, the prognoses of both groups were evaluated. RESULTS: The onset age of all AL-CA patients was 57 years old. It occurred more commonly in men (21 cases, 70%) and the light chains of immunoglobulin composed mainly of type λ (22 cases, 73.3%). Renal involvements occurred in 17 cases (56.7%). The median value of difference between involved and uninvolved serum immunoglobulin free light chain levels (dFLC) was 162.9 (57.9–401.6) mg/L. More subjects in the high dFLC group had higher BNP (P=0.005), and shorter median survival than those in the low dFLC group (15 months vs 47 months, P<0.001). Similar results of median survival were observed when the patients were redivided by a new cut-off value of 180 mg/L for dFLC (high dFLC group: 22 months, low dFLC group: 40 months, P=0.001), or a κ/λ ratio in which patients with κ type sFLC-ratio<3.79 and λ type sFLC-ratio≥0.06 were grouped into the low sFLC-ratio (37 months), and the reverse the high sFLC-ratio ones (25 months, P=0.021). In multivariate analysis, dFLC and New York Heart Association (NYHA) classification of cardiac function were two risk factors associated with all-cause mortality in patients, of them the hazard ratio for higher dFLC was 12.13 (95%CI 2.98–49.30, P<0.001). CONCLUSION: Measurement of the sFLC level could implicate the prognosis of AL-CA.