Associations of serum total light chain kappa and lambda levels with all-cause mortality in Chinese centenarians.

Abstract

The purpose of this study was to determine the relationship between the serum levels of kappa (κ) and lambda (λ) total light chain (TLC), the κ/λ ratio, and the combined serum TLCκ and TLCλ (ΣTLC) levels in Chinese centenarians and all-cause mortality. The association between serum TLC and all-cause mortality was investigated using restricted cubic spline (RCS) analysis, Cox proportional hazards models, and Kaplan‒Meier curves. The study included 906 centenarians (18.8% male), 838 (92.5%) of whom died during a median follow-up of 30 months. The proportions of centenarians with abnormal TLCκ and TLCλ levels were 68.1% and 49.0%, respectively. RCS analysis indicated that the levels of TLCκ, TLCλ, and ΣTLC were associated with all-cause mortality (P < 0.05), whereas the κ/λ ratio was not (P > 0.05). Cox proportional hazards analysis demonstrated that the highest quartiles of TLCκ, TLCλ, and ΣTLC were associated with an increased risk of death, with hazard ratios of 1.434 (95% confidence interval [CI], 1.061-1.939; P = 0.019), 1.351 (95% CI, 1.013-1.802; P = 0.041), and 1.891 (95% CI, 1.347-2.654; P < 0.001), respectively. Kaplan-Meier analysis illustrated that centenarians with higher levels of TLCκ, TLCλ, and ΣTLC had significantly shorter median survival times (26 months versus 35 months, P < 0.001; 26 months versus 32 months, P = 0.003; and 26 months versus 36 months, P < 0.001, respectively). Our findings suggest that serum levels of TLCκ, TLCλ, and ΣTLC are significantly associated with all-cause mortality in centenarians. Trial registration Not applicable.