Researchers developed a risk stratification model for prognosis in systemic immunoglobulin light-chain (AL) amyloidosis with renal involvement, with results published in the British Journal of Haematology.
Renal involvement is present in approximately 70% of cases of AL amyloidosis. In addition to other possible prognostic factors in AL amyloidosis, the researchers examined a possible biomarker of renal and cardiac health in development of their model: the level of galectin-3 (Gal-3).
To construct the prognostic model, the researchers evaluated records and serum samples from 253 patients with AL amyloidosis and renal involvement. Univariate analyses of 10 variables showed most of them to be predictive of all-cause mortality.
However, multivariate analyses revealed only 3 factors were independent predictors for all-cause mortality. These were, at baseline, a level of high-sensitivity cardiac troponin T (hs-cTnT) of at least 0.026 ng/mL, a difference between involved and uninvolved free light chains (dFLC) of at least 75.89 mg/L, and a level of Gal-3 of at least 20.24 ng/mL.
Multivariate hazard ratios (HRs) for all-cause mortality were 2.65 for hs-cTnT (95% CI, 1.66-4.23; P <.001), 1.81 for dFLC (95% CI, 1.28-2.52; P =.001), and 1.46 for Gal-3 (95% CI, 1.03-2.09; P =.033).
Based on these 3 risk factors, the researchers gave the prognostic model 4 levels of risk (1 through 4, in increasing order of severity). The model was internally validated through bootstrap analysis. The model risk factors were each given a value of 1. The model’s lowest risk-level was defined by a total combined score of 0, indicating the lack of any of the risk factors.
Patients included in this study who were assigned to the lowest level of risk showed a median overall survival (OS) duration of 100 months following diagnosis, while those in the highest level of risk had a median OS duration of 15 months following diagnosis.
“By combining Gal-3, hs-cTnT and dFLC, we have developed a reliable risk stratification system [that] was internally validated to be satisfactory and applicable for predicting mortality in patients with renal AL amyloidosis,” the researchers stated.
- Li T, Huang X, Wang Q, et al. A risk stratification for systemic immunoglobulin light-chain amyloidosis with renal involvement [published online July 26, 2019]. Br J Haematol. doi:10.1111/bjh.16112