Red blood cell distribution width (RDW) may be a predictor of overall survival (OS) among patients with light-chain amyloidosis, according to research published in the International Journal of Hematology.
Light-chain amyloidosis is a complex disorder with varying symptoms, and depending on its presentation, it can require high selectivity for the correct treatment plan. Identifying patients that are at high risk for death is important, but a widely used, low-cost biomarker for diagnostic screening is not currently available.
Researchers evaluated whether RDW, which is generally included in complete blood cell count tests and shows the heterogeneity of red blood cells, may be a viable marker for OS in patients with light-chain amyloidosis.
The authors used a RDW cutoff of 13.8% and found it had a sensitivity of 78.6% and a specificity of 79.2%. In 94 evaluated patients, 48% had a high RDW (at least 13.8%), whereas 52% had a low RDW (less than 13.8%). Characteristics in the 2 groups were mostly similar, with no significant differences in revised Mayo stage, organs involved, age, or gender.
High RDW was prognostic for OS across groups and had prognostic significance after multivariate analysis (P =.050). For example, among the 30 patients with revised Mayo stage I disease, 18 (60%) had high RDW and 12 (40%) had low RDW, with a respective 3-year OS of 75% and 100% (P =.0086).
RDW was not associated with cardiac or renal involvement, and even in the absence of cardiac amyloidosis, high RDW conferred worse OS (P =.0064).
At 3 months post-treatment, an RDW increase corresponded to worse OS in both groups, particularly in patients with an already high RDW (P =.027). Low or reduced RDW was associated with improved survival.
“[Because of] its cost effectiveness, the significance of RDW for survival, which is independent of previously known factors, is important for the prognosis of patients with light-chain amyloidosis,” the authors wrote.
- Yogo T, Okazuka K, Nashimoto J, et al. Red blood cell distribution width is a simple and novel biomarker for survival in light‐chain amyloidosis. Int J Hematol. 2019;110:431-7. doi:10.1007/s12185-019-02692-0