A multicenter retrospective study of plasma d‑dimer levels for evaluating treatment response in multiple myeloma.

Multiple myeloma (MM) is a malignant hematological tumor characterized by the proliferation of monoclonal plasma cells, often accompanied by systemic complications such as bone destruction, renal dysfunction, and hypercoagulability. Plasma D-dimer, as a fibrinolytic marker, may be associated with disease activity. However, there are few reports on the application of plasma D-dimer in evaluating treatment efficacy in MM. This multicenter retrospective study aimed to evaluate the utility of plasma D-dimer levels in predicting treatment response in patients with MM. 160 patients with newly diagnosed MM were enrolled. Blood samples were collected from these patients during their first hospital visit and again after eight cycles of chemotherapy to measure D-dimer levels. This study explores the relationship between plasma D-dimer levels before and after treatment and patient clinical characteristics. Patients showed no statistically different plasma D-dimer levels at initial consultation across treatment-response groups: CR group (0.96 µg/mL [0.67–1.9]), PR group (0.88 µg/mL [0.56–1.39]), SD group (0.68 µg/mL [0.56–0.89]), and PD group (0.91 µg/mL [0.52–1.55]). After chemotherapy, both the absolute change (Dd) and percentage change (Ddp) in D-dimer levels showed significant differences among groups (p < 0.05). The CR and PR groups exhibited significantly greater reductions in D-dimer (Dd: -0.42 and − 0.40 µg/mL; Ddp: -45.2% and − 39.1%) compared to the PD group (Dd: 0.16 µg/mL; Ddp: 18.7%). Patients with overall response (OR) (CR and PR groups) had significantly greater decreases in both Dd and Ddp compared to no-response patients (PD and SD groups) (p < 0.001). Our results suggested that changes in plasma D-dimer levels before and after treatment may provide valuable insights for assessing chemotherapy efficacy in MM.