The cut-offs for kappa/lambda ratio in bone marrow immunohistochemistry for the diagnosis of multiple myeloma

Red Cell Distribution Width at Diagnosis Reflects Advanced Disease While Dynamic Changes Predict Survival at Relapse in Multiple Myeloma: A Retrospective Study

Introduction Multiple myeloma (MM) is a complex plasma cell malignancy characterized by clonal proliferation and monoclonal immunoglobulin production. Despite the availability of several prognostic markers for MM, many are challenging to implement routine clinical practice due to cost, complexity, or lack of standardization. Red cell distribution width (RDW), a cost-effective and routinely measured parameter in complete blood counts, has gained increasing attention as a prognostic marker due to its association with disease severity and outcomes in MM. This study investigates the prognostic utility of RDW in MM, focusing on its relationship with patient outcomes, particularly in those undergoing autologous stem cell transplantation (ASCT). Methods This retrospective study included 218 patients diagnosed with MM between 2010 and 2018. Demographic, clinical, and laboratory data, including RDW levels at ASCT and first relapse, were collected. Patients were stratified into high (>16.5%) and low (≤16.5%) RDW groups. The impact of RDW levels and their changes on progression-free survival (PFS) and overall survival (OS) were analyzed using Kaplan-Meier and log-rank tests. Results Higher RDW levels at diagnosis were significantly associated with advanced disease stages, notably R-ISS stage 3 (p=0.022). While no significant survival differences were observed based on baseline RDW levels, dynamic changes in RDW from diagnosis to first relapse were strongly prognostic. Patients maintaining low RDW had the longest PFS (37 months) and OS (88.8 months), whereas those transitioning from low to high RDW experienced the shortest PFS (nine months) and OS (40.6 months). At relapse, patients with low RDW demonstrated superior outcomes (PFS: 34 vs. 14 months, OS: 81.2 vs. 40.6 months; p<0.001). ASCT markedly improved survival outcomes, with longer PFS (p=0.028) and OS (p<0.001). Higher hemoglobin levels (>10 g/dL) were also associated with extended PFS (p=0.038). Reassessing RDW prior to ASCT did not yield significant differences, suggesting that the prognostic value of RDW lies in its dynamic changes, particularly around relapse events. Conclusions RDW levels at diagnosis reflect advanced disease stages in MM but are not independent predictors of survival. However, dynamic changes in RDW, particularly from diagnosis to relapse, highlight its potential as a robust marker for monitoring disease progression and relapse risk. ASCT remains a cornerstone of MM management, significantly improving survival outcomes and complementing RDW trends in prognosis. Standardizing RDW thresholds and integrating its dynamic trends into clinical workflows could enhance risk stratification and personalized treatment strategies. Prospective, multi-center trials are essential to validate these findings and establish RDW's role in comprehensive prognostic frameworks for MM.

Improving Interpretation Consistency of Serum Capillary Electrophoresis by Development of Quantitative Graphic Indexes

Capillary zone electrophoresis-immunosubtraction (CZE-IS) is an essential laboratory test in diagnosing plasma cell neoplasms. However, the current interpretation of the test results is subjective. To evaluate CZE-IS in a more precise manner, this study proposed five key indexes, namely sharpness index, light chain index, immunoglobulin G index, immunoglobulin A index, and immunoglobulin M index. The reference intervals of these indexes were established using CZE-IS curve data from a clinical laboratory of a referral medical center. A total of 1000 cases with normal electrophoretic patterns were sampled for reference intervals establishment, and an additional 20 cases were included for validation. The following reference intervals in the γ zone were established: 1-6 (sharpness index), 1.06-2.71 (light chain index), 37-454 (immunoglobulin G index), (-9)-41 (immunoglobulin A index), and (-16)-46 (immunoglobulin M index). For the β2 zone, the reference intervals were 3-17 (sharpness index), 0.44-1.90 (light chain index), (-7)-61 (immunoglobulin G index), 2-117 (immunoglobulin A index), and (-12)-35 (immunoglobulin M index). The diagnostic performance of reference intervals of the proposed indexes in validation ranged from 95% to 100%. CZE-IS indexes provide the objective quantification of key characteristics of CZE-IS curves and improve the precision of CZE-IS interpretation.

Tumor-associated macrophages modulate angiogenesis and tumor growth in a xenograft mouse model of multiple myeloma

Tumor-associated macrophages (TAMs) are closely associated with poor multiple myeloma (MM) prognosis. Therefore, in-depth understanding of the mechanism by which TAM supports MM progression may lead to its effective treatment. We used the MM nude mouse subcutaneous xenograft model to evaluate the efficacy of the macrophage-depleting agent clodronate liposome (Clo) against MM and elucidate the mode of action of this therapy. At the same time, observe whether the elimination of TAM in vivo while silencing the expression of VEGFA has the same effect as in vitro experiments. We also used Clo to eliminate macrophages and reinjected M1 or M2 TAM through mouse tail veins to investigate the effects of various macrophage subtypes on MM xenograft tumor growth. We applied qRT-PCR, immunohistochemistry, and enzyme-linked immunosorbent assay to quantify VEGFA, CD31, and CD163 expression in tumor tissues and sera. Removal of TAMs from the tumor microenvironment impeded tumor growth. The combination of Clo plus VEGFA siRNA had a stronger inhibitory effect on tumor growth than Clo alone, and M2 and M1 macrophages promoted and inhibited tumor growth, respectively. Macrophage depletion combined with cytokine blocking is a promising MM treatment. Targeted M2 macrophage elimination together with cytokine block may be more effective at inhibiting MM growth than either treatment alone. The results of the present study lay an empirical foundation for the development of novel therapeutic strategies for MM.