4色与8色荧光抗体组合检测多发性骨髓瘤患者微小残留病的比较分析

OBJECTIVE: To explore and compare 4-color and 8-color fluorescence antibody panels for detecting minimal residual disease of multiple myeloma patients after therapy. METHODS: One 8-color antibody panel was built including CD38 and CD138 for the identification of plasma cells (PCs), membrane antigen CD45, CD19, CD56 and CD117, cytoplasmic Kappa (cκ) and Lambda (cλ) light chain antigen. Six tubes of 4-color panels were built, among them, membrane antigen CD45/CD19, CD56/CD117, CD19/CD56 and light chains were analyzed combined by CD38/CD138 for PCs gate in the tubes M1-3 and tube C-(κ/λ), respectively; CD19 or CD45 and cκ/cλ light chains were detected in the tube MC1-(CD38) for CD38/SSC identified PCs gate and tube MC2-(CD138) for CD138/SSC identified PCs gate separately. Twenty normal volunteer bone marrows and seventy-three specimens from multiple myeloma patients after complete remission were measured and analyzed. RESULTS: MRD positive samples were discriminated in 82.19% of the specimen evaluated through either abnormal plasma cells (aPCs) or clonal plasma cells (cPCs) by 8-color antibody panel. Among of them, consistency was 89.04%. The median percentage of cPCs was 0.105%. The lowest sensitivity of experiment was 0.004%. Percentage of PCs identified by CD38/ SSC gate was higher than that by CD38/CD138 (P<0.001) and CD138/SSC gate (P=0.001) apparently. The lowest MRD positive rate was found in tube C (65.75%), which lower than 8-color panel obviously (P=0.024). The percentages of aPCs measured by tube M2-(56/117) were significantly lower than other tubes (P=0.014). MRD positive rate determined by cPCs was higher than that by aPCs both in the tube MC1-(CD38) and tube MC2-(CD138), whose concordance rate were 68.49% and 79.45%, respectively. Compared with 8-color panel, tube MC2-(CD138) the best choice among six tubes of 4-color panels, which has the best sensitivity, accuracy and negative predicted value, higher positive predicted value and specificity. Tube M1-(45/19) was the second choice. CONCLUSION: CD38/CD138 are the best markers for gating PCs. Membrane antigen and cκ/cλ detected simultaneously is a better method for MM MRD detection and 8-color antibody panel is an ideal approach. Two tubes of 4-color antibody combination, M1-(45/19) and MC2-(CD138) are recommended in the 4-color panels.