Awasthi Namrata Punit, Mishra Sridhar, Gupta Gaurav, Kumari Swati, Bajpayee Abhishek, Singh Pradyumn, Husain Nuzhat
Department of Pathology, Dr. Ram Manohar Lohia Institute of Medical Sciences, Gomti Nagar, Lucknow, Uttar Pradesh, India.
Department of Medical Oncology, Dr. Ram Manohar Lohia Institute of Medical Sciences, Gomti Nagar, Lucknow, Uttar Pradesh, India.
Indian J Pathol Microbiol. 2023 Apr-Jun;66(2):295-300. doi: 10.4103/ijpm.ijpm_505_21.
Identification of plasma cells into abnormal (APC) and normal (NPC) compartments is of utmost importance in flow cytometric (FC) analysis of multiple myeloma (MM) and related plasma cell dyscrasias for diagnosis, prognosis, and follow-up. No single phenotypic marker is sufficient to distinguish NPC from APC.
43 newly diagnosed cases of MM and 13 controls were included in the study. Bone marrow (BM) samples from the 2 pass were processed on the same day with antibodies against CD38, CD138, CD19, CD81, CD45, CD117, CD200, CD56, cytoKappa, and cytoLambda in a 4-color experiment with CD38 and CD138 as gating antibodies.
Mean APC% in cases was 96.5%. The expected Immunophenotype (IP) of APC which is CD19-/56+/45-/81-/117+/200+ was found in only 13/43 MM cases. In 30/43 cases, APC revealed deviation from expected IP either for single or a combination of markers. Sensitivity for APC detection was highest for CD19 (95.2%) followed by CD56 (90.4%) and CD81 (83.7%). Specificity was highest for CD19 (100%), CD56 (100%), and CD81 (100%) followed by CD117 (92.3%). Combination of markers with maximum sensitivity to detect APC (97.6%) was CD81- or CD19- and CD200+ or CD56+ (two markers); and for NPC (92.3%) was CD81+ and CD19+ and CD56- (three markers).
Plasma cell IP can be highly variable with multiple minor subpopulations in both cases and normal controls. CD 19 and CD56 are highly informative markers for a 4-color experiment. Assessment of multiple markers in an 8-10 color experiment is more informative but the lack of advanced flow cytometers should not limit the use of FC in a 4-color approach. Our results emphasize that even basic equipment with limited fluorochrome can provide meaningful information if used appropriately.
在多发性骨髓瘤（MM）及相关浆细胞异常增殖症的流式细胞术（FC）分析中，将浆细胞区分为异常（APC）和正常（NPC）部分对于诊断、预后评估及随访至关重要。没有单一的表型标志物足以区分NPC和APC。
本研究纳入43例新诊断的MM患者和13例对照。对2次采集的骨髓（BM）样本在同一天进行处理，在以CD38和CD138作为门控抗体的四色实验中，使用抗CD38、CD138、CD19、CD81、CD45、CD117、CD200、CD56、细胞角蛋白κ和细胞角蛋白λ的抗体。
病例组中APC的平均百分比为96.5%。APC预期的免疫表型（IP）为CD19-/56+/45-/81-/117+/200+，仅在13/43例MM病例中发现。在30/43例病例中，APC显示出单个或多个标志物组合偏离预期IP。检测APC的敏感性以CD19最高（95.2%），其次是CD56（90.4%）和CD81（83.7%）。特异性以CD19（100%）、CD56（100%）和CD81（100%）最高，其次是CD117（92.3%）。检测APC敏感性最高（97.6%）的标志物组合是CD81-或CD19-以及CD200+或CD56+（两个标志物）；检测NPC敏感性最高（92.3%）的标志物组合是CD81+、CD19+和CD56-（三个标志物）。
在病例组和正常对照组中，浆细胞IP可能因多个小亚群而高度可变。CD19和CD56是四色实验中信息丰富的标志物。在八色至十色实验中评估多个标志物信息更丰富，但缺乏先进的流式细胞仪不应限制采用四色方法进行FC检测。我们的结果强调，即使是配备有限荧光染料的基本设备，如果使用得当也能提供有意义的信息。
