Choi Jaeguk, Yu Kyunghee, Lee Seung-Tae, Shin Saeam, Choi Jong Rak
Department of Laboratory Medicine, Severance Hospital, Seoul, Korea.
Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Korea.
Ann Lab Med. 2025 May 1;45(3):322-328. doi: 10.3343/alm.2024.0582. Epub 2025 Mar 25.
FISH is the standard method for detecting cytogenetic abnormalities (CAs) in patients with multiple myeloma, and pre-enrichment of plasma cells is recommended to increase detection rates. However, optimal strategies to ensure sufficient plasma cell retrieval when standard enrichment techniques fail remain underexplored. We investigated factors influencing the success of fluorescence-activated cell sorting (FACS) and assessed the use of direct FISH in cases in which FACS failed.
A retrospective analysis was conducted on 457 bone marrow samples submitted for FISH between November 2016 and May 2022. FACS was considered successful when plasma cells (CD38+ and CD138+ cells) constituted >1% of the total number of cells. Direct FISH was performed for samples with FACS failure.
FACS was successful in 70.9% of cases and had a high positivity rate (94.8%). Shorter sample transfer times significantly improved FACS success, with a 77.1% success rate for transfer times <2 hrs, compared with 67.8% for longer times ( =0.0388). Plasma cell percentage was a strong determinant of FACS success, with a median of 31.2% in successful cases versus 8.5% in failures ( <0.0001). Even when FACS failed, direct FISH detected CAs in 43.6% of cases.
Plasma cell percentage and sample transfer time are critical factors influencing FACS success. While FACS-FISH demonstrates superior sensitivity in detecting CAs, direct FISH serves as a valuable alternative when FACS fails. These findings highlight the importance of optimizing sample handling and FISH protocols for accurate cytogenetic analysis of multiple myeloma.
荧光原位杂交（FISH）是检测多发性骨髓瘤患者细胞遗传学异常（CA）的标准方法，建议对浆细胞进行预富集以提高检测率。然而，当标准富集技术失败时，确保充分回收浆细胞的最佳策略仍未得到充分探索。我们研究了影响荧光激活细胞分选（FACS）成功的因素，并评估了在FACS失败的病例中直接进行FISH的应用。
对2016年11月至2022年5月期间提交进行FISH检测的457份骨髓样本进行回顾性分析。当浆细胞（CD38 +和CD138 +细胞）占细胞总数的>1%时，FACS被认为成功。对FACS失败的样本进行直接FISH检测。
FACS在70.9%的病例中成功，阳性率较高（94.8%）。较短的样本转移时间显著提高了FACS的成功率，转移时间<2小时的成功率为77.1%，而较长时间的成功率为67.8%（P = 0.0388）。浆细胞百分比是FACS成功的重要决定因素，成功病例的中位数为31.2%，失败病例为8.5%（P < 0.0001）。即使FACS失败，直接FISH在43.6%的病例中检测到了CA。
浆细胞百分比和样本转移时间是影响FACS成功的关键因素。虽然FACS-FISH在检测CA方面显示出更高的灵敏度，但当FACS失败时，直接FISH是一种有价值的替代方法。这些发现强调了优化样本处理和FISH方案以进行多发性骨髓瘤准确细胞遗传学分析的重要性。
