다발골수종(Multiple Myeloma)은 치료가 완료된 이후에도 재발 위험이 높은 혈액암이다. 그 주요 원인 중 하나는 치료 반응이 완전관해(CR)로 평가됐더라도, 혈액 속에 눈에 보이지 않는 잔존 암세포(MRD, Minimal Residual Disease)가 남아있을 수 있기 때문이다.

지금까지 MRD 여부를 간접적으로 판단하기 위해 혈청단백 전기영동(SPE)과 면역고정전기영동(IFE) 같은 검사법이 널리 사용돼 왔다. 그러나 이들 검사는 민감도가 낮아, 소량의 단클론 단백질이나 미세 암세포를 놓칠 가능성이 높다는 한계가 지적돼 왔다.

이러한 문제를 보완하기 위해 도입된 혈청유리경쇄검사는 유리 면역글로불린 경쇄(Free Light Chains)를 정량화함으로써 진단 및 치료 반응 모니터링 정확도를 크게 향상시켰다. 실제로 이 검사는 기존 검사법보다 민감도가 높아, 조기 진단과 치료 반응 평가에 있어 중요한 지표로 활용되고 있다. 그러나 혈청유리경쇄검사 역시 MRD 수준의 극소량 암세포를 감지하는 데는 한계가 있는 것으로 보고된다.

이와 관련, 체외진단 전문기업 다우바이오메디카 담당자는 “질량분석법에 기반한 MRD검사는 해외에서는 상용화된 장비가 사용되는 추세다. 국내에도 근시일내에 도입되어 다발골수종 재발 검사에 활용될 것으로 기대하고 있다”고 말했다.

Advanced MRD Detection Marks New Era in Precision Diagnostics for Multiple Myeloma

Multiple myeloma (MM) is a hematologic malignancy known for its high relapse rate, even after achieving complete response (CR) following treatment. A key reason for this recurrence lies in the presence of minimal residual disease (MRD)—invisible cancer cells that may remain in the bloodstream despite apparent remission.

Traditionally, tests such as serum protein electrophoresis (SPE) and immunofixation electrophoresis (IFE) have been used to indirectly assess MRD. However, their limited sensitivity makes them prone to missing low levels of monoclonal proteins and residual tumor cells.

To address this gap, the serum free light chain (FLC) assay was introduced. By quantifying free immunoglobulin light chains, this method significantly improved diagnostic sensitivity and treatment monitoring. Nevertheless, the FLC assay still has limitations in detecting the trace levels of disease characteristic of MRD.

In response, the clinical community is now turning to mass spectrometry (MS)-based MRD testing, which offers ultra-high sensitivity and specificity. At the recent Spring Conference of the Korean Society of Clinical Chemistry, Professor Sang-Hoon Song of Seoul National University Hospital presented on the clinical utility of MS in a session titled “Proteomics in Multiple Myeloma.”

According to Prof. Song, MS-based MRD testing can detect monoclonal proteins at much lower levels than traditional electrophoretic methods. Additionally, this technique minimizes interference from immunoglobulin-based therapies such as daratumumab or isatuximab—an important advantage in today’s treatment landscape. MS also does not require high-throughput sequencing or expensive molecular platforms, making it more feasible for broader clinical adoption.

Accurate MRD detection is not only crucial for assessing treatment response but also for predicting relapse risk and guiding therapeutic strategies. Experts anticipate that high-sensitivity diagnostic tools like MS will play a pivotal role in improving survival and enabling personalized treatment in multiple myeloma.

A representative from Dow Biomedica, a leading in vitro diagnostics company, commented:

“Mass spectrometry-based MRD testing is already gaining ground internationally using commercially available platforms. We expect to see its adoption in Korea in the near future for monitoring relapse in multiple myeloma patients.”