The Prognostic Value of CPCs Quantified by Flow Cytometry in Patients With Multiple Myeloma: a Prospective, Multicenter Clinical Trial

Circulating plasma cells (CPCs) represents a phenotypic subset of bone marrow multiple myeloma (MM) cells, which would contribute to the progression and dissemination of the tumor. High-sensitivity techniques such as multiparameter flow cytometry provide a tool for better detection of CPCs; however, a clear threshold has not been identified. The primary objective of the current study is to identify an optimal threshold for CPCs quantified by 8-color flow cytometry (with antibodies to CD38, CD138, CD45, CD56, CD19, CD27 and cytoplasmic kappa and lambda immunoglobulin light chains) and determine the specific relationship between CPCs level and the prognosis of MM. In addition, the evaluation of CPCs at multiple time points will be performed to explore whether CPCs detection might be used in place of bone marrow aspiration for disease monitoring.

Inclusion criteria

Patients must meet all of the following inclusion criteria.

• Newly diagnosed multiple myeloma patients.
• Patients without any previous anti-myeloma treatment.
• Age: 18-80years old (adult).
• No history of cancer.
• Informed consent.

Exclusion criteria

Patients meeting any of the following exclusion criteria will not be included in the study.

• Received therapy for multiple myeloma.
• Patients diagnosed with monoclonal gammopathy of undetermined significance, smoldering myeloma, nonsecretory myeloma, plasma cell leukemia, amyloidosis, waldenstrom macroglobulinemia or POEMS.
• Imminent or emerging infection.
• Known to be seropositive for a history of HIV.
• A participant is a woman who is pregnant, breastfeeding, or planning to become pregnant while enrolled in this trial.
• Known or suspected of not being able to comply with the study protocol.