Key markers for diagnosis of minimal residual disease in multiple myeloma

Abstract

Introduction. Therapeutic advances in recent years, the appearance on the market each time of new drugs that allow patients to achieve complete remission, a long period without progression dictate the need to control treatment by monitoring residual disease in multiple myeloma. Monitoring of multiple myeloma is the detection of a small number of tumor cells after therapy in a patient, which may be the cause of recurrence of the disease – control of minimal residual disease (MRD). This article discusses the key diagnostic markers (CD45, CD56 and CD19) of minimal residual multiple myeloma disease at initial diagnosis and after induction therapy. There are various diagnostic methods of research that can reliably assess the response to therapy and predict the occurrence of relapse. The main methods for detecting MRD are allele-specific polymerase chain reaction, next-generation sequencing and multicolor flow cytometry. The diagnosis of MRD by flow cytometry is the most widely used quite fast, quantitative, sensitive and affordable method, it is used for the primary diagnosis of multiple myeloma, as well as for monitoring MRD. It is important to identify the aberrant immunophenotype during the initial diagnosis for the correct subsequent assessment of MRD. MRD of multiple myeloma is considered an important component in the course of patient therapy before hematopoietic stem cell autotransplantation to assess the effectiveness of therapy, control and prognosis of the disease.The aim of the work MRD-study with the key diagnostic markers in multiple myeloma (CD45, CD56 and CD19).Materials and methods. The study was carried out in 59 patients with multiple myeloma. For all patients, in addition to standard methods of diagnosis and staging of the disease, bone marrow morphology (myelogram) and immunophenotype were examined. Eight-color flow cytometry with a panel of monoclonal antibodies for the diagnosis of plasma cell tumors Euro-Flow 2012 was used to diagnose MRD.Results. MRD was assessed by markers CD45, CD56 and CD19 in patients with multiple myeloma after induction therapy. The incidence of MRD-positivity for CD45 was 87.5 %, for CD56 – 97.5 %, for CD19 – 95.5 %. The incidence of MRD-negative status was for CD45 was 12.5 %, for CD56 – 2.5 % and for CD19 – 4,5 %.Conclusion. The use of a complex of these markers allows the most accurate determination of the MRD-negative status, taking into account the primary immunophenotype of malignant plasma cells.