I. International Health Organization (WHO) diagnostic criteria for MM (2001)
1.Main criteria
(1) bone marrow plasmacytosis (>30%)
(2) tissue biopsy confirmed the presence of plasmacytoma
(3) M-component: serum IgG>3.5g/dL or IgA>2.0g/dL, urine periprotein>1g/24h.
2.Secondary criteria
(1) Bone marrow plasmacytosis (10%-30%)
(2) M-component is present but the level is lower than the above level
(3) Osteolytic lesions are present
(4) More than 50% reduction of normal immunoglobulins: IgG<600mg/dL, IgA<100mg/dL, IgM<50mg/dL.
3.Diagnosis MM requirements
① with at least 1 major criterion and 1 minor criterion.
②or have at least 3 secondary criteria and which must include (1) and (2) of them. The patient should have symptoms of progressive disease related to the diagnostic criteria.
II. International Myeloma Working Group (IMWG) Diagnostic Criteria for MM (2003)
1. Symptomatic MM
(1) The presence of M-protein in blood or urine
(2) Clonal plasma cells or plasmacytoma in bone marrow
(3) Associated organ or tissue damage (end-organ damage, including hypercalcemia, renal damage, anemia, or bone damage)
2, asymptomatic MM
(1) M-protein ≥ 30g/L
(2) and/or clonal plasma cells in the bone marrow ≥ 10%
(3) no associated organ or tissue damage or asymptomatic
IMWG experts believe that asymptomatic MM patients, even if diagnosed with MM, can be closely monitored until the end-organ damage of hypercalcemia, renal damage, anemia, or bone damage occurs; once one of these end-organ damages of hypercalcemia, renal damage, anemia, or bone damage occurs, both treatment should be started.
Differential diagnosis
Certain chronic diseases (e.g., rheumatic system diseases, chronic tuberculosis infection, renal disease, chronic liver disease, etc.) or lymphomas can cause reactive plasmacytosis and monoclonal prolactinemia of undetermined significance (MGUS), which require differential diagnosis from MM; in addition, some severe osteoporosis or hypophosphatasia or metastatic carcinoma need to be differentiated from bone destruction in MM.
Treatment
1.Treatment principles
(1) In general, patients with asymptomatic MM do not need treatment; treatment is only started for symptomatic myeloma.
(2) For high-risk asymptomatic MM patients 80% can be transformed into MM within 2 years, and early therapeutic intervention is possible.
High-risk asymptomatic MM is defined as.
(i) ≥ 60% abnormal plasma cells in the bone marrow.
(ii) creatinine clearance <40 ml/min.
(iii) serum free light chain ratio ≥100.
④ Evidence of the following active lesions on skeletal imaging: magnetic resonance imaging (MRI) ≥ 1 or more bone damages; positive PET-CT; whole-body low-dose CT finding >5m bone damages.
2.General treatment
(1) Hemoglobin below 60g/L treated with red blood cell infusion or subcutaneous erythropoietin injection if necessary.
(2) Hypercalcemia isotonic saline hydration, prednisone, calcitonin, bisphosphonate drugs, treatment of the original disease.
(3) Hyperuricemia hydration, allopurinol oral.
(4) Hyperviscosity protopathogenic treatment, temporary plasma exchange if necessary.
(5) Renal failure prodrome treatment, hemodialysis if necessary.
(6) Combined application of antibiotic therapy for infection, and regular prophylactic gammaglobulin injection is effective for patients with recurrent infections.
3.Chemotherapy
Commonly used drugs include.
(1) targeted drugs are currently mainly proteasome inhibitors (bortezomib, carfilzomib) and immunomodulators (thalidomide, lenalidomide or pomalidomide) 2.
(2) Traditional chemotherapeutic drugs including mafenamic acid, adriamycin and cyclophosphamide.
(3) Glucocorticoids such as dexamethasone and prednisone.
Common combinations of chemotherapy regimens are: proteasome inhibitors/immunomodulators + glucocorticoids; or proteasome inhibitors/immunomodulators + conventional chemotherapy drugs + glucocorticoids; or conventional chemotherapy drugs + glucocorticoids (which are conventional chemotherapy regimens).
The efficacy of regimens containing new proteasome inhibitors/immunomodulators has been shown to be significantly better than conventional chemotherapy regimens. Therefore, MM patients should be treated with regimens containing new proteasome inhibitors/immunomodulators as much as possible.
(1) Patients who are suitable for autologous transplantation are treated with a combination regimen that does not contain marfalan to avoid its damage to hematopoietic stem cells.
(2) Patients who are not suitable for autologous transplantation such as elderly patients older than 65 years old, traditional drugs can be used in combination regimens containing Marfalan.
4.Hematopoietic stem cell transplantation
Autologous hematopoietic stem cell transplantation is recommended for all patients who are eligible, and allogeneic hematopoietic stem cell transplantation can be considered for some young and high-risk patients as appropriate.
5.Radiotherapy
For limited myeloma, local bone pain and those with spinal cord compression symptoms.