Multiple myeloma (MM) is a common plasma cell malignancy, accounting for the second largest hematological malignancy. Proteasome inhibitors represented by bortezomib (BTZ) have been the main treatment for patients with newly diagnosed and relapsed or refractory myeloma in nearly two decades. Although BTZ has improved the prognosis of MM patients, MM remains incurable in most patients, mainly because MM cells become resistant to BTZ. This review is to better understand the mechanism of MM resistance to BTZ and explore possible new therapeutic strategies.
Humans ; Bortezomib/therapeutic use* ; Multiple Myeloma/pathology* ; Proteasome Inhibitors/pharmacology* ; Prognosis ; Plasma Cells/pathology* ; Drug Resistance, Neoplasm ; Antineoplastic Agents/pharmacology* ; Cell Line, Tumor

OBJECTIVE: to analyze the effect of circulating plasma cells(CPC) on the prognosis of patients with multiple myeloma(MM) in the era of new drugs, and to explore the new definition standard of primary plasma cell leukemia(pPCL). METHODS: The clinical data of 321 patients with newly diagnosed MM and 21 patients with pPCL admitted to our hospital from January 2014 to May 2022 were retrospectively analyzed. According to the proportion of CPC in peripheral blood smears, all patients were divided into 4 groups: CPC 0% group(211 cases), CPC 1%-4% group(69 cases), CPC 5%-19% group(41 cases) and CPC≥20% group(21 cases). The clinical features of patients in each group were compared and the prognosis fators was analyzed. RESULTS: The median OS of the four groups were 44.5,21.3,24.6 and 12.8 months, respectively. Among them, 295 patients(86.3%) were treated with new drugs, and the median OS of the four groups were not reached, 26.7, 24.6 and 14.9 months, respectively. As the survival curves of CPC 5%-19% group and CPC≥20% group were similar, the patients were divided into CPC<5% group and CPC≥5% group, the median OS of CPC<5% group was better than that in CPC≥5% (43.5 vs 22.3 months, P<0.001). In addition, the median OS of patients in the CPC 1%-4% group was also significantly lower than that in the CPC 0% group and similar to that in the CPC≥5% group. Multivariate analysis showed that 1%-4% CPC was an independent risk factor for the OS of patients with CPC<5%. The patients with CPC<5% were stratified by R-ISS staging, and the OS of R-ISS stage Ⅰ or stage Ⅱ with 1%-4% CPC was similar to that of R-ISS stage Ⅲ. The newly defined pPCL patients showed increased tumor load and obvious invasive characteristics. Multivariate analysis showed no independent prognostic factors for pPCL, and high-risk cytogenetic abnormalities(HRCA) had no significant effect on the prognosis. CONCLUSION The validity of IMWG's new pPCL definition standard was verified, and it was found that the survival of MM with 1%-4% CPC also is poor and the prognosis is very close to pPCL. In addition, the newly defined pPCL has unique clinical and biological characteristics.
Humans ; Multiple Myeloma/pathology* ; Plasma Cells/pathology* ; Retrospective Studies ; Prognosis ; Leukemia, Plasma Cell/diagnosis*

The multiple myeloma (MM), the second most common hematologic malignancy, is malignant proliferative disease of plasma cells. Although the application of many targeted drugs has significantly prolonged the survival time of MM patients, it is still an incurable disease. In recent years, the immunosuppression caused by interaction between tumor microenvironment(TME) and tumor cells has attracted people's attention gradually. As a kind of immunosuppressive cells in TME, regulatory T cells (Treg) play an important role in the progress of MM. Treg is related to the proliferation and metastasis of tumors, and can lead to the progress of MM by promoting the angiogenesis and generating immunosuppressive TME. In this review, we briefly summarized the latest research progress on the impact of Treg on the pathogenesis of MM.
Humans ; Multiple Myeloma/pathology* ; T-Lymphocytes, Regulatory/pathology* ; Immune Tolerance ; Plasma Cells/pathology* ; Immunosuppression Therapy ; Tumor Microenvironment

Objective To investigate the effect of human platelet-rich plasma-derived exosomes(PRP-exos)on the proliferation of Schwann cell(SC)cultured in vitro. Methods PRP-exos were extracted by polymerization-precipitation combined with ultracentrifugation.The morphology of PRP-exos was observed by transmission electron microscopy,and the concentration and particle size distribution of PRP-exos were determined by nanoparticle tracking analysis.Western blotting was employed to determine the expression of the marker proteins CD63,CD81,and CD9 on exosome surface and the platelet membrane glycoprotein CD41.The SCs of rats were isolated and cultured,and the expression of the SC marker S100β was detected by immunofluorescence staining.The fluorescently labeled PRP-exos were co-cultured with SCs in vitro for observation of their interaction.EdU assay was employed to detect the effect of PRP-exos on SC proliferation,and CCK-8 assay to detect the effects of PRP-exos at different concentrations(0,10,20,40,80,and 160 μg/ml)on SC proliferation. Results The extracted PRP-exos appeared as uniform saucer-shaped vesicles with the average particle size of(122.8±38.7)nm and the concentration of 3.5×10¹² particles/ml.CD63,CD81,CD9,and CD41 were highly expressed on PRP-exos surface(P<0.001,P=0.025,P=0.004,and P=0.032).The isolated SCs expressed S100β,and PRP-exos could be taken up by SCs.PRP-exos of 40,80,and 160 μg/ml promoted the proliferation of SCs,and that of 40 μg/ml showed the best performance(all P<0.01). Conclusions High concentrations of PRP-exos can be extracted from PRP.PRP-exos can be taken up by SCs and promote the proliferation of SCs cultured in vitro.
Humans ; Rats ; Animals ; Exosomes/metabolism* ; Platelet-Rich Plasma ; Schwann Cells ; Coculture Techniques ; Cell Proliferation ; Cells, Cultured

Objective: To investigate the value of plasma cells for diagnosing lymph node diseases. Methods: Common lymphadenopathy (except plasma cell neoplasms) diagnosed from September 2012 to August 2022 were selected from the pathological records of Changhai Hospital, Shanghai, China. Morphological and immunohistochemical features were analyzed to examine the infiltration pattern, clonality, and IgG and IgG4 expression of plasma cells in these lymphadenopathies, and to summarize the differential diagnoses of plasma cell infiltration in common lymphadenopathies. Results: A total of 236 cases of lymphadenopathies with various degrees of plasma cell infiltration were included in the study. There were 58 cases of Castleman's disease, 55 cases of IgG4-related lymphadenopathy, 14 cases of syphilitic lymphadenitis, 2 cases of rheumatoid lymphadenitis, 18 cases of Rosai-Dorfman disease, 23 cases of Kimura's disease, 13 cases of dermal lymphadenitis and 53 cases of angioimmunoblastic T-cell lymphoma (AITL). The main features of these lymphadenopathies were lymph node enlargement with various degrees of plasm cell infiltration. A panel of immunohistochemical antibodies were used to examine the distribution of plasma cells and the expression of IgG and IgG4. The presence of lymph node architecture could help determine benign and malignant lesions. The preliminary classification of these lymphadenopathies was based on the infiltration features of plasma cells. The evaluation of IgG and IgG4 as a routine means could exclude the lymph nodes involvement of IgG4-related dieases (IgG4-RD), and whether it was accompanied by autoimmune diseases or multiple-organ diseases, which were of critical evidence for the differential diagnosis. For common lesions of lymphadenopathies, such as Castleman's disease, Kimura's disease, Rosai-Dorfman's disease and dermal lymphadenitis, the expression ratio of IgG4/IgG (>40%) as detected using immunhistochemistry and serum IgG4 levels should be considered as a standard for the possibility of IgG4-RD. The differential diagnosis of multicentric Castleman's diseases and IgG4-RD should be also considered. Conclusions: Infiltration of plasma cells and IgG4-positive plasma cells may be detected in some types of lymphadenopathies and lymphomas in clinicopathological daily practice, but not all of them are related to IgG4-RD. It should be emphasized that the characteristics of plasma cell infiltration and the ratio of IgG4/IgG (>40%) should be considered for further differential diagnosis and avoiding misclassification of lymphadenopathies.
Humans ; Castleman Disease/pathology* ; Plasma Cells/pathology* ; Immunoglobulin G4-Related Disease ; China ; Lymphadenopathy/pathology* ; Inflammation/pathology* ; Lymph Nodes/pathology* ; Diagnosis, Differential ; Lymphadenitis/pathology* ; Immunoglobulin G/metabolism*

Humans ; Plasma Cells/pathology* ; Hyperplasia/pathology* ; Immunoblastic Lymphadenopathy ; B-Lymphocytes/pathology* ; Lymphoma, T-Cell

Humans ; Multiple Myeloma/diagnosis* ; Plasma Cells ; Bone Marrow

Bone Marrow ; Humans ; Multiple Myeloma/diagnosis* ; Plasma Cells ; Prognosis

Colon ; Dendritic Cell Sarcoma, Follicular/surgery* ; Dendritic Cells, Follicular ; Granuloma, Plasma Cell/diagnostic imaging* ; Herpesvirus 4, Human ; Humans

Diagnosis, Differential ; Humans ; Multiple Myeloma ; Plasma Cells