Clinical And Biological Characteristics Of Non-IgM Lymphoplasmacytic Lymphoma

Objective:.In this article,we study the non-IgM lymphoplasmacytic lymphoma(LPL)patients with clinical and biological characteristics,first-line treatment and prognosis,and compare them with Waldenstrom macroglobulinemia(WM)to explore the similarities and differences between them and deepen the understanding of non-IgM Lymphoplasmacytic lymphoma.Background:Lymphoplasmacytic lymphoma(LPL)is a rare indolent lymphatic system malignant tumor that a variety of small B lymphocytes,plasmacytoid lymphocytes and plasma cells involved,often have bone marrow,lymph node,spleen and other extranodal organs involvement.Most LPL patients often secrete monoclonal IgM components,only a few patients may be accompanied by increased IgG or IgA,or no monoclonal immunoglobulin secretion.Lymphoplasmacytic cell with involvement of the bone marrow with serum IgM monoclonal immunoglobulin could diagnose WM.Research on Lymphoplasmacytic lymphoma is mainly focused on WM,while rare is known about non-IgM lymphoplasmacytic lymphoma.Domestic reports on this disease are mainly individual cases,and there are no large-scale studies.There were a total of 23 patients with non-IgM lymphoplasmacytic lymphoma in our center,which is the largest series study in China.METHODS:Records of 340 patients with LPL were retrospectively analyzed between July 1993 and August 2020,slecting 23 non-IgM lymphoplasmacytic lymphoma patints.Record clinical,biological,therapeutic,and prognostic indicators.All of the 23 patients underwent monoclonal immunoglobulin-related tests;Chromosome karyotype and Flow CytoMetrywere both detected in 18 patients.The cytogenetic aberrations were detected by fluorescence in situ hybridisation(FISH)in 21 patients.MYD88 gene mutation were tested in 18 patients and next generation sequencing in 8 petients.The association between two categorical variables was estimated by Fisher’s exact test,and quantitative variables was evaluated by Chi-square test.RESULTS:The study included 340 patients with lymphoplasmic lymphoma,311 of whom secreted monoclonal IgM and 6 of whom secreted both monoclonal IgM and IgG.23 patients with non IgM LPL,including IgA in 2 cases and IgG in 14 cases,not secrete monoclonal immunoglobulin in 7 cases.10 males and 13 females with a median age of 62 year(range 35 to 81).13 patients presented with lymphadenopathies,14 with splenomegaly and 5 with extranodal involvement.Anemia and fatigue were found in 15 cases at diagnosis.18 patients developed anemia,with a median HGB level of 80.0(48155)g/L.All patients had bone marrow involvement.All of the 23 patients had bone marrow involvement and anemia.Flow cytometry was performed in 18 patients,and the median percentage of abnormal cells was 24.46%.CD5-CD10-was presentde in 15 patients.Chromosome karyotypes were examined in 18 patients,and normal karyotypes were found in 14 patients Cytogenetic aberrations had been detected by FISH in 21 patients.No abnormality was found in 16 patients.Three patients had IGH gene rearrangement,one patient had RB and MYB deletion and+12.18 patients were tested for MYD88 gene mutation,the total of MYD88 mution was 55.8%.The next generation sequencing revealed that 7 panients had MYD88 mutations and 2 patients had CRCX4 mutations.A total of 17 patients received treatment,15 patints were treated with new drug based regimens,and 2 patients with traditional regimens.16 patients were evaluated for efficacy,and 3 patients achieved complete remission.The overall remission rate of firstline treatment was 87.5%.Further comparison with the clinical and biological characteristics of WM patients showed a higher proportion of female patients in the nonIgM group(P=0.007)and a higher proportion of patients receiving new drug therapyies(P=0.044).CONCLUSION:By comparison,the clinical and biological characteristics of non-IgM lymphoplasmacytic lymphoma were similar to Waldenstrom macroglobulinemia patients.