| Background and ObjectiveDiffuse large B-cell lymphoma(DLBCL)is a highly aggressive class of malignant tumors,the most common subtype of non-hodgkin lymphoma(non-hodgkin's lymphoma NHL),accounting for about 50.7%of NHL in China.The most common antigen expression studies in B cell lymphoma are CD20 antigens.CD20 antigen is a non-glycosylated hydrophobic phosphoric acid transmembrane protein with a molecular weight of 33 kda to 35 kda,and has an extracellular circular structure with four transmembrane regions.Meanwhile,as a broad-spectrum B cell immunophenotype marker,CD20 is widely expressed in multiple developmental stages from the former B cell to the mature B cell,but the expression is lost in the first and second ends of B lymphocyte development,including plasma cell,pro-B cell and hematopoietic stem cell stage.Moreover CD20 antigens play an important role in B cell activation,differentiation and cell cycle.Related studies have shown that CD20 protein is expressed in more than 90%B cell lymphoma,and about 95%to 98%of DLBCL are expressed.Therefore,CD20 become the target antigen of monoclonal antibody-like immunoretargeted therapy drugs.What's more,what we usually say DLBCL without special description means CD20 positive DLBCL.The most studied are CD20 positive DLBCL,reports of CD20 negative DLBCL are rare,as the disease accounts for only 1%?2%of all patients.Recent studies have shown that CD20 negative DLBCL are usually limited to several variant subtypes with plasmacyte characteristics and terminal B cell differentiation.The most common subtypes include plasmacytoid lymphoma(PBL),primary exudative lymphoma(PEL),large B cell lymphoma originating from human herpesvirus 8 associated multicenter castleman disease,and ALK positive large cell lymphoma.In addition,as a rare disease,the incidence is low,the current domestic and foreign cases are mostly reported by case analysis,so clinicians do not fully understand the diagnosis and treatment of the disease.The purpose of this study was to improve the understanding of CD20 negative diffuse large B cell lymphoma and to reduce the rate of missed diagnosis and misdiagnosis and to provide more basis and ideas for further study of the disease.Materials and methodsRetrospective analysis of 17 patients treated in our hospital between January 2011?December 2019,all of them were diagnosed as CD20 negative by histopathology and immunohistochemistry(Mum-1?Ki-67?CD20?CD79a?Bcl-6?CD3?CD10?CD43?CD21?CD5?Bcl-2 and Cyclincdl,etc.).Two of them were not treated and missed for economic reasons.After diagnosis,one case was treated with CTOD(cyclophosphamide+dexamethasone+pirarubicin)regimen.After the condition was controlled,he was discharged from hospital,then lost his visit,the prognosis was unknown,and the data of the other 14 cases were perfect.The international prognostic index(IPI)score,sex,presence or absence of B symptoms,location of onset,ECOG score,clinical stage,extranodal involvement status,lactate dehydrogenase(LDH)value and so on were queried and recorded in the medical record inquiry system.And the collected data usingSPSS21.0 software line statistical processing analysis to sum up.Results:(1)There is no significant difference in the incidence of CD20 negative DLBCL between men and women,most of which occur in the middle-aged and elderly,with a median age of 53 years,and children are rare;(2)The CD20 negative DLBCL usually occurs in the extranodal organs with more involved sites,including bone marrow,abdominal cavity,nasal cavity,mediastinum,maxillary sinus,subcutaneous soft tissue,etc.And the clinical manifestation is not specific;(3)CD20 negative DLBCL Ann Arbor staging:11 cases(78.57%)in ???;8 cases(57.14%)with B symptoms;11 patients(78.57%)Ki-67?80%;12 patients(85.71%)with extranodal involvement(>1).(4)The treatment plan of CD20 negative DLBCL is not uniform,the choice of the plan is mainly individualized according to the patient's autoimmune state,the location of the lesion,the clinical manifestation,etc.The commonly used treatment plan is chemotherapy,and the CHOP and the high dose intensity chemotherapy(EPOCH?Hyper CVADMA)are the main ones.the initial efficacy(complete remission rate 55.56%,partial remission rate 33.33%,disease stabilization rate 11.11%)of the first-line high-dose intensity chemotherapy regimen was better than that of the first-line traditional chop-like chemotherapy regimen(partial remission rate 66.67%,disease stabilization rate 33.33%),but the effect of the two on the OS?PFS was not statistically significant(P=0.427 and P=0.271);(5)The median total survival time(mOS)was 23 months and the median progression-free survival(mPFS)was 14.5 months in patients with CD20 negative DLBCL in the study.Multivariate analysis revealed B symptoms(P=0.012)as poor prognostic factors.Age,sex,Ann Arbor stage,LDH,ki-67,extra-conjunctival involvement,and IPI scores had no effect on prognosis.Conclusion:1.CD20 negative DLBCL is a rare heterogeneous lymphoproliferative disorder with unique biological behavior.The main clinical features of the patients are low survival rate,atypical cell morphology,high invasiveness and chemotherapeutic resistance;2.CD20 negative DLBCL is poor prognosis and easy to relapse after short relief;B symptoms is its poor prognostic factors;High dose intensity chemotherapy has no effect on prognosis;... |
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