Purpose To explore the clinicopathological features and potential clinical value of marginal zone lym-phoma(MZL)derived from T-bet positive memory B cell.Methods Clinical data of 67 cases of MZL were collected.Hematoxylin-eosin,immunohistochemistry,and multiple immunofluorescence stains,B cell receptor high throughput sequencing technology were used to study the histology,immunophenotype,and immunoglobulin heavy chain variable gene(IGHV)repertoire.Results T-bet was expressed in some MZL patients(34/67,50.75％),which was correla-ted with clinicopathological characteristics such as gender,clinical stage,and Ki67 proliferation index(P＜0.05),and also the progression-free survival was poor(P=0.012 2).T-bet positivity was a risk factor affecting the progres-sion of MZL.Microscopically,T-bet positive MZL frequently presented T-bet positive tumor B cells surrounded follicu-lar germinal center,"MALT ball"-type lymphoepithelial lesions,and IgG positive neoplastic plasma cells(P＜0.05).T-bet had no biased influence on the VH gene usage(P＞0.05).The common VH families were IGHV4 and IGHV3,and the segments were IGHV4-34 and IGHV3-30.The positivity of T-bet was associated with somatic hypermutation(SHM)state(P=0.014 9).The SHM was mainly in the range of 2％-4.9％in T-bet positive MZL,while in T-bet negative MZL the SHM was mostly greater than 5％.The VH gene usage was not correlated with the clinicopathological features of patients(P＞0.05).IGHV4 was correlated with progression-free survival in T-bet positive MZL(P=0.038 2).Conclusion The expression of T-bet in MZL is closely related to the clinicopathological features such as histology,plasma cell immunophenotype and IGHV gene repertoire,and the prognosis of patients is poor,which may be a potential molecular marker affecting the progression of MZL.

Purpose To explore the clinicopathological features and potential clinical value of marginal zone lym-phoma(MZL)derived from T-bet positive memory B cell.Methods Clinical data of 67 cases of MZL were collected.Hematoxylin-eosin,immunohistochemistry,and multiple immunofluorescence stains,B cell receptor high throughput sequencing technology were used to study the histology,immunophenotype,and immunoglobulin heavy chain variable gene(IGHV)repertoire.Results T-bet was expressed in some MZL patients(34/67,50.75％),which was correla-ted with clinicopathological characteristics such as gender,clinical stage,and Ki67 proliferation index(P＜0.05),and also the progression-free survival was poor(P=0.012 2).T-bet positivity was a risk factor affecting the progres-sion of MZL.Microscopically,T-bet positive MZL frequently presented T-bet positive tumor B cells surrounded follicu-lar germinal center,"MALT ball"-type lymphoepithelial lesions,and IgG positive neoplastic plasma cells(P＜0.05).T-bet had no biased influence on the VH gene usage(P＞0.05).The common VH families were IGHV4 and IGHV3,and the segments were IGHV4-34 and IGHV3-30.The positivity of T-bet was associated with somatic hypermutation(SHM)state(P=0.014 9).The SHM was mainly in the range of 2％-4.9％in T-bet positive MZL,while in T-bet negative MZL the SHM was mostly greater than 5％.The VH gene usage was not correlated with the clinicopathological features of patients(P＞0.05).IGHV4 was correlated with progression-free survival in T-bet positive MZL(P=0.038 2).Conclusion The expression of T-bet in MZL is closely related to the clinicopathological features such as histology,plasma cell immunophenotype and IGHV gene repertoire,and the prognosis of patients is poor,which may be a potential molecular marker affecting the progression of MZL.