The Expression And Significance Of T-helper Cell Markers GATA3 And T-bet In Primary Mediastinal Large B Cell Lymphoma

Objective:Primary mediastinal large B-cell lymphoma is one of subtypes of diffuse large B-cell lymphoma,which originating in thymus and accounting for 6%-12%of the diffuse large Bcell lymphoma.Meanwhile,PMBCL and CHL represent two major types of mature B-cell lymphoma of the mediastinum.PMBCL,mediastinal CHL and PMBCL share many clinicopathologic characteristics,their treatment strategies and responses are remarkably different.In addition,according to the reports,T cell mediated immunity plays an important role in enhancing antitumor response and Th is an important regulatory/effector cell in immune response,which can be dividedinto Th1 and Th2 types,Th1 and Th2 are derived from the common precursor cell Th0 differentiation,while transcription factors Tbet and GATA3 specifically regulate Th0 differentiation and play a key role in the Th1/Th2 switch.Therefore,it is reasonable to speculate whether T-helper cell GATA3 and T-bet can be used as effective immune markers to the differentiate the three types of B-cell lymphomas.Methods:In this study,immunohistochemistry was used to detect the expression of GATA3 and T-bet in tumor cells and background T cells in 19 cases of PMBCL,45 cases of DLBCL and 10 cases of CHL.Results:In our study,in the samples of 19 patients of PMBCL,GATA3 was not expressed in tumor cells(0/19),and the positive expression rate of background T cells was 89.47%(17/19;positive cells were counted at high power field,Range: 112-488/HPF,median number:244/HPF);T-bet was also not expressed in tumor cells(0/19),and the positive expression rate of background T cells was 94.73%(18/19;Range: 2-320/HPF,median number:69/HPF).In 45 DLBCL samples,GATA3 tumor cells and background T cells were negatively expressed(0/45).In 10 CHL samples,the positive expression rate of GATA3 in tumor cells was 100%(10/10),and the expression rate of background T cells was 0%.The positive expression rate of T-bet in tumor cells was 40%(4/10),and the positive expression rate of T-bet in background T cells was 100%(10/10;Range: 51-368/HPF,median number:176/HPF).In 45 DLBCL samples,all the tissue sections of all patients showed negative expression of T-bet tumor cells,while the positive expression rate of T-bet in background T cells was 100%(45/45;Range: 75-176/HPF,median number: 81/HPF).Conclusion:GATA-3 was positively expressed in CHL tumor cells,but not PMBCL and DLBCL tumor cells.In the background T cells,GATA-3 has a high expression rate in PMBCL,but negative expression in DLBCL and CHL.T-bet has a certain expression rate in CHL,but has no positive expression in PMBCL and DLBCL.The positive expression of gata-3 and t-bet in tumor cells may serve as a marker for the differential diagnosis of CHL and the other two types of lymphoma,while the positive expression of gata-3 in background T cells may provide help for the differential diagnosis of PMBCL and DLBCL.