Immunophenotypes And Cytogenetic Alterations In219Cases Of Diffuse Large B-cell Lymphoma

[Objective] To investigate the features of immunophenotypes and cytogenetic alterations, as well as the distribution of immunophenotypes subtypes based on Hans algorithm in a large group of diffuse large B-cell lymphoma (DLBCL) cases from Chinese patients.[Methods]219cases of DLBCL from Qilu Hospital and Tianjin Tumor Hospital of eastern China were collected. The expression of CD10, BCL-6, MUM1, BCL-2, and other markers in219cases were detected using tissue microarray and immunohistochemistry. Hans algorithm was applied to classify DLBCL into GCB and non-GCB subtypes. Interphase fluorescence in situ hybridization (FISH) was used to determine the incidence of the t(14;18) translocation, bcl-2amplification and bcl-6rearrangement. Statistical analysis of the correlation between them was performed. The data from seven studies on DLBCL of Chinese patients which published in last two years were also collected and analyzed using SPSS17.0.[Results](1) Our study:*The positive rates of CD10, BCL-6, MUM1and BCL-2were18.3%(40/219),47.9%(105/219),68.0%(149/219) and63.0%(138/219), respectively.â‘¡Of219DLBCL cases, non-GCB subtype (75.3%) was significantly more common than GCB subtype (24.7%)(P<0.001).â‘¢Bcl-2gene alteration were detected in49cases (25.8%), including5cases having the t(14;18)(2.6%) which all exist in GCB subtype, and44cases of bcl-2amplification (23.2%) which4cases (8.5%) exist in GCB subtype and40cases (28.0%) in non-GCB subtype (P=0.0136).â‘£Bcl-6gene rearrangement was detected in42cases (22.1%), which7cases (14.9%) in GCB and35cases (24.5%) in non-GCB, no significant difference was shown (P=0.1889).⑤A significant negative correlation between bcl-2gene amplification and bcl-6gene rearrangement was seen (r=-0.1796, P=0.0134). Amongst5cases with t(14;18) translocation,2cases accompanied by bcl-6gene rearrangement.49cases with bcl-2gene alterations including translocation and amplification were all but one expressing BCL-2protein, and no significant association between bcl-6gene rearrangement and BCL-6protein expression (P=0.7266).â‘¥No significant difference between nodal and extranodal DLBCLs in immunophenotypes, subtypes based on Hans algorithm, and bcl-2and bcl-6gene alterations.(2) Comprehensive analysis of eight studies:of total1259cases, non-GCB subtype (69.8%) was significantly more common than GCB subtype (30.2%)(P<0.001). The positive rates of CD10and MUM-1were similar among eight studies (P=0.0470å'ŒP=0.0484), but a significant difference exists for BCL-6and BCL-2(P<0.001).[Conclusions](1) Non-GCB subtype is significantly more common than GCB subtype in Diffuse Large B-cell Lymphoma from Chinese Patients. Some distinct features of immunophenotypes and cytogenetic alterations of DLBCL are in Chinese patients compared with Western patients. Such as DLBCLs from Chinese patients were lower expression of CD10, higher expression of MUM1and BCL-2, and much lower rate of t(14;18) translocation than those from Western patients, which are worth to do more study to elucidate.(2) No significant difference between nodal and extranodal DLBCLs in immunophenotypes, cytogenetic alterations and subtypes based on Hans algorithm in general.(3) The comprehensive analysis reveals that although the test results of CD10and MUM1are similar in different labs, a significant difference of BCL-6test was there. Thanks for that the positive rate of BCL-6just makes a weak impact on Hans algorithm, so the classification of GCB and nonGCB subtypes of DLBCL based on CD10, BCL-6and MUM1expressions is practicable.