Immunologic and molecular studies of CD5-positive diffuse large B-cell lymphoma (DLBCL). - Differences between CD5^+ and CD5^- DLBCL -

研究CD5阳性弥漫性大B细胞淋巴瘤(DLBCL)的临床病理、免疫学和分子生物学特征，并比较CD5^+DLBCL和CD5^-DLBCL。CD5^-DLBCL是指发病年龄大、以女性为主、常累及结外部位和病程较差的亚群。重排免疫球蛋白重链基因可变区(VH)基因的体细胞突变频率和模式显示，35例CD5+DLBCL分为胚系或低频率突变(&lt；5%)组13例和体细胞VH基因高突变(&gt；5%)组22例。5例有1个核苷酸替换的病例和6例有生殖系突变的病例发现了bcl6基因启动子区的体细胞突变。低组包括1例核苷酸替换和1例生殖系，高组包括3例核苷酸替换和3例生殖系。低组中除1例CD38和1例CD148外，无1例表达CD27、CD38和CD147，而高组部分病例表达CD27、CD38和CD147。部分基因在DNA芯片中的表达模式为CD5^+DLBCL和CD5^-DLBCL。因此，我们发现CD5^+DLBCL与CD5^-DLBCL有一定的差异，认为CD5^+DLBCL是DLBCL的一个独立亚群。CD5~+DLBCL患者需要在常规化疗基础上进行新的治疗。

We studied clinicopathologic, Immunologic and molecular characteristics of CD5-positve (^+) diffuse large B-cell lymphoma (DLBCL) and compared CD5^+ DLBCL to CD5^- DLBCL. CD5^- DLBCLs are identified a subgroup which represents elderly onset, female predominance, frequent involvement of extranodal sites and a poor clinical course. Somatic mutation frequency and pattern of the rearranged immunoglobulin heavy chain gene variable region (VH) gene indicated that 35 cases of CD5+ DLBCLs were divided into 13 cases with germline or low frequency mutation (<5%) ; low group and 22 cases with somatically hypermutated VH gene (>5%) ; high group. Somatic mutation of bcl-6 gene promoter region was found in five cases with one nucleotide substitution and six cases with germline. Low group included a case with nucleotide substitution and a case with germline, and high group included three cases with nucleotide substitution and three cases with germline. No cases in low group expressed CD27, CD38 or CD147 except CD38 in one and CD148 in one, but some cases in high group expressed these molecules. The pattern of expression of some genes in DNA microarray was different CD5^+ DLBCL and CD5^- DLBCL. Thus, we found some differences between CD5^+ DLBCL and CD5^- DLBCL, and concluded CD5^+ DLBCL was a distinct subgroup of DLBCL. A new therapy other than conventional chemotherapy is needed for the patients with CD5^+ DLBCL.