胃肠道黏膜相关边缘区B细胞淋巴瘤和弥漫性大B细胞淋巴瘤中API2-MALT1融合基因表达的差异

目的 比较t(11;18)(q21;q21)/API2-MALX1融合基因在胃肠道黏膜相关边缘区B细胞淋巴瘤(MALN淋巴瘤)和弥漫性大B细胞淋巴瘤(DLBCL)中的发生情况,探讨t(11;18)(q21;q21)与胃肠道MALT淋巴瘤和DLBCL间演进的关系.方法 收集57例胃肠道MALT淋巴瘤(包括38例胃和19例肠),32例胃肠道DLBCL(包括28例胃和4例肠)和7例胃DLBCL同时合并MALT淋巴瘤成分,用荧光原位杂交(FISH)检测API2-MALT1融合基因.使用的探针包括API2-MALT1双色融合易位探针和MALT1双色分离重排探针.结果 在MALT淋巴瘤中有21.1%(12/57,包括10例胃和2例肠)发现API2-MALT1融合基因,而在32例DLBCL和7例DLBCL与MALT淋巴瘤混合的病例中均未检测出API2-MALT1融合基因.两组经统计学比较差异有统计学意义(X~2=9.383,P=0.001).结论 API2-MALT1融合基因是MALT淋巴瘤中特异的遗传学异常,而不见于DLBCL或DLBCL与MAIX淋巴瘤共存的病例中,提示至少在胃肠道API2-MALT1阳性的MALT淋巴瘤一般不会发生大细胞转化,而胃肠道DLBCL可能为原发或由t(11;18)阴性的部分MALT淋巴瘤转化而来.

Prevalence of API2-MALT1 fusion gene in gastrointestinal mucosa-associated lymphoid tissue lymphomas and diffuse large B cell lymphomas

Objective To investigate the difference of the prevalence of t(11;18) (q21;q21)/ AP12-MALT1 fusion gene between gastrointestinal mucosa-associated lymphoid tissue (MALT) lymphoma and diffuse large B cell lymphoma (DLBCL). Methods A total of 57 cases gastrointestinal MALT lymphomas (38 gastric and 19 intestinal lymphomas), 32 DLBCL (28 gastric and 4 intestinal lymphomas) and 7 cases gastric DLBCL accompanied MALT lymphoma were collected from the Cancer Hospital of Fudan University. API2-MALT1 fusion gene was detected by fluorescent in situ hybridization (FISH) using both dual fusion translocation and break apart probes. Results Among gastrointestinal MALT lymphomas, API2-MALT1 fusion gene was found in 12 of 57 cases (21.1% , 10 gastric and 2 intestinal lymphomas). In contrast, the fusion gene was not found in all 32 DLBCL and 7 gastric DLBCL with MALT lymphoma component. There was statistical significant difference between two groups (X~2=9.383, P=0.001). Conclusions API2-MALT1 fusion gene is a distinctive genetic aberration in MALT lymphomas, and is not present in DLBCL. The findings suggest that gastrointestinal tract MALT lymphomas with API2-MALT1 fusion geue may not transform into DLBCL, which may represent primary lymphoma or transformed API2-MALT1 negative MALT lymphomas.