Immunogenotypic and Viral Analyzes of Lethal Midline Granuloma

所谓的致死性中线肉芽肿是一个非常重要的临床和理论的兴趣。致死性中线肉芽肿的病因尚不清楚，其发病机制是可变的，关于精确的分类和自然史存在争议。在这项研究中，我们报告了11例致死性中线肉芽肿的免疫病理学，免疫基因型和病毒特征。其活检标本的组织病理学诊断最初为多形性网状细胞增多症或中线恶性网状细胞增多症。免疫组化显示9例未成熟或异型细胞具有T细胞、CD 2、CD 3、CD 4、CD 8表型，2例具有自然杀伤细胞、CD 2、CD 56表型。这些细胞也被发现为HLA-DR阳性，这表明它们是活化的细胞。然而，T细胞的免疫组织学不能提供类似的克隆性线索，因为在B细胞肿瘤中，通过轻链的免疫表型分析是可能的。随着T- 关于我们 细胞受体基因，有可能分析淋巴细胞来源的肿瘤的谱系和克隆性。7例Southern杂交分析显示5例TCR基因重排，TCR β或TCR γ链重排，无1例免疫球蛋白重链重排。这些发现代表了大多数致死性中线肉芽肿内单克隆T细胞增殖的确凿证据。此外，表型和免疫基因型分析显示，一些疾病起源于自然杀伤细胞谱系。应用Southern印迹法和体外杂交法检测鼻肿瘤活检标本中EB病毒DNA，同时用双色免疫荧光法检测EB病毒核抗原（EBNA）和T细胞表面标志物。免疫荧光和北方杂交结果显示，鼻肿瘤细胞中有EBNA 2基因和潜伏膜蛋白基因的表达。结果表明，致死性中线肉芽肿与EB病毒存在因果关系。根据免疫分型和病毒学研究，致死性中线肉芽肿组织学诊断为多形性网状细胞增多症/中线恶性网状细胞增多症，证实为EB病毒相关的T淋巴细胞增生性疾病。少

So-called lethal midline granuloma is of great clinical and theoretical interest. The etiology of lethal midline granuloma is unknown and the pathogenesis is variable, with debate as to precise classification and natural history. In this study, we reported immunopathological, immunogenotypic and viral features in 11 cases of lethal midline granuloma. The histopathological diagnosis of their biopsy specimens was initially polymorphic reticulosis or midline malignant reticulosis. Immunohistologic study of the specimens revealed that immature or atypical cells had phenotypes of T-cells, CD2, CD3, CD4, CD8 in 9 cases and of natural killer cells, CD2 and CD56 in other 2 cases. Those cells were also found to be positive for HLA-DR,which indicated that they were activated cells. Immunohistology in T-cells, however, was not able to give a similar clue to clonarity as it was possible within B-cells neoplasms by immunophenotyping the light chains. With the establishment of cDNA probes for the T- … More cell receptor genes it was possible to analyze neoplasms of lymphocyte origin for lineage and clonality. The Southern blot analysis of 7 cases showed rearrangement of TCR gene, TCRbeta or TCRgamma chain in 5 cases, whereas none of them showed rearragement of immunoglobulin heavy chain. These findings represented conclusive evidence for a monoclonal T-cell proliferation within the majority of lethal midline granuloma. In addition, phenotypic and immunogenotypic analyzes revealed that some of the disease originated in natural killer cell lineage. EpsteinBarr virus (EBV) DNA was detected in the nasal tumour biopsy specimens by Southern blotting and in vitro hybridisation with simultaneous detection of EBV determined nuclear antigen (EBNA) and T cell surface markers by two color immunofluorescence. Further immuno-fluorescence and northern blotting revealed that EBNA2 gene and also latent membrane protein gene were expressed in the nasal tumour cells. The patients had high titres of antibodies to EBV.These findings suggest that lethal midline granuloma is causally associated with EBV.On the ground of immungenotypi and viral studies, lethal midline granuloma histologically diagnosed as polymorphic reticulosis/midline malignant reticulosis are proven to be a Epstein-Barr virus associated T-cell lymphoproliferative disorder. Less