Immunogenotypic and Viral Analyzes of Lethal Midline Granuloma

所谓致死性中线肉芽肿在临床上和理论上都有很大的意义。致死性中线肉芽肿的病因不明，发病机制多变，对其精确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、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网状病或中线恶性网状病。免疫组织学研究显示，未成熟或非典型细胞9例具有t细胞、CD2、CD3、CD4、CD8表型，2例具有自然杀伤细胞、CD2和CD56表型。这些细胞也被发现对HLA-DR呈阳性，这表明它们是活化细胞。然而，t细胞的免疫组织学不能给出克隆性的类似线索，因为在b细胞肿瘤中，通过对轻链进行免疫表型分析是可能的。随着T细胞受体基因cDNA探针的建立，对淋巴细胞源性肿瘤的谱系和克隆性分析成为可能。7例病例的Southern blot分析显示TCR基因重排，5例出现tcrβ或tcrγ链重排，均未发现免疫球蛋白重链重排。这些发现为单克隆t细胞增殖在大多数致死性中线肉芽肿中提供了确凿的证据。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。采用Southern印迹法和体外杂交法同时检测eb病毒核抗原（EBNA）和T细胞表面标记物，在鼻肿瘤活检标本中检测eb病毒（EBV） DNA。免疫荧光和northern blot结果显示，EBNA2基因和潜伏膜蛋白基因在鼻肿瘤细胞中均有表达。患者有高滴度的EBV抗体。这些发现表明致命性中线肉芽肿与EBV有因果关系。在免疫型和病毒研究的基础上，组织学上诊断为多形性网状病/中线恶性网状病的致死性中线肉芽肿被证明是一种爱泼斯坦-巴尔病毒相关的t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