Immunogenotypic and Viral Analyzes of Lethal Midline Granuloma

所谓的致死性中线肉芽肿具有重大的临床和理论意义。致死性中线肉芽肿的病因尚不清楚，发病机制也各不相同，关于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病例的免疫病理学、免疫基因型和病毒特征。他们的活检标本的组织病理学诊断最初为多形性网状细胞增生症或中线恶性网状细胞增生症。对标本的免疫组织学研究显示，9例中未成熟或非典型细胞具有T细胞表型，CD2、CD3、CD4、CD8，另外2例具有自然杀伤细胞表型，CD2和CD56。这些细胞还被发现HLA-DR呈阳性，这表明它们是激活的细胞。然而，T 细胞的免疫组织学无法提供与 B 细胞肿瘤内的克隆性类似的线索，通过对轻链进行免疫表型分析。随着 T 细胞受体基因 cDNA 探针的建立，分析淋巴细胞起源的肿瘤的谱系和克隆性成为可能。 7例Southern印迹分析显示TCR基因重排，5例TCRbeta或TCRgamma链重排，无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表明，一些疾病起源于自然杀伤细胞谱系。通过 Southern 印迹和体外杂交在鼻肿瘤活检标本中检测到 EpsteinBarr 病毒 (EBV) DNA，同时通过两种颜色免疫荧光检测 EBV 确定的核抗原 (EBNA) 和 T 细胞表面标记。进一步的免疫荧光和RNA印迹显示鼻肿瘤细胞中表达EBNA2基因和潜在膜蛋白基因。患者体内有高滴度的 EBV 抗体。这些发现表明致死性中线肉芽肿与 EBV 存在因果关系。根据免疫基因型和病毒研究，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的致死性中线肉芽肿被证明是 Epstein-Barr 病毒相关的 T 细胞淋巴增殖性疾病。较少的

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