Biemer J J
St. Joseph's Hospital, Tampa, FL 33607.
Ann Clin Lab Sci. 1990 May-Jun;20(3):175-91.
An increased incidence of malignant lymphomas is common to all types of immunodeficient patients whether they be of the natural or constitutionally occurring type, acquired as in acquired immunodeficiency syndrome (AIDS) or of iatrogenic origin as in organ transplantation. Although there is some degree of heterogeneity, the most characteristic feature of these immunodeficient states is alteration of T-cell cytotoxic function. The malignant lymphomas show a variety of relatively common features, notably: rapid onset following the appearance of the immunodeficient state, a high degree of clinical aggressiveness, and a tendency to present in extranodal sites, particularly the central nervous system (CNS) and gastrointestinal tract. The tumors are almost invariably of B-lymphocytic cell origin and while the histologic classifications reflect some diversity, the vast majority of tumors are described as Burkitt-like or diffuse large cell type. There appears to be a high degree of correlation with a preceding fulminant Epstein-Barr virus (EBV) infection resulting in marked B-cell lymphoproliferation in the absence of effective T-cell control. Initially, the B-cell proliferation is clearly polyclonal and reactive in nature, although as time evolves, there appears to be selection of oligoclonal and even monoclonal cell populations. Such cells are latently infected with EBV and may express EBV nuclear protein two and latent membrane protein, which are characteristically seen in proliferating B-lymphocytes in response to growth transformation by EBV. While desoxyribonucleic acid (DNA) probes may continue to demonstrate multiple lymphoid clonal populations, it is hypothesized that the hyperproliferative state favors genetic alterations which select out a single malignant clone. This transformed clone is evidenced by expression of a translocated, activated c-myc oncogene and decreased evidence of EBV nuclear protein two and latent membrane protein, that is, characteristics of Burkitt's lymphoma. Other large cell malignant lymphoma phenotypes may show similar findings. While most studies have continued to suggest that EBV plays a key role in the development of non-Hodgkin's lymphoma (NHL) of AIDS patients, some recent studies have suggested a less dominant role. Therefore, further exploration of the world of molecular biology will be needed to demonstrate whether other factors, namely additional viruses and/or oncogenes play a similar or significant role in the lymphomas of immunodeficient patients.
各类免疫缺陷患者，无论其免疫缺陷是自然发生或先天性的，还是后天获得性的，如获得性免疫缺陷综合征（艾滋病），或是医源性的，如器官移植，其恶性淋巴瘤的发病率均会升高。尽管存在一定程度的异质性，但这些免疫缺陷状态最典型的特征是T细胞细胞毒性功能的改变。恶性淋巴瘤表现出多种相对常见的特征，尤其是：免疫缺陷状态出现后发病迅速、临床侵袭性高，且倾向于发生在结外部位，特别是中枢神经系统（CNS）和胃肠道。这些肿瘤几乎均起源于B淋巴细胞，虽然组织学分类存在一定差异，但绝大多数肿瘤被描述为伯基特样或弥漫大细胞型。其发病似乎与先前爆发性的爱泼斯坦 - 巴尔病毒（EBV）感染高度相关，在缺乏有效的T细胞控制时，EBV感染会导致明显的B细胞淋巴增殖。最初，B细胞增殖本质上明显是多克隆且具有反应性的，不过随着时间推移，似乎会出现寡克隆甚至单克隆细胞群体的选择。这些细胞潜伏感染EBV，并可能表达EBV核蛋白2和潜伏膜蛋白，这是增殖的B淋巴细胞在对EBV诱导的生长转化作出反应时的典型表现。虽然脱氧核糖核酸（DNA）探针可能继续显示多个淋巴克隆群体，但据推测，这种过度增殖状态有利于发生基因改变，从而筛选出单个恶性克隆。这种转化的克隆可通过易位激活的c - myc癌基因的表达以及EBV核蛋白2和潜伏膜蛋白表达减少得到证实，即伯基特淋巴瘤的特征。其他大细胞恶性淋巴瘤表型可能也有类似发现。虽然大多数研究继续表明EBV在艾滋病患者非霍奇金淋巴瘤（NHL）的发生中起关键作用，但最近一些研究表明其作用没那么突出。因此，需要进一步探索分子生物学领域，以证明其他因素，即其他病毒和/或癌基因在免疫缺陷患者淋巴瘤中是否发挥类似或重要作用。
