Huemer H P, Larcher C, Prodinger W M, Petzer A L, Mitterer M, Falser N
Institute for Hygiene, University of Innsbruck, Austria.
Clin Exp Immunol. 1993 Aug;93(2):195-9. doi: 10.1111/j.1365-2249.1993.tb07965.x.
In this study we established a novel solid-phase immunoassay for CD21 using the time-resolved fluorescence of lanthanide chelates. The capture assay was able to detect concentrations of as low as 100 pg of CD21 antigen per millilitre of sample and was used for quantitative determination of CD21 in lysates of different cell lines as well as in patient serum specimens. CD21 was measured in lysates of tonsils and cell lines of B, T cell and myelomonocyte lineage, and appeared to consist of monomeric antigen under the detergent conditions used. Elevated levels of soluble CD21 were observed in serum of patients with Epstein-Barr virus (EBV) infection, a disease known to be associated with polyclonal B cell activation, and in infection with the lymphotropic rubella virus. Significantly increased levels were also found in malignancies which are associated with EBV. In patients with nasopharyngeal carcinoma (NPC), a correlation with the titre of EBV-specific IgA was observed, thus supporting a possible role of soluble CD21 as a marker for disease activity in certain malignancies. Our data suggest that measurement of soluble CD21 could serve as a marker for activation of the immune system and diseases involving the B cell lymphoid system. Possible mechanisms and functions of soluble CD21 are discussed.
在本研究中，我们利用镧系螯合物的时间分辨荧光建立了一种新型的CD21固相免疫测定法。该捕获测定法能够检测到每毫升样品中低至100 pg的CD21抗原浓度，并用于定量测定不同细胞系裂解物以及患者血清标本中的CD21。在扁桃体裂解物以及B细胞、T细胞和骨髓单核细胞系的细胞系中检测了CD21，在所使用的去污剂条件下，其似乎由单体抗原组成。在已知与多克隆B细胞活化相关的爱泼斯坦-巴尔病毒（EBV）感染患者的血清中，以及在嗜淋巴细胞风疹病毒感染患者的血清中，观察到可溶性CD21水平升高。在与EBV相关的恶性肿瘤中也发现水平显著升高。在鼻咽癌（NPC）患者中，观察到其与EBV特异性IgA滴度相关，从而支持可溶性CD21作为某些恶性肿瘤疾病活动标志物的可能作用。我们的数据表明，可溶性CD21的测定可作为免疫系统激活以及涉及B细胞淋巴系统疾病的标志物。文中讨论了可溶性CD21可能的机制和功能。
