Setor de Microbiologia, Departamento de Patologia e Medicina Legal, Universidade Federal do Ceará , Fortaleza, CE , Brasil.
Braz J Microbiol. 2012 Jan;43(1):393-404. doi: 10.1590/S1517-838220120001000048. Epub 2012 Jun 1.
Epstein-Barr virus (EBV) has been associated with 10% of gastric carcinomas. The aim of this study was to determine the frequency of EBV in gastric carcinomas in Brazil assessed by in situ hybridization (ISH) and PCR, which would contribute to the characterization of the clinical and pathological aspects of EBV-associated gastric carcinomas. One hundred and ninety-two gastric carcinoma cases were collected at hospitals in two Brazilian states. Seventy-three out of 151 cases were PCR(+), while 11/160 cases were ISH(+). Nine out of eleven ISH(+) cases displayed a diffuse staining pattern and 2 out of 11 a focal pattern. Both techniques showed that the EBV(+) cases were characterized by their association with males, older patients, lower gastric region, intestinal type, advanced stage and poorly to moderately differentiated tumors. The concordance between the two techniques was 55.8% (Cohen's kappa index = 0.034). Four cases were ISH(+)/PCR(-), while 49 cases were PCR(+)/ISH(-). Only two cases showed stained lymphocytes by ISH and one of them was PCR(-). The observed discrepancy between the two techniques could not be explained just by the elevated accuracy of PCR. ISH(+)/PCR(-) carcinomas may be encountered if EBV is not present in the whole tumor tissue or if there are polymorphisms in the sequences of the viral genome amplified. On the other hand, the high frequency of PCR(+) results associated with the absence of ISH staining in lymphocytes and/or tumors cells suggests that the virus may be present in tumor cells or other cell types without expressing EBER1, the target of the ISH technique.
爱泼斯坦-巴尔病毒（EBV）与 10%的胃癌相关。本研究旨在通过原位杂交（ISH）和聚合酶链反应（PCR）确定巴西胃癌中 EBV 的频率，这将有助于 EBV 相关胃癌的临床和病理特征的描述。从巴西两个州的医院收集了 192 例胃癌病例。在 151 例病例中，有 73 例 PCR（+），而在 160 例病例中，有 11 例 ISH（+）。11 例 ISH（+）病例中有 9 例显示弥漫性染色模式，而 11 例中有 2 例显示局灶性模式。两种技术均表明 EBV（+）病例的特征是与男性、老年患者、胃下部、肠型、晚期和低分化或中分化肿瘤相关。两种技术的一致性为 55.8%（Cohen's kappa 指数=0.034）。4 例为 ISH（+）/PCR（-），而 49 例为 PCR（+）/ISH（-）。只有 2 例通过 ISH 显示染色的淋巴细胞，其中 1 例为 PCR（-）。两种技术之间观察到的差异不能仅仅用 PCR 的准确性提高来解释。如果 EBV 不存在于整个肿瘤组织中，或者病毒基因组扩增的序列存在多态性，则可能会遇到 ISH（+）/PCR（-）的癌。另一方面，PCR 结果阳性率高，而淋巴细胞和/或肿瘤细胞中缺乏 ISH 染色表明，病毒可能存在于肿瘤细胞或其他细胞类型中，而不表达 ISH 技术的靶标 EBER1。
