慢性乙肝患者外周血HBcAg18-27V／I变异体特异性淋巴细胞分析

目的分析不同HBcAg18-27V／I变异体特异性淋巴细胞的频数在慢性乙肝患者外周血中的差异。方法收集44例ALT≥2×ULN的慢性乙肝患者外周血淋巴细胞，通过PCR方法分析感染者病毒学背景（HBV基因型、HBcAg18-27V／I、HLA-A2基因型），应用流式细胞仪分别检测HBcAg18-27V-Tetramer（＋）CD8（＋）和HBcAg18-27I-Tetramer（＋）CD8（＋）的淋巴细胞频数。结果华南地区慢性乙肝患者主要为HLA-A2基因型（22／44）；感染的HBV主要为B基因型（35／44）。其中HBcAg18-27为I变异体的占优势（43／44），在A2阳性组中，HBcAg18-27I-Tetramer（＋）CD8（＋）的淋巴细胞频数与HBcAg18-27V-Tetramer（＋）CD8（＋）的淋巴细胞频数（0．41±0．52 VS 0．28＋0．43）比较差异有统计学意义（P〈0．001）。结论在HBV基因型B／C为主的地区．应用HBcAg18-27V表位进行细胞免疫学研究而不考虑HBV病毒学背景的结果可能导致一定的偏差。

Analysis of HBcAg18-27V/I Mutant Specific Cytotoxic T Lymphocytes （CTL） in Peripheral Blood of Patients with Chronic Hepatitis B

Objective To analyze the differences between HBcAg18-27V-tetramer specific CTL and HBcAg18- 27I-tetramer specific CTL in peripheral blood of patients with chronic hepatitis B infection. Method Peripheral blood mononuclear cells （PBMC） were collected from 44 patients with chronic hepatitis B infection （ALT≥2×ULN）. The HBV and HLA genotyping, and the mutation of HBcAg18-27 were determined by polymerase chain reaction. CD8＋ HBcAg18-27V/I specific CTLs were analysed using flow cytometry. Result 22 out of 44 chronic hepatitis B patients had HLA-A2 genotype. The HBV genotype B was the major genotypes （33 out of 44） in these areas. In addition, HBcAg18-27I was the major variant （43/44）. For those patients with the HLA-A2 genotype, the frequency of HBcAg18-27I-tetramer specific CTL （0.41＋0.52） was significantly higher than the HBcAg18-27V specific CTL （0.28±0.43,P〈0.001）. Conclusion In the HBV （genotype B/C） prevalent area, serological analysis of HBcAg18- 27V is not sufficient. Additional virological analysis should also be performed.