Down-regulation of human leukocyte antigens class I on peripheral T lymphocytes and NK cells from subjects in region of high-incidence gastrointestinal tumor.

BACKGROUND: Many types of human tumors can suppress the immune system to enhance their survival. Loss or down-regulation of human leukocyte antigens (HLA) class I on tumors is considered to be a major mechanism of tumor immune escape. Our previous studies found that HLA class I on peripheral-blood mononuclear cells was significantly lower in gastric cancer patients. The present study made an analysis of HLA class I expression on peripheral-blood T lymphocytes and NK cells from subjects of Lijiadian village, a village with high-incidence gastrointestinal tumor. METHODS: A total of 181 villagers from Lijiadian village and 153 normal controls from the Department of Health Examination Center were enrolled in this study. Using a multi-tumor markers detection system, these villagers were divided into two groups: high-risk group (tumor markers positive group) and low-risk group (tumor markers negative group). The percentage of T lymphocytes and NK cells and levels of HLA class I on their surface were determined in these subjects by flow cytometry. RESULTS: Percentages of T lymphocytes and NK cells in peripheral-blood mononuclear cells did not vary with age. The expression level of HLA class I on peripheral T lymphocytes and NK cells was not affected by age or gender, but was significantly down-regulated in Lijiadian villagers (P < 0.05), especially on the surface of NK cells (P < 0.01). Compared with the low-risk group, there was a significant reduction of HLA class I on peripheral T lymphocytes (P < 0.05) and NK cells (P < 0.05) in the high-risk group. CONCLUSIONS: HLA class I on peripheral T lymphocytes and NK cells may be involved in tumorigenesis and development of gastrointestinal tumor, and understanding their changes in expression may provide new insights into the mechanism of tumor immunity.

[Study on the genotyping of human papillomavirus using a new DNA liquid chip in women of high-risk group of Shandong province].

OBJECTIVE: To evaluate the diagnostic applicability of human papillomavirus (HPV) liquid chip assay which is based on Luminex XMAP System, and perform a HPV epidemiologic study with the liquid chip in women of Shandong province. METHODS: To detect HPV genotypes on a 96-well plate with the liquid chip which can simultaneously detect and identify 26 common HPV genotypes in a total of 2925 cervical scrapes obtained from gynecological outpatients as well as to analyze the relationship between HPV types and different cervical diseases by studying the distribution of HPV genotypes and pathologic diagnosis. RESULTS: Among 639 cases who performed pathologic/cytological and histological diagnoses, 184 cases are in group of normal cytology, 266 cases in group of, 77 cases in group of cervical intra-epithelial neoplasia (CIN) I, 7 cases in group of CIN I - II, 46 cases in group of CIN I - II, 46 cases in group of CIN I - II and 13 cases in group of cervical cancer. The overall incidence of HPV in our samples is 36.0% (1054/2925) and 23 types of all 26 types on liquid chip are found. The most common genotypes found are HPV-16 (26.75%), HPV-52 (25.75%), HPV-58 (10.47%), HPV-18 (8.87%) and HPV-11 (6.94%). Among all the positive types, 87.32% are high-risk HPV and 13.68% are low-risk HPV genotypes. Both single and multiple types are easily identified, showing 66.22% ( n = 698) single type and 33.78% ( n = 356) multiple types. Of all the 1054 HPV-positive cases, 261 (24.8%) is occupied by women 21 to 25 years of age and progressively lower by older age groups, reaching 4.9% by women between 51 to 67 years old. The incidence of HPV in our samples is 23.37%, 33.08%, 54.54%, 57.14%, 82.61%, 91.30% and 100% for normal cytology, inflammation,CIN I ,CIN I - II, CIN II ,CIN III, and carcinomas specimens, respectively. Infections with more that one virus are common, accounted for 4.89%, 7.14%, 18.18%, 28.57%, 41.30%, 43.37% and 38.46% for normal cytology, inflammation, CIN I, CIN I - II, CIN II, CIN III, and carcinomas specimens, respectively. Based on the criteria of histology and pathology, the sensitivity, specificity, positive-predictive value and negative-predictive value of HPV liquid chip assay for detecting all cases of CIN II, III are 88.57%, 76.63%, 68.89% and 92.16% respectively. Conclusion The common types of HPV infection are 16, 52, 58, 18, 11, 6, 56 and 31. The HPV-positive rate increased along with the increase of grading on cervical lesions. There are more younger women among all the HPV-positive ones. Multiplex HPV genotyping by liquid chip appears to be highly suitable for diagnostic screening as well as the conduction of large-scale epidemiological studies.