Characterization of specific CD4 and CD8 T-cell responses in QuantiFERON TB Gold-Plus TB1 and TB2 tubes.

The new generation of the IGRA QuantiFERON-TB Gold Plus (QFT-Plus) includes two antigen tubes, TB1 and TB2 which contain specific Mycobacterium tuberculosis peptides designed to stimulate both CD4 and CD8 T-cells. TB1 is designed to target cell mediated responses from CD4 T-cells, while TB2 contains newly designed peptides designed to also stimulate CD8 T-cells. We identified specific CD4 and CD8 T-cell clones that recognize different regions spanning the length of the CFP-10 protein in M. tuberculosisto directly test in QFT-Plus TB1 and TB2 tubes, followed by Interferon-gamma detection by the QFT-Plus ELISA. These clones showed specific responses to the different QFT-Plus tubes, the CD4 T-cell clone showed dose-dependent responses to both TB1 and TB2 tubes, while the CD8 T-cell clones showed specific and targeted responses to the QFT-Plus TB2 tube (>140-fold difference) versus the QFT-Plus TB1 tubes using the QFT-Plus ELISA. This testing provides direct evidence of the specificity of CD8 T-cell mediated response in QFT-Plus TB2 tubes.

Human papillomavirus prevalence in a population of women living in Port-au-Prince and Leogane, Haiti.

BACKGROUND: There have been no published studies of carcinogenic human papillomavirus (HPV)--the necessary cause of cervical cancer--in Haiti, a nation that has one of the greatest burdens of cervical cancer globally. OBJECTIVE: Characterize prevalence of carcinogenic HPV and the prevalence of individual carcinogenic HPV genotypes in women with cervical precancer or cancer, cervical intraepithelial neoplasia grade 2 (CIN2) or more severe (CIN2+). METHODS: Women (n=9,769; aged 25-60 years) were screened for carcinogenic HPV by Hybrid Capture 2 (HC2; Qiagen, Gaithersburg, MD). Carcinogenic HPV positives underwent colposcopy and visible lesions were biopsied. A subset of carcinogenic HPV positives was tested for individual HPV genotypes using a GP5+/6+ assay. RESULTS: The prevalence of carcinogenic HPV was 19.0% (95% confidence interval: 18.4%-19.9%) and decreased with increasing age (ptrend < 0.001). Women with 3 or more sexual partners and who started sex before the age of 18 years had twice the age-adjusted prevalence of carcinogenic HPV of women with one partner and who started sex after the age of 21 (24.3% vs. 12.9%, respectively). HPV16 and HPV35 were the most common HPV genotypes detected in CIN2+ and more common in women with CIN2+ than those without CIN2+. HPV16 and/or HPV18 were detected in 21.0% of CIN2 (n = 42), 46.2% of CIN3 (n = 52), and 80% of cancers (n = 5). CONCLUSIONS: The prevalence of carcinogenic HPV in Haiti was much greater than the prevalence in other Latin American countries. High carcinogenic HPV prevalence and a lack of cervical cancer screening may explain the high burden of cervical cancer in Haiti.

Detection of human papillomavirus in anal specimens using the hybrid capture 2 assay.

The hc2 human papillomavirus DNA test (HC2) is effective when screening women for cervical dysplasia, and it might be effective in the screening for anal dysplasia. Differences between the anal and the cervical canals could affect the test performance. This prospective study (n=292) measured the HC2 signal and in agreement with a histologic endpoint of high-grade dysplasia for anal specimens collected in various ways. Sensitivities were 91%, 85%, and 62% for specimens collected in a sample transport medium and a liquid-based cytology medium processed by Gyn or Non-Gyn protocol, respectively. HC2 sensitivity and specificity to predict high-grade anal dysplasia were similar for brush or swab specimen collections, but HC2 signal was 6 times higher with the brush. Specificity and sensitivity were similar whether the sample was collected first or after a cytology sample for brush or swab, but swab specimens at the second collection had an HC2 signal (mean) 48% lower than that of the first collection, and the swab cellularity was lower. The presence of maximum stool decreased the HC2 signal in anal swab specimens. Consensus polymerase chain reaction (PCR) confirmed that the 13 human papillomavirus probe types in HC2 were optimal for performance. HC2 could potentially be further investigated for use in screening anal dysplasia. A larger prospective study is indicated.