Corrina Wright

Comparison of Seven Tests for High-Grade Cervical Intraepithelial Neoplasia in Women with Abnormal Smears: the Predictors 2 Study

ABSTRACT High-risk human papillomavirus (HPV) DNA/RNA testing provides higher sensitivity but lower specificity than cytology for the identification of high-grade cervical intraepithelial neoplasia (CIN). Several new HPV tests are now available for this purpose, and a direct comparison of their properties is needed. Seven tests were evaluated with samples in liquid PreservCyt transport medium from 1,099 women referred for colposcopy: the Hybrid Capture 2 (Qiagen), Cobas (Roche), PreTect HPV-Proofer (NorChip), Aptima HPV (Gen-Probe), and Abbott RealTime assays, the BD HPV test, and CINtec p16INK4a cytology (mtm laboratories) immunocytochemistry. Sensitivity, specificity, and positive predictive value (PPV) were based on the worst histology found on either the biopsy or the treatment specimen after central review. Three hundred fifty-nine women (32.7%) had CIN grade 2+ (CIN2+), with 224 (20.4%) having CIN3+. For detection of CIN2+, Hybrid Capture 2 had 96.3% sensitivity, 19.5% specificity, and 37.4% PPV. Cobas had 95.2% sensitivity, 24.0% specificity, and 37.6% PPV. The BD HPV test had 95.0% sensitivity, 24.2% specificity, and 37.8% PPV. Abbott RealTime had 93.3% sensitivity, 27.3% specificity, and 38.2% PPV. Aptima had 95.3% sensitivity, 28.8% specificity, and 39.3% PPV. PreTect HPV-Proofer had 74.1% sensitivity, 70.8% specificity, and 55.4% PPV. CINtec p16INK4a cytology had 85.7% sensitivity, 54.7% specificity, and 49.1% PPV. Cytology of a specimen taken at colposcopy (mild dyskaryosis or worse) had 88.9% sensitivity, 58.1% specificity, and 50.7% PPV. Our study confirms that, in a referral setting, HPV testing by a number of different tests provides high sensitivity for high-grade disease. Further work is needed to confirm these findings in a routine screening setting.

Comparing the performance of six human papillomavirus tests in a screening population

Background:Several new assays have been developed for high-risk HPV testing of cervical samples; we compare six HPV tests in a screening population.Methods:Residual material from liquid-based PreservCyt samples was assayed. Four tests (Hybrid Capture 2, Cobas, Abbott and Becton-Dickinson (BD)) measured HPV DNA while two used RNA (APTIMA and NorChip).Results:Positivity rates ranged from 13.4 to 16.3% for the DNA-based tests with a significantly lower positivity rate for the Abbott assay. The Gen-Probe APTIMA assay was positive in 10.3% of women, which was significantly lower than all the DNA tests; the NorChip PreTect HPV-Proofer test was much lower at 5.2%. 40 CIN2+ cases were identified, of which 19 were CIN3+. All CIN3+ cases were HPV positive by all tests except for one, which was negative by the Abbott assay and five which were negative by the NorChip test.Conclusion:All HPV tests except NorChip showed high sensitivity for high-grade lesions positive by cytology, suggesting co-testing is unnecessary when using HPV tests. Positivity rates in cytology-negative specimens were similar for the DNA-based tests, but lower for the APTIMA test suggesting this maintains the high sensitivity of DNA tests, but with better specificity.

Comparison of human papillomavirus testing strategies for triage of women referred with low-grade cytological abnormalities

AIM To compare triage strategies using different human papillomavirus (HPV) consensus and genotyping tests and a p16(INK4a) test. METHODS 1228 women referred with a borderline or single mildly dyskaryotic smear. Samples were taken at colposcopy using PreservCyt. Tests included Hybrid Capture 2, Abbott RealTime PCR, BD HPV, Cobas 4800, PreTect HPV-Proofer, APTIMA and p16(INK4a). Results were based on the worst histology within 9 months. RESULTS 97/1228 (7.9%) women had CIN3+ (203/1228 (17%) CIN2+). HPV testing alone using Hybrid Capture 2, Abbott RealTime PCR, BD HPV, Cobas 4800 or APTIMA had a sensitivity for CIN3+ ranging from 99.0% to 100.0% and specificity for <CIN2 from 23.3% to 34.7%. p16(INK4a) had a sensitivity of 86.8% and specificity of 50.7%. PreTect HPV-Proofer had a sensitivity of 85.1% and specificity of 73.2%. Testing for HPV type 16 only had sensitivities ranging from 66.0% to 75.5% and specificities from 81.3% to 87.6%. Dual testing with HPV type 16 combined with p16(INK4a) gave a high sensitivity for CIN3+ (78.7% to 98.0%) and specificity for <CIN2 of 58.6% to 81.5%. CONCLUSIONS Triage with sensitive HPV testing assays can substantially reduce the number of unnecessary referrals in women with low grade cytology with virtually no loss of sensitivity. Even greater gains can be made if p16 and type 16 are used, but some cases of CIN2 will be missed. In both cases short term surveillance will be needed.

Performance of Xpert MTB/RIF in the Diagnosis of Tuberculous Mediastinal Lymphadenopathy by Endobronchial Ultrasound

RATIONALE The Xpert (GeneXpert) MTB/RIF, an integrated polymerase chain reaction assay, has not been systematically studied in extrapulmonary and in particular mediastinal tuberculosis (TB). OBJECTIVES To investigate the performance of Xpert MTB/RIF in the diagnosis of intrathoracic nodal TB in a large tertiary urban medical center in the UK. METHODS We collected clinical, cytological, and microbiological data from two cohorts: 116 consecutive patients referred with mediastinal lymphadenopathy with detailed diagnostic information obtained, and an immediately subsequent second cohort of 52 consecutive patients with microbiologically confirmed mediastinal TB lymphadenopathy. All data were derived between January 2010 and October 2012. All patients underwent endobronchial ultrasound and transbronchial needle aspiration (TBNA). The performance of a single Xpert MTB/RIF assay alongside standard investigations, cytology, and microscopy/culture was evaluated against culture-confirmed TB. MEASUREMENTS AND MAIN RESULTS Microbiologically confirmed TB mediastinal lymphadenopathy was diagnosed in a total of 88 patients from both cohorts. Three culture-negative cases with associated caseating granulomatous inflammation on TBNA were given a probable diagnosis. A single Xpert MTB/RIF assay demonstrated overall sensitivity for culture-positive TB of 72.6% (62.3-81.0%). Xpert specificity from cohort 1 was 96.3% (89.1-99.1%). The positive predictive value was 88.9% (69.7-97.1%), negative predictive value was 86.5% (76.9-92.1%), and odds ratio was 51.3 (24.0-98.0) for correctly identifying culture-positive disease. Xpert captured all microscopy-positive cases (14 of 14) and the majority of microscopy-negative cases (48 of 71, 67.6%). Among the cases that were culture positive by TBNA, Xpert identified two-thirds of the multiple drug-resistant TB cases, leading to immediate regimen change up to 5 weeks ahead of positive cultures. The use of Xpert combined with cytology increased the sensitivity to 96.6%. CONCLUSIONS Xpert MTB/RIF provides a rapid, useful, and accurate test to diagnose mediastinal nodal TB in intermediate-incidence settings. The additional use of TBNA cytology further enhances the sensitivity of Xpert. This combination can facilitate rapid risk assessment and prompt TB treatment.

Performance of the Xpert HPV assay in women attending for cervical screening

Objectives This study evaluated the Xpert HPV Assay in women attending screening in general practice by comparing Xpert with two established HPV tests, cytology and histology. Methods A prospective study in women aged 20–60 years attending screening in Bristol, Edinburgh and London using residual Preservcyt cytology samples. Sample order was randomised between Roche cobas4800 and Cepheid Xpert assays with Qiagen hc2 third. Results 3408 cases were included in the primary analysis. Positivity for Xpert was 19.6%, cobas 19.2% and hc2 19.9% with high concordance (kappa=86.8% vs cobas, 81.55 vs hc2). Xpert, cobas and hc2 showed similar sensitivity (98.7%, 97.5%, 98.7%) for CIN2+. All pairwise comparisons had high concordance (Kappa ≥0.78 with any abnormal cytology. Xpert and hc2 were positive for all cases of ≥moderate dyskaryosis (N=63)), cobas was negative in two. Histology was available for 172 participants. 79 reported CIN2+, 47 CIN3+. All CIN3+ was positive on Xpert and hc2 and one case negative for cobas. One case of CIN2 was negative for all assays. Conclusions The performance of Xpert HPV Assay in a general screening population is comparable to established HPV tests. It offers simplicity of testing, flexibility with non-batching of individual samples and rapid turnaround time.

Innate activation of human primary epithelial cells broadens the host response to Mycobacterium tuberculosis in the airways

Early events in the human airways determining whether exposure to Mycobacterium tuberculosis (Mtb) results in acquisition of infection are poorly understood. Epithelial cells are the dominant cell type in the lungs, but little is known about their role in tuberculosis. We hypothesised that human primary airway epithelial cells are part of the first line of defense against Mtb-infection and contribute to the protective host response in the human respiratory tract. We modelled these early airway-interactions with human primary bronchial epithelial cells (PBECs) and alveolar macrophages. By combining in vitro infection and transwell co-culture models with a global transcriptomic approach, we identified PBECs to be inert to direct Mtb-infection, yet to be potent responders within an Mtb-activated immune network, mediated by IL1β and type I interferon (IFN). Activation of PBECs by Mtb-infected alveolar macrophages and monocytes increased expression of known and novel antimycobacterial peptides, defensins and S100-family members and epithelial-myeloid interactions further shaped the immunological environment during Mtb-infection by promoting neutrophil influx. This is the first in depth analysis of the primary epithelial response to infection and offers new insights into their emerging role in tuberculosis through complementing and amplifying responses to Mtb.

Primary nodal anthracosis identified by EBUS-TBNA as a cause of FDG PET/CT positive mediastinal lymphadenopathy

Isolated mediastinal lymphadenopathy can result from a number of potentially serious aetiologies. Traditionally those presenting with mediastinal lymphadenopathy would undergo mediastinoscopy to elucidate a final diagnosis or receive empirical treatment. There is now increased utilization of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA), in this setting. Five cases of mediastinal lymphadenopathy are presented here in which lymph node anthracosis was identified as the primary diagnosis using EBUS-TBNA. They were female, non-smokers presenting with non-specific symptoms, who retrospectively reported cooking over wood fires. Four were from South Asia. Three were investigated by F-18-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) scanning and increased signal was identified in the anthracotic nodes sampled. With expansion of PET/CT and EBUS-TBNA services it is likely that primary nodal anthracosis will be encountered more frequently and should be considered in the differential diagnosis of those with PET/CT positive lymphadenopathy. It may mimic pathologies including tuberculosis and malignancy, thus accurate sampling and follow-up are essential.

Post-tuberculous fibrosing mediastinitis: a review of the literature

Fibrosing mediastinitis (FM) is a rare disease where there is thickening of the fibrous tissue in the mediastinum. While histoplasmosis is the the most common recognised cause, the link with tuberculosis (TB) has been rarely documented. We review the link between TB and FM, and describe a case of probable TB-related FM.Our case is of a 74-year-old man who presented with breathlessness 3 years after fully treated TB. Scans revealed a calcified soft tissue mass within the mediastinum, and a diagnosis of fibrosing mediastinitis resulting in pulmonary hypertension was made. Tests for histoplasmosis and IgG4 staining were negative. Surgical intervention was not felt to be beneficial, and he was treated with prednisolone and mycophenolate mofetil.In the review, we highlight the two forms of mediastinitis—granulomatous versus fibrous, and how these two entities may be on a spectrum of disease progression. We also explore the prevalence, clinical presentation, pathogenesis, imaging techniques and treatment options of TB-related FM.