Evaluation of Pre-Analytical Variables for Human Papillomavirus Primary Screening from Self-Collected Vaginal Swabs

Human papillomavirus (HPV) primary screening is an effective approach to assessing cervical cancer risk. Self-collected vaginal swabs can expand testing access, but the data defining analytical performance criteria necessary for adoption of self-collected specimens are limited, especially for those occurring outside the clinic, where the swab remains dry during transport. Here, we evaluated the performance of self-collected vaginal swabs for HPV detection using the Cobas 6800. There was insignificant variability between swabs self-collected by the same individual (n = 15 participants collecting 5 swabs per participant), measured by amplification of HPV and human β-globin control DNA. Comparison of self-collected vaginal swab and provider-collected cervical samples (n = 144 pairs) proved highly concordant for HPV detection (total agreement = 90.3%; positive percentage agreement = 84.2%). There was no relationship between the number of dry storage days and amplification of HPV (n = 68; range, 4 to 41 days). Exposure of self-collected dry swabs to extreme summer and winter temperatures did not affect testing outcomes. A second internal control (RNase P) demonstrated that lack of amplification for β-globin from self-collected specimens was consistent with poor, but not absent, cellularity. These data suggest that self-collected vaginal samples enable accurate clinical HPV testing, and that extended ambient dry storage or exposure to extreme temperatures does not influence HPV detection. Furthermore, lack of β-globin amplification in HPV-negative samples accurately identified participants who required recollection.

Recommendations for Use of p16/Ki67 Dual Stain for Management of Individuals Testing Positive for Human Papillomavirus

OBJECTIVES

The Enduring Consensus Cervical Cancer Screening and Management Guidelines Committee developed recommendations for dual stain (DS) testing with CINtec PLUS Cytology for use of DS to triage high-risk human papillomavirus (HPV)-positive results.

METHODS

Risks of cervical intraepithelial neoplasia grade 3 or worse were calculated according to DS results among individuals testing HPV-positive using data from the Kaiser Permanente Northern California cohort and the STudying Risk to Improve DisparitiES study in Mississippi. Management recommendations were based on clinical action thresholds developed for the 2019 American Society for Colposcopy and Cervical Pathology Risk-Based Management Consensus Guidelines. Resource usage metrics were calculated to support decision-making. Risk estimates in relation to clinical action thresholds were reviewed and used as the basis for draft recommendations. After an open comment period, recommendations were finalized and ratified through a vote by the Consensus Stakeholder Group.

RESULTS

For triage of positive HPV results from screening with primary HPV testing (with or without genotyping) or with cytology cotesting, colposcopy is recommended for individuals testing DS-positive. One-year follow-up with HPV-based testing is recommended for individuals testing DS-negative, except for HPV16- and HPV18-positive results, or high-grade cytology in cotesting, where immediate colposcopy referral is recommended. Risk estimates were similar between the Kaiser Permanente Northern California and STudying Risk to Improve DisparitiES populations. In general, resource usage metrics suggest that compared with cytology, DS requires fewer colposcopies and detects cervical intraepithelial neoplasia grade 3 or worse earlier.

CONCLUSIONS

Dual stain testing with CINtec PLUS Cytology is acceptable for triage of HPV-positive test results. Risk estimates are portable across different populations.

Using Natural Language Processing to Improve Discrete Data Capture From Interpretive Cervical Biopsy Diagnoses at a Large Health Care Organization

CONTEXT.—

The terminology used by pathologists to describe and grade dysplasia and premalignant changes of the cervical epithelium has evolved over time. Unfortunately, coexistence of different classification systems combined with nonstandardized interpretive text has created multiple layers of interpretive ambiguity.

OBJECTIVE.—

To use natural language processing (NLP) to automate and expedite translation of interpretive text to a single most severe, and thus actionable, cervical intraepithelial neoplasia (CIN) diagnosis.

DESIGN.—

We developed and applied NLP algorithms to 35 847 unstructured cervical pathology reports and assessed NLP performance in identifying the most severe diagnosis, compared to expert manual review. NLP performance was determined by calculating precision, recall, and F score.

RESULTS.—

The NLP algorithms yielded a precision of 0.957, a recall of 0.925, and an F score of 0.94. Additionally, we estimated that the time to evaluate each monthly biopsy file was significantly reduced, from 30 hours to 0.5 hours.

CONCLUSIONS.—

A set of validated NLP algorithms applied to pathology reports can rapidly and efficiently assign a discrete, actionable diagnosis using CIN classification to assist with clinical management of cervical pathology and disease. Moreover, discrete diagnostic data encoded as CIN terminology can enhance the efficiency of clinical research.

Effective Access to Laboratory Test Results: A Health Equity Issue that Enhances Diagnostic Excellence

Access to laboratory test results through patient portals is a health equity issue for patients with limited English proficiency (LEP), particularly for Spanish-speaking patients, the largest minority group in the USA. Gaps ranging from linguistic, cultural, and socioeconomic disparities to lack of systematic approaches (e.g., implementation of specific support protocols, policies) are among the identified factors that limit LEP patients' access to patient portals. This paper summarizes initiatives healthcare providers, laboratory professionals, and portal developers can use to address disparities that affect >26 million LEPs while improving their health equity.

Distribution of High-Sensitivity Cardiac Troponin and N-Terminal Pro-Brain Natriuretic Peptide in Healthy Transgender People

Importance

Sex-specific differences in the commonly used cardiac biomarkers high-sensitivity cardiac troponin (hs-cTn) and N-terminal pro-brain natriuretic peptide (NT-proBNP) are apparent. There is an absence of medical literature delineating the concentration differences for these biomarkers in transgender individuals without cardiac disease.

Objective

To determine the distribution of hs-cTn and NT-proBNP in healthy transgender people.

Design, Setting, and Participants

In this cross-sectional prospective study, healthy transgender individuals prescribed testosterone or estradiol for 12 months or more were recruited from internal medicine and primary care clinics that specialize in transgender medical care between November 1, 2017, and July 1, 2018.

Exposures

Testosterone or estradiol for 12 months.

Main Outcomes and Measures

Concentrations for hs-cTnI (troponin I), hs-cTnT (troponin T), and NT-proBNP were measured.

Results

Transgender people prescribed testosterone (n = 79; mean [SD] age, 28.8 [7.8] years) or estrogen (n = 93; mean [SD] age, 35.1 [11.7] years) were recruited. The concentration of hs-cTn was significantly higher in transgender men relative to transgender women. For Abbott hs-cTnI levels, the median (IQR) concentration observed in transgender men and women was 0.9 (0.6-1.7) ng/L and 0.6 (0.3-1.0) ng/L, respectively. Results were similar across 2 additional hs-cTn assays. In contrast, NT-proBNP level was higher in transgender women. The median (IQR) NT-proBNP concentration was significantly higher in transgender women ( 49 [32-86] ng/L) than in transgender men (17 [13-27] ng/L).

Conclusions and Relevance

Findings of this cross-sectional study suggest that the differences in concentration for hs-cTn and NT-proBNP between transgender men and women were similar to what is observed between cisgender men and women. Sex hormones, rather than sex assigned at birth, may be a stronger driver of the observed concentration differences between healthy men and women for biomarkers of cardiac disease.

Accuracy and Efficiency of Deep-Learning-Based Automation of Dual Stain Cytology in Cervical Cancer Screening

Background

With the advent of primary human papillomavirus testing followed by cytology for cervical cancer screening, visual interpretation of cytology slides remains the last subjective analysis step and suffers from low sensitivity and reproducibility.

Methods

We developed a cloud-based whole-slide imaging platform with a deep-learning classifier for p16/Ki-67 dual-stained (DS) slides trained on biopsy-based gold standards. We compared it with conventional Pap and manual DS in 3 epidemiological studies of cervical and anal precancers from Kaiser Permanente Northern California and the University of Oklahoma comprising 4253 patients. All statistical tests were 2-sided.

Results

In independent validation at Kaiser Permanente Northern California, artificial intelligence (AI)-based DS had lower positivity than cytology (P < .001) and manual DS (P < .001) with equal sensitivity and substantially higher specificity compared with both Pap (P < .001) and manual DS (P < .001), respectively. Compared with Pap, AI-based DS reduced referral to colposcopy by one-third (41.9% vs 60.1%, P < .001). At a higher cutoff, AI-based DS had similar performance to high-grade squamous intraepithelial lesions cytology, indicating a risk high enough to allow for immediate treatment. The classifier was robust, showing comparable performance in 2 cytology systems and in anal cytology.

Conclusions

Automated DS evaluation removes the remaining subjective component from cervical cancer screening and delivers consistent quality for providers and patients. Moving from Pap to automated DS substantially reduces the number of colposcopies and also achieves excellent performance in a simulated fully vaccinated population. Through cloud-based implementation, this approach is globally accessible. Our results demonstrate that AI not only provides automation and objectivity but also delivers a substantial benefit for women by reduction of unnecessary colposcopies.

Role of Screening History in Clinical Meaning and Optimal Management of Positive Cervical Screening Results

BACKGROUND

Cervical cancer is caused by persistent human papillomavirus (HPV) infection. US consensus management guidelines for a positive cervical screening result typically focus on the current screening result only. A negative testing history may alter risk of the following positive screening results, caused by a new HPV infection, and therefore its optimal management.

METHODS

Women ages 30 years and older were screened with triennial HPV and cytology co-testing at Kaiser Permanente Northern California from 2003 to 2014. We estimated the subsequent 5-year risks of cervical intraepithelial neoplasia grade 3 or more severe diagnoses (CIN3+) in a cohort of 1 156 387 women following abnormal (atypical squamous cells of undetermined significance [ASC-US] or worse) cytology and/or positive HPV testing, when the test result followed 0 (n = 990 013), 1 (n = 543 986), 2 (n = 245 974), or 3 (n = 79 946) consecutive negative co-test(s). All statistical tests were two-sided.

RESULTS

Following 0-3 successive negative co-tests, 5-year CIN3+ risks following a positive HPV test decreased progressively from 7.2% (95% CI = 7.0% to 7.4%) to 1.5% (95% CI = 0.7% to 3.4%) (Ptrend < .001). Similarly, risks following an abnormal (ASC-US or worse) cytology result decreased from 6.6% (95% CI = 6.4% to 6.9%) to 1.1% (95% CI = 0.5% to 2.3%) (Ptrend < .001). Risks following low-grade squamous intraepithelial lesion, the risk threshold for referral to colposcopy in the United States, decreased from 5.2% (95% CI = 4.7% to 5.7%) to 0.9% (95% CI = 0.2% to 4.3%). Risks following high-grade squamous intraepithelial lesion or more severe, a specific marker for the presence of precancerous lesions, decreased from 50.0% (95% CI = 47.5% to 52.5%) to 10.0% (95% CI = 2.6% to 34.4%).

CONCLUSIONS

Following one or more sequential antecedent, documented negative co-tests or HPV tests, women with HPV-positive ASC-US or low-grade squamous intraepithelial lesion might have sufficiently low CIN3+ risk that they do not need colposcopy referral and might instead undergo 6-12-month surveillance for evidence of higher risk before being referred to colposcopy.

A study of the risks of CIN3+ detection after multiple rounds of HPV testing: Results of the 15-year cervical cancer screening experience at Kaiser Permanente Northern California

Many countries are transitioning to HPV testing for cervical cancer screening, despite a lack of long-term experience. To anticipate multi-round screening performance, we analyzed 15-year HPV testing results at Kaiser Permanente Northern California (KPNC). We evaluated HPV test result patterns among women aged 30-64 undergoing triennial HPV/cytology cotesting at KPNC during 2003-2018. We calculated incidence rates and proportion of CIN3+ diagnoses associated with the most frequent HPV testing patterns overall and stratified by age. From 2003 to 2018, a total of 1,361,581 women had a valid HPV test result, and 7,087 were diagnosed with CIN3+. Incidence rates of CIN3+ after HPV positivity were lowest when HPV detection was new and highest in women with prevalent infections (770 vs. 13,910/100,000 person-years). Repeat test negativity reduced subsequent incidence rates of CIN3+ to extremely low levels (18/100,000 person-years following four consecutive negative results). For mixed patterns of positivity/negativity, the recency and frequency of positive tests were associated with increased rates of CIN3+ diagnosis. Most CIN3+ cases (76%) were diagnosed in women who were positive at baseline (the first known positive HPV result); 16% were attributed to apparent newly detected infections and 3% to possible reappearing infections. These results corroborate previous findings that current HPV positivity, particularly when prevalent rather than new, is associated with the highest rates of CIN3+. In a screening program implementing HPV testing, most CIN3+ is detected at the first HPV positive test.

Relative Performance of HPV and Cytology Components of Cotesting in Cervical Screening

Background

The main goal of cervical screening programs is to detect and treat precancer before cancer develops. Human papillomavirus (HPV) testing is more sensitive than cytology for detecting precancer. However, reports of rare HPV-negative, cytology-positive cancers are motivating continued use of both tests (cotesting) despite increased testing costs.

Methods

We quantified the detection of cervical precancer and cancer by cotesting compared with HPV testing alone at Kaiser Permanente Northern California (KPNC), where 1 208 710 women age 30 years and older have undergone triennial cervical cotesting since 2003. Screening histories preceding cervical cancers (n = 623) and precancers (n = 5369) were examined to assess the relative contribution of the cytology and HPV test components in identifying cases. The performances of HPV testing and cytology were compared using contingency table methods, general estimating equation models, and nonparametric statistics; all statistical tests were two-sided.

Results

HPV testing identified more women subsequently diagnosed with cancer (P < .001) and precancer (P < .001) than cytology. HPV testing was statistically significantly more likely to be positive for cancer at any time point (P < .001), except within 12 months (P = .10). HPV-negative/cytology-positive results preceded only small fractions of cases of precancer (3.5%) and cancer (5.9%); these cancers were more likely to be regional or distant stage with squamous histopathology than other cases. Given the rarity of cancers among screened women, the contribution of cytology to screening translated to earlier detection of at most five cases per million women per year. Two-thirds (67.9%) of women found to have cancer during 10 years of follow-up at KPNC were detected by the first cotest performed.

Conclusions

The added sensitivity of cotesting vs HPV alone for detection of treatable cancer affected extremely few women.

Clinical Evaluation of Human Papillomavirus Screening With p16/Ki-67 Dual Stain Triage in a Large Organized Cervical Cancer Screening Program

IMPORTANCE

As cervical cancer screening transitions from Papanicolaou cytologic screening to primary human papillomavirus (HPV) testing worldwide, effective triage tests are needed to decide who among the HPV-positive women should receive further diagnostic evaluation to avoid unnecessary colposcopies and biopsies.

OBJECTIVE

To evaluate the performance of the p16/Ki-67 dual stain (DS) and HPV16/18 genotyping for the triage of HPV-positive women.

DESIGN, SETTING, AND PARTICIPANTS

A prospective observational study was conducted within the cervical cancer screening program at Kaiser Permanente Northern California of 3225 HPV-positive women undergoing HPV and Papanicolaou cytologic testing with a valid DS result from September 16 to October 31, 2015, with follow-up through December 31, 2018.

EXPOSURES

Human papillomavirus screening with partial genotyping and cytologic triage compared with DS triage.

MAIN OUTCOMES AND MEASURES

Cervical intraepithelial neoplasia grade 3 or more severe (CIN3+) and grade 2 or more severe (CIN2+), diagnosed within 3 years after sample collection.

RESULTS

A total of 3225 women (mean [SD] age, 37.9 [11.3] years) participated in the study. For triage of HPV-positive women with partial genotyping, DS showed better risk stratification for CIN3+ than did Papanicolaou cytologic testing, with women with positive DS results having a higher risk than women with positive Papanicolaou test results for CIN3+ (218 of 1818 [12.0%; 95% CI, 10.5%-13.5%] vs 219 of 2128 [10.3%; 95% CI, 9.0%-11.6%]; P = .005). Similarly, DS showed better risk stratification for CIN3+ compared with Papanicolaou cytologic testing in HPV-positive women, irrespective of genotyping. The greatest reassurance against CIN3+ was observed in HPV16/18-negative women with negative DS results, with a risk low enough to extend retesting intervals. Dual stain triage strategies required substantially fewer colposcopies per detection of CIN3+ compared with Papanicolaou cytologic testing, with a 32.1% (859 of 2677) reduction of colposcopies compared with the currently recommended triage strategy of HPV screening with Papanicolaou cytologic testing. Results for CIN2+ were very similar.

CONCLUSIONS AND RELEVANCE

Triage of HPV-positive women with DS was superior to Papanicolaou cytologic testing in this study, demonstrating equal immediate detection of precancerous lesions and substantially reduced referral to colposcopy. These findings suggest that DS can safely replace Papanicolaou cytologic testing as a triage strategy for primary HPV screening, and that retesting intervals in HPV16/18-negative women with negative DS results can be safely extended to 3 years.

Reference Intervals Generated by Electronic Medical Record Data Mining with Clinical Exclusions: Age-Specific Intervals for Thyroid-Stimulating Hormone from 33038 Euthyroid Patients

BACKGROUND

Serum thyroid-stimulating hormone (TSH) reference intervals are dependent on population characteristics, including prevalent thyroid disease and iodine status. Studies in the US have demonstrated increasing TSH levels with age, and the American Thyroid Association recommends higher TSH goals for older patients taking thyroid supplementation, but few laboratories offer age-specific reference intervals for TSH. Our objective was to establish TSH reference ranges in our racially diverse population in northern California.

METHODS

Data mining of electronic medical records was used with the a posteriori approach to select a euthyroid reference population for TSH reference intervals. A report gathered all TSH results from 2 weeks from >1 year in the past, excluding results from patients with thyroid-related disease or medication use at any time before or after the TSH test.

RESULTS

The reference population numbered 33038 and consisted of approximately 44% of the total TSH results reported in the selected time periods. The population identified as 46.5% white, 18.3% Asian, 17.0% Hispanic/Latino, 8.0% black/African American, and 10.3% other or unknown. These data demonstrate an increase in the median and 97.5 percentile of TSH levels with increasing age in adults. No clinically significant difference was seen between female and male individuals or between the self-identified races, except for lower TSH levels in the black/African American population.

CONCLUSIONS

The a posteriori approach using data mining for disease-specific criteria proved to be an efficient method for obtaining a large healthy reference population. Age-specific TSH reference ranges could prevent inappropriate diagnoses of subclinical hypothyroidism in older patients.

High sensitivity 8-color flow cytometry assay for paroxysmal nocturnal hemoglobinuria granulocyte and monocyte detections

Flow cytometry is the gold standard in diagnosis of paroxysmal nocturnal hemoglobinuria (PNH) by detecting the absence of glycol-phosphatidyl inositol (GPI)-linked protein expression on granulocyte and monocyte surfaces. However, the current assays are not optimized and require improvement, particularly in reducing background fluorescence and optimizing sensitivity and specificity. With more fluorochromes available and with advances in instrument engineering, rare populations may be identified with high sensitivity. The present study assessed an 8-color combination of comprehensive GPI-linked markers, namely fluorescein-labeled proaerolysin (FLAER), cluster of differentiation 157 (CD157), CD24 and CD14, and the lineage markers for granulocyte (CD15) and monocyte (CD64) cells to detect PNH clones. Additionally, to optimize the PNH flow assay, a 'dump' channel was used, comprised of CD5 and CD19, to exclude non-specific binding in order to reduce background. This method aimed to improve sensitivity and reduce the background to create an optimized PNH flow cocktail. The results demonstrated that the current 4-color PNH combination identifies a CD55^- and FLAER⁺ population that is not PNH clones. By contrast, the 8-color panel delineated PNH clones from both monocyte and granulocytes by using granulocyte antigen (CD15) and monocyte antigen (CD64) as a gating strategy. The sensitivity was 0.01% for granulocytes and 0.05% for monocytes with an acquisition of 100,000 monocyte and granulocyte events. The background on a normal whole blood sample was 0.00076% on monocytes and 0.00277% on granulocytes. Thus, overall, the 8-color PNH assay exhibited high levels of specificity and sensitivity. The 8-color combination facilitated the improvement and enhancement of sensitivity in PNH clone identification, and may provide a useful tool for pathologists in PNH diagnosis and for monitoring patients at risk of developing classical/hemolytic PNH, to enable treatment to be delivered promptly.

Epidemiologic Evidence That Excess Body Weight Increases Risk of Cervical Cancer by Decreased Detection of Precancer

Purpose Obesity has been inconsistently linked to increased cervical cancer incidence and mortality; however, the effect of obesity on cervical screening has not been explored. We investigated the hypothesis that increased body mass might decrease detection of cervical precancer and increase risk of cervical cancer even in women undergoing state-of-the-art screening. Methods We conducted a retrospective cohort study of 944,227 women age 30 to 64 years who underwent cytology and human papillomavirus DNA testing (ie, cotesting) at Kaiser Permanente Northern California (January 2003 to December 2015). Body mass index was categorized as normal/underweight (< 25 kg/m²), overweight (25 to < 30 kg/m²), or obese (≥ 30 kg/m²). We estimated 5-year cumulative risks of cervical precancer and cancer by category of body mass index using logistic Weibull survival models. Results We observed lower risk of cervical precancer (n = 4,489) and higher risk of cervical cancer (n = 490) with increasing body mass index. Specifically, obese women had the lowest 5-year risk of precancer (0.51%; 95% CI, 0.48% to 0.54% v 0.73%; 95% CI, 0.70% to 0.76% in normal/underweight women; P trend < .001). In contrast, obese women had the highest 5-year risk of cancer (0.083%; 95% CI, 0.072% to 0.096% v 0.056%; 95% CI, 0.048% to 0.066% in normal/underweight women; P trend < .001). Results were consistent in subgroups defined by age (30 to 49 v 50 to 64 years), human papillomavirus status (positive v negative), and histologic subtype (glandular v squamous). Approximately 20% of cervical cancers could be attributed to overweight or obesity in the women in our study who underwent routine cervical screening. Conclusion In this large, screened population, overweight and obese women had an increased risk of cervical cancer, likely because of underdiagnosis of cervical precancer. Improvements in equipment and/or technique to assure adequate sampling and visualization of women with elevated body mass might reduce cervical cancer incidence.

Effect of Several Negative Rounds of Human Papillomavirus and Cytology Co-testing on Safety Against Cervical Cancer: An Observational Cohort Study

BACKGROUND

Current U.S. cervical cancer screening and management guidelines do not consider previous screening history, because data on multiple-round human papillomavirus (HPV) and cytology "co-testing" have been unavailable.

OBJECTIVE

To measure cervical cancer risk in routine practice after successive negative screening co-tests at 3-year intervals.

DESIGN

Observational cohort study.

SETTING

Integrated health care system (Kaiser Permanente Northern California, Oakland, California).

PATIENTS

990 013 women who had 1 or more co-tests from 2003 to 2014.

MEASUREMENTS

3- and 5-year cumulative detection of (risk for) cervical intraepithelial neoplasia grade 3, adenocarcinoma in situ, and cervical cancer (≥CIN3) in women with different numbers of negative co-tests, overall and within subgroups defined by previous co-test results or baseline age.

RESULTS

Five-year ≥CIN3 risks decreased after each successive negative co-test screening round (0.098%, 0.052%, and 0.035%). Five-year ≥CIN3 risks for an HPV-negative co-test, regardless of the cytology result, nearly matched the performance (reassurance) of a negative co-test for each successive round of screening (0.114%, 0.061%, and 0.041%). By comparison, ≥CIN3 risks for the cytology-negative co-test, regardless of the HPV result, also decreased with each successive round, but 3-year risks were as high as 5-year risks after an HPV-negative co-test (0.199%, 0.065%, and 0.043%). No interval cervical cancer cases were diagnosed after the second negative co-test. Independently, ≥CIN3 risks decreased with age. Length of previous screening interval did not influence future ≥CIN3 risks.

LIMITATION

Interval-censored observational data.

CONCLUSION

After 1 or more negative cervical co-tests (or HPV tests), longer screening intervals (every 5 years or more) might be feasible and safe.

PRIMARY FUNDING SOURCE

National Cancer Institute Intramural Research Program.

Why does cervical cancer occur in a state-of-the-art screening program?

BACKGROUND

The goal of cervical screening is to detect and treat precancers before some become cancer. We wanted to understand why, despite state-of-the-art methods, cervical cancers occured in relationship to programmatic performance at Kaiser Permanente Northern California (KPNC), where >1,000,000 women aged ≥30years have undergone cervical cancer screening by triennial HPV and cytology cotesting since 2003.

METHODS

We reviewed clinical histories preceding cervical cancer diagnoses to assign "causes" of cancer. We calculated surrogate measures of programmatic effectiveness (precancers/(precancers and cancers)) and diagnostic yield (precancers and cancers per 1000 cotests), overall and by age at cotest (30-39, 40-49, and ≥50years).

RESULTS

Cancer was rare and found mainly in a localized (treatable) stage. Of 623 cervical cancers with at least one preceding or concurrent cotest, 360 (57.8%) were judged to be prevalent (diagnosed at a localized stage within one year or regional/distant stage within two years of the first cotest). Non-compliance with recommended screening and management preceded 9.0% of all cancers. False-negative cotests/sampling errors (HPV and cytology negative), false-negative histologic diagnoses, and treatment failures preceded 11.2%, 9.0%, and 4.3%, respectively, of all cancers. There was significant heterogeneity in the causes of cancer by histologic category (p<0.001 for all; p=0.002 excluding prevalent cases). Programmatic effectiveness (95.3%) and diagnostic yield were greater for squamous cell versus adenocarcinoma histology (p<0.0001) and both decreased with older ages (ptrend<0.0001).

CONCLUSIONS

A state-of-the-art intensive screening program results in very few cervical cancers, most of which are detected early by screening. Screening may become less efficient at older ages.

Serum Fibrosis Marker Panels FIB-4 Index and Aspartate Aminotransferase (AST)-to-Platelet Ratio Index (APRI) Are Equivalent to AST Alone at Predicting Liver Fibrosis in a Cohort of 1731 Patients Infected with Hepatitis C Virus

BACKGROUND

Efficient tools are needed to stage liver disease before treatment of patients infected with hepatitis C virus (HCV). Compared to biopsy, several studies demonstrated favorable performance of noninvasive multianalyte serum fibrosis marker panels [fibrosis-4 (FIB-4) index] and aspartate aminotransferase (AST)-to-platelet ratio index (APRI), but suggested cutoffs vary widely. Our objective was to evaluate FIB-4 index and APRI and their component tests for staging fibrosis in our HCV-infected population and to determine practical cutoffs to help triage an influx of patients requiring treatment.

METHODS

Transient elastography (TE) results from 1731 HCV-infected patients were mapped to an F0-F4 equivalent scale. Each patient's APRI and FIB-4 index were calculated. Areas under the receiver operator curve (AUROCs) and false-positive and false-negative rates were calculated to retrospectively compare the performance of the indices and their component tests.

RESULTS

The highest AUROCs for distinguishing severe (F3-F4) from mild-to-moderate (F0-F2) fibrosis had overlapping 95% CIs: APRI (0.77; 0.74-0.79), FIB-4 index (0.76; 0.73-0.78), and AST (0.74; 0.72-0.77). Cutoffs had false-negative rates of 2.7%-2.8% and false-positive rates of 6.4%-7.4% for all 3 markers.

CONCLUSIONS

AST was as effective as FIB-4 index and APRI at predicting fibrosis. Published cutoffs for APRI and FIB-4 index would have been inappropriate in our population, with false-negative rates as high as 11%. For our purposes, no serum fibrosis marker was sufficiently sensitive to rule-out significant fibrosis, but cutoffs developed for AST, FIB-4 index, and APRI all had specificities of 79.2%-80.3% for ruling-in severe fibrosis and could be used to triage 1/3 of our population for treatment without waiting for TE or liver biopsy.

Improving American Healthcare Through "Clinical Lab 2.0": A Project Santa Fe Report

Project Santa Fe was established both to provide thought leadership and to help develop the evidence base for the valuation of clinical laboratory services in the next era of American healthcare. The participants in Project Santa Fe represent major regional health systems that can operationalize laboratory-driven innovations and test their valuation in diverse regional marketplaces in the United States. We provide recommendations from the inaugural March 2016 meeting of Project Santa Fe. Specifically, in the transition from volume-based to value-based health care, clinical laboratories are called upon to provide programmatic leadership in reducing total cost of care through optimization of time-to-diagnosis and time-to-effective therapeutics, optimization of care coordination, and programmatic support of wellness care, screening, and monitoring. This call to action is more than working with industry stakeholders on the basis of our expertise; it is providing leadership in creating the programs that accomplish these objectives. In so doing, clinical laboratories can be effectors in identifying patients at risk for escalation in care, closing gaps in care, and optimizing outcomes of health care innovation. We also hope that, through such activities, the evidence base will be created for the new value propositions of integrated laboratory networks. In the very simplest sense, this effort to create “Clinical Lab 2.0” will establish the impact of laboratory diagnostics on the full 100% spend in American healthcare, not just the 2.5% spend attributed to in vitro diagnostics. In so doing, our aim is to empower regional and local laboratories to thrive under new models of payment in the next era of American health care delivery.

Challenges in harmonizing integrated healthcare network laboratories: multi-center evaluation of the hCG5 assay

BACKGROUND

Beckman Coulter recently introduced a new hCG assay manufactured for the Access 2 and DxI platforms. This assay is the first to use the 5th International Standard (5th IS) as its primary calibration material. Clinical laboratories are required to validate the method performance before testing and reporting patient results.

METHODS

Beckman Coulter Access 2 instruments (n=41) across Kaiser Permanente Northern California were evaluated for their performance characteristics using the hCG5 reagent. Precision, linearity, dilution verification, and patient sample comparisons were performed on each instrument.

RESULTS

The assay was linear up to 1350IU/L. Intra-day and inter-day precision ranged from 1.0%-3.3% and 1.8-7.3%, respectively, for the low QC material (mean concentration 4.6IU/L). Percent bias between the previous assay (hCG2) and the hCG5 assay was 3.2 to 22.7% for hCG concentrations <1000IU/L and -2.9 to 30% for concentrations >1000IU/L. On board and manual dilutions agreed within 15% following proper adjustment of the instrument dilution factor.

CONCLUSIONS

Achieving Access 2 inter-instrument agreement on specimens needing dilutions (hCG>1350IU/L) requires validation of the on board dilution factor. Laboratories should use QC material above the linear range to monitor instrument dilution accuracy and precision.

Falsely undetectable TSH in a cohort of South Asian euthyroid patients

CONTEXT

An index case of a clinically euthyroid woman of South Asian descent was identified with discordant TSH results: undetectable TSH on our routine assay and normal TSH on an alternate assay. Low TSH concentrations due to functionally compromising TSH mutations have been reported. Here we describe a new phenomenon of functional TSH that is undetectable by 4 widely used US Food and Drug Administration (FDA)-approved TSH immunoassays marketed by a single vendor.

OBJECTIVE

The purpose of this study was to identify additional cases and investigate the cause of the falsely undetectable TSH.

DESIGN

All samples with TSH results of <0.01 μIU/mL were retested with a second TSH assay. Discordant samples were evaluated on up to 8 FDA-approved TSH immunoassays and the TSHβ gene was sequenced. Retrospectively, thyroid function tests, diagnoses, and medications from 1.6 million individuals were analyzed.

RESULTS

Out of approximately 2 million individuals, we have identified a cohort of 20 hypothyroid and euthyroid patients of shared ethnicity with falsely undetectable TSH (<0.01 μIU/mL) in 4 of 8 commercially available TSH assays. Half of these individuals were initially treated based on repeated falsely undetectable TSH values (7 euthyroid patients were treated with methimazole and 2 hypothyroid patients had doses of levothyroxine decreased). In all cases, a retrospective chart review revealed that clinical assessments and free T4 and total T3 results were inconsistent with the undetectable TSH results. Specific antibodies failing to detect TSH in these cases were identified in the 4 affected assays. A novel TSHβ point mutation was identified.

CONCLUSIONS

Our data suggest that these individuals have a previously unrecognized, functionally normal, TSH variant to which some monoclonal antibodies fail to bind. To assure appropriate patient management, clinicians and laboratorians need to be aware that certain TSH variants may be undetectable in some hyperselective TSH assays.

Development of an equation to correct for hemolysis in direct bilirubin measurements

BACKGROUND

Direct bilirubin is measured for the investigation of pediatric and adult jaundice. Package inserts suggest that hemolysis decreases direct bilirubin measurements, but no published studies have adequately described the extent of interference.

METHODS

The influence of hemolysis on direct bilirubin quantification (Beckman AU680) was evaluated by titrating increasing amounts of hemoglobin into specimens with variable starting concentrations of direct bilirubin. An equation was derived to predict the nominal interference-free concentration of direct bilirubin as a function of measured concentration and hemolysis-index.

RESULTS

Hemolysis decreased the direct bilirubin concentration reported by the AU680. The extent of interference is a function of both the interference-free concentration of direct bilirubin and the degree of hemolysis.

CONCLUSIONS

The concentration of direct bilirubin in hemolyzed specimens can be predicted.

Identification of one or two α-globin gene deletions by isoelectric focusing electrophoresis

OBJECTIVES

To investigate the utility of isoelectric focusing electrophoresis (IEF) for identifying patients with α-thalassemia, which results from the deletion of 1 or more of the α-globin genes.

METHODS

Samples were selected based on their hemoglobin H (HbH) concentration observed using IEF. The samples were analyzed for the most common α-globin gene deletions using molecular analysis.

RESULTS

α-Globin gene deletions corresponding to α-thalassemia trait or silent carrier were observed in all samples with the HbH less than 2% phenotype. The genotypes of the specimens with HbH greater than 5% were consistent with HbH disease, while the wild-type phenotype control samples showed a wild-type genotype.

CONCLUSIONS

Low concentrations of HbH can be detected in a patient with 1 or 2 α-gene deletions using IEF.

Risk factors for anal HPV infection and anal precancer in HIV-infected men who have sex with men

BACKGROUND

Carcinogenic human papillomaviruses (HPVs) cause a large proportion of anal cancers. Human immunodeficiency virus (HIV)-infected men who have sex with men (MSM) are at increased risk of HPV infection and anal cancer compared with HIV-negative men. We evaluated risk factors for HPV infection and anal precancer in a population of HIV-infected MSM.

METHODS

Our study included 305 MSM at an HIV/AIDS clinic in the Kaiser Permanente Northern California Health Maintenance Organization. Logistic regression was used to estimate associations of risk factors comparing men without anal HPV infection; men with anal HPV infection, but no precancer; and men with anal precancer.

RESULTS

Low CD4 count (<350 cells/mm(3)) and previous chlamydia infection were associated with an increased risk of carcinogenic HPV infection (odds ratio [OR], 3.65; 95% confidence interval [CI], 1.28-10.40 and OR, 4.24; 95% CI, 1.16-15.51, respectively). History of smoking (OR, 2.71 95% CI, 1.43-5.14), duration, recency, and dose of smoking increased the risk of anal precancer among carcinogenic HPV-positive men but had no association with HPV infection.

CONCLUSIONS

We found distinct risk factors for anal HPV infection and anal precancer. Risk factors for HPV infection and anal precancer are similar to established risk factors for cervical cancer progression.

Human papillomavirus genotype attribution and estimation of preventable fraction of anal intraepithelial neoplasia cases among HIV-infected men who have sex with men

BACKGROUND

The prevention of human papillomavirus (HPV)-induced anal cancer in high-risk populations such as human immunodeficiency virus (HIV)-infected men who have sex with men (MSM) remains an urgent priority, given rising incidence rates despite widespread antiretroviral therapy use.

METHODS

HPV genotypes and anal disease prevalence, by cytology and histopathologic findings, were evaluated among 363 HIV-infected MSM. We modeled fractions of high-grade anal intraepithelial neoplasia (HGAIN) attributable to individual carcinogenic HPV genotypes and estimated the range of the proportion of HGAIN cases potentially preventable by prophylactic HPV vaccines.

RESULTS

HPV16 was the most common genotype overall (26.4% of cases) and among HGAIN cases (55%). Prevalence of multiple (≥ 2) carcinogenic HPV genotypes increased from 30.9% in cases of AIN grade <1 to 76.3% in cases of AIN grade 3 (P(trend) < .001). The fractions of HGAIN cases attributable to carcinogenic HPV16/18 targeted by currently licensed bivalent and quadrivalent HPV vaccines ranged from 12% to 61.5%, and the fractions attributable to carcinogenic HPV16/18/31/33/45/52/58 targeted by an investigational nonavalent HPV vaccine ranged from 39% to 89.4%.

CONCLUSIONS

Our analytical framework allows estimation of HGAIN cases attributable to individual HPV genotypes in the context of multiple concurrent HPV infections, which are very common among HIV-infected MSM. Our results suggest that licensed and investigational HPV prophylactic vaccines have the potential to prevent a substantial proportion of HGAIN cases in this population.

A comparison of human papillomavirus genotype-specific DNA and E6/E7 mRNA detection to identify anal precancer among HIV-infected men who have sex with men

BACKGROUND

Human papillomavirus (HPV) RNA detection is reportedly more specific for the detection of anogenital precancer than HPV DNA but it is unknown whether this is due to detection of RNA or due to HPV genotype restriction.

METHODS

A total of 363 human immunodeficiency virus (HIV)-positive men who have sex with men had two anal cytology samples taken and were evaluated using high-resolution anoscopy and biopsies of visible lesions. Anal specimens were tested for E6/E7 RNA for five carcinogenic HPV genotypes (HPV16, 18, 31, 33, and 45) and tested for the DNA of 13 carcinogenic HPV genotypes.

RESULTS

DNA testing was more likely to be positive than RNA testing (53% vs. 48%; P = 0.02) for the same five HPV genotypes in aggregate. When restricted to five HPV genotypes targeted by the RNA test, the sensitivity to detect anal precancer was the same for DNA and RNA (81%), whereas RNA was more specific than DNA (65% vs. 58%; P = 0.007). In comparison, DNA detection of all 13 carcinogenic HPV genotypes was more sensitive (96% vs. 81%; P = 0.001) but much less specific (65% vs. 33%; P < 0.001) as compared with RNA detection of the five HPV genotypes.

CONCLUSION

After controlling for HPV genotypes, RNA was only slightly more specific than DNA detection for anal precancer.

IMPACT

DNA or RNA testing for a subset of the most carcinogenic HPV genotypes may be useful for distinguishing between those HPV-positive men at higher and lower risk of anal precancer and cancer.