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Introduction: Plasma Aβ42/40 ratio can help predict amyloid PET status, but its clinical utility in Alzheimer's disease (AD) assessment is unclear. Methods: Aβ42/40 ratio was measured by LC-MS/MS for 250 specimens with associated amyloid PET imaging, diagnosis, and demographic data, and for 6,192 consecutive clinical specimens submitted for Aβ42/40 testing. Results: High diagnostic sensitivity and negative predictive value (NPV) for Aβ- PET positivity were observed, consistent with the clinical performance of other plasma LC-MS/MS assays, but with greater separation between Aβ42/40 values for individuals with positive vs. negative Aβ-PET results. Assuming a moderate prevalence of Aβ-PET positivity, a cutpoint was identified with 99% NPV, which could help predict that AD is likely not the cause of patients' cognitive impairment and help reduce PET evaluation by about 40%. Conclusion: High-throughput plasma Aβ42/40 LC-MS/MS assays can help identify patients with low likelihood of AD pathology, which can reduce PET evaluations, allowing for cost savings. [ABSTRACT FROM AUTHOR]

Background: Prompt diagnosis of juvenile idiopathic arthritis (JIA) is important to avoid long term complications. Elevated serum 14–3-3η levels improve the diagnostic sensitivity of rheumatoid factor (RF) and cyclic citrullinated peptide (CCP) antibody in adult rheumatoid arthritis (RA), and have been associated with more severe phenotype. We investigated the prevalence and clinical significance of serum 14–3-3η in different types of JIA. Methods: JIA patients (n = 151) followed by the Pediatric Rheumatology Core at Children's Hospital of Los Angeles were categorized into 5 groups: polyarticular JIA RF+ (PJIA RF+; n = 39), PJIA RF- (n = 39), psoriatic arthritis (PsA; n = 19), enthesitis-related arthritis (ERA; n = 18), and oligoarticular JIA (OJIA [control group]; n = 36). RF, CCP antibody, and 14–3-3η were measured for all patients. 14–3-3η serum levels > 0.2 ng/mL were considered positive. Disease activity was assessed by the Juvenile Arthritis Disease Activity Score-71 (JADAS-71). Results: Elevated 14–3-3η levels were detected in 34/151 (23%) patients, and across all groups tested. Most patients with 14–3-3η had titers ≥4 times above the cutoff value. The majority (22, 65%) of 14–3-3η-positive patients were also positive for RF or CCP antibodies, 16 (47%) were positive for all 3, and 12 (35%) were single-positive for 14–3-3η. The highest prevalence of 14–3-3η was in PJIA RF+ patients (49%), followed by OJIA (22%). Positivity for 14–3-3η was not significantly associated with disease activity or age at diagnosis. Conclusion: Serum 14–3-3η can be detected in all forms of JIA tested but appears to be most common in PJIA RF+. 14–3-3η does not appear to correlate with disease activity in JIA. [ABSTRACT FROM AUTHOR]

Background: The number of pulmonary nodules detected in the US is expected to increase substantially following recent recommendations for nationwide CT-based lung cancer screening. Given the low specificity of CT screening, non-invasive adjuvant methods are needed to differentiate cancerous lesions from benign nodules to help avoid unnecessary invasive procedures in the asymptomatic population. We have constructed a serum-based multi-biomarker panel and assessed its clinical accuracy in a retrospective analysis of samples collected from participants with suspicious radiographic findings in the Prostate, Lung, Chest and Ovarian (PLCO) cancer screening trial. Methods: Starting with a set of 9 candidate biomarkers, we identified 8 that exhibited limited pre-analytical variability with increasing clotting time, a key pre-analytical variable associated with the collection of serum. These 8 biomarkers were evaluated in a training study consisting of 95 stage I NSCLC patients and 186 smoker controls where a 5-biomarker pulmonary nodule classifier (PNC) was selected. The clinical accuracy of the PNC was determined in a blinded study of asymptomatic individuals comprising 119 confirmed malignant nodule cases and 119 benign nodule controls selected from the PLCO screening trial. Results: A PNC comprising 5 biomarkers: CEA, CYFRA 21-1, OPN, SCC, and TFPI, was selected in the training study. In an independent validation study, the PNC resolved lung cancer cases from benign nodule controls with an AUC of 0.653 (p < 0.0001). CEA and CYFRA 21-1, two of the markers included in the PNC, also accurately distinguished malignant lesions from benign controls. Conclusions: A 5-biomarker blood test has been developed for the diagnostic evaluation of asymptomatic individuals with solitary pulmonary nodules. [ABSTRACT FROM AUTHOR]

Background: Support for early detection of lung cancer has emerged from the National Lung Screening Trial (NLST), in which low-dose computed tomography (LDCT) screening reduced lung cancer mortality by 20 % relative to chest x-ray. The US Preventive Services Task Force (USPSTF) recently recommended annual screening for the high-risk population, concluding that the benefits (life years gained) outweighed harms (false positive findings, abortive biopsy/surgery, radiation exposure). In making their recommendation, the USPSTF noted that the moderate net benefit of screening was dependent on the resolution of most false-positive results without invasive procedures. Circulating biomarkers may serve as a valuable adjunctive tool to imaging. Results: We developed a broad-based proteomics discovery program, integrating liquid chromatography/mass spectrometry (LC/MS) analyses of freshly resected lung tumor specimens (n = 13), lung cancer cell lines (n = 17), and conditioned media collected from tumor cell lines (n = 7). To enrich for biomarkers likely to be found at elevated levels in the peripheral circulation of lung cancer patients, proteins were prioritized based on predicted subcellular localization (secreted, cell-membrane associated) and differential expression in disease samples. 179 candidate biomarkers were identified. Several markers selected for further validation showed elevated levels in serum collected from subjects with stage I NSCLC (n = 94), relative to healthy smoker controls (n = 189). An 8-marker model was developed (TFPI, MDK, OPN, MMP2, TIMP1, CEA, CYFRA 21-1, SCC) which accurately distinguished subjects with lung cancer (n = 50) from high risk smokers (n = 50) in an independent validation study (AUC = 0.775). Conclusions: Integrating biomarker discovery from multiple sample types (fresh tissue, cell lines and conditioned medium) has resulted in a diverse repertoire of candidate biomarkers. This unique collection of biomarkers may have clinical utility in lung cancer detection and diagnoses. [ABSTRACT FROM AUTHOR]

Genetic factors may play a role in fibrosis progression in patients with chronic hepatitis C (CHC). A cirrhosis risk score (CRS7) with seven single nucleotide polymorphisms was previously shown to correlate with cirrhosis in patients with CHC. This study aimed to assess the validity of CRS7 as a marker of fibrosis progression and cirrhosis and as a predictor of clinical outcomes in patients with CHC.A total of 938 patients (677 Caucasians, 165 African-Americans, and 96 Hispanic/Other) in the Hepatitis C Antiviral Long-term Treatment against Cirrhosis Trial were studied. CRS7 was categorized a priori as high risk (n=440), medium risk (n=310), or low risk (n=188). Patients were assessed for four possible outcomes: fibrosis progression, cirrhosis, clinical outcomes [decompensation or hepatocellular carcinoma (HCC)], or HCC alone.Twenty-nine percent (142/493) developed an increase in fibrosis score by greater than or equal to 2 points on follow-up biopsies, 58% had cirrhosis on one or more biopsies, 35% developed at least one clinical outcome, and 13% developed HCC. CRS7 (trend test) was associated with risk for fibrosis progression (P=0.04) with adjusted hazard ratio of 1.27 (95% confidence interval: 1.01-1.58) and with cirrhosis (P=0.05) with adjusted odds ratio of 1.19 (1.00-1.41). Rates of HCC and clinical outcomes were increased in patients with higher CRS7 scores, but were not statistically significant (P=0.12 clinical outcomes, and P=0.07 HCC). A single nucleotide polymorphism in AZIN1 was significantly associated with fibrosis progression.CRS7 was validated as a predictor of fibrosis progression and cirrhosis among Hepatitis C Antiviral Long-term Treatment against Cirrhosis patients, who all had advanced fibrosis. CRS7 was not predictive of clinical outcome. [ABSTRACT FROM AUTHOR]

Susceptibility to sporadic Parkinson's disease (PD) is thought to be influenced by both genetic and environmental factors and their interaction with each other. Statistical models including multiple variants in axon guidance pathway genes have recently been purported to be capable of predicting PD risk, survival free of the disease and age at disease onset; however the specific models have not undergone independent validation. Here we tested the best proposed risk panel of 23 single nucleotide polymorphisms (SNPs) in two PD sample sets, with a total of 525 cases and 518 controls. By single marker analysis, only one marker was significantly associated with PD risk in one of our sample sets (rs6692804: P = 0.03). Multimarker analysis using the reported model found a mild association in one sample set (two sided P = 0.049, odds ratio for each score change = 1.07) but no significance in the other (two sided P = 0.98, odds ratio = 1), a stark contrast to the reported strong association with PD risk (P = 4.64610-38, odds ratio as high as 90.8). Following a procedure similar to that used to build the reported model, simulated multi-marker models containing SNPs from randomly chosen genes in a genome wide PD dataset produced P-values that were highly significant and indistinguishable from similar models where disease status was permuted (3.13610-23 to 4.90610-64), demonstrating the potential for overfitting in the model building process. Together, these results challenge the robustness of the reported panel of genetic markers to predict PD risk in particular and a role of the axon guidance pathway in PD genetics in general. [ABSTRACT FROM AUTHOR]

Background: A digital Diabetes Prevention Program (dDPP) has been shown to reduce the 8-year risk of diabetes in the first year of implementation in a workforce setting. We asked whether the dDPP reduced the risk of diabetes in a second year. Methods: Individuals were included in the study if they (i) participated in an employer-sponsored wellness program with year-end biometric screening for 4 consecutive years (2016 to 2019), (ii) had prediabetes-range fasting glucose (100 to 125 mg/dL) or Hb1Ac (5.7% to 6.4%), (iii) a BMI ≥25 kg/m2 at the end of 2017, and (iv) completed ≥9 lessons in a dDPP initiated at the beginning of 2018. In the first year of the dDPP, individuals participated in weekly online lessons. In the second year, no new content was introduced, but individuals had access to lessons delivered in year 1. Results: The baseline characteristics from the 2017 year-end screen are provided (Table). On average, participants (n=401) completed 25.1 lessons (SD: 12.3). In the second year of intervention, levels of BMI, fasting glucose, triglycerides and HDL-C, all components of the 8-year diabetes risk score, improved relative to changes observed in the year before intervention. The 8-year risk of developing diabetes was also reduced (Table). Conclusions: The risk of developing type 2 diabetes was reduced in the second year of a dDPP. Disclosure: C.E. Birse: Employee; Self; Quest Diagnostics. M.S. Fragala: Employee; Self; Quest Diagnostics. A.R. Arellano: None. L.A. Bare: Employee; Self; Quest Diagnostics. C. Castro Sweet: Employee; Self; Omada Health. R.J. Lagier: Employee; Self; Quest Diagnostics. Employee; Spouse/Partner; Thermo Fisher Scientific. [ABSTRACT FROM AUTHOR]

Background: Digital behavioral counseling has previously been shown to reduce levels of risk factors for diabetes including fasting glucose and HbA1c. We asked whether the 8-year risk of developing diabetes could be reduced within the first year of a digital counseling program. Methods: Individuals were included in the study if they (i) participated in an employer-sponsored wellness program with year-end biometric screening for 3 consecutive years (2016, 2017, and 2018), (ii) had prediabetes-range fasting glucose (100 to 125 mg/dL) or Hb1Ac (5.7% to 6.4%), (iii) a BMI ≥25 kg/m2 at the end of 2017, and (iv) completed at least 9 lessons in a digital behavioral counseling program initiated at the beginning of 2018. Paired t-Tests were used to assess changes in yearly trajectories of diabetes risk factors before and after intervention (Table). Results: The baseline characteristics of the cohort at the 2017 year-end screen are provided (Table). On average, participants (n=460) were engaged in the counseling program for 9.1 months (SD: 1.2) and completed 25.1 lessons (SD: 12.3). After participation, levels of all biometric variables included in the 8-year risk model* shifted in a favorable direction; the 8-year risk of developing diabetes was reduced (Table). Conclusions: Digital behavioral counseling was effective in reducing risk factors and the 8-year risk of diabetes during the first year of the program. Disclosure: C.E. Birse: Employee; Self; Quest Diagnostics. Stock/Shareholder; Self; Quest Diagnostics. M.S. Fragala: Employee; Self; Quest Diagnostics. A. Satish: None. K.C. McNamara: Employee; Self; Omada Health, Inc. C.M. Castro Sweet: Employee; Self; Omada Health, Inc. R.J. Lagier: Employee; Self; Quest Diagnostics. [ABSTRACT FROM AUTHOR]

Susceptibility to sporadic Parkinson's disease (PD) is thought to be influenced by both genetic and environmental factors and their interaction with each other. Statistical models including multiple variants in axon guidance pathway genes have recently been purported to be capable of predicting PD risk, survival free of the disease and age at disease onset; however the specific models have not undergone independent validation. Here we tested the best proposed risk panel of 23 single nucleotide polymorphisms (SNPs) in two PD sample sets, with a total of 525 cases and 518 controls. By single marker analysis, only one marker was significantly associated with PD risk in one of our sample sets (rs6692804: P = 0.03). Multi-marker analysis using the reported model found a mild association in one sample set (two sided P = 0.049, odds ratio for each score change = 1.07) but no significance in the other (two sided P = 0.98, odds ratio = 1), a stark contrast to the reported strong association with PD risk (P = 4.64x10(-38), odds ratio as high as 90.8). Following a procedure similar to that used to build the reported model, simulated multi-marker models containing SNPs from randomly chosen genes in a genome wide PD dataset produced P-values that were highly significant and indistinguishable from similar models where disease status was permuted (3.13x10(-23) to 4.90x10(-64)), demonstrating the potential for overfitting in the model building process. Together, these results challenge the robustness of the reported panel of genetic markers to predict PD risk in particular and a role of the axon guidance pathway in PD genetics in general.