Validating the ratio of insulin like growth factor binding protein 4 to sex hormone binding globulin as a prognostic predictor of preterm birth in Viet Nam: a case-cohort study

OBJECTIVE

To validate a serum biomarker developed in the USA for preterm birth (PTB) risk stratification in Viet Nam.

METHODS

Women with singleton pregnancies (n = 5000) were recruited between 19+0-23+6 weeks' gestation at Tu Du Hospital, Ho Chi Minh City. Maternal serum was collected from 19+0-22+6 weeks' gestation and participants followed to neonatal discharge. Relative insulin-like growth factor binding protein 4 (IGFBP4) and sex hormone binding globulin (SHBG) abundances were measured by mass spectrometry and their ratio compared between PTB cases and term controls. Discrimination (area under the receiver operating characteristic curve, AUC) and calibration for PTB <37 and <34 weeks' gestation were tested, with model tuning using clinical factors. Measured outcomes included all PTBs (any birth ≤37 weeks' gestation) and spontaneous PTBs (birth ≤37 weeks' gestation with clinical signs of initiation of parturition).

RESULTS

Complete data were available for 4984 (99.7%) individuals. The cohort PTB rate was 6.7% (n = 335). We observed an inverse association between the IGFBP4/SHBG ratio and gestational age at birth (p = 0.017; AUC 0.60 [95% CI, 0.53-0.68]). Including previous PTB (for multiparous women) or prior miscarriage (for primiparous women) improved performance (AUC 0.65 and 0.70, respectively, for PTB <37 and <34 weeks' gestation). Optimal performance (AUC 0.74) was seen within 19-20 weeks' gestation, for BMI >21 kg/m2 and age 20-35 years.

CONCLUSION

We have validated a novel serum biomarker for PTB risk stratification in a very different setting to the original study. Further research is required to determine appropriate ratio thresholds based on the prevalence of risk factors and the availability of resources and preventative therapies.

Patient result monitoring of HbA1c shows small seasonal variations and steady decrease over more than 10 years

OBJECTIVES

Internal and external quality assurance materials often use highly processed matrixes. This can render the materials non-commutable. Monitoring laboratory methods with patient medians helps in identifying and correcting systematic errors that may affect diagnostic accuracy. The aim of the present study was to use HbA1c patient results for monitoring of method performance over time.

METHODS

Test HbA1c results from 2010 to 2022 was analyzed (n=722,553) regarding changes over time and seasonal variation. The HbA1c testing was initially performed on a Cobas 501 instrument using immunological detection but in May 2017 the method was replaced by capillary electrophoresis on Capillarys 3 Tera.

RESULTS

There was a steady decrease in HbA1c values. From 2011 to 2021 the decrease was for 0.10 percentile 6.6 %, lower quartile 7.9 %, median 10.2 %, mean values 9 %, upper quartile 11.2 %, and 0.90 percentile 9.3 %. No clear shift in HbA1c levels was observed due to the shift in methods. The median HbA1c values per month was approximately 44 mmol/mol (6.2 %, DCCT/NGSP). The only month with a median HbA1c that differed by more than 1 mmol/mol was July with a median value of 42 mmol/mol (6.0 %).

CONCLUSIONS

The patient data showed a similar decrease as in the National Diabetes Register which indicates that the method is stable over time without any sudden changes and that the seasonal variation is low. The continuous decrease in HbA1c values over time is most likely to a shift towards earlier detection of patient with diabetes and improved treatment.

The moderating effect of physical activity on the relationship between neutrophil count and depressive symptoms

Variations in immune cell counts can trigger depressive symptoms, while physical activity effectively reduces the risk and severity of depressive symptoms. This study, based on the NHANES database, analyzes the relationship between neutrophil count and depressive symptoms and explores the moderating effect of physical activity on this relationship. Cross-sectional data from the NHANES database were extracted, including immune cell counts, PHQ-9 scores for self-assessment of depressive symptoms, and Global Physical Activity Questionnaire (GPAQ) scores (PA). The interrelations among physical activity, neutrophil count, and depressive symptoms were analyzed. After controlling for confounding factors, neutrophil count was found to have a significant role in identifying depressive symptoms with an odds ratio (OR) [95% Confidence Interval (CI)] = 1.13 [1.02, 1.251]; the moderating effect of physical activity on the impact of neutrophil count on depressive symptoms was statistically significant (coefficient = -0.0028, P < 0.05). Neutrophil count may be a significant factor in identifying depressive symptoms in adults. As an effective moderating factor, physical activity can mitigate the impact of neutrophil count on depressive symptoms to a certain extent.

Serum zinc and periodontitis in non-diabetic smoking and non-smoking adults: NHANES 2011-2014

OBJECTIVE

This study aimed to evaluate the association of serum zinc with periodontitis in non-diabetics based on smoking status, using a representative sample of adults in the United States.

METHODS

A total of 1051 participants who underwent full-mouth periodontal examination and serum zinc testing were enrolled from NHANES 2011 to 2014. The covariate-adjusted association of serum zinc concentrations with periodontitis was explored using multivariable logistic regression, restricted cubic spines, and sensitivity analysis.

RESULTS

The mean age of the 1051 adults was 54.5 years, 59.37% were male, and 20.65% had periodontitis. Analysis of the results showed that serum zinc was associated with periodontitis. The overall adjusted odds of periodontitis were 9% (odds ratio [OR]: 0.91; 95% confidence interval [CI]: 0.83-1.00) and 14% (OR: 0.86; 95% CI: 0.75-0.98) for nonsmokers and smokers, respectively. Smokers with T3 serum zinc exhibited a 53% reduction in the fully adjusted odds of periodontitis (OR: 0.47; 95% CI: 0.23-0.96), when compared to the reference group (T1 serum zinc), with serum zinc as the categorical variable.

CONCLUSIONS

Serum zinc levels were associated with the risk of periodontitis in non-diabetic smokers but not non-smokers.

ICSH review of internal quality control policy for blood cell counters

INTRODUCTION

This paper is a report of an ICSH review of policies and practices for internal quality control (IQC) policy for haematology cell counters among regulatory bodies, cell counter manufacturers and diagnostic laboratories. It includes a discussion of the study findings and links to separate ICSH guidance for such policies and practices. The application of internal quality control (IQC) methods is an essential pre-requisite for all clinical laboratory testing including the blood count (Full Blood Count, FBC, or Complete Blood Count, CBC).

METHODS

The ICSH has gathered information regarding the current state of practice through review of published guidance from regulatory bodies, a questionnaire to six major cell counter manufacturers (Abbott Diagnostics, Beckman Coulter, Horiba Medical Diagnostic Instruments & Systems, Mindray Medical International, Siemens Healthcare Diagnostics and Sysmex Corporation) and a survey issued to 191 diagnostic laboratories in four countries (China, Republic of Ireland, Spain and the United Kingdom) on their IQC practice and approach to use of commercial IQC materials.

RESULTS

This has revealed diversity both in guidance and in practice around the world. There is diversity in guidance from regulatory organizations in regard to IQC methods each recommends, clinical levels to use and frequency to run commercial controls, and finally recommended sources of commercial controls. The diversity in practice among clinical laboratories spans the areas of IQC methods used, derivation of target values and action limits used with control materials, and frequency of running commercial controls materials.

CONCLUSIONS

These findings and their implications for IQC Practice are discussed in this paper. They are used to inform a separate guidance document, which proposes a harmonized approach to address the issues faced by diagnostic laboratories.

ICSH guidance for internal quality control policy for blood cell counters

This paper is a description of the ICSH guidance for internal quality control (IQC) policy for blood cell counters. It follows from and links to a separate ICSH review for such policies and practices. The ICSH has gathered information regarding the current state of practice through review of published guidance from regulatory bodies, a questionnaire to six major cell counter manufacturers and a survey issued to 191 diagnostic laboratories in four countries (China, the Republic of Ireland, Spain, and the United Kingdom) on their IQC practice and approach to the use of commercial IQC materials. This has revealed diversity both in guidance and in practice around the world. There is diversity in guidance from regulatory organizations in regard to IQC methods each recommends, clinical levels to use and frequency to run commercial controls, and finally recommended sources of commercial control materials. The diversity in practice among clinical laboratories spans the areas of IQC methods used, derivation of target values, and action limits used with commercial control materials, and frequency of running commercial controls materials. These findings and their implications for IQC Practice are addressed in this guidance document, which proposes a harmonized approach to address the issues faced by diagnostic laboratories.

The relationship between a series of inflammatory markers on the risk of heart failure in different gender groups: Analysis from NHANES 2015-2018

BACKGROUND

A better understanding of the level-grade inflammation for the development and worsening of heart failure (HF) in different gender groups is an unmet need. We performed an updated analysis on the impact of a series of systemic inflammation markers on HF.

METHODS

This compensatory cross-sectional study enrolled participants from the National Health and Nutrition Examination Survey (NHANES) 2015-2018. HF was based on the self-reported questions. Univariate and multivariate logistic regression were used to investigate the association between systemic immune-inflammation index (SII), high sensitivity C-reactive protein (hs-CRP), lymphocyte-to-monocyte ratio (LMR), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and HF. For patients of different genders, P for trend was used to analyze potential linear trend relationships and the restricted cubic splines (RCS) were used to describe non-linear relationships. The additive interaction was evaluated by the relative excess risk due to interaction (RERI), attributable proportion (AP), and the synergy index (SI). The multiplicative interaction was evaluated by odds ratio (OR) and 95% confidence interval (CI) of product-term.

RESULTS

A total of 5,830 participants from the NHANES database were divided into two groups: the HF group (n = 210) and the non-HF group (n = 5620). After gender stratification, hs-CRP (OR: 1.01, 95% CI: 1.00-1.03), SII (OR: 1.00, 95% CI: 1.00-1.01), NLR (OR: 1.22, 95% CI: 1.11-1.35) and LMR (OR: 0.79, 95% CI: 0.65-0.93) were independent meaningful factors for HF in males, there was no non-linear relationship between the three factors (SII, NLR, hs-CRP, all P for non-linear > 0.05) and the prevalence of HF, but we detected a non-linear relationship between LMR and the prevalence of HF in males (P for non-linear < 0.05). An additive interaction of hs-CRP and NLR on the risk of HF in males (RERI (OR): 0.67, 95% CI: 0.12-1.34; AP (OR): 0.14, 95% CI: 0.02-0.24; SI (OR): 1.22, 95% CI: 1.03-1.44).

CONCLUSIONS

In summary, hs-CRP, NLR, and LMR are superior meaningful markers for HF in males. SII may be a meaningful systemic inflammation warning marker for HF, which needs to be discriminated against with caution. Only detected a non-linear relationship between LMR and the prevalence of HF in males. NLR and hs-CRP may have an additive interaction in the prevalence of male HF patients. The outcome compensated for previous studies that still needed more studies for validation.

Effect of blood lead levels on periodontitis in American adults: a cross-sectional analysis from the national health and nutrition examination survey

BACKGROUND

The primary objective of this study was to assess the impact of blood lead levels on the development and progression of periodontitis.

METHODS

This study included 8600 participants from the National Nutrition and Health Examination Survey conducted the United States between 2009 and 2014. The exposure variable was the blood lead level, while the outcome variable was periodontitis. To evaluate the relationship between the blood lead level and periodontitis, a multivariate logistic regression model was used.

RESULTS

A positive association was observed between blood lead levels and the risk of periodontitis in Model 1 (OR = 7.04, 95% CI = 5.95-8.31). After adjusting for age (continuous), sex, ethnicity, and BMI (continuous) in Model 2, the significant association between blood lead levels and periodontitis risk remained evident (OR = 3.06, 95% CI: 2.54-3.70). Consequently, even after comprehensive adjustment for potential confounding factors in Model 3, the robust association between blood lead levels and periodontitis risk persisted (OR = 2.08, 95% CI = 1.67-2.60). When considering the serum lead concentration as a categorical variable and after adjusting for potential confounders in Model 3, we observed that the odds ratios (ORs) of periodontitis in the T2 (0.94 µg/dL-1.60 µg/dL) and T3 (lead ≥ 1.60 µg/dL) groups increased from 1.27 (OR = 1.27, 95% CI: 1.11-1.44) to 1.57 (OR = 1.57, 95% CI: 1.36-1.81) compared to T1 group. Subgroup analysis revealed no effect modifiers.

CONCLUSIONS

Our main findings suggest that there is no safe range of blood lead levels regarding periodontitis risk and that increasing blood lead levels can significantly increase the prevalence of periodontitis.

Diabetes: a potential mediator of associations between polycyclic aromatic hydrocarbon exposure and stroke

Epidemiological evidence suggests associations between exposure to polycyclic aromatic hydrocarbons (PAHs) and cardiovascular diseases (CVD), while diabetes is a common risk factor for CVD. The present study aims to clarify the effect of high PAH exposure on diabetes and stroke in general population. A total of 7849 individuals aged 20 years or older from the National Health and Nutrition Examination Survey 2007-2016 were included in the study. The logistic regression analysis modeled the association between PAH exposure and diabetes as well as stroke. The analysis yielded odds ratios (ORs) and 95% confidence intervals (CIs). The study also evaluated the potential mediating role of diabetes in the relation between PAH exposure and stroke via mediating effect analyses. Of the 7849 eligible participants, 1424 cases of diabetes and 243 cases of stroke were recorded. After adjusting for covariates including age, gender, smoking status, drinking status, education level, marital status, physical activity, hypertension, low-density lipoprotein cholesterol, and BMI, the ORs for stroke in the highest quartile (Q4) of total urinary PAHs were 1.97 (95% CI 1.11-3.52, P = 0.022) as compared to the lowest quartile (Q1) of total urinary PAHs. The ORs for diabetes in the Q4 of total urinary PAHs were 1.56 (95% CI 1.15-2.12, P = 0.005), while the ORs between Q4 and Q1 for stroke and diabetes concerning exposure to 2-hydroxynaphthalene were 2.23 (95% CI 1.17-4.25, P = 0.016) and 1.40 (95% CI 1.07-1.82, P = 0.015), respectively. The mediation analysis found that diabetes accounted for 5.00% of the associations between urinary PAHs and the prevalence of stroke. Urinary metabolites of PAH have been linked to stroke and diabetes. Increasing the risk of diabetes may play a significant role in mediating the association between exposure to PAHs and increased risk of stroke. Monitoring and improving glucose metabolism in individuals with high exposure to PAHs may aid in reducing the prevalence of stroke.

Ongoing Analytical Procedure Performance Verification Using a Risk-Based Approach to Determine Performance Monitoring Requirements

The analytical procedure life cycle (APLC) provides a holistic framework to ensure analytical procedure fitness for purpose. USP's general chapter <1220> considers the validation activities that take place across the entire analytical procedure lifecycle and provides a three-stage framework for its implementation. Performing ongoing analytical procedure performance verification (OPPV) (stage 3) ensures that the procedure remains in a state of control across its lifecycle of use post validation (qualification) and involves an ongoing program to collect and analyze data that relate to the performance of the procedure. Knowledge generated during stages 1 (procedure design) and 2 (procedure performance qualification) is used as the basis for the design of the routine monitoring plan to support performance verification (stage 3). The extent of the routine monitoring required should be defined based on risk assessment, considering the complexity of the procedure, its intended purpose, and knowledge about process/procedure variability. The analytical target profile (ATP) can be used to provide or guide the establishment of acceptance criteria used to verify the procedure performance during routine use (e.g., through a system/sample suitability test (SST) or verification criteria applicable to procedure changes or transfers). An ATP however is not essentially required to perform OPPV, and a procedure performance monitoring program can be implemented even if the full APLC framework has not been applied. In these situations, verification criteria can be derived from existing validation or system suitability criteria. Elements of the life cycle approach can also be applied retrospectively if deemed useful.

QComics: Recommendations and Guidelines for Robust, Easily Implementable and Reportable Quality Control of Metabolomics Data

The implementation of quality control strategies is crucial to ensure the reproducibility, accuracy, and meaningfulness of metabolomics data. However, this pivotal step is often overlooked within the metabolomics workflow and frequently relies on the use of nonstandardized and poorly reported protocols. To address current limitations in this respect, we have developed QComics, a robust, easily implementable and reportable method for monitoring and controlling data quality. The protocol operates in various sequential steps aimed to (i) correct for background noise and carryover, (ii) detect signal drifts and "out-of-control" observations, (iii) deal with missing data, (iv) remove outliers, (v) monitor quality markers to identify samples affected by improper collection, preprocessing, or storage, and (vi) assess overall data quality in terms of precision and accuracy. Notably, this tool considers important issues often neglected along quality control, such as the need of separately handling missing values and truly absent data to avoid losing relevant biological information, as well as the large impact that preanalytical factors may elicit on metabolomics results. Altogether, the guidelines compiled in QComics might contribute to establishing gold standard recommendations and best practices for quality control within the metabolomics community.

Blood Cadmium and Abdominal Aortic Calcification in Population with Different Weight Statuses: a Population-Based Study

The aim of our study was to assess the effect of blood cadmium levels (B-Cd) on abdominal aortic calcification (AAC). We used the data from the 2013-2014 NHANES database. A total of 1530 participants were included in our study, with a mean AAC score of 1.40 ± 0.10, and a prevalence of severe AAC of 7.98%. Participants with higher B-Cd quartiles showed a higher prevalence of severe AAC. B-Cd was positively associated with higher AAC scores and increased risk of severe AAC. In the obese population, blood cadmium levels showed a positive association with the risk of severe AAC. There may be a positive correlation between B-Cd levels and AAC scores and risk of severe AAC, and this correlation is more pronounced in the obese population. Therefore, the cadmium load in AAC patients in the obese population should be considered in clinical work.

Advances in clinical chemistry patient-based real-time quality control (PBRTQC)

Patient-Based Real-Time Quality Control involves monitoring an assay using patient samples rather than external material. If the patient population does not change, then a shift in the long-term assay population results represents the introduction of a change in the assay. The advantages of this approach are that the sample(s) are commutable, it is inexpensive, the rules are simple to interpret and there is virtually continuous monitoring of the assay. The disadvantages are that the laboratory needs to understand their patient population and how they may change during the day, week or year and the initial change of mindset required to adopt the system. The concept is not new, having been used since the 1960s and widely adopted on hematology analyzers in the mid-1970s. It was not widely used in clinical chemistry as there were other stable quality control materials available. However, the limitations of conventional quality control approaches have become more evident. There is a greater understanding of how to collect and use patient data in real time and a range of powerful algorithms which can identify changes in assays. There are more assays on more samples being run. There is also a greater interest in providing a theoretical basis for the validation and integration of these techniques into routine practice.

Advances in internal quality control

Quality control practices in the modern laboratory are the result of significant advances over the many years of the profession. Major advance in conventional internal quality control has undergone a philosophical shift from a focus solely on the statistical assessment of the probability of error identification to more recent thinking on the capability of the measurement procedure (e.g. sigma metrics), and most recently, the risk of harm to the patient (the probability of patient results being affected by an error or the number of patient results with unacceptable analytical quality). Nonetheless, conventional internal quality control strategies still face significant limitations, such as the lack of (proven) commutability of the material with patient samples, the frequency of episodic testing, and the impact of operational and financial costs, that cannot be overcome by statistical advances. In contrast, patient-based quality control has seen significant developments including algorithms that improve the detection of specific errors, parameter optimization approaches, systematic validation protocols, and advanced algorithms that require very low numbers of patient results while retaining sensitive error detection. Patient-based quality control will continue to improve with the development of new algorithms that reduce biological noise and improve analytical error detection. Patient-based quality control provides continuous and commutable information about the measurement procedure that cannot be easily replicated by conventional internal quality control. Most importantly, the use of patient-based quality control helps laboratories to improve their appreciation of the clinical impact of the laboratory results produced, bringing them closer to the patients.Laboratories are encouraged to implement patient-based quality control processes to overcome the limitations of conventional internal quality control practices. Regulatory changes to recognize the capability of patient-based quality approaches, as well as laboratory informatics advances, are required for this tool to be adopted more widely.

Adequate Intake of Dietary Fiber May Relieve the Detrimental Impact of Blood Lead on Dyslipidemia among US Adults: A Study of Data from the National Health and Nutrition Examination Survey Database

Lead (Pb) exposure is a well-established risk factor for dyslipidemia, and people are exposed to it in multiple ways daily. Dietary fiber is presumed to improve lipid metabolism disorders, but it is still unknown whether it can relieve the detrimental impact of Pb on dyslipidemia. We used publicly accessible data from the 2011-2016 cycles of the National Health and Nutrition Examination Survey (NHANES). A total of 2128 US adults were enrolled for the subsequent analysis. Heavy metal concentrations in blood were measured using inductively coupled plasma mass spectrometry (ICP-MS). A weighted logistic regression was conducted to calculate odds ratios (ORs) and 95% confidence intervals (CIs). The dose-response relationship between blood heavy metals and dyslipidemia was explored using a weighted restricted cubic spline (RCS) analysis. After fully adjusting for potential confounding factors (age, gender, race, education level, ratio of family income to poverty, marital status, body mass index, physical activity, waist circumference, smoke, alcohol drinking and history of metabolic syndrome, hypertension, and diabetes), a positive association between blood Pb levels and dyslipidemia risk was revealed (OR = 1.20, 95% CI: 1.03-1.40). Dietary fiber intake may significantly modify the association between blood Pb levels and dyslipidemia (p-interaction = 0.049), with a stronger association (OR = 1.26, 95% CI: 1.05-1.52) being revealed in individuals with an inadequate intake of dietary fiber (<14 g/1000 kcal/day), but a null association (OR = 1.01, 95% CI: 0.72-1.42) being observed in those with an adequate intake of dietary fiber (≥14 g/1000 kcal/day). Moreover, the weighted RCS analysis showed that compared with the average blood Pb exposure level (4.24 µg/dL), a lower blood Pb exposure level (3.08 µg/dL) may contribute to the risk of dyslipidemia in the group with an inadequate dietary fiber intake. Our findings suggest that Pb exposure in blood may be a risk factor for dyslipidemia. However, an adequate dietary fiber intake may offset the risk of dyslipidemia caused by blood Pb exposure. Since avoiding Pb exposure in daily life is difficult, increasing dietary fiber intake in the future might be a promising approach to alleviate dyslipidemia caused by Pb exposure.

Association between urinary phthalate metabolites and nephrolithiasis in adults: A cross-sectional analysis with NHANES 2007-2018

Nephrolithiasis is highly prevalent and brings health and economic burdens to patients. The augmentation of nephrolithiasis may be associated with exposure to phthalate metabolites. However, few studies investigated the effect of various phthalates exposure on nephrolithiasis. We analyzed data from 7139 participants aged 20 years or above from the National Health and Nutrition Examination Survey (NHANES) 2007-2018. Serum calcium level-stratified univariate and multivariate linear regression analyses were performed to explore the relationship between urinary phthalate metabolites and nephrolithiasis. As a result, the prevalence of nephrolithiasis was approximately 9.96%. After adjusting for confounding factors, associations were found between serum calcium concentration with monoethyl phthalate (P = 0.012) and mono-isobutyl phthalate (P = 0.003) compared with tertile 1 (T1). In adjusted analysis, nephrolithiasis was positively associated with middle and high tertiles of mono benzyl phthalate (P < 0.05) compare with low tertile group. Furthermore, high-level exposure to mono-isobutyl phthalate had a similar positive association with nephrolithiasis (P = 0.028). Our findings provide evidence that exposure to certain phthalate metabolites (i.e. MiBP and MBzP) may be associated with a high risk of nephrolithiasis depending on serum calcium level.

Association Between Sleep Time and Pro- and Anti-Inflammatory Biomarkers Is Mediated by Abdominal Obesity Among Adolescents

OBJECTIVES

Movement behaviors and abdominal obesity are associated with higher inflammatory biomarkers. However, the role of waist circumference as a mediating factor is still unknown. Thus, our aims were to (1) test the associations between 24-hour movement behavior variables (physical activity, sedentary behavior, and sleep), abdominal obesity, and pro- and anti-inflammatory biomarkers; and (2) investigate whether abdominal obesity had a mediating effect between the investigated associations.

METHODS

This multicenter cross-sectional study included 3591 adolescents (aged 12-17 y) from 4 Brazilian cities. Waist circumference (in centimeters; at half the distance between the iliac crest and at the lower costal margin), 24-hour movement behaviors (validated questionnaire), high-sensitive C-reactive protein, and adiponectin (serum plasma) were evaluated. We used multiple mediation regression models (95% confidence interval) to determine if waist circumference mediated the association between 24-hour movement behaviors and pro- and anti-inflammatory biomarkers.

RESULTS

The results revealed that screen time and moderate to vigorous physical activity were not associated with pro- or anti-inflammatory biomarkers. However, sleep duration (in hours per day) was negatively associated with pro- (C-reactive protein, β = -0.08; 95% confidence interval, -0.38 to -0.02) and anti- (adiponectin, β = -0.31; 95% confidence interval, -2.13 to -0.12) inflammatory biomarkers. Our results also showed that waist circumference mediated the association between sleep duration and high-sensitive C-reactive protein (2.7%), and adiponectin (2.8%).

CONCLUSION

Sleep duration was inversely associated with pro- and anti-inflammatory biomarkers, and these relations were mediated by abdominal obesity. Therefore, adolescents having healthy sleep can have implications for reducing waist circumference and inflammatory indicators.

Optimization of the first extraction protocol for metabolomic studies of Brucella abortus

Brucellosis is a zoonosis prevalent worldwide and very recurrent in less developed or developing regions. This zoonosis affects livestock, generating high financial losses to producers, in addition to transmitting diseases to humans through meat consumption or handling contaminated products and animals. In this study, five extraction methods for Brucella abortus intracellular metabolites, using different solvent compositions and cell membrane disruption procedures, were evaluated. Derivatized extracts were analyzed by GC-HRMS. Raw data were processed in XCMS Online and the results were evaluated through multivariate statistical analysis using the MetaboAnalyst platform. The identification of the extracted metabolites was performed by the Unknowns software using the NIST 17.L library. The extraction performance of each method was evaluated for thirteen representative metabolites, comprising four different chemical classes. Most of these compounds are reported in the cell membrane composition of Gram-negative bacteria. The method based on extraction with methanol/chloroform/water presented the best performance in the evaluation of the extracted compounds and in the statistical results. Therefore, this method was selected for extracting intracellular metabolites from cultures of Brucella abortus for untargeted metabolomics analysis.

Capillary Electrophoresis with Interchangeable Cartridges for Versatile and Automated Analyses of Dried Blood Spot Samples

A novel concept for highly versatile automated analyses of dried blood spot (DBS) samples by commercial capillary electrophoresis (CE) is presented. Two interchangeable CE cartridges with different fused-silica capillaries were used for the DBS elutions and the DBS eluate analyses, respectively. The application of one CE cartridge with a wide-bore capillary reduced DBS processing times to a minimum (1-2 min per sample) while fitting the other CE cartridge with a narrow-bore capillary served for highly efficient CE analyses. A comprehensive investigation of major variables affecting liquid handling in CE (capillary length, internal diameter, and temperature) was carried out with the aim of optimizing both procedures and enabling their maximum flexibility. The application of two CE cartridges also enabled the employment of CE detectors with different instrumental set-ups and/or principles as was demonstrated by the optical detection of nonsteroidal anti-inflammatory drugs (NSAIDs) and the conductivity detection of amino acids (AAs). The presented methods were optimized for the automated CE analyses of 36 DBS samples formed by a volumetric collection of 5 μL of capillary blood onto Whatman 903 discs and processed by direct in-vial elution using the CE instrument. The precision of liquid transfers for the automated DBS elutions was better than 0.9% and the precision of CE analyses did not exceed 5.1 and 12.3% for the determination of NSAIDs and AAs, respectively. Both methods were linear (R2 ≥ 0.996) over the therapeutic (NSAIDs) and the endogenous (AAs) concentration ranges, had limits of quantification below the typical analyte concentrations in human blood, and achieved sample throughputs of more than 6 DBSs per hour.

Seroprevalence of IgG Antibodies Directed against Dengue, Chikungunya and West Nile Viruses and Associated Risk Factors in Madagascar, 2011 to 2013

Arboviruses have been shown to circulate in Madagascar, including West Nile, dengue, and chikungunya viruses, though the extent of their circulation remains poorly documented. We estimated the seroprevalence of these three arboviruses in Madagascar and determined risk factors associated with seropositivity. Serum samples obtained from 1680 individuals surrounding the Sentinel Health Centers network in all regions of the country were analyzed using ELISA and hemagglutination inhibition assays for dengue, chikungunya, and West Nile viruses IgG antibodies, and multivariate logistic regression models were run. Overall, 6.5% [IC 95% 3.2-9.9] were seropositive for dengue virus, predominantly of Dengue serotype 1, 13.7% [IC 95% 6.5-20.9] for chikungunya virus, and 12.7% [IC 95% 9.0-16.5] for West Nile virus. There was no association with age, showing that dengue and chikungunya viruses were likely recently introduced. Eastern and Northern parts were more affected by dengue and chikungunya viruses, while West Nile virus seemed to circulate in all parts of the country. Dengue and chikungunya seropositivity were notably associated with high levels of vegetation, as well as frequent work in the forest, and West Nile seropositivity with the presence of cultivated areas, as well as standard of living. This analysis gives a new insight into arboviruses circulation and transmission patterns in Madagascar.

Autonomous capillary electrophoresis processing and analysis of dried blood spots for high-throughput determination of uric acid

A new set-up for fully autonomous and high-throughput capillary electrophoresis (CE) analyses of dried blood spot (DBS) samples is presented. The DBS samples were prepared by collecting exactly 5 μL of capillary blood from a finger-prick onto a pre-punched DBS disc in a disposable plastic CE vial and by in-vial blood drying. The vials with the DBS samples were then loaded into a commercial CE instrument for a fully unmanned sample processing and analysis. A fused-silica capillary of the CE instrument was first used for the transfer of 100 μL of elution solvent to each vial, in-vial DBS elution, and in-vial eluate homogenization. The same capillary was also used for at-line injection, separation, and selective analysis of the resulting eluates. Novel CE sequences were tailor-programmed for consecutive processing and analyses of multiple DBSs, which facilitated a fully autonomous determination of uric acid with a throughput of 240 DBS samples per day (24 h). The presented analytical protocol (using 100 μm i. d./30 cm capillary; 30 mM 2-(N-morpholino)-ethanesulfonic acid, 30 mM l-histidine, and 30 μM cetyltrimethylammonium bromide background electrolyte solution; and UV detection at 292 nm) provided excellent precision at endogenous and spiked uric acid concentrations with RSD values of peak areas below 3.2%. Calibration curves were linear over the 33.3 - 1200 μM range (R² better than 0.998), limits of detection and quantification in the original capillary blood were 10 and 33.3 μM, respectively, and were well below the uric acid clinical range (140-420 μM). The stability of uric acid in DBS samples stored at laboratory temperature for up to 2 months was also excellent demonstrating less than a 4.2% decrease in uric acid concentrations. The actual set-up might thus be highly attractive for clinical subjects and laboratories because it is minimally invasive and requires minimum intervention from laboratory staff.

Detection of antinuclear antibodies: recommendations from EFLM, EASI and ICAP

OBJECTIVES

Antinuclear antibodies (ANA) are important for the diagnosis of various autoimmune diseases. ANA are usually detected by indirect immunofluorescence assay (IFA) using HEp-2 cells (HEp-2 IFA). There are many variables influencing HEp-2 IFA results, such as subjective visual reading, serum screening dilution, substrate manufacturing, microscope components and conjugate. Newer developments on ANA testing that offer novel features adopted by some clinical laboratories include automated computer-assisted diagnosis (CAD) systems and solid phase assays (SPA).

METHODS

A group of experts reviewed current literature and established recommendations on methodological aspects of ANA testing. This process was supported by a two round Delphi exercise. International expert groups that participated in this initiative included (i) the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Working Group "Autoimmunity Testing"; (ii) the European Autoimmune Standardization Initiative (EASI); and (iii) the International Consensus on ANA Patterns (ICAP).

RESULTS

In total, 35 recommendations/statements related to (i) ANA testing and reporting by HEp-2 IFA; (ii) HEp-2 IFA methodological aspects including substrate/conjugate selection and the application of CAD systems; (iii) quality assurance; (iv) HEp-2 IFA validation/verification approaches and (v) SPA were formulated. Globally, 95% of all submitted scores in the final Delphi round were above 6 (moderately agree, agree or strongly agree) and 85% above 7 (agree and strongly agree), indicating strong international support for the proposed recommendations.

CONCLUSIONS

These recommendations are an important step to achieve high quality ANA testing.

Blood selenium level can alleviate the nephrotoxicity of lead and cadmium in the general population of the United States: a retrospective cross section analysis of population-based nationally representative data

The current understanding of the interplay between blood selenium, cadmium and lead levels, and chronic kidney disease (CKD) is limited. Our objective was to investigate whether elevated blood selenium levels can mitigate the nephrotoxic effects of lead and cadmium. The exposure variables examined in this study include blood selenium, cadmium, and lead levels measured by ICP-MS. The outcome of interest was CKD, defined as an estimated glomerular filtration rate (eGFR) below 60 mL/min/1.73 m². In total, 10630 participants (mean (SD) age:48.9 ± 18.4; 48.3% male) were included in this analysis. The median (IQR) of blood selenium, cadmium, and lead levels was 191 (177-207) μg/L, 0.300 (0.180-0.540) μg/L, and 0.940 (0.570-1.510) μg/dL, respectively. We observed a significant positive association between cadmium and lead levels and CKD (OR; 1.86; 95%CI: 1.31- 2.64; OR:2.23; 95%CI:1.54-3.24). However, selenium had a negative association with CKD (OR:0.096; 95%CI:0.020-0.457). Based on a reference group with a selenium concentration of ≤ 191 μg/L and cadmium level of > 0.300 μg/L, a significant protective factor in the CKD was seen in subjects with high plasma selenium and lower cadmium concentrations (OR:0.685; 95%CI:0.515-0.912). Then selenium concentration of ≤ 191 μg/L and lead level of > 0.940 μg/dL were set as a reference group, and the OR for CKD decreased among the other group (OR:0.564; 95%CI;0.417- 0.762). The subgroup analysis indicated that there were no effect modifiers. Blood selenium has the potential to mitigate the nephrotoxic effects of lead and cadmium in the general population of the United States.

Method Development for Detecting Low Level Volatile Organic Compounds (VOCs) among Workers and Residents from a Carpentry Work Shop in a Palestinian Village

Volatile organic compounds (VOCs) are considered a major public health concern in industrial location areas. The presence of exposure to (VOCs) has raised concern regarding the health effects caused by chronic human exposure as this will increase cancer diseases in the village. An analytical method has been developed and modified to help us detect 38 VOCs in the blood of 38 volunteers who are related to a carpentry shop at the parts-per-trillion level. To measure and evaluate the potential risk, several devices, such as portable passive monitors and air-collected samples, in addition to blood concentration, were used to study three different occupational groups. Ten of the volunteers are employees at the shop, 10 volunteers live very close to the shop, and 10 of them are students in an elementary school very close to the shop. In this study, we developed an automated analytical method using headspace (HS) together with solid-phase microextraction (SPME) connected to capillary gas chromatography (GC) equipped with quadrupole mass spectrometry (MS). The detection limits for the method used were measured in the range from 0.001 to 0.15 ng/L, using linear calibration curves that have three orders of magnitude. The detected concentrations ranged from 3 ng L^-1 for trichloroethene to 91 ng L^-1 for toluene and 270 ng L^-1 for 2,4-diisocyanate, which was derived from the paint solvents used for the wood in the carpentry shop and the paints on the walls. More than half of all assessed species (80%) had mean concentration values less than 50 ng L^-1, which is the maximum allowed for most VOCs. The major chemical types among the compounds quantified will be those we found in our previous study in the surrounding air of a carpentry workshop in Deir Ballout in Palestine, which were toluene diisocyanate and butyl cyanate. Some were found to be highly present air. Most of the measurements were below the guidelines of the World Health Organization (WHO). Despite the fact that this study only involved a small number of smokers, smoking was found to be connected with several blood and breath components. This group includes unsaturated hydrocarbons (1,3-butadiene, 1,3-pentadiene, 2-butene), furans (2,5-dimethylfuran), and acetonitrile. The proposed classification of measured species into systemic (blood-borne) and exogenous volatiles is strictly hypothetical, as some species may have several origins.

The relationship between vitamin K and metabolic dysfunction-associated fatty liver disease among the United States population: National Health and Nutrition Examination Survey 2017-2018

Background

The effect of vitamin K is associated with several pathological processes in fatty liver. However, the association between vitamin K levels and metabolic dysfunction-associated fatty liver disease (MAFLD) remains unclear.

Objective

Here, we investigated the relationship between vitamin K intake and MAFLD risk by employing the American National Health and Nutrition Examination Surveys (NHANES) including 3,571 participants.

Methods

MAFLD was defined as hepatic steatosis with one or more of the following: overweight or obesity, type 2 diabetes, or >2 other metabolic risk abnormalities. The total vitamin K was the sum of dietary and supplement dietary intake. The relationship of between log₁₀(vitamin K) and MAFLD was investigated using survey-weighted logistic regression and stratified analysis, with or without dietary supplementation.

Results

The MAFLD population had a lower vitamin K intake than the non-MAFLD population (p = 0.024). Vitamin K levels were inversely associated with MAFLD in the fully adjusted model (OR = 0.488, 95% CI: 0.302-0.787, p = 0.006). Consistent results were seen in the group without dietary supplements (OR = 0.373, 95% CI: 0.186-0.751, p = 0.009) but not in the group consuming dietary supplements (OR = 0.489, 95% CI: 0.238-1.001, p = 0.050).

Conclusion

Vitamin K intake may be a protective factor for MAFLD, especially for individual not using dietary supplements. Nevertheless, more high-quality prospective studies are needed to clarify the causal relationship between them.

A longitudinal study on physiological stress in individuals at ultra high-risk of psychosis

INTRODUCTION

Individuals at ultra high-risk (UHR) of psychosis exhibit significantly higher stress levels than healthy controls (HC). This study investigates how physiological stress measures differ between HC and UHR individuals and how physiological stress is associated with attenuated psychotic symptoms and changes over time in UHR individuals. Additionally, it examines how the use of medication affects physiological levels of stress.

METHOD

The study included 72 UHR individuals and 36 HC. UHR were included according to the comprehensive assessment of at-risk mental state (CAARMS); a total-CAARMS score measured the attenuated psychotic symptoms and was calculated from the four psychosis subscales. HC and UHR were examined at baseline, and 47 UHR individuals were followed up after six months. Physiological stress measures were salivary cortisol, alpha-amylase (SAA) and heart-rate variability (HRV). Saliva was collected at four-time points during the day.

RESULTS

There was no significant difference regarding cortisol (awakening response) or SAA measures between HC and UHR individuals. The use of antipsychotics and antidepressants was associated with low HRV in UHR individuals. In an exploratory analysis of 19 UHR individuals, we found an association between the change in total-CAARMS (six months total-CAARMS minus baseline total CAARMS) and the change in HRV during sleep (six months HRV minus baseline HRV).

CONCLUSION

Our findings indicate that the use of antipsychotics and antidepressants could be associated with lower HRV in UHR individuals. There might be potential to investigate how HRV develops during the course of illness in UHR individuals.

Rules for mass spectrometry applications in the clinical laboratory

MS-based analytical methods now play an important role in medical laboratory analysis. Predominantly triple-stage mass spectrometry is used for the quantification of small molecule biomarkers and xenobiotics in blood and urine. The spectrum of applications ranges from completely in-house developed analytical methods, to industrially manufactured kit solutions used on generic equipment, to the first closed MS-based analysis systems. It is to be expected that the weights will shift in the coming years. Thus, operation and evaluation for most applications will remain very challenging and very different from the far more user-friendly and fully automated systems - mainly photometry-based - which are commonly used in clinical laboratories. General regulatory requirements for medical analysis differ significantly between countries globally. General requirements for in-house developed assay methods are valid in some countries, but concrete and methodology-specific rules for operation and quantification when using MS methods in the medical diagnostic laboratory are not applied. This differs significantly from other bio-analytical areas such as food monitoring, pharmaceutical research, or forensics, where legally binding, detailed rules exist in some cases, e.g., for substance identification. Internationally used relevant and helpful general standards with regard to mass spectrometric examination procedures in the clinical laboratory are in particular CLSI 62A and ISO 15189, while the IVDR in the EU primarily regulates the manufacture of diagnostic articles and not their application. In addition, from many years of application experience, some general advice can be recommended as rules that can contribute to robustness and patient safety in the clinical application of MS procedures; with emphasis on: reasonable method description, batch release, competence management, maintenance, and continuity management. This article also proposes some procedural basic requirements for the application of MS procedures in the clinical laboratory.

Validation of Linear Range HER2/Estrogen Receptor/Progesterone Receptor IHControls for Daily Quality Assurance

OBJECTIVES

To evaluate a new US Food and Drug Administration (FDA)-cleared immunohistochemistry (IHC) control (IHControls [Boston Cell Standards]) comprising peptide epitopes for HER2, estrogen receptor (ER), and progesterone receptor (PR) attached to cell-sized microspheres and to compare its performance against conventional tissue controls.

METHODS

IHControls and tissue/cell line controls for HER2, ER, and PR were compared side by side daily at 5 clinical IHC laboratories for 1 to 2 months. Separately, the sensitivity of the 2 types of controls was evaluated in simulated IHC assay failure experiments by diluting the primary antibody. Additional evaluations included lot-to-lot manufacturing reproducibility of 3 independent lots and specificity against 26 antigenically irrelevant IHC stains.

RESULTS

Side-by-side testing revealed a 99.6% concordance between IHControls and tissue controls across 5 IHC laboratories and 766 individual evaluations. Three discordant quality control events were the result of operator error. Simulated assay failure data showed that both IHControls and tissue controls are similarly capable of detecting IHC staining errors. Manufacturing reproducibility of IHControls showed less than 10% variability (coefficient of variation). No cross-reactions were detected from 26 antigenically irrelevant IHC stains.

CONCLUSIONS

IHControls, the first FDA-cleared IHC controls, can sensitively and accurately detect IHC assay problems, similar to tissue controls.

Association between heavy metals exposure and infertility among American women aged 20-44 years: A cross-sectional analysis from 2013 to 2018 NHANES data

Background

Infertility has been confirmed as a significant medical and social problem. Heavy metal exposure refers to a risk factor for infertility, which is capable of damaging the reproductive system of males and females. However, heavy metal exposure and female infertility have rarely been investigated. The aim of this study was to analyze the association between heavy metal exposure and female infertility.

Methods

A cross-sectional study using data from three cycles of the National Health and Nutrition Examination Survey (NHANES, 2013-2018) was performed. Female infertility was evaluated by positive responses to question rhq074 in the questionnaire. Cadmium (Cd), lead (Pb), mercury (Hg), and arsenic (As) levels in blood or urine were examined by inductively coupled plasma mass spectrometry. The correlation between heavy metal and female infertility was analyzed through weighted logistic regression.

Results

A total of 838 American women aged 20-44 years were covered in the study. Among all participants, 112 (13.37%) women were subjected to infertility. Urinary Cd and urinary As levels were significantly higher in infertile women than in control women (P < 0.05, P < 0.05). Urinary As showed a positive correlation with the prevalence of female infertility, and the risk of infertility rose with the increase of urinary As levels (P for trend = 0.045). Urinary Cd was associated with female infertility in some weighted logistic regression (Crude, Q2: OR = 3.99, 95% CI 1.82, 8.74, Q3: OR = 2.90, 95% CI 1.42, 5.92. Model 1, Q2: OR = 3.68, 95% CI 1.64, 8.27, Q3: OR = 2.33, 95% CI 1.13, 4.48. Model 2, Q2: OR = 4.11, 95% CI 1.63, 10.07, Q3: OR = 2.44, 95% CI 1.07, 5.53. Model 3, Q2: OR = 3.77, 95% CI 1.52, 9.35). Moreover, blood Pb (OR = 1.52, 95% CI 1.07, 2.16), urinary Pb (OR = 1.68, 95% CI 1.11, 2.55), and urinary As (OR = 1.02, 95% CI 1.00, 1.03) were positively correlated with the risk of infertility in women aged 35-44 years. The blood Pb (OR = 1.67, 95% CI 1.16, 2.40, 2.49) and urinary Pb (OR = 1.54, 95% CI 1.00, 2.38) in women with BMI ≥25 were positively correlated with the risk of infertility.

Conclusions

Urinary As was significantly associated with female infertility, and the risk of infertility increased with higher urinary As levels. To some extent, urinary Cd was correlated with infertility. Blood/urine Pb was related to infertility in advanced age and overweight/obese women. The results of this study need to be further validated in future prospective studies.

Healthy Eating Index-2015 in relation to risk of metabolic dysfunction-associated fatty liver disease among US population: National Health and Nutrition Examination Survey 2017-2018

Background

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a serious chronic disease in the US. Dietary patterns provide good guidance for the prevention of chronic diseases. The Healthy Eating Index (HEI-2015) is a dietary pattern based on the dietary characteristics of the US.

Objective

Since the relation between HEI-2015 and MAFLD is unclear, this study examined their associations using the US National Health and Nutrition Examination Surveys (NHAENS) during 2017-2018.

Methods

This study included data from 4,062 participants aged ≥20 years, without viral hepatitis or pregnancy. MAFLD is defined as hepatic steatosis with one or more of the following: (1) overweight or obesity (body mass index ≥25 kg/m²); (2) type 2 diabetes; or (3) two or more other metabolic risk abnormalities. HEI-2015 scores were calculated from food intake information collected by the 24-h meal review method. The relationship of HEI-2015 with MAFLD was calculated using survey-weighted logistic regression analysis after adjusting for sex, age, race, education level, smoking status, alcohol use, levels of C-reactive protein, Aspartate Aminotransferase, Alanine Aminotransferase, a body shape index, minutes of sedentary activity, levels of cholesterol and glucose, energy take, drugs use, hypertension, and diabetes.

Results

When compared to the study population with no MAFLD, the patients with MAFLD showed a lower weighted mean HEI (48.0 ± 0.6). HEI-2015 was inversely associated with MAFLD in the fully adjusted model [Q4 vs. Q1, OR = 0.567 (0.407-0.790), P = -0.002]. Among the 13 HEI-2015 components, total vegetables, greens and beans, total fruits, whole fruits, and whole grains were negatively associated with MAFLD, while added sugars were positively associated with MAFLD. This inverse association was consistent in subgroups of the participants stratified by sex, age, education level, race, body shape index, minutes of sedentary activity, hypertension, and diabetes.

Conclusion

A higher HEI-2015 is associated with a lowered risk of MAFLD which is more obvious among participations who were women, young, Mexican Americans, with higher education, and with no hypertension or diabetes.

Data-Driven Anomaly Detection in Laboratory Medicine: Past, Present, and Future

BACKGROUND

Anomaly detection is an integral component of operating a clinical laboratory. It covers both the recognition of laboratory errors and the rapid reporting of clinically impactful results. Procedures for identifying laboratory errors and highlighting critical results can be improved by applying modern data-driven approaches.

CONTENT

This review will prepare the reader to appraise anomaly detection literature, identify common sources of anomalous results in the clinical laboratory, and offer potential solutions for common shortcomings in current laboratory practices.

SUMMARY

Laboratories should implement data-driven approaches to detect technical anomalies and keep them from entering the medical record, while also using the full array of clinical metadata available in the laboratory information system for context-dependent, patient-centered result interpretations.

Analytical validation and quality control/quality assurance practices for improved rigor and reproducibility of biochemical assays in orthopaedic research

Orthopaedic research, and biomedical research in general, has made enormous strides to develop treatments for conditions long thought to be inevitable or untreatable; however, there is growing concern about the quality of published research. Considerable efforts have been made to improve overall research quality, integrity, and rigor, including meaningful proposals focused on transparency of reporting, appropriate use of statistics, and reporting of negative results. However, we believe that there is another key component to rigor and reproducibility that is not discussed sufficiently-analytical validation and quality control (QC). In this commentary, we discuss QC and method validation principles and practices that are systematically applied in the clinical laboratory setting to verify and monitor the analytical performance of quantitative assays, and the utility of applying similar practices to biochemical assays in the orthopaedic research setting. This commentary includes (1) recommendations for validation and QC practices, including examples of assay performance limitations uncovered by validation experiments performed in our laboratory, and (2) a description of an ongoing QC program developed to monitor the ongoing performance of commonly used assays in our lab. We hope that this commentary and the examples presented here will be thought-provoking and inspire further discussion and adaptation of analytical validation and QC procedures to advance our shared pursuit of high-quality, rigorous, and reproducible orthopaedic research.

Technical quality assurance and quality control for medical laboratories: a review and proposal of a new concept to obtain integrated and validated QA/QC plans

Technical quality assurance (QA) and quality control (QA/QC) are important activities within medical laboratories to ensure the adequate quality of obtained test results. QA/QC tools available at medical laboratories include external QC and internal QC, patient-based real-time quality control (PBRTQC) tools such as moving average quality control (MAQC), limit checks, delta checks, and multivariate checks, and finally, analyzer flagging. Recently, for PBRTQC tools, new optimization and validation methods based on error detection simulation have been developed to obtain laboratory-specific insights into PBRTQC error detection. These developments have enabled implementation and application of these individual tools in routine clinical practice. As a next step, they also enable performance comparison of the individual QA/QC tools and integration of all the individual QA/QC tools in order to obtain the most powerful and efficient QA/QC plans. In this review, a brief overview of the individual QA/QC tools and their characteristics is provided and the error detection simulation approaches are explained. Finally, a new concept entitled integrated quality assurance and control (IQAC) is presented. To enable IQAC, a conceptual framework is suggested and demonstrated for sodium, based on available published data. The proposed IQAC framework provides ways and tools by which the performance of different QA/QC tools can be compared in a so-called QA/QC error detection table to enable optimization and validation of the overall QA/QC plan in terms of alarm rate as well as pre-analytical, analytical, and post-analytical error detection performance.

The next wave of innovation in laboratory automation: systems for auto-verification, quality control and specimen quality assurance

Laboratory automation in clinical laboratories has made enormous differences in patient outcomes, with a wide range of tests now available that are accurate and have a rapid turnaround. Total laboratory automation (TLA) has mechanised tube handling, sample preparation and storage in general chemistry, immunoassay, haematology, and microbiology and removed most of the tedious tasks involved in those processes. However, there are still many tasks that must be performed by humans who monitor the automation lines. We are seeing an increase in the complexity of the automated laboratory through further platform consolidation and expansion of the reach of molecular genetics into the core laboratory space. This will likely require rapid implementation of enhanced real time quality control measures and these solutions will generate a significantly greater number of failure flags. To capitalise on the benefits that an improved quality control process can deliver, it will be important to ensure that an automation process is implemented simultaneously with enhanced, real time quality control measures and auto-verification of patient samples in middleware. Therefore, it appears that the best solution may be to automate those critical decisions that still require human intervention and therefore include quality control as an integral part of total laboratory automation.

Internal quality control - past, present and future trends

Objectives

This paper offers an historical view, through a summary of the internal quality control (IQC) models used from second half of twentyth century to those performed today and wants to give a projection on how the future should be addressed.

Methods

The material used in this work study are all papers collected referring IQC procedures. The method used is the critical analysis of the different IQC models with a discussion on the weak and the strong points of each model.

Results

First models were based on testing control materials and using multiples of the analytical procedure standard deviation as control limits. Later, these limits were substituted by values related with the intended use of test, mainly derived from biological variation. For measurands with no available control material methods based on replicate analysis of patient' samples were developed and have been improved recently; also, the sigma metrics that relates the quality desired with the laboratory performance has resulted in a highly efficient quality control model. Present tendency is to modulate IQC considering the workload and the impact of analytical failure in the patent harm.

Conclusions

This paper remarks the strong points of IQC models, indicates the weak points that should be eliminated from practice and gives a future projection on how to promote patient safety through laboratory examinations.

Diet quality and exposure to endocrine-disrupting chemicals among US adults

Human exposure to endocrine-disrupting chemicals (EDCs) may increase risk for chronic disease. Diet is a significant source of EDC exposure, yet healthy diets recommended for chronic disease prevention have not been thoroughly examined for associations with EDC exposure. Using data from the National Health and Nutrition Examination Survey 2013-2016, we examined associations of dietary patterns with exposure to non-persistent EDCs potentially consumed through diet. EDCs were measured in spot urine samples. Diet was assessed using 24-h recalls. Multivariable linear regression was used to examine associations of three healthy diet scores [Healthy Eating Index (HEI), relative Mediterranean Diet (rMED), and Dietary Approaches to Stop Hypertension] and fast-food consumption with EDCs. In fully adjusted models, no diet was associated with exposure to the bisphenols, phthalates, or polycyclic aromatic hydrocarbons examined. A 1-point increase in rMED (of 18 possible points) was associated with 2.7% (95% CI: 1.7%, 3.8%) greater urinary nitrate. A 10-point increase in HEI (of 100 possible points) was associated with 5.3% (95% CI: 2.8%, 7.9%) greater nitrate and 6.8% (95% CI: 4.5%, 9.2%) greater perchlorate. Because perchlorate and nitrate can disrupt thyroid hormone production, we conducted an exploratory analysis to examine whether these chemicals mediate an association between diet and thyroid hormones. A 10-point increase in HEI was associated with 0.6% reduced serum total thyroxine (95% CI: 1.7%, 0.5%) among all adults, with 57.5% of the effect explained by perchlorate. Nitrate mediated an association of rMED with modestly reduced total triiodothyronine among females. Most EDCs examined had no association with the diets evaluated, indicating that recommended healthy diets were not protective against EDC exposures. As observed with two thyroid antagonists, some recommended diets may increase EDC exposures and related adverse health outcomes. Additional work should identify effective food production and processing practices to reduce dietary exposures to potentially harmful EDCs.

Establishment of reference values for plasma neurofilament light based on healthy individuals aged 5–90 years

The recent development of assays that accurately quantify neurofilament light, a neuronal cytoskeleton protein, in plasma has generated a vast literature supporting that it is a sensitive, dynamic, and robust biomarker of neuroaxonal damage. As a result, efforts are now made to introduce plasma neurofilament light into clinical routine practice, making it an easily accessible complement to its cerebrospinal fluid counterpart. An increasing literature supports the use of plasma neurofilament light in differentiating neurodegenerative diseases from their non-neurodegenerative mimics and suggests it is a valuable biomarker for the evaluation of the effect of putative disease-modifying treatments (e.g. in multiple sclerosis). More contexts of use will likely emerge over the coming years. However, to assist clinical interpretation of laboratory test values, it is crucial to establish normal reference intervals. In this study, we sought to derive reliable cut-offs by pooling quantified plasma neurofilament light in neurologically healthy participants (5–90 years) from eight cohorts. A strong relationship between age and plasma neurofilament light prompted us to define the following age-partitioned reference limits (upper 95th percentile in each age category): 5–17 years = 7 pg/mL; 18–50 years = 10 pg/mL; 51–60 years = 15 pg/mL; 61–70 years = 20 pg/mL; 70 + years = 35 pg/mL. The established reference limits across the lifespan will aid the introduction of plasma neurofilament light into clinical routine, and thereby contribute to diagnostics and disease-monitoring in neurological practice.

Physical activity reduces the role of blood cadmium on depression: A cross-sectional analysis with NHANES data

Cadmium (Cd) exposure is recognized as an important risk factor for psychological health, but suitable physical activity may relieve depression. However, it remains unknown whether physical activity (PA) can reduce the effect of cadmium exposure on depression. Therefore, a cross-sectional data from National Health and Nutrition Examination Survey (NHANES) 2015-2018 was used. The Nine-item Patient Health Questionnaire (PHQ-9) was used to assess depression among the participants. PA was calculated according to the metabolic equivalent (MET), weekly frequency, and duration of each activity. Logistic regression and restricted cubic spline models were used to examine the associations of Cd and depression. A total of 5560 adults aged 20 years and above were finally included in this study. The results indicated a positive correlation between blood Cd and depression. The multivariate-adjusted ORs (95% CI) of the highest quartile were 2.290 (1.754-2.990) for depression, which was still significant after controlling other heavy metals (P < 0.05). Under Cd exposure, the high intensity of physical activity group had the lowest risk of depression (OR = 2.226, 95%CI: 1.447-3.425), while the group with no physical activity had the highest risk (OR = 2.443, 95%CI: 1.382-4.318). Our results indicate that inner Cd exposure may be a risk factor for depression, and physical activity can moderate this relationship to some degree.

Applicability of the long‐term uncertainty in measurement ( LTUM ) method for analytical performance assessment in clinical cytometry laboratories

Background

Methods

Results

Conclusions

The Quantitation of Squalene and Squalane in Bronchoalveolar Lavage Fluid Using Gas Chromatography Mass Spectrometry

Chemicals of unknown inhalational toxicity are present in electronic cigarette and vaping products. E-cigarettes typically contain nicotine and other relatively hydrophilic chemicals while vaping products typically contain cannabinoids and other hydrophobic chemicals. For example, vaping products can include hydrophobic terpenes such as squalane (SQA) and squalene (SQE). However, little is known about the SQA and SQE transmission from liquid to aerosol. SQA and SQE are used in commercial products that are applied dermally and ingested orally, but limited information is available on their inhalational exposure and toxicity. We developed and validated a quantitative method to measure SQE and SQA in bronchoalveolar lavage fluid to assess if these chemicals accumulate in lung epithelial lining fluid after inhalation. Calibration curves spanned a range of 0.50–30.0 µg analyte per mL bronchoalveolar lavage fluid. Recoveries were found to be 97–105% for SQE and 81–106% for SQA. Limits of detection were 0.50 μg/ml for both SQE and SQA. The method was applied to bronchoalveolar lavage fluid samples of patients from the 2019 outbreak of e-cigarette, or vaping, product use-associated lung injury (EVALI) and a comparison group. Neither SQA nor SQE was detected above the method LOD for any samples analyzed; conversely, SQA or SQE were reproducibly measured in spiked quality control BAL fluids (relative standards deviations <15% for both analytes). Further applications of this method may help to evaluate the potential toxicity of SQA and SQE chronically inhaled from EVPs.

Predicting Blood Parasite Load and Influence of Expression of iNOS on the Effect Size of Clinical Laboratory Parameters in Acute Trypanosoma cruzi Infection With Different Inoculum Concentrations in C57BL/6 Mice

In Chagas disease, the initial responses of phagocyte-mediated innate immunity are strongly associated with the control of Trypanosoma cruzi and are mediated by various signaling pathways, including the inducible nitric oxide synthetase (iNOS) pathway. The clinical and laboratory manifestations of Chagas disease depend on the parasite–host relationship, i.e., the responsive capacity of the host immune system and the immunogenicity of the parasite. Here, we evaluated effect sizes in clinical and laboratory parameters mediated by acute infection with different concentrations of T. cruzi inoculum in mice immunosuppressed via iNOS pathway inactivation. Infection was induced in C57BL/6 wild-type and iNOS^-/- mice with the “Y” strain of T. cruzi at three inoculum concentrations (3 × 10², 3 × 10³, and 3 × 10⁴). Parasitemia and mortality in both mouse strains were monitored. Immunohistochemistry was performed to quantify amastigotes in cardiac tissues and cardiac musculature cells. Biochemical parameters, such as blood urea nitrogen, sodium, albumin, and globulin concentrations, among others, were measured, and cytokine concentrations were also measured. Effect sizes were determined by the eta squared formula. Compared with that in wild-type animals, mice with an absence of iNOS expression demonstrated a greater parasite load, with earlier infection and a delayed parasitemia peak. Inoculum concentration was positively related to death in the immunosuppressed subgroup. Nineteen parameters (hematological, biochemical, cytokine-related, and histopathological) in the immunocompetent subgroup and four in the immunosuppressed subgroup were associated with parasitemia. Parasitemia, biochemical parameters, and hematological parameters were found to be predictors in the knockout group. The impact of effect sizes on the markers evaluated based on T. cruzi inoculum concentration was notably high in the immunocompetent group (Cohen’s d = 88.50%; p <.001). These findings contribute to the understanding of physiopathogenic mechanisms underlying T. cruzi infection and also indicate the influence of the concentration of T. cruzi during infection and the immunosuppression through the iNOS pathway in clinical laboratory heterogeneity reported in acute Chagas disease.

A gas chromatography-mass spectrometry method for quantifying squalane and squalene in aerosol emissions of electronic cigarette, or vaping, products

Numerous chemicals of unknown inhalational toxicity have been measured in electronic cigarette, or vaping, products (EVPs). In addition, little is known about the liquid-to-aerosol transmission and deliveries of these chemicals, including oil-like terpenes such as squalene (SQE) and squalane (SQA). To provide information on the aerosol deliveries of these compounds from EVPs, we developed and validated a quantitative method to measure squalene and squalane in EVP aerosol emissions. Validation parameters include measurement repeatability (SQA and SQE %RSD <6%), intermediate precision (SQA: %RSD 11%, SQE: %RSD 17%), accuracy (SQA: 86-107%, SQE: 104-113%), matrix effects, method robustness, and analyte stability. Limits of detection were 6.06 ng/mL puffed air volume for both squalene and squalane. The method was used to measure squalene and squalane in aerosol emissions of 153 EVPs associated with case patients from a recent outbreak of e-cigarette, or vaping, product use associated lung injury (EVALI). The EVPs analyzed were organized into nicotine, cannabidiol, and tetrahydrocannabinol products by the percentage of nicotine, cannabidiol, and tetrahydrocannabinol in total particulate matter after vaping. In case-associated tetrahydrocannabinol products the detection rates and mean concentrations were 82.4% and 33.0 ng/mL puffed air for squalene and 4.41% and 7.80 ng/mL puffed air for squalane.

Multirule procedures vs moving average algorithms for IQC: An appropriate comparison reveals how best to combine their strengths

BACKGROUND

Moving Average Algorithms (MAA) have been widely recommended for use in Patient Based Real Time Quality Control applications (PBRTQC) to supplement or replace traditional Internal Quality Control (IQC) techniques. A recent "proof of concept" study recommends applying MAAs to IQC data to replace traditional IQC procedures because they "outperform Westgard Rules," which is a current standard of practice for IQC.

METHODS

We generated power curves for multi-rule procedures with 2 and 4 control measurements per QC event, as well as a Simple Moving Average having block sizes of 5, 10, and 20 control measurements. We also assessed time to detection in terms of the Average Number of QC Events required to detect different sizes of systematic errors.

RESULTS

As expected, the more control measurements included in the control technique, the better the error detection. However, when QC performance is considered on the Sigma Scale, high Sigma methods require only 1 or 2 control measurements to detect medically important systematic errors. MAAs have very low ability to detect error at the first few QC events following shift, so they suffer a lag phase in detecting medically important errors. MAAs are most useful for methods having 4.0 Sigma performance or less. Even then, large systematic shifts are more quickly detected by simple single and multirule procedures.

CONCLUSIONS

Choice of control techniques (rules, means, ranges, etc.) should consider the Sigma-metric of the method. For methods having Sigmas of 4 or greater, traditional single rule and multirule procedures with Ns up to 4 are most effective; below 4 Sigma, a multirule coupled with a Simple Moving Average (SMA) rule with Ns of 4 to 8 can improve error detection.

The Use of qPCR to Detect Cryphonectria parasitica in Plants

Cryphonectria parasitica is a fungal pathogen that causes lethal bark necrosis in chestnut. A duplex qPCR allowing detection of the pathogen and its host, Castanea sativa, is described. The method can be used for early detection of the pathogen in chestnut bark tissues with an internal control of false-negative results caused by PCR inhibitors and/or DNA extraction failure. A positive amplification control of qPCR that allows detection of any deviation from a normal qPCR run based on a control chart is also described. As C. parasitica is a regulated pathogen in Europe, the protocol also provides information on the way to collect and handle bark samples to fulfil biosecurity rules.

Detection of SARS-CoV-2 infection clusters: The useful combination of spatiotemporal clustering and genomic analyses

Background

The need for effective public health surveillance systems to track virus spread for targeted interventions was highlighted during the COVID-19 pandemic. It spurred an interest in the use of spatiotemporal clustering and genomic analyses to identify high-risk areas and track the spread of the SARS-CoV-2 virus. However, these two approaches are rarely combined in surveillance systems to complement each one's limitations; spatiotemporal clustering approaches usually consider only one source of virus transmission (i.e., the residential setting) to detect case clusters, while genomic studies require significant resources and processing time that can delay decision-making. Here, we clarify the differences and possible synergies of these two approaches in the context of infectious disease surveillance systems by investigating to what extent geographically-defined clusters are confirmed as transmission clusters based on genome sequences, and how genomic-based analyses can improve the epidemiological investigations associated with spatiotemporal cluster detection.

Methods

For this purpose, we sequenced the SARS-CoV-2 genomes of 172 cases that were part of a collection of spatiotemporal clusters found in a Swiss state (Vaud) during the first epidemic wave. We subsequently examined intra-cluster genetic similarities and spatiotemporal distributions across virus genotypes.

Results

Our results suggest that the congruence between the two approaches might depend on geographic features of the area (rural/urban) and epidemic context (e.g., lockdown). We also identified two potential superspreading events that started from cases in the main urban area of the state, leading to smaller spreading events in neighboring regions, as well as a large spreading in a geographically-isolated area. These superspreading events were characterized by specific mutations assumed to originate from Mulhouse and Milan, respectively. Our analyses propose synergistic benefits of using two complementary approaches in public health surveillance, saving resources and improving surveillance efficiency.