The Value of Reducing Inconclusive and False-Positive Newborn Screening Results for Congenital Hypothyroidism, Congenital Adrenal Hyperplasia and Maple Syrup Urine Disease in The Netherlands.

Inconclusive and false-positive newborn screening (NBS) results can cause parental stress and increase healthcare expenditures. These results can be reduced by improving NBS algorithms. This was recently done for Congenital Hypothyroidism (CH), Congenital Adrenal Hyperplasia (CAH) and Maple Syrup Urine Disease (MSUD) in the Dutch NBS program. The current study estimates the financial consequences of these improved algorithms related to the reduction in inconclusive results and false-positives. For each improved algorithm, the care pathway of an inconclusive/false-positive result was analyzed. The costs associated with the improvements, based on the change in inconclusive results/false-positives, were assessed to estimate the cost reduction per year. The improvements resulted in a reduction of inconclusive results and/or false-positives, without increasing false-negatives. For CH, false positives decreased by 26 per year with a related cost reduction of EUR 31,156. For CAH, 95 second heel punctures and seven false-positives per year were avoided, leading to a related cost reduction of EUR 7340. For MSUD, five false-positives per year were avoided with a related cost reduction of EUR 11,336. The improved screening algorithms led to a cost reduction of EUR 49,832 annually. Together with the known negative psychosocial effects associated with an inconclusive or false-positive NBS result, these results highlight the importance of improving NBS algorithms.

A higher incidence of chondral injuries on the medial femoral condyle in concomitant ACL ruptures, no significant difference in treatment: A systematic review.

PURPOSE: The associated damage to articular cartilage in anterior cruciate ligament (ACL) injured patients is a well-recognized phenomenon; however, there is a relative paucity in the literature regarding the different treatment techniques and outcomes. The purpose of this systematic review was to identify patients treated for acute ACL rupture and associated cartilage injury, with interest in the surgical management of these chondral injuries and any difference in patient-reported outcome measures (PROMs) differing techniques. METHODS: A systematic review was performed looking for treatment or management of International Cartilage Repair Society grade 3 or 4 articular cartilage injury at the time of ACL reconstruction. RESULTS: Seventeen studies fit the criteria, a total of 892 patients were included, 64.6% were male with a mean age of 33.7 and the average time to follow-up was 41.7 months. 68.2% of the lesions were on the medial femoral condyle (MFC) with a mean lesion size of 3.9 cm2. Six different operative methods of dealing with chondral lesions were identified, there was no significant difference in PROMs between the techniques, although there was a significant difference between the preoperative and postoperative outcome measures. CONCLUSIONS: The systematic review found that chondral defects on the MFC are more common in concomitant ACL injuries, despite the pattern of bone bruising being more common on the lateral femoral condyle as reported in the literature. It also found no significant difference in the PROMs between the six different techniques identified for the concomitant management of ACL reconstruction and chondral defects. LEVEL OF EVIDENCE: Level II.

Methotrexate accumulation in target intestinal mucosa and white blood cells differs from non-target red blood cells of patients with Crohn's disease.

BACKGROUND: Intracellular methotrexate polyglutamates (MTX-PGs) concentrations are measurable in red blood cells (RBCs) during MTX treatment. MTX-PG3 concentrations correlate with efficacy in patients with Crohn's disease (CD). Since RBCs are not involved in pathogenesis of CD and lack extended MTX metabolism, we determined MTX-PGs accumulation in peripheral blood mononuclear cells (PBMCs: effector cells) and intestinal mucosa (target cells) and compared those with RBCs as a potential more precise biomarker. METHODS: In a multicentre prospective cohort study, blood samples of patients with CD were collected during the first year of MTX therapy. Mucosal biopsies were obtained from non-inflamed rectum and/or inflamed intestine. MTX-PGs concentrations in mucosa, PBMCs and RBCs were measured by liquid chromatography-tandem mass spectrometry. RESULTS: From 80 patients with CD, a total of 27 mucosal biopsies, 9 PBMC and 212 RBC samples were collected. From 12 weeks of MTX therapy onwards, MTX-PG3 was the most predominant species (33%) in RBCs. In PBMCs, the distribution was skewed towards MTX-PG1 (48%), which accounted for an 18 times higher concentration than in RBCs. Long-chain MTX-PGs were highly present in mucosa: 21% of MTX-PGtotal was MTX-PG5. MTX-PG6 was measurable in all biopsies. CONCLUSIONS: MTX-PG patterns differ between mucosa, PBMCs and RBCs of patients with CD.

Faecal Volatile Organic Compound Analysis in De Novo Paediatric Inflammatory Bowel Disease by Gas Chromatography-Ion Mobility Spectrometry: A Case-Control Study.

The gut microbiota and its related metabolites differ between inflammatory bowel disease (IBD) patients and healthy controls. In this study, we compared faecal volatile organic compound (VOC) patterns of paediatric IBD patients and controls with gastrointestinal symptoms (CGIs). Additionally, we aimed to assess if baseline VOC profiles could predict treatment response in paediatric IBD patients. We collected faecal samples from a cohort of de novo therapy-naïve paediatric IBD patients and CGIs. VOCs were analysed using gas chromatography-ion mobility spectrometry (GC-IMS). Response was defined as a combination of clinical response based on disease activity scores, without requiring treatment escalation. We included 109 paediatric IBD patients and 75 CGIs, aged 4 to 17 years. Faecal VOC profiles of paediatric IBD patients were distinguishable from those of CGIs (AUC ± 95% CI, p-values: 0.71 (0.64-0.79), <0.001). This discrimination was observed in both Crohn's disease (CD) (0.75 (0.67-0.84), <0.001) and ulcerative colitis (UC) (0.67 (0.56-0.78), 0.01) patients. VOC profiles between CD and UC patients were not distinguishable (0.57 (0.45-0.69), 0.87). Baseline VOC profiles of responders did not differ from non-responders (0.70 (0.58-0.83), 0.1). In conclusion, faecal VOC profiles of paediatric IBD patients differ significantly from those of CGIs.

Appropriate use of blood cultures in the emergency department through machine learning (ABC): study protocol for a randomised controlled non-inferiority trial.

INTRODUCTION: The liberal use of blood cultures in emergency departments (EDs) leads to low yields and high numbers of false-positive results. False-positive, contaminated cultures are associated with prolonged hospital stays, increased antibiotic usage and even higher hospital mortality rates. This trial aims to investigate whether a recently developed and validated machine learning model for predicting blood culture outcomes can safely and effectively guide clinicians in withholding unnecessary blood culture analysis. METHODS AND ANALYSIS: A randomised controlled, non-inferiority trial comparing current practice with a machine learning-guided approach. The primary objective is to determine whether the machine learning based approach is non-inferior to standard practice based on 30-day mortality. Secondary outcomes include hospital length-of stay and hospital admission rates. Other outcomes include model performance and antibiotic usage. Participants will be recruited in the EDs of multiple hospitals in the Netherlands. A total of 7584 participants will be included. ETHICS AND DISSEMINATION: Possible participants will receive verbal information and a paper information brochure regarding the trial. They will be given at least 1 hour consideration time before providing informed consent. Research results will be published in peer-reviewed journals. This study has been approved by the Amsterdam University Medical Centers' local medical ethics review committee (No 22.0567). The study will be conducted in concordance with the principles of the Declaration of Helsinki and in accordance with the Medical Research Involving Human Subjects Act, General Data Privacy Regulation and Medical Device Regulation. TRIAL REGISTRATION NUMBER: NCT06163781.

Nonoperative Treatment as an Option for Isolated Anterior Cruciate Ligament Injury: A Systematic Review and Meta-analysis.

Background: An anterior cruciate ligament (ACL) tear is a risk factor for early osteoarthritis (OA) onset. Generally, ACL reconstruction (ACLR) is associated with better outcomes. However, there is a lack of evidence regarding the effect of operative versus nonoperative treatment for preventing premature knee OA in isolated ACL tears while achieving good functional outcomes. Purpose/Hypothesis: The purpose of the study was to compare the outcomes of ACLR to primarily nonoperative management of isolated ACL tears. It was hypothesized that the outcomes between treatment types would be similar. Study Design: Systematic review; Level of evidence, 3. Methods: This systematic review was registered on the International Prospective Register of Systematic Reviews (PROSPERO) (registration No. CRD42021285901) and was conducted according to the Cochrane Handbook guidelines. We systematically searched for randomized and nonrandomized studies that compared ACLR with nonoperative treatments in isolated ACL tears in 3 databases until October 25, 2021. The risk of bias and quality of evidence of the included studies was assessed in accordance with the Cochrane guidelines. The primary outcome was radiologic signs of OA, and the secondary outcomes were functional parameters. Using the common effects model, we calculated pooled mean differences (MDs) and odds ratios (ORs) with 95% CIs. Results: Five studies-2 randomized controlled trials (RCTs) and 3 retrospective non-RCTs-were included. There was a moderate risk of bias in 2 studies and a serious risk of bias in 1 study. The quality of evidence was rated low because of the higher risk of bias and inconsistency. Nonoperatively treated knees showed a trend toward lower odds of developing radiological signs of OA (OR, 1.84 [95% CI, 0.90 to 3.75]); however, surgically reconstructed knees had significantly better stability (MD, -2.44 [95% CI, -3.21 to -1.66 ]) and a trend toward better but clinically not meaningful Lysholm scores (MD, 2.88 [95% CI, -1.09 to 6.85]). The qualitative synthesis showed that surgical reconstruction was protective against subsequent injuries but not superior when returning to previous activity levels or various functional tests. Conclusion: Findings indicated that there is no certain evidence that ACLR for an isolated ACL tear is superior to nonoperative treatment. Clinicians should consider nonoperative treatments with a well-designed rehabilitative program as a primary option. However, these findings must be interpreted with caution because of low study quality and high risk of bias.

Micronutrient Status of Critically Ill Patients with COVID-19 Pneumonia.

Micronutrient deficiencies can develop in critically ill patients, arising from factors such as decreased intake, increased losses, drug interactions, and hypermetabolism. These deficiencies may compromise important immune functions, with potential implications for patient outcomes. Alternatively, micronutrient blood levels may become low due to inflammation-driven redistribution rather than consumption. This explorative pilot study investigates blood micronutrient concentrations during the first three weeks of ICU stay in critically ill COVID-19 patients and evaluates the impact of additional micronutrient administration. Moreover, associations between inflammation, disease severity, and micronutrient status were explored. We measured weekly concentrations of vitamins A, B6, D, and E; iron; zinc; copper; selenium; and CRP as a marker of inflammation state and the SOFA score indicating disease severity in 20 critically ill COVID-19 patients during three weeks of ICU stay. Half of the patients received additional (intravenous) micronutrient administration. Data were analyzed with linear mixed models and Pearson's correlation coefficient. High deficiency rates of vitamins A, B6, and D; zinc; and selenium (50-100%) were found at ICU admission, along with low iron status. After three weeks, vitamins B6 and D deficiencies persisted, and iron status remained low. Plasma levels of vitamins A and E, zinc, and selenium improved. No significant differences in micronutrient levels were found between patient groups. Negative correlations were identified between the CRP level and levels of vitamins A and E, iron, transferrin, zinc, and selenium. SOFA scores negatively correlated with vitamin D and selenium levels. Our findings reveal high micronutrient deficiency rates at ICU admission. Additional micronutrient administration did not enhance levels or expedite their increase. Spontaneous increases in vitamins A and E, zinc, and selenium levels were associated with inflammation resolution, suggesting that observed low levels may be attributed, at least in part, to redistribution rather than true deficiencies.

The effect of hormonal contraceptive therapy on clinical laboratory parameters: a literature review.

Hormonal contraceptives (HC) are widely used among women in reproductive ages. In this review, the effects of HCs on 91 routine chemistry tests, metabolic tests, and tests for liver function, hemostatic system, renal function, hormones, vitamins and minerals were evaluated. Test parameters were differently affected by the dosage, duration, composition of HCs and route of administration. Most studies concerned the effects of combined oral contraceptives (COC) on the metabolic, hemostatic and (sex) steroids test results. Although the majority of the effects were minor, a major increase was seen in angiotensinogen levels (90-375 %) and the concentrations of the binding proteins (SHBG [∼200 %], CBG [∼100 %], TBG [∼90 %], VDBP [∼30 %], and IGFBPs [∼40 %]). Also, there were significant changes in levels of their bound molecules (testosterone, T3, T4, cortisol, vitamin D, IGF1 and GH). Data about the effects of all kinds of HCs on all test results are limited and sometimes inconclusive due to the large variety in HC, administration routes and dosages. Still, it can be concluded that HC use in women mainly stimulates the liver production of binding proteins. All biochemical test results of women using HC should be assessed carefully and unexpected test results should be further evaluated for both methodological and pre-analytical reasons. As HCs change over time, future studies are needed to learn more about the effects of other types, routes and combinations of HCs on clinical chemistry tests.

Optimizing the Dutch newborn screening for congenital hypothyroidism by incorporating amino acids and acylcarnitines in a machine learning-based model.

Objective: Congenital hypothyroidism (CH) is an inborn thyroid hormone (TH) deficiency mostly caused by thyroidal (primary CH) or hypothalamic/pituitary (central CH) disturbances. Most CH newborn screening (NBS) programs are thyroid-stimulating-hormone (TSH) based, thereby only detecting primary CH. The Dutch NBS is based on measuring total thyroxine (T4) from dried blood spots, aiming to detect primary and central CH at the cost of more false-positive referrals (FPRs) (positive predictive value (PPV) of 21% in 2007-2017). An artificial PPV of 26% was yielded when using a machine learning-based model on the adjusted dataset described based on the Dutch CH NBS. Recently, amino acids (AAs) and acylcarnitines (ACs) have been shown to be associated with TH concentration. We therefore aimed to investigate whether AAs and ACs measured during NBS can contribute to better performance of the CH screening in the Netherlands by using a revised machine learning-based model. Methods: Dutch NBS data between 2007 and 2017 (CH screening results, AAs and ACs) from 1079 FPRs, 515 newborns with primary (431) and central CH (84) and data from 1842 healthy controls were used. A random forest model including these data was developed. Results: The random forest model with an artificial sensitivity of 100% yielded a PPV of 48% and AUROC of 0.99. Besides T4 and TSH, tyrosine, and succinylacetone were the main parameters contributing to the model's performance. Conclusions: The PPV improved significantly (26-48%) by adding several AAs and ACs to our machine learning-based model, suggesting that adding these parameters benefits the current algorithm.

Oral Versus Subcutaneous Methotrexate in Immune-Mediated Inflammatory Disorders: an Update of the Current Literature.

PURPOSE: This review aims to critically evaluate the potential benefit of either oral or subcutaneous administration of methotrexate (MTX) in various immune-mediated inflammatory disorders (IMIDs) through analysis of efficacy, toxicity, pharmacokinetics and pharmacodynamics of both administration routes. RECENT FINDINGS: Recent studies comparing the efficacy of oral versus subcutaneous MTX administration in IMIDs have revealed contradicting results. Some reported higher efficacy with subcutaneous administration, while others found no significant difference. Regarding toxicity, some studies have challenged the notion that subcutaneous administration is better tolerated than oral administration, while others have supported this. Pharmacokinetic studies suggest higher plasma bioavailability and increased accumulation of MTX-polyglutamates (MTX-PGs) in red blood cells (RBCs) with subcutaneous administration during the initial treatment phase. However, after several months, similar intracellular drug levels are observed with both administration routes. There is no conclusive evidence supporting the superiority of either oral or subcutaneous MTX administration in terms of efficacy and adverse events in IMIDs. Subcutaneous administration leads to higher plasma bioavailability and initial accumulation of MTX-PGs in RBCs, but the difference seems to disappear over time. Given the variable findings, the choice of administration route may be based on shared decision-making, offering patients the option of either oral or subcutaneous administration of MTX based on individual preferences and tolerability. Further research is needed to better understand the impact of MTX-PGs in various blood cells and TDM on treatment response and adherence to MTX therapy.

Therapeutic drug monitoring of methotrexate in patients with Crohn's disease.

BACKGROUND: Therapeutic drug monitoring (TDM) has the potential to improve efficacy and diminish side effects. Measuring methotrexate-polyglutamate (MTX-PG) in erythrocytes might enable TDM for methotrexate in patients with Crohn's disease (CD). AIM: To investigate the relationship between MTX-PGs and methotrexate drug survival, efficacy and toxicity METHODS: In a multicentre prospective cohort study, patients with CD starting subcutaneous methotrexate without biologics were included and followed for 12 months. Primary outcome was subcutaneous methotrexate discontinuation or requirement for step-up therapy. Secondary outcomes included faecal calprotectin (FCP), Harvey Bradshaw Index (HBI), hepatotoxicity and gastrointestinal intolerance. Erythrocyte MTX-PGs were analysed at weeks 8, 12, 24 and 52 or upon treatment discontinuation. RESULTS: We included 80 patients with CD (mean age 55 ± 13y, 35% male) with a median FCP of 268 µg/g (IQR 73-480). After the 12-month visit, 21 patients (26%) were still on subcutaneous methotrexate monotherapy. Twenty-one patients stopped because of disease activity, 29 because of toxicity, and four for both reasons. Five patients ended study participation or stopped methotrexate for another reason. A higher MTX-PG3 concentration was associated with a higher rate of methotrexate drug survival (HR 0.86, 95% CI 0.75-0.99), lower FCP (ß -3.7, SE 1.3, p < 0.01) and with biochemical response (FCP ≤250 if baseline >250 µg/g; OR 1.1, 95% CI 1.0-1.3). Higher MTX-PGs were associated with less gastrointestinal intolerance. There was no robust association between MTX-PGs and HBI or hepatotoxicity. CONCLUSIONS: Higher MTX-PG3 concentrations are related to better methotrexate drug survival and decreased FCP levels. Therefore, MTX-PG3 could be used for TDM if a target concentration can be established.

Is methotrexate safe for men with an immune-mediated inflammatory disease and an active desire to become a father? Results of a prospective cohort study (iFAME-MTX).

INTRODUCTION: Current scientific evidence guiding the decision whether men with an active desire to become a father should be treated with methotrexate (MTX) remains controversial. We aimed to prospectively evaluate the testicular toxicity profile of MTX focusing on several markers of male fertility, including semen parameters and sperm DNA fragmentation index (sDFI). As a secondary outcome, we aimed to evaluate whether MTX-polyglutamates can be detected in spermatozoa and seminal plasma and to evaluate the enzymatic activity in spermatozoa of folylpolyglutamate synthetase (FPGS). METHODS: In a prospective cohort study, men ≥18 years who started therapy with MTX were invited to participate (MTX-starters). Participants were instructed to produce two semen samples (a pre-exposure and a post-exposure sample after 13 weeks). Healthy men ≥18 years were invited to participate as controls. Conventional semen analyses, male reproductive endocrine axis and sDFI were compared between groups. FPGS enzymatic activity and MTX-PG1-5 concentrations were determined by mass spectrometry analytical methods. RESULTS: In total, 20 MTX-starters and 25 controls were included. The pre-exposure and postexposure semen parameters of MTX-starters were not statistically significant different. Compared with healthy controls, the conventional semen parameters and the sDFI of MTX-starters were not statistically significant different. These data were corroborated by the marginal accumulation of MTX-PGs in spermatozoa, consistent with the very low FPGS enzymatic activity associated with the expression of an alternative FPGS splice-variant. DISCUSSION: Treatment with MTX is not associated with testicular toxicity, consistent with the very low concentration of intracellular MTX-PG. Therefore, therapy with MTX can be safely started or continued in men and with a wish to become a father.

Methotrexate Polyglutamates Exposure - Response Modeling in a Large Cohort of Rheumatoid Arthritis Patients Starting Methotrexate.

Methotrexate polyglutamates (MTX-PG) concentrations in red blood cells (RBCs) have been suggested as a biomarker of response in patients with rheumatoid arthritis (RA) receiving low-dose MTX therapy. We investigated the association and interpatient variability between RBC-MTX-PG3-5 -exposure and response in patients with RA starting MTX. Data of three prospective cohorts were available. The relationship between exposure and Disease Activity Score in 28 joints (DAS28) was analyzed using a population pharmacokinetic-pharmacodynamic model. Relevant covariates were tested using full covariate modeling and backward elimination. From 395 patients, 3,401 MTX-PG concentrations and 1,337 DAS28 measurements were available between 0 and 300 days after MTX treatment onset. The developed model adequately described the time course of MTX-PG3-5 and DAS28. The median MTX-PG3-5 level at month 1 was 30.9 nmol/L (interquartile range (IQR): 23.6-43.7; n = 41) and at month 3: 69.3 nmol/L (IQR: 17.9-41.2; n = 351). Clearance of MTX-PG3-5 from RBCs was 28% lower (95% confidence interval (CI): 23.6-32.8%) in a woman and 10% lower (95% CI: 7.7-12.4%) in a 65-year-old compared with a 35-year-old patient. MTX-PG3-5 concentrations associated with DAS28: half-maximal effective concentration (EC50 ) was 9.14 nmol/L (95% CI: 4.2 nmol/L-14.1 nmol/L). EF at 80% (EC80 ) above 47 nmol/L was regarded as the optimal response. Independent of the MTX-PG 3-5 - response association, co-administration of disease-modifying antirheumatic drugs and corticosteroids improved response (additive effect on maximum effect (Emax )), whereas smoking, high body mass index and low albumin decreased Emax . In patients with RA starting MTX, RBC-MTX-PG3-5 was associated with clinical response. A dose increase is suggested when MTX-PG3-5 at month 1 is below 9.15 nmol/L, continued with the same dose when the concentration is above 47 nmol/L, and consider other treatment options above 78 nmol/L from 3 months onwards.

Methotrexate Provokes Disparate Folate Metabolism Gene Expression and Alternative Splicing in Ex Vivo Monocytes and GM-CSF- and M-CSF-Polarized Macrophages.

Macrophages constitute important immune cell targets of the antifolate methotrexate (MTX) in autoimmune diseases, including rheumatoid arthritis. Regulation of folate/MTX metabolism remains poorly understood upon pro-inflammatory (M1-type/GM-CSF-polarized) and anti-inflammatory (M2-type/M-CSF-polarized) macrophages. MTX activity strictly relies on the folylpolyglutamate synthetase (FPGS) dependent intracellular conversion and hence retention to MTX-polyglutamate (MTX-PG) forms. Here, we determined FPGS pre-mRNA splicing, FPGS enzyme activity and MTX-polyglutamylation in human monocyte-derived M1- and M2-macrophages exposed to 50 nmol/L MTX ex vivo. Moreover, RNA-sequencing analysis was used to investigate global splicing profiles and differential gene expression in monocytic and MTX-exposed macrophages. Monocytes displayed six-eight-fold higher ratios of alternatively-spliced/wild type FPGS transcripts than M1- and M2-macrophages. These ratios were inversely associated with a six-ten-fold increase in FPGS activity in M1- and M2-macrophages versus monocytes. Total MTX-PG accumulation was four-fold higher in M1- versus M2-macrophages. Differential splicing after MTX-exposure was particularly apparent in M2-macrophages for histone methylation/modification genes. MTX predominantly induced differential gene expression in M1-macrophages, involving folate metabolic pathway genes, signaling pathways, chemokines/cytokines and energy metabolism. Collectively, macrophage polarization-related differences in folate/MTX metabolism and downstream pathways at the level of pre-mRNA splicing and gene expression may account for variable accumulation of MTX-PGs, hence possibly impacting MTX treatment efficacy.

Machine learning to improve false-positive results in the Dutch newborn screening for congenital hypothyroidism.

OBJECTIVE: The Dutch Congenital hypothyroidism (CH) Newborn Screening (NBS) algorithm for thyroidal and central congenital hypothyroidism (CH-T and CH-C, respectively) is primarily based on determination of thyroxine (T4) concentrations in dried blood spots, followed by thyroid-stimulating hormone (TSH) and thyroxine-binding globulin (TBG) measurements enabling detection of both CH-T and CH-C, with a positive predictive value (PPV) of 21%. A calculated T4/TBG ratio serves as an indirect measure for free T4. The aim of this study is to investigate whether machine learning techniques can help to improve the PPV of the algorithm without missing the positive cases that should have been detected with the current algorithm. DESIGN & METHODS: NBS data and parameters of CH patients and false-positive referrals in the period 2007-2017 and of a healthy reference population were included in the study. A random forest model was trained and tested using a stratified split and improved using synthetic minority oversampling technique (SMOTE). NBS data of 4668 newborns were included, containing 458 CH-T and 82 CH-C patients, 2332 false-positive referrals and 1670 healthy newborns. RESULTS: Variables determining identification of CH were (in order of importance) TSH, T4/TBG ratio, gestational age, TBG, T4 and age at NBS sampling. In a Receiver-Operating Characteristic (ROC) analysis on the test set, current sensitivity could be maintained, while increasing the PPV to 26%. CONCLUSIONS: Machine learning techniques have the potential to improve the PPV of the Dutch CH NBS. However, improved detection of currently missed cases is only possible with new, better predictors of especially CH-C and a better registration and inclusion of these cases in future models.

Pharmacokinetics of oral and subcutaneous methotrexate in red and white blood cells in patients with early rheumatoid arthritis: the methotrexate monitoring trial.

OBJECTIVE: To investigate the pharmacokinetics of methotrexate polyglutamate (MTX-PG) accumulation in red blood cells (RBCs) and peripheral blood mononuclear cells (PBMCs) in patients with early rheumatoid arthritis (RA) after oral and subcutaneous MTX treatment. METHODS: In a clinical prospective cohort study (Methotrexate Monitoring study), newly diagnosed patients with RA were randomised for oral or subcutaneous MTX. At 1, 2, 3 and 6 months after therapy initiation, blood was collected and RBCs and PBMCs were isolated. MTX-PG1-6 concentrations were determined by mass spectrometry methods using stable isotopes of MTX-PG1-6 as internal standards. RESULTS: 43 patients (mean age: 58.5 years, 77% female) were included. PBMCs and RBCs revealed disparate pharmacokinetic profiles in both absolute MTX-PG accumulation levels and distribution profiles. Intracellular MTX-PG accumulation in PBMCs was significantly (p<0.001) 10-fold to 20-fold higher than RBCs at all time points, regardless of the administration route. MTX-PG distribution in PBMCs was composed of mostly MTX-PG1 (PG1>PG2>PG3). Remarkably, the distribution profile in PBMCs remained constant over 6 months. RBCs accumulated mainly MTX-PG1 and lower levels of MTX-PG2-5 at t=1 month. After 3 months, MTX-PG3 was the main PG-moiety in RBCs, a profile retained after 6 months of MTX therapy. Subcutaneous MTX administration results in higher RBC drug levels than after oral administration, especially shortly after treatment initiation. CONCLUSIONS: This is the first study reporting disparate MTX-PG accumulation profiles in RBCs versus PBMCs in newly diagnosed patients with RA during 6 months oral or subcutaneous MTX administration. This analysis can contribute to improved MTX therapeutic drug monitoring for patients with RA. TRIAL REGISTRATION NUMBER: NTR 7149.

The usefulness of implementing minimum retest intervals in reducing inappropriate laboratory test requests in a Dutch hospital.

OBJECTIVES: Inappropriate use of laboratory testing remains a challenging problem worldwide. Minimum retest intervals (MRI) are used to reduce inappropriate laboratory testing. However, their effectiveness and the usefulness in reducing inappropriate laboratory testing is still a matter of debate. The aim of this study was to evaluate the effectiveness of broadly implemented MRIs as a means of reducing inappropriate laboratory test requests. METHODS: We performed a retrospective study in a general care and teaching hospital in the Netherlands, where MRI alerts have been implemented as standard care since June 7th 2017. Clinical chemistry test orders in adult internal medicine patients placed between July 13th 2017 and December 31st 2019 were included. The primary outcome was the effectiveness of MRIs, expressed as percentages of tests ordered and barred as a result of MRIs. RESULTS: Of a total of 218,511 test requests, 4,159 (1.90%) got an MRI alert. These MRIs were overruled by physicians in 21.76% of the cases. As a result of implementing MRIs, 3,254 (1.49%) tests were barred. The financial savings for the department of internal medicine directly related to the included barred laboratory tests during this period were 11,880 euros on a total amount of 636,598 euros for all performed tests. CONCLUSIONS: Only a small proportion of laboratory tests are barred after implementation of MRIs, with a limited impact on the annual costs. However, MRIs provide a continuous reminder to focus on appropriate testing and the effectiveness of MRIs is potentially higher than described in this study.

A meta-analysis of methotrexate polyglutamates in relation to efficacy and toxicity of methotrexate in inflammatory arthritis, colitis and dermatitis.

AIMS: In immune-mediated inflammatory diseases (IMIDs), early symptom control is a key therapeutic goal. Methotrexate (MTX) is the first-line treatment across IMIDs. However, MTX is underutilized and suboptimally dosed, partly due to the inability of making individualized treatment decisions through therapeutic drug monitoring (TDM). To implement TDM in clinical practice, establishing a relationship between drug concentration and disease activity is paramount. In this meta-analysis, we investigated the relationship between concentrations of MTX polyglutamates (MTX-PG) in erythrocytes and efficacy as well as toxicity across IMIDs. METHODS: Studies analysing MTX-PG in relation to disease activity and/or toxicity were included for inflammatory arthritis (rheumatoid [RA] and juvenile idiopathic arthritis [JIA]), inflammatory bowel disease (Crohn's and ulcerative colitis) and dermatitis (psoriasis and atopic dermatitis). Meta-analyses were performed resulting in several summary effect measures: regression coefficient (ß), correlation coefficient and mean difference (of MTX-PG in responders vs. nonresponders) for IMIDs separately and collectively. RESULTS: Twenty-five studies were included. In RA and JIA, higher MTX-PG was significantly associated with lower disease activity at 3 months (ß: -0.002; 95% confidence interval [CI]: -0.004 to -0.001) and after 4 months of MTX use (ß: -0.003; 95% CI: -0.005 to -0.002). Similarly, higher MTX-PG correlated with lower disease activity in psoriasis (R: -0.82; 95% CI: -0.976 to -0.102). Higher MTX-PG was observed in RA, JIA and psoriasis responders (mean difference: 5.2 nmol/L MTX-PGtotal ; P < .01). CONCLUSION: We showed that higher concentrations of erythrocyte MTX-PG were associated with lower disease activity in RA, JIA and psoriasis. These findings are an important step towards implementation of TDM for MTX treatment across IMIDs.

Diagnostic stewardship for blood cultures in the emergency department: A multicenter validation and prospective evaluation of a machine learning prediction tool.

BACKGROUND: Overuse of blood cultures (BCs) in emergency departments (EDs) leads to low yields and high numbers of contaminated cultures, accompanied by increased diagnostics, antibiotic usage, prolonged hospitalization, and mortality. We aimed to simplify and validate a recently developed machine learning model to help safely withhold BC testing in low-risk patients. METHODS: We extracted data from the electronic health records (EHR) for 44.123 unique ED visits with BC sampling in the Amsterdam UMC (locations VUMC and AMC; the Netherlands), Zaans Medical Center (ZMC; the Netherlands), and Beth Israel Deaconess Medical Center (BIDMC; United States) in periods between 2011 and 2021. We trained a machine learning model on the VUMC data to predict blood culture outcomes and validated it in the AMC, ZMC, and BIDMC with subsequent real-time prospective evaluation in the VUMC. FINDINGS: The model had an Area Under the Receiver Operating Characteristics curve (AUROC) of 0.81 (95%-CI = 0.78-0.83) in the VUMC test set. The most important predictors were temperature, creatinine, and C-reactive protein. The AUROCs in the validation cohorts were 0.80 (AMC; 0.78-0.82), 0.76 (ZMC; 0.74-0.78), and 0.75 (BIDMC; 0.74-0.76). During real-time prospective evaluation in the EHR of the VUMC, it reached an AUROC of 0.76 (0.71-0.81) among 590 patients with BC draws in the ED. The prospective evaluation showed that the model can be used to safely withhold blood culture analyses in at least 30% of patients in the ED. INTERPRETATION: We developed a machine learning model to predict blood culture outcomes in the ED, which retained its performance during external validation and real-time prospective evaluation. Our model can identify patients at low risk of having a positive blood culture. Using the model in practice can significantly reduce the number of blood culture analyses and thus avoid the hidden costs of false-positive culture results. FUNDING: This research project was funded by the Amsterdam Public Health - Quality of Care program and the Dutch "Doen of Laten" project (project number: 839205002).