Matthijs Oyaert

Dr. Matthijs Oyaert

orcid

Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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12 February 2022 in Diagnostic Microbiology and Infectious Disease
Verified
Journal Article
Closed access
JEJan Van Elslande
Jan Van Elslande
MOMatthijs Oyaert
Matthijs Oyaert
NLNatalie Lorent
Natalie Lorent
YWYannick Vande Weygaerde
Yannick Vande Weygaerde
GPGijs Van Pottelbergh
Gijs Van Pottelbergh
PVPieter Vermeersch
Pieter Vermeersch

5 June 2024 in Clinical Chemistry and Laboratory Medicine (CCLM)
Verified
Journal Article
Closed access
TKTimo T. Kouri
Timo T. Kouri
WHWalter Hofmann
Walter Hofmann
RFRosanna Falbo
Rosanna Falbo
MOMatthijs Oyaert
Matthijs Oyaert
SSSören Schubert
Sören Schubert
MPMartine Pestel-Caron
Martine Pestel-Caron
Background: The EFLM Task and Finish Group Urinalysis has updated the ECLM European Urinalysis Guidelines (2000) on urinalysis and urine bacterial culture, to improve accuracy of these examinations in European clinical laboratories, and to support diagnostic industry to develop new technologies. Recommendations: Graded recommendations were built in the following areas: Medical needs and test requisition: Strategies of urine testing are described to patients with complicated or uncomplicated urinary tract infection (UTI), and high or low-risk to kidney disease. Specimen collection: Patient preparation, and urine collection are supported with two quality indicators: contamination rate (cultures), and density of urine (chemistry, particles). Chemistry: Measurements of both urine albumin and α1-microglobulin are recommended for sensitive detection of kidney disease in high-risk patients. Performance specifications are given for urine protein measurements and quality control of multiproperty strip tests. Particles: Procedures for microscopy are reviewed for diagnostic urine particles, including urine bacteria. Technologies in automated particle counting and visual microscopy are updated with advice how to verify new instruments with the reference microscopy. Bacteriology: Chromogenic agar is recommended as primary medium in urine cultures. Limits of significant growth are reviewed, with an optimised workflow for routine specimens, using leukocyturia to reduce less important antimicrobial susceptibility testing. Automation in bacteriology is encouraged to shorten turn-around times. Matrix assisted laser desorption ionization time-of-flight mass spectrometry is applicable for rapid identification of uropathogens. Aerococcus urinae, A. sanguinicola and Actinotignum schaalii are taken into the list of uropathogens. A reference examination procedure was developed for urine bacterial cultures.

22 March 2022 in Frontiers in Immunology
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Journal Article
Open access
MOMatthijs Oyaert
Matthijs Oyaert
MSMarie-Angélique De Scheerder
Marie-Angélique De Scheerder
SHSophie Van Herrewege
Sophie Van Herrewege
GLGuy Laureys
Guy Laureys
SASofie Van Assche
Sofie Van Assche
EPElizaveta Padalko
Elizaveta Padalko
Background: Immunocompromised patients are at increased risk of severe COVID-19 and impaired vaccine response. In this observational prospective study, we evaluated immunogenicity of the BNT162b2 mRNA vaccine in cohorts of primary or secondary immunocompromised patients.Methods: Five clinical groups of immunocompromised patients [primary immunodeficiency (PID) (n=57), people living with HIV (PLWH) (n=27), secondary immunocompromised patients with a broad variety of underlying rheumatologic (n=23) and homogeneous (multiple sclerosis) neurologic (n=53) conditions and chronic kidney disease (CKD) (n=39)] as well as a healthy control group (n=54) were included. Systemic humoral and cellular immune responses were evaluated by determination of anti-SARS-CoV-2 Spike antibodies using a TrimericS IgG assay (Diasorin) and through quantification of interferon gamma release in response to SARS-CoV-2 antigen with QuantiFERON SARS-CoV-2 assay (Qiagen), respectively. Responses were measured at pre-defined time-points after complete vaccination.Results: All healthy controls, PLWH and CKD-patients had detectable antibodies 10 to 14 days (T2) and 3 months (T3) after administration of the second vaccination. In contrast, only 94.5% of the PID, 50.0% of the rheumatologic and 48.0% of neurologic patients developed antibodies at T2 and only 89.1% of the PID, 52.4% of the rheumatologic and 50.0% of neurologic patients developed antibodies at T3. At T3 no significant differences in cellular response between the healthy control group and the PLWH and CKD groups were found, while proportions of reactive subjects were lower in PID and rheumatologic patients and higher in neurologic patients. Humoral and cellular immune responses significantly correlated in the healthy control, PID, PLWH groups for all 3 antigens.Conclusion: Patients with acquired or inherited immune disorders may show variable immune responses to vaccination with the BNT162b2 mRNA vaccine against SARS-CoV-2. Whether humoral, cellular or both immune responses are delayed depends on the patient group, therapy and individual risk factors. These data may guide the counselling of patients with immune disorders regarding vaccination of SARS-CoV-2.

25 February 2019 in Journal of Clinical Laboratory Analysis
Verified
Journal Article
Open access
PDF file
MOMatthijs Oyaert
Matthijs Oyaert
JDJoris R. Delanghe
Joris R. Delanghe
Objectives: Urinalysis is one of the most frequently ordered diagnostic laboratory tests. In order to reduce workload and costs, rapid screening tests such as urine test strip analyses are applied. The aim of this study was to evaluate the analytical performance of the UC‐3500 as well as the diagnostic performance in comparison with reference methods.Design and methods: We measured within‐run and between‐run imprecision based on quantitative reflectance values. 347 prospectively included urine specimens were investigated for the presence of glucose, protein, albumin, leukocyte esterase, and hemoglobin peroxidase activity, and ordinal scale results were compared to an automated urine particle analyzer (UF‐5000, Sysmex, Kobe, Japan) and wet chemistry (Roche Cobas 8000, Mannheim, Germany).Results: Within‐run and between‐run imprecision results based on reflectance data for both the 9 and 11 parameter test strips ranged from 0.07% to 1.36% for the low‐level control and from 0.37% to 6.13% for the high‐level control, depending on the parameter. Regarding diagnostic performance, the sensitivity/specificity for glucose, protein, albumin, leukocyte esterase, and hemoglobin peroxidase was 100/60%, 94.2/88.2%, 81.8/89.2%, 81.7/92.8%, and 85.1/88.6%, respectively; the negative predictive value was 100%, 83.3%, 89.1%, 94.6%, and 96.1%. The Spearman correlation coefficients of the UC‐3500 vs reference methods ranged from 0.915 to 0.967, depending on the parameter.Conclusion: This fully automated urine test strip analyzer overall shows a satisfying performance and can reliably screen out negative urine samples in order to focus on further characterization of positive samples in the following steps of the workflow.

1 January 2017 in Clinical Chemistry and Laboratory Medicine (CCLM)
Verified
Journal Article
Open access
PDF file
MOMatthijs Oyaert
Matthijs Oyaert
ABAn Boel
An Boel
JJJulie Jacobs
Julie Jacobs
SBStefanie Van Den Bremt
Stefanie Van Den Bremt
MSMaxime De Sloovere
Maxime De Sloovere
LHLieve Van Hoovels
Lieve Van Hoovels
Background: We evaluated the analytical performance of six different faecal calprotectin immunoassays together with their diagnostic accuracy in the discrimination between functional and organic bowel disorders.Methods: The faecal samples were obtained from inflammatory bowel disease patients (n=27) at the time of diagnosis [Crohn’s disease (n=15), colitis ulcerosa (n=12)], gastroenterologic disease control patients (n=52) and rheumatologic disease control patients (n=26). All individuals included in the study underwent a concurrent ileocolonoscopy. Analytical performance (imprecision, accuracy, carry-over, correlation and agreement) and diagnostic accuracy (sensitivity, specificity, likelihood ratios) of the different assays were evaluated.Results: All methods demonstrated good analytical performance, but within-run and total imprecision varied depending on the assay methodology used. Using Passing Bablok and Bland-Altman analyses, low quantitative agreement was observed between the assays. All assays showed excellent diagnostic accuracy, with areas under the receiver operating characteristic curves (ROC) ranging from 0.974 to 0.998. The AUCs were not significantly different between assays (p>0.05). Diagnostic sensitivity at the cut-off at a fixed specificity of 75% ranged from 95.2% to 100%. Introduction of multiple result intervals increased the clinical interpretation of all the assays.Conclusions: Analytical and diagnostic performance of the evaluated faecal calprotectin assays is good, but numerical values differ substantially between the assays necessitating the use of different clinical cut-offs. Introduction of multiple result intervals aids in clinical decision-making.

28 September 2023 in Diagnostics
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Journal Article
Open access
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RTRaïsa Thielemans
Raïsa Thielemans
RSReinhart Speeckaert
Reinhart Speeckaert
CDCharlotte Delrue
Charlotte Delrue
SBSander De Bruyne
Sander De Bruyne
MOMatthijs Oyaert
Matthijs Oyaert
Marijn M. SpeeckaertMarijn M. Speeckaert
Marijn M. Speeckaert
Uromodulin, also known as Tamm-Horsfall protein, represents the predominant urinary protein in healthy individuals. Over the years, studies have revealed compelling associations between urinary and serum concentrations of uromodulin and various parameters, encompassing kidney function, graft survival, cardiovascular disease, glucose metabolism, and overall mortality. Consequently, there has been a growing interest in uromodulin as a novel and effective biomarker with potential applications in diverse clinical settings. Reduced urinary uromodulin levels have been linked to an elevated risk of acute kidney injury (AKI) following cardiac surgery. In the context of chronic kidney disease (CKD) of different etiologies, urinary uromodulin levels tend to decrease significantly and are strongly correlated with variations in estimated glomerular filtration rate. The presence of uromodulin in the serum, attributable to basolateral epithelial cell leakage in the thick ascending limb, has been observed. This serum uromodulin level is closely associated with kidney function and histological severity, suggesting its potential as a biomarker capable of reflecting disease severity across a spectrum of kidney disorders. The UMOD gene has emerged as a prominent locus linked to kidney function parameters and CKD risk within the general population. Extensive research in multiple disciplines has underscored the biological significance of the top UMOD gene variants, which have also been associated with hypertension and kidney stones, thus highlighting the diverse and significant impact of uromodulin on kidney-related conditions. UMOD gene mutations are implicated in uromodulin-associated kidney disease, while polymorphisms in the UMOD gene show a significant association with CKD. In conclusion, uromodulin holds great promise as an informative biomarker, providing valuable insights into kidney function and disease progression in various clinical scenarios. The identification of UMOD gene variants further strengthens its relevance as a potential target for better understanding kidney-related pathologies and devising novel therapeutic strategies. Future investigations into the roles of uromodulin and regulatory mechanisms are likely to yield even more profound implications for kidney disease diagnosis, risk assessment, and management.