{"id":{"repo_id":"ghent","oai_identifier":"oai:archive.ugent.be:469344"},"canonical_url":"https://search.dev.ndltd.org/etd/ghent/oai:archive.ugent.be:469344","repository":{"repo_id":"ghent","name":"Ghent University","base_url":"https://biblio.ugent.be/oai"},"display":{"title":"Markers and outcome measures in chronic immune mediated artrhritis: from association studies to prediction models.","abstract":"This work aims to illustrate how single biomarkers and standardized clinical measures can be used in the daily clinical practice rheumatologist’s decision making and how different markers and measures can be combined into prediction models and composite indices. The first part focuses on association studies. Three association studies of carriage of Crohn’s disease associated CARD15 polymorphisms are shown. We first investigated the association between carriage of CARD15 polymorphisms and SpA related symptoms in Crohn’s disease. Inversely, the association between gut inflammation in SpA and carriage of CARD15 polymorphisms was explored. Also, an association between carriage of CARD15 polymorphisms and anti-Saccharomyces cerevisiae antibodies in Crohn’s disease patients is demonstrated. The diagnostic properties of a test are explored into more detail in part 2, illustrated by the rheumatoid factor (RF) and anti-citrullinated protein/peptide antibodies (ACPA) determination in rheumatoid arthritis (RA). ACPA is a very specific test for RA, but the specificity of this test may differ between study populations. Combinations of ACPA, RF and HLA-shared epitope testing are explored by different (predicted) probabilities plots, based on logistic regression. They demonstrate that combined ACPA and continuous RF-testing is the most relevant combination. In part 3, different single clinical measures and composite indices to measure response to treatment in RA are evaluated. 511 RA patients treated with infliximab are investigated. After a loading regimen at week 0, 2, 6 and 14, the treating rheumatologist could decide to give a dose increase at week 22. This decision to give a dose increase can be considered as a measure of insufficient response and could be best modeled by the DAS28 at the moment of decision. The same patients were followed over 4 years and also DAS28, measured at week 14 or week 22, could best predict 4-year attrition to therapy. In the last part, different methods to construct prediction models are evaluated. Discriminant analysis and logistic regression may be less performing in real life datasets with missing values and high dimensionality. In such cases, computer intensive methods – such as support vector machines and multilayerd perceptrons - may be useful.","abstract_html":"This work aims to illustrate how single biomarkers and standardized clinical measures can be used in the daily clinical practice rheumatologist’s decision making and how different markers and measures can be combined into prediction models and composite indices. The first part focuses on association studies. Three association studies of carriage of Crohn’s disease associated CARD15 polymorphisms are shown. We first investigated the association between carriage of CARD15 polymorphisms and SpA related symptoms in Crohn’s disease. Inversely, the association between gut inflammation in SpA and carriage of CARD15 polymorphisms was explored. Also, an association between carriage of CARD15 polymorphisms and anti-Saccharomyces cerevisiae antibodies in Crohn’s disease patients is demonstrated. The diagnostic properties of a test are explored into more detail in part 2, illustrated by the rheumatoid factor (RF) and anti-citrullinated protein/peptide antibodies (ACPA) determination in rheumatoid arthritis (RA). ACPA is a very specific test for RA, but the specificity of this test may differ between study populations. Combinations of ACPA, RF and HLA-shared epitope testing are explored by different (predicted) probabilities plots, based on logistic regression. They demonstrate that combined ACPA and continuous RF-testing is the most relevant combination. In part 3, different single clinical measures and composite indices to measure response to treatment in RA are evaluated. 511 RA patients treated with infliximab are investigated. After a loading regimen at week 0, 2, 6 and 14, the treating rheumatologist could decide to give a dose increase at week 22. This decision to give a dose increase can be considered as a measure of insufficient response and could be best modeled by the DAS28 at the moment of decision. The same patients were followed over 4 years and also DAS28, measured at week 14 or week 22, could best predict 4-year attrition to therapy. In the last part, different methods to construct prediction models are evaluated. Discriminant analysis and logistic regression may be less performing in real life datasets with missing values and high dimensionality. In such cases, computer intensive methods – such as support vector machines and multilayerd perceptrons - may be useful.","abstract_has_math":false,"creators":["Vander Cruyssen, Bert"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["De Keyser, F"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2006,"date_issued":"2006","date_published":"2006","updated_at":"2026-07-24T02:23:03Z","subjects":[],"languages":["und"],"rights":["info:eu-repo/semantics/openAccess"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["https://biblio.ugent.be/publication/469344","http://doi.org/1854/5929","https://biblio.ugent.be/publication/469344/file/1878646"],"render_values":[{"text":"https://biblio.ugent.be/publication/469344","href":"https://biblio.ugent.be/publication/469344","code":true},{"text":"http://doi.org/1854/5929","href":"http://doi.org/1854/5929","code":true},{"text":"https://biblio.ugent.be/publication/469344/file/1878646","href":"https://biblio.ugent.be/publication/469344/file/1878646","code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/1854/LU-469344","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["De Keyser, F"]},{"key":"dc:creator","label":"Author","values":["Vander Cruyssen, Bert"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2006"]},{"key":"dc:type","label":"Dc Type","values":["dissertation","info:eu-repo/semantics/doctoralThesis","info:eu-repo/semantics/publishedVersion"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["und"]},{"key":"dc:rights","label":"Dc Rights","values":["info:eu-repo/semantics/openAccess"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://biblio.ugent.be/publication/469344","http://hdl.handle.net/1854/LU-469344","http://doi.org/1854/5929","https://biblio.ugent.be/publication/469344/file/1878646"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["This work aims to illustrate how single biomarkers and standardized clinical measures can be used in the daily clinical practice rheumatologist’s decision making and how different markers and measures can be combined into prediction models and composite indices. The first part focuses on association studies. Three association studies of carriage of Crohn’s disease associated CARD15 polymorphisms are shown. We first investigated the association between carriage of CARD15 polymorphisms and SpA related symptoms in Crohn’s disease. Inversely, the association between gut inflammation in SpA and carriage of CARD15 polymorphisms was explored. Also, an association between carriage of CARD15 polymorphisms and anti-Saccharomyces cerevisiae antibodies in Crohn’s disease patients is demonstrated. The diagnostic properties of a test are explored into more detail in part 2, illustrated by the rheumatoid factor (RF) and anti-citrullinated protein/peptide antibodies (ACPA) determination in rheumatoid arthritis (RA). ACPA is a very specific test for RA, but the specificity of this test may differ between study populations. Combinations of ACPA, RF and HLA-shared epitope testing are explored by different (predicted) probabilities plots, based on logistic regression. They demonstrate that combined ACPA and continuous RF-testing is the most relevant combination. In part 3, different single clinical measures and composite indices to measure response to treatment in RA are evaluated. 511 RA patients treated with infliximab are investigated. After a loading regimen at week 0, 2, 6 and 14, the treating rheumatologist could decide to give a dose increase at week 22. This decision to give a dose increase can be considered as a measure of insufficient response and could be best modeled by the DAS28 at the moment of decision. The same patients were followed over 4 years and also DAS28, measured at week 14 or week 22, could best predict 4-year attrition to therapy. In the last part, different methods to construct prediction models are evaluated. Discriminant analysis and logistic regression may be less performing in real life datasets with missing values and high dimensionality. In such cases, computer intensive methods – such as support vector machines and multilayerd perceptrons - may be useful."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Markers and outcome measures in chronic immune mediated artrhritis: from association studies to prediction models."]}]}],"canonical_facts":{"dc:contributor":["De Keyser, F"],"dc:creator":["Vander Cruyssen, Bert"],"dc:date":["2006"],"dc:description":["This work aims to illustrate how single biomarkers and standardized clinical measures can be used in the daily clinical practice rheumatologist’s decision making and how different markers and measures can be combined into prediction models and composite indices. The first part focuses on association studies. Three association studies of carriage of Crohn’s disease associated CARD15 polymorphisms are shown. We first investigated the association between carriage of CARD15 polymorphisms and SpA related symptoms in Crohn’s disease. Inversely, the association between gut inflammation in SpA and carriage of CARD15 polymorphisms was explored. Also, an association between carriage of CARD15 polymorphisms and anti-Saccharomyces cerevisiae antibodies in Crohn’s disease patients is demonstrated. The diagnostic properties of a test are explored into more detail in part 2, illustrated by the rheumatoid factor (RF) and anti-citrullinated protein/peptide antibodies (ACPA) determination in rheumatoid arthritis (RA). ACPA is a very specific test for RA, but the specificity of this test may differ between study populations. Combinations of ACPA, RF and HLA-shared epitope testing are explored by different (predicted) probabilities plots, based on logistic regression. They demonstrate that combined ACPA and continuous RF-testing is the most relevant combination. In part 3, different single clinical measures and composite indices to measure response to treatment in RA are evaluated. 511 RA patients treated with infliximab are investigated. After a loading regimen at week 0, 2, 6 and 14, the treating rheumatologist could decide to give a dose increase at week 22. This decision to give a dose increase can be considered as a measure of insufficient response and could be best modeled by the DAS28 at the moment of decision. The same patients were followed over 4 years and also DAS28, measured at week 14 or week 22, could best predict 4-year attrition to therapy. In the last part, different methods to construct prediction models are evaluated. Discriminant analysis and logistic regression may be less performing in real life datasets with missing values and high dimensionality. In such cases, computer intensive methods – such as support vector machines and multilayerd perceptrons - may be useful."],"dc:format":["application/pdf"],"dc:identifier":["https://biblio.ugent.be/publication/469344","http://hdl.handle.net/1854/LU-469344","http://doi.org/1854/5929","https://biblio.ugent.be/publication/469344/file/1878646"],"dc:language":["und"],"dc:rights":["info:eu-repo/semantics/openAccess"],"dc:title":["Markers and outcome measures in chronic immune mediated artrhritis: from association studies to prediction models."],"dc:type":["dissertation","info:eu-repo/semantics/doctoralThesis","info:eu-repo/semantics/publishedVersion"]},"updated_at":"2026-07-24T02:23:03Z"}