{"doi":"10.1093/ndt/gfn739","title":"Increased indoleamine 2,3-dioxygenase (IDO) activity and elevated serum levels of tryptophan catabolites in patients with chronic kidney disease: a possible link between chronic inflammation and uraemic symptoms","abstract":null,"journal":"Nephrology Dialysis Transplantation","year":2009,"id":619151,"datarank":0.8257997303898545,"base_score":5.5053315359323625,"endowment":5.5053315359323625,"self_citation_contribution":0.8257997303898545,"citation_network_contribution":0.0,"self_endowment_contribution":0.8257997303898545,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":245,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":null,"is_data_producer":false,"deposit_databanks":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":null,"fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1597681,"name":"J.-P. Zeden","orcid":null,"position":1,"is_corresponding":false},{"id":1597682,"name":"C. Fotopoulou","orcid":null,"position":2,"is_corresponding":false},{"id":1597683,"name":"S. von Haehling","orcid":null,"position":3,"is_corresponding":false},{"id":1597684,"name":"R. Pschowski","orcid":null,"position":4,"is_corresponding":false},{"id":1597685,"name":"D. Hasper","orcid":null,"position":5,"is_corresponding":false},{"id":1597686,"name":"H.-D. Volk","orcid":null,"position":6,"is_corresponding":false},{"id":1597687,"name":"C. Schuett","orcid":null,"position":7,"is_corresponding":false},{"id":1597688,"name":"P. Reinke","orcid":null,"position":8,"is_corresponding":false},{"id":1597680,"name":"J. C. Schefold","orcid":null,"position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"resolved":true,"title":"Increased indoleamine 2,3-dioxygenase (IDO) activity and elevated serum levels of tryptophan catabolites in patients with chronic kidney disease: a possible link between chronic inflammation and uraemic symptoms","abstract":"BACKGROUND: Tryptophan (Trp) is catabolized by indoleamine 2,3-dioxygenase (IDO). Changes in Trp metabolism and IDO activity in chronic kidney disease (CKD) have not been widely studied, and the impact of haemodialysis is uncertain. Here we investigate Trp catabolism, IDO activity and the role of inflammation in moderate to very severe CKD and haemodialysis. METHODS: Eighty individuals were included in a prospective blinded endpoint analysis. Using tandem mass spectrometry, serum levels of Trp, kynurenine (Kyn), kynurenic-acid (Kyna), quinolinic-acid (Quin), 5-hydroxytryptophan (OH-Trp), serotonin (5-HT), estimated IDO activity and inflammatory markers were assessed in 40 CKD patients (age 57 +/- 14 years, 21 male, creatinine 4.5 +/- 2.7, n = 17 receiving haemodialysis), and in 40 healthy controls (age 34 +/- 9 years, 26 male). RESULTS: Trp levels were unchanged in CKD (P = 0.78 versus controls). Serum levels of Kyn, Kyna and Quin increased with CKD severity (stages 4, 5 versus controls all P < or = 0.01). IDO activity was significantly induced in CKD and correlated with disease severity (stages 3-5 versus controls, all P < or = 0.01) and inflammatory markers [high-sensitivity C-reactive protein (hsCRP), soluble TNF-receptor-1 (sTNFR-I); both P < or = 0.03]. IDO products (Kyn, Kyna, Quin) correlated also with hsCRP and sTNFR-I (all P < or = 0.04). Haemodialysis did not influence IDO activity (P = 0.26) and incompletely removed Kyn, Kyna, Quin, OH-Trp and 5-HT by 22, 26, 50, 44 and 34%, respectively. In multiple regression, IDO activity correlated with hsCRP and sTNFR-I (both P < or = 0.03) independent of serum creatinine, age and body weight. CONCLUSIONS: IDO activity and serum levels of tryptophan catabolites of the kynurenine pathway increase with CKD severity. In CKD, induction of IDO may primarily be a consequence of chronic inflammation.","is_dataset_classified":null,"base_score":5.5053315359323625,"endowment":5.5053315359323625,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"19155537","pmcid":null,"openalex_id":"https://openalex.org/W2109207751","authors":[],"funders":[],"total_grants":0,"fwci":4.1355,"citation_percentile":0.94230769,"influential_citations":0,"citation_trend":[{"year":2012,"count":13},{"year":2013,"count":12},{"year":2014,"count":10},{"year":2015,"count":17},{"year":2016,"count":13},{"year":2017,"count":21},{"year":2018,"count":17},{"year":2019,"count":9},{"year":2020,"count":14},{"year":2021,"count":17},{"year":2022,"count":25},{"year":2023,"count":17},{"year":2024,"count":14},{"year":2025,"count":11},{"year":2026,"count":8}],"oa_status":"bronze","license":null,"oa_locations":[{"url":"https://academic.oup.com/ndt/article-pdf/24/6/1901/7632875/gfn739.pdf","host_type":"journal"},{"url":"https://academic.oup.com/ndt/article-pdf/24/6/1901/7632875/gfn739.pdf","host_type":"publisher"},{"url":"http://academic.oup.com/ndt/article-pdf/24/6/1901/7632875/gfn739.pdf","host_type":"publisher"},{"url":"https://doi.org/10.1093/ndt/gfn739","host_type":"journal"},{"url":"https://pubmed.ncbi.nlm.nih.gov/19155537","host_type":"repository"}],"fields_of_study":["Tryptophan and brain disorders","Dialysis and Renal Disease Management","Bipolar Disorder and Treatment"],"mesh_terms":["Adult","Aged","C-Reactive Protein","Creatinine","Female","Renal Dialysis","Humans","5-Hydroxytryptophan","Inflammation","Kidney Failure, Chronic","Kynurenic Acid","Kynurenine","Male","Middle Aged","Prognosis","Prospective Studies","Serotonin","Tryptophan","Uremia","Case-Control Studies","Quinolinic Acid","Inflammation Mediators","Receptors, Tumor Necrosis Factor, Type I","Indoleamine-Pyrrole 2,3,-Dioxygenase","Renal Insufficiency, Chronic"],"keywords":["Kynurenine","Medicine","Internal medicine","Indoleamine 2,3-dioxygenase","Quinolinic acid","Kidney disease","Endocrinology","Kynurenine pathway","Kynurenic acid","Inflammation","Renal function","Tryptophan","Receptor","Antagonist","Amino acid","Biology","Biochemistry"],"sdg_mappings":[{"sdg_number":0,"sdg_label":"Good health and well-being"}],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-08-03T06:10:22.319830Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}