{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T12:46:54Z","timestamp":1788266814143,"version":"build-2803163510"},"reference-count":27,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2025,3,28]],"date-time":"2025-03-28T00:00:00Z","timestamp":1743120000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Medical University of Bialystok, Poland","award":["B.SUB.25.442"],"award-info":[{"award-number":["B.SUB.25.442"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Psoriasis is a systemic disease affecting 2\u20133% of the general population. Tryptophan (TRP) is an amino acid metabolized in the kynurenine pathway (KP). The aim of this study was to assess the kynurenine pathway\u2019s metabolites in serum and urine of psoriatic patients and explore the possible interplay with the disease\u2019s pathogenesis and its comorbidities. The study involved 60 patients with plaque psoriasis and 30 healthy volunteers matched for gender, age, and BMI. Serum and urine samples were taken from the participants and tested for TRP, indoleamine 2,3-dioxygenase (IDO), 2,3-tryptophan dioxygenase (TDO), kynurenine (KYN), kynurenic acid (KYNA), quinolinic acid (QUIN), and numerous laboratory parameters. Correlations between the metabolites\u2019 levels and clinical, laboratory parameters and depression occurrence were statistically evaluated. Concentrations of tryptophan, kynurenic acid, and quinolinic acid in serum and urine were significantly higher among patients with psoriasis (p &lt; 0.05 and p &lt; 0.001, p &lt; 0.05 and p &lt; 0.05 and p &lt; 0.001 and p &lt; 0.001, respectively). A significant stimulation of the kynurenine pathway in serum and urine of patients with psoriasis suggests its role in its pathogenesis and interplay between chronic inflammation or comorbidities. Further research is needed to discover whether the increase in KP metabolites is an indicator of inflammation or a compensatory mechanism in psoriasis.<\/jats:p>","DOI":"10.3390\/ijms26073139","type":"journal-article","created":{"date-parts":[[2025,3,28]],"date-time":"2025-03-28T13:36:49Z","timestamp":1743169009000},"page":"3139","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Peripheral Kynurenine Pathway Metabolites in Patients with Psoriasis"],"prefix":"10.3390","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1414-4569","authenticated-orcid":false,"given":"Anna","family":"Stepaniuk","sequence":"first","affiliation":[{"name":"Department of Dermatology and Venerology, Medical University of Bialystok, Zurawia 14, 15-540 Bialystok, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8018-9960","authenticated-orcid":false,"given":"Anna","family":"Baran","sequence":"additional","affiliation":[{"name":"Department of Dermatology and Venerology, Medical University of Bialystok, Zurawia 14, 15-540 Bialystok, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3985-4244","authenticated-orcid":false,"given":"Justyna Magdalena","family":"Hermanowicz","sequence":"additional","affiliation":[{"name":"Department of Pharmacodynamics, Medical University of Bialystok, Mickiewicza 2C, 15-089 Bialystok, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Beata","family":"Sieklucka","sequence":"additional","affiliation":[{"name":"Department of Monitored Pharmacotherapy, Medical University of Bialystok, Mickiewicza 2C, 15-089 Bialystok, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3751-0608","authenticated-orcid":false,"given":"Dariusz","family":"Pawlak","sequence":"additional","affiliation":[{"name":"Department of Pharmacodynamics, Medical University of Bialystok, Mickiewicza 2C, 15-089 Bialystok, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5923-910X","authenticated-orcid":false,"given":"Iwona","family":"Flisiak","sequence":"additional","affiliation":[{"name":"Department of Dermatology and Venerology, Medical University of Bialystok, Zurawia 14, 15-540 Bialystok, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,3,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"527","DOI":"10.1007\/s40257-024-00857-0","article-title":"Managing the Patient with Psoriasis and Metabolic Comorbidities","volume":"25","author":"Bellinato","year":"2024","journal-title":"Am. J. Clin. Dermatol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"732","DOI":"10.1111\/1346-8138.15840","article-title":"Psoriasis: Comorbidities","volume":"48","author":"Yamazaki","year":"2021","journal-title":"J. Dermatol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"377","DOI":"10.1016\/j.jaad.2016.07.064","article-title":"Psoriasis and Comorbid Diseases Part I. Epidemiology","volume":"76","author":"Takeshita","year":"2017","journal-title":"J. Am. Acad. Dermatol."},{"key":"ref_4","first-page":"2020-vol 1","article-title":"Renal dysfunction in psoriatic patients","volume":"37","author":"Grandinetti","year":"2020","journal-title":"G. Ital. Nefrol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"401","DOI":"10.24869\/psyd.2017.401","article-title":"Analysis of the Prevalence of Mental Disorders in Psoriasis: The Relevance of Psychiatric Assessment in Dermatology","volume":"29","author":"Reis","year":"2017","journal-title":"Psychiatr. Danub."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1038\/s41380-019-0414-4","article-title":"The Kynurenine Pathway: A Finger in Every Pie","volume":"25","author":"Savitz","year":"2020","journal-title":"Mol. Psychiatry"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Correia, A.S., and Vale, N. (2022). Tryptophan Metabolism in Depression: A Narrative Review with a Focus on Serotonin and Kynurenine Pathways. Int. J. Mol. Sci., 23.","DOI":"10.3390\/ijms23158493"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"11786469221096643","DOI":"10.1177\/11786469221096643","article-title":"The Footprint of Kynurenine Pathway in Cardiovascular Diseases","volume":"15","author":"Ala","year":"2022","journal-title":"Int. J. Tryptophan. Res."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1089\/met.2017.0097","article-title":"Dysregulation of Tryptophan Catabolism in Metabolic Syndrome","volume":"16","author":"Mallmann","year":"2018","journal-title":"Metab. Syndr. Relat. Disord."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"633","DOI":"10.1159\/000455840","article-title":"Psoriasis and Obesity","volume":"232","author":"Jensen","year":"2016","journal-title":"Dermatology"},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Lee, H., Jang, H.B., Yoo, M., Park, S.I., and Lee, H. (2020). Amino Acid Metabolites Associated with Chronic Kidney Disease: An Eight-Year Follow-Up Korean Epidemiology Study. Biomedicines, 8.","DOI":"10.3390\/biomedicines8070222"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Krupa, A., Krupa, M.M., and Pawlak, K. (2022). Indoleamine 2,3 Dioxygenase 1-The Potential Link between the Innate Immunity and the Ischemia-Reperfusion-Induced Acute Kidney Injury?. Int. J. Mol. Sci., 23.","DOI":"10.3390\/ijms23116176"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1007\/s43440-021-00329-w","article-title":"Kynurenine pathway in kidney diseases","volume":"74","author":"Zakrocka","year":"2021","journal-title":"Pharmacol. Rep."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1830","DOI":"10.1016\/j.jaci.2015.09.055","article-title":"The tryptophan metabolism enzyme L-kynureninase is a novel inflammatory factor in psoriasis and other inflammatory diseases","volume":"137","author":"Harden","year":"2016","journal-title":"J. Allergy Clin. Immunol."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Krupa, A., and Kowalska, I. (2021). The Kynurenine Pathway-New Linkage between Innate and Adaptive Immunity in Autoimmune Endocrinopathies. Int. J. Mol. Sci., 22.","DOI":"10.3390\/ijms22189879"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Chen, X., Xu, D., Yu, J., Song, X., Li, X., and Cui, Y. (2024). Tryptophan Metabolism Disorder-Triggered Diseases, Mechanisms, and Therapeutic Strategies: A Scientometric Review. Nutrients, 16.","DOI":"10.3390\/nu16193380"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1044","DOI":"10.1002\/jcp.30587","article-title":"Kynureninase contributes to the pathogenesis of psoriasis through pro-inflammatory effect","volume":"237","author":"Wang","year":"2022","journal-title":"J. Cell Physiol."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Fujii, K., Yamamoto, Y., Mizutani, Y., Saito, K., and Seishima, M. (2020). Indoleamine 2,3-Dioxygenase 2 Deficiency Exacerbates Imiquimod-Induced Psoriasis-Like Skin Inflammation. Int. J. Mol. Sci., 21.","DOI":"10.3390\/ijms21155515"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"11786469221078191","DOI":"10.1177\/11786469221078191","article-title":"Loss of Indoleamine-2,3-Dioxygenase-1 (IDO1) in Knockout Mice Does Not Affect the Development of Skin Lesions in the Imiquimod-Induced Mouse Model of Psoriasis","volume":"15","author":"Choudhary","year":"2022","journal-title":"Int. J. Tryptophan Res."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1113","DOI":"10.1038\/s41591-018-0060-4","article-title":"Genetic deficiency of indoleamine 2,3-dioxygenase promotes gut microbiota-mediated metabolic health","volume":"24","author":"Laurans","year":"2018","journal-title":"Nat. Med."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"541","DOI":"10.1381\/096089206776945066","article-title":"Bariatric surgery cannot prevent tryptophan depletion due to chronic immune activation in morbidly obese patients","volume":"16","author":"Brandacher","year":"2006","journal-title":"Obes. Surg."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Yang, Y., Liu, X., Liu, X., Xie, C., and Shi, J. (2024). The role of the kynurenine pathway in cardiovascular disease. Front. Cardiovasc. Med., 11.","DOI":"10.3389\/fcvm.2024.1406856"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"8132569","DOI":"10.1155\/2021\/8132569","article-title":"Correlation of Indoleamine-2,3-Dioxygenase and Chronic Kidney Disease: A Pilot Study","volume":"2021","author":"Pan","year":"2021","journal-title":"J. Immunol. Res."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"745","DOI":"10.1001\/jamadermatol.2022.1609","article-title":"Association Between Psoriasis and Nonalcoholic Fatty Liver Disease Among Outpatient US Adults","volume":"158","author":"Ruan","year":"2022","journal-title":"JAMA Dermatol."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Teunis, C., Nieuwdorp, M., and Hanssen, N. (2022). Interactions between Tryptophan Metabolism, the Gut Microbiome and the Immune System as Potential Drivers of Non-Alcoholic Fatty Liver Disease (NAFLD) and Metabolic Diseases. Metabolites, 12.","DOI":"10.3390\/metabo12060514"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"2100078","DOI":"10.1002\/mnfr.202100078","article-title":"The Kynurenine Pathway Is Upregulated by Methyl-deficient Diet and Changes Are Averted by Probiotics","volume":"65","author":"Tillmann","year":"2021","journal-title":"Mol. Nutr. Food Res."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1016\/S0140-6736(67)92970-4","article-title":"Remission of psoriasis with low dietary tryptophan","volume":"2","author":"Spiera","year":"1967","journal-title":"Lancet"}],"container-title":["International Journal of Molecular Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1422-0067\/26\/7\/3139\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T17:04:27Z","timestamp":1760029467000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1422-0067\/26\/7\/3139"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,3,28]]},"references-count":27,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2025,4]]}},"alternative-id":["ijms26073139"],"URL":"https:\/\/doi.org\/10.3390\/ijms26073139","relation":{},"ISSN":["1422-0067"],"issn-type":[{"value":"1422-0067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,3,28]]}}}