{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,31]],"date-time":"2026-07-31T14:09:08Z","timestamp":1785506948921,"version":"3.56.0"},"reference-count":43,"publisher":"MDPI AG","issue":"15","license":[{"start":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T00:00:00Z","timestamp":1785369600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Int. J. Mol. Sci.","IJMS"],"abstract":"<jats:p>Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by persistent inflammation and progressive joint destruction. Increasing evidence suggests that fungal dysbiosis may influence immune responses through the interleukin-17A (IL-17A) pathway. This study aimed to determine the prevalence of peripheral blood Candida albicans DNA in patients with RA, quantify serum IL-17A concentrations, and evaluate the association between fungal DNA positivity and IL-17A levels. A total of 100 participants, including 50 patients with RA and 50 healthy controls, were enrolled. Candida albicans DNA was detected by conventional polymerase chain reaction (PCR) targeting the INT1 gene, while serum IL-17A concentrations were measured using enzyme-linked immunosorbent assay (ELISA). The association between fungal DNA positivity and serum IL-17A concentrations was assessed using point-biserial correlation analysis. Candida albicans DNA was detected significantly more frequently in RA patients than in healthy controls (38% vs. 10%; p &lt; 0.001). Serum IL-17A concentrations were significantly higher in RA patients, with the highest levels observed in C. albicans-positive patients (46.2 \u00b1 8.7 pg\/mL), followed by C. albicans-negative RA patients (32.5 \u00b1 6.4 pg\/mL) and healthy controls (15.1 \u00b1 5.2 pg\/mL) (p &lt; 0.001). Point-biserial correlation analysis demonstrated a significant positive association between C. albicans DNA positivity and serum IL-17A concentrations (rpb = 0.672, p &lt; 0.001). Peripheral blood Candida albicans DNA positivity was associated with elevated serum IL-17A concentrations in patients with RA. These findings support an association between fungal DNA detection and enhanced IL-17A-mediated immune responses; however, the cross-sectional design precludes any inference of causality. Further longitudinal studies incorporating quantitative fungal detection are warranted.<\/jats:p>","DOI":"10.3390\/ijms27156831","type":"journal-article","created":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T11:38:54Z","timestamp":1785411534000},"page":"6831","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Genetic Detection of Candida albicans and Measurement of IL-17 Levels in Rheumatoid Arthritis Patients: A Study Using Conventional PCR and ELISA Techniques"],"prefix":"10.3390","volume":"27","author":[{"given":"Abdullah AbdulKareem Ahmed","family":"Al-Obaidi","sequence":"first","affiliation":[{"name":"Biological Research Unit for Tropical Regions, Faculty of Science, University of Baghdad, Baghdad 10071, Iraq"},{"name":"Department of Biology, Graduate School of Natural and Applied Sciences, Erciyes University, Kayseri 38039, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Farah Thamer","family":"Samawi","sequence":"additional","affiliation":[{"name":"High Institute of Forensic Sciences, Al-Nahrain University, Baghdad 64074, Iraq"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mehmet G\u00f6khan","family":"Hal\u0131c\u0131","sequence":"additional","affiliation":[{"name":"Department of Biology, Faculty of Science, Erciyes University, Kayseri 38039, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2205","DOI":"10.1056\/NEJMra1004965","article-title":"The pathogenesis of rheumatoid arthritis","volume":"365","author":"McInnes","year":"2011","journal-title":"N. Engl. J. Med."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"18001","DOI":"10.1038\/nrdp.2018.1","article-title":"Rheumatoid arthritis","volume":"4","author":"Smolen","year":"2018","journal-title":"Nat. Rev. Dis. Primers"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"569","DOI":"10.1038\/nrrheum.2011.121","article-title":"The microbiome and rheumatoid arthritis","volume":"7","author":"Scher","year":"2011","journal-title":"Nat. Rev. Rheumatol."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Merino, N., Aronson, H.S., Bojanova, D.P., Feyhl-Buska, J., Wong, M.L., Zhang, S., and Giovannelli, D. (2019). Living at the extremes: Extremophiles and the limits of life in a planetary context. Front. Microbiol., 10, Erratum in Front. Microbiol.\u00a02019, 10, 1785.","DOI":"10.3389\/fmicb.2019.00780"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1365","DOI":"10.1016\/j.immuni.2019.05.023","article-title":"Gut mycobiota in immunity and inflammatory disease","volume":"50","author":"Li","year":"2019","journal-title":"Immunity"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"635","DOI":"10.1038\/nri.2017.55","article-title":"Fungal dysbiosis and inflammatory disease","volume":"17","author":"Iliev","year":"2017","journal-title":"Nat. Rev. Immunol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1445","DOI":"10.1056\/NEJMra1315399","article-title":"Invasive candidiasis","volume":"373","author":"Kullberg","year":"2015","journal-title":"N. Engl. J. Med."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"e000536","DOI":"10.1136\/rmdopen-2017-000536","article-title":"Glucocorticoids in rheumatoid arthritis: Current status and future studies","volume":"6","author":"Hua","year":"2020","journal-title":"RMD Open"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1136\/ard-2022-223356","article-title":"EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease-modifying antirheumatic drugs: 2022 update","volume":"82","author":"Smolen","year":"2023","journal-title":"Ann. Rheum. Dis."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"895","DOI":"10.1038\/nm.3914","article-title":"The oral and gut microbiomes are perturbed in rheumatoid arthritis and partly normalized after treatment","volume":"21","author":"Zhang","year":"2015","journal-title":"Nat. Med."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"780","DOI":"10.4049\/jimmunol.1500909","article-title":"IL-17-mediated immunity to the opportunistic fungal pathogen Candida albicans","volume":"195","author":"Conti","year":"2015","journal-title":"J. Immunol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"177","DOI":"10.1111\/j.1365-2567.2008.03017.x","article-title":"Interleukin-17 in host defence against bacterial, mycobacterial and fungal pathogens","volume":"126","author":"Curtis","year":"2009","journal-title":"Immunology"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"425","DOI":"10.1016\/j.chom.2012.04.008","article-title":"Th17 cells in immunity to Candida albicans","volume":"11","author":"Gaffen","year":"2012","journal-title":"Cell Host Microbe"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2328","DOI":"10.1016\/S0140-6736(17)31472-1","article-title":"Pathogenetic insights from the treatment of rheumatoid arthritis","volume":"389","author":"McInnes","year":"2017","journal-title":"Lancet"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"415","DOI":"10.1038\/nrrheum.2015.53","article-title":"The IL-23\u2013IL-17 axis in inflammatory arthritis","volume":"11","author":"Lubberts","year":"2015","journal-title":"Nat. Rev. Rheumatol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1038\/s41413-018-0016-9","article-title":"Rheumatoid arthritis: Pathological mechanisms and modern pharmacologic therapies","volume":"6","author":"Guo","year":"2018","journal-title":"Bone Res."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"2023","DOI":"10.1016\/S0140-6736(16)30173-8","article-title":"Rheumatoid arthritis","volume":"388","author":"Smolen","year":"2016","journal-title":"Lancet"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"3478","DOI":"10.1128\/JCM.00905-15","article-title":"Clinical performance of Aspergillus PCR for testing serum and plasma: A study by the European Aspergillus PCR Initiative","volume":"53","author":"White","year":"2015","journal-title":"J. Clin. Microbiol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"490","DOI":"10.1128\/CMR.00091-13","article-title":"Molecular and nonmolecular diagnostic methods for invasive fungal infections","volume":"27","author":"Arvanitis","year":"2014","journal-title":"Clin. Microbiol. Rev."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"521","DOI":"10.1038\/s41579-020-0367-2","article-title":"Host\u2013microbiota interactions in immune-mediated diseases","volume":"18","author":"Ruff","year":"2020","journal-title":"Nat. Rev. Microbiol."},{"key":"ref_21","first-page":"25","article-title":"Reframing immune-mediated inflammatory diseases through shared mechanisms","volume":"21","author":"Schett","year":"2021","journal-title":"Nat. Rev. Immunol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"R50","DOI":"10.1186\/ar4480","article-title":"Rheumatoid arthritis patients exhibit impaired Candida albicans-specific Th17 responses","volume":"16","author":"Bishu","year":"2014","journal-title":"Arthritis Res. Ther."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"von Elm, E., Altman, D.G., Egger, M., Pocock, S.J., G\u00f8tzsche, P.C., Vandenbroucke, J.P., and for the STROBE Initiative (2007). The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: Guidelines for reporting observational studies. PLoS Med., 4.","DOI":"10.1371\/journal.pmed.0040296"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1580","DOI":"10.1136\/ard.2010.138461","article-title":"2010 Rheumatoid arthritis classification criteria: An American College of Rheumatology\/European League Against Rheumatism collaborative initiative","volume":"69","author":"Aletaha","year":"2010","journal-title":"Ann. Rheum. Dis."},{"key":"ref_25","unstructured":"Fletcher, R.H., Fletcher, S.W., and Fletcher, G.S. (2021). Clinical Epidemiology: The Essentials, Wolters Kluwer. [6th ed.]."},{"key":"ref_26","unstructured":"Green, M.R., and Sambrook, J. (2012). Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory Press. [4th ed.]."},{"key":"ref_27","unstructured":"Crowther, J.R. (2009). ELISA: Methods and Protocols, Humana Press. [2nd ed.]."},{"key":"ref_28","unstructured":"Clinical and Laboratory Standards Institute (2007). Procedures for the Collection of Diagnostic Blood Specimens by Venipuncture: Approved Standard, Clinical and Laboratory Standards Institute. [6th ed.]. CLSI document H3-A6."},{"key":"ref_29","unstructured":"Clinical and Laboratory Standards Institute (2010). Procedures for the Handling and Processing of Blood Specimens for Common Laboratory Tests: Approved Guideline, Clinical and Laboratory Standards Institute. [4th ed.]. CLSI document GP44-A4."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"126","DOI":"10.1016\/j.mam.2005.12.003","article-title":"RNA integrity and the effect on the real-time qRT-PCR performance","volume":"27","author":"Fleige","year":"2006","journal-title":"Mol. Asp. Med."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1128\/CDLI.6.1.89-95.1999","article-title":"Variables that affect assays for plasma cytokines and soluble activation markers","volume":"6","author":"Aziz","year":"1999","journal-title":"Clin. Diagn. Lab. Immunol."},{"key":"ref_32","unstructured":"(2023). DNeasy Blood & Tissue Handbook, Qiagen."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1014","DOI":"10.1111\/j.1365-2672.2012.05384.x","article-title":"PCR inhibitors: Occurrence, properties and removal","volume":"113","author":"Schrader","year":"2012","journal-title":"J. Appl. Microbiol."},{"key":"ref_34","first-page":"105","article-title":"Rapid PCR method for detecting Candida albicans using primers derived from the integrin-like protein gene \u03b1INT1 of Candida albicans","volume":"38","author":"Lim","year":"2000","journal-title":"J. Microbiol."},{"key":"ref_35","unstructured":"R&D Systems (2023). Quantikine\u00ae Human IL-17A Immunoassay (Catalog No. D1700): Instructions for Use, Bio-Techne."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1849","DOI":"10.1084\/jem.20070663","article-title":"Phenotypic and functional features of human Th17 cells","volume":"204","author":"Annunziato","year":"2007","journal-title":"J. Exp. Med."},{"key":"ref_37","unstructured":"BioTek Instruments (2012). ELx808\u2122 Absorbance Microplate Reader: Operator\u2019s Manual, BioTek Instruments."},{"key":"ref_38","unstructured":"IBM Corp (2019). IBM SPSS Statistics for Windows (Version 26.0), IBM Corp."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"591","DOI":"10.1093\/biomet\/52.3-4.591","article-title":"An analysis of variance test for normality (complete samples)","volume":"52","author":"Shapiro","year":"1965","journal-title":"Biometrika"},{"key":"ref_40","unstructured":"Field, A. (2018). Discovering Statistics Using IBM SPSS Statistics, SAGE Publications. [5th ed.]."},{"key":"ref_41","unstructured":"Cohen, J. (1988). Statistical Power Analysis for the Behavioral Sciences, Lawrence Erlbaum Associates. [2nd ed.]."},{"key":"ref_42","first-page":"69","article-title":"Statistics corner: A guide to appropriate use of correlation coefficient in medical research","volume":"24","author":"Mukaka","year":"2012","journal-title":"Malawi Med. J."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"175","DOI":"10.3758\/BF03193146","article-title":"G*Power 3: A flexible statistical power analysis program for the social, behavioral, and biomedical sciences","volume":"39","author":"Faul","year":"2007","journal-title":"Behav. Res. 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