{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,19]],"date-time":"2026-08-19T11:29:32Z","timestamp":1787138972783,"version":"build-2736575974"},"reference-count":52,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2026,8,19]],"date-time":"2026-08-19T00:00:00Z","timestamp":1787097600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Diagnostics"],"abstract":"<jats:p>Background: Carbohydrate antigen 19-9 (CA19-9) is widely used as a tumor marker for pancreatic and hepatobiliary malignancies. However, inter-assay variability may affect the interpretation of results. This study compared the analytical performance, reference values, diagnostic accuracy, and clinical concordance of CA19-9 measured by chemiluminescent microparticle immunoassay (CMIA) and electrochemiluminescence immunoassay (ECLIA) in a Thai population. Methods: Serum CA19-9 concentrations were measured using both CMIA and ECLIA in 398 subjects comprising 145 healthy individuals, 115 patients with benign conditions, and 138 patients with malignancies. Method comparison, reference interval assessment, receiver operating characteristic (ROC) analysis, and concordance analysis were performed. Population-specific cut-off values were established and compared with manufacturer-recommended thresholds. Results: CMIA produced modestly but significantly higher CA19-9 concentrations than ECLIA in healthy individuals, resulting in higher upper reference limits. The two assays showed strong correlations across the study population (R2 = 0.922). Among malignant conditions, CMIA generally yielded higher CA19-9 values than ECLIA, with significant differences observed in pancreatic cancer and cholangiocarcinoma (p &lt; 0.001). Values in benign conditions were largely comparable, except in cirrhosis, where ECLIA produced higher values. Diagnostic performance was similar between CMIA and ECLIA (AUC 0.856 vs. 0.840). Population-derived cut-off values (34.945 kU\/L for CMIA and 34.395 kU\/L for ECLIA) showed diagnostic performance comparable to manufacturer-recommended cut-offs and improved inter-assay concordance, particularly in cholangiocarcinoma. Conclusions: CMIA and ECLIA demonstrated strong analytical correlation and comparable diagnostic performance for CA19-9. Nevertheless, systematic inter-assay differences indicate that results should be interpreted using assay-specific reference intervals and clinical decision thresholds. Population-specific cut-off values may further improve clinical interpretation, particularly in regions with a high prevalence of hepatobiliary malignancies.<\/jats:p>","DOI":"10.3390\/diagnostics16162638","type":"journal-article","created":{"date-parts":[[2026,8,19]],"date-time":"2026-08-19T11:04:12Z","timestamp":1787137452000},"page":"2638","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Comparative Analytical Performance and Clinical Agreement of Chemiluminescence Microparticle Immunoassay and Electrochemiluminescence Immunoassay for CA19-9: A Diagnostic Accuracy Study"],"prefix":"10.3390","volume":"16","author":[{"given":"Jongkonnee","family":"Wongpiyabovorn","sequence":"first","affiliation":[{"name":"Center of Excellence in Immune-Mediated Diseases, Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-0303-1934","authenticated-orcid":false,"given":"Nasornthan","family":"Yutthakasaemsan","sequence":"additional","affiliation":[{"name":"Center of Excellence in Immune-Mediated Diseases, Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sunida","family":"Vandelaer","sequence":"additional","affiliation":[{"name":"Center of Excellence in Immune-Mediated Diseases, Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"862","DOI":"10.1016\/j.pan.2018.09.004","article-title":"Dilemma of elevated CA 19-9 in biliary pathology","volume":"18","author":"Tsen","year":"2018","journal-title":"Pancreatology"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"468","DOI":"10.4240\/wjgs.v12.i12.468","article-title":"Carbohydrate antigen 19-9\u2014tumor marker: Past, present, and future","volume":"12","author":"Lee","year":"2020","journal-title":"World J. Gastrointest. Surg."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"742","DOI":"10.3892\/ol.2020.11633","article-title":"Clinical significance and diagnostic value of serum NSE, CEA, CA19-9, CA125 and CA242 levels in colorectal cancer","volume":"20","author":"Luo","year":"2020","journal-title":"Oncol. Lett."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"2287","DOI":"10.1111\/jog.14427","article-title":"Serum CA19-9, CA-125 and CEA as tumor markers for mucinous ovarian tumors","volume":"46","author":"Lertkhachonsuk","year":"2020","journal-title":"J. Obstet. Gynaecol. Res."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"706","DOI":"10.3748\/wjg.v29.i4.706","article-title":"Diagnostic and economic value of carcinoembryonic antigen, carbohydrate antigen 19-9, and carbohydrate antigen 72-4 in gastrointestinal cancers","volume":"29","author":"Liu","year":"2023","journal-title":"World J. Gastroenterol. WJG"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"e202400491","DOI":"10.1002\/cmdc.202400491","article-title":"Tumor-Associated Carbohydrate Antigen 19-9 (CA 19-9), a Promising Target for Antibody-Based Detection, Diagnosis, and Immunotherapy of Cancer","volume":"19","author":"Nakisa","year":"2024","journal-title":"ChemMedChem"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Tang, J., Ge, Q.M., Huang, R., Shu, H.Y., Su, T., Wu, J.L., Pan, Y.C., Liang, R.B., Zhang, L.J., and Shao, Y. (2021). Clinical Significance of CYFRA21-1, AFP, CA-153, CEA, and CA-199 in the Diagnosis of Lung Cancer Ocular Metastasis in Hypertension Population. Front. Cardiovasc. Med., 8.","DOI":"10.3389\/fcvm.2021.670594"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"110902","DOI":"10.1016\/j.clinbiochem.2025.110902","article-title":"CA19-9, CEA and PIVKA-II as a novel panel of serum markers for diagnosis of pancreatic cancer","volume":"137","author":"Wang","year":"2025","journal-title":"Clin. Biochem."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Sachan, A., Saluja, S.S., Nekarakanti, P.K., Mahajan, B., Nag, H.H., and Mishra, P.K. (2020). Raised CA19-9 and CEA have prognostic relevance in gallbladder carcinoma. BMC Cancer, 20.","DOI":"10.1186\/s12885-020-07334-x"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1165","DOI":"10.1245\/s10434-016-5717-y","article-title":"Use of Tumor Markers in Gastrointestinal Cancers: Surgeon Perceptions and Cost-Benefit Trade-Off Analysis","volume":"24","author":"Acharya","year":"2017","journal-title":"Ann. Surg. Oncol."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Cao, S., Hu, Y., Gao, X., Liao, Q., and Zhao, Y. (2016). Serum Carbohydrate Antigen 19-9 in Differential Diagnosis of Benign and Malignant Pancreatic Cystic Neoplasms: A Meta-Analysis. PLoS ONE, 11.","DOI":"10.1371\/journal.pone.0166406"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"13","DOI":"10.5009\/gnl15568","article-title":"Cholangiocarcinoma: Current Knowledge and New Developments","volume":"11","author":"Blechacz","year":"2017","journal-title":"Gut Liver"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"435","DOI":"10.1177\/1533034616666644","article-title":"Clinical Significance of Serum HE4, CA125, CA724, and CA19-9 in Patients with Endometrial Cancer","volume":"16","author":"Bian","year":"2017","journal-title":"Technol. Cancer Res. Treat."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1069","DOI":"10.1507\/endocrj.EJ23-0186","article-title":"Proposed carbohydrate antigen 19-9 (CA19-9) cut-off values for the detection of pancreatic cancer in patients with poorly controlled diabetes: A real-world study","volume":"70","author":"Yamada","year":"2023","journal-title":"Endocr. J."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2732","DOI":"10.1038\/s41598-018-21048-y","article-title":"Evaluation of Serum CEA, CA19-9, CA72-4, CA125 and Ferritin as Diagnostic Markers and Factors of Clinical Parameters for Colorectal Cancer","volume":"8","author":"Gao","year":"2018","journal-title":"Sci. Rep."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"e71710","DOI":"10.1002\/cam4.71710","article-title":"Pattern and Clinical Significance of CA19-9 Expression in Human Cancer: A Tissue Microarray Study on 14,966 Tumors","volume":"15","author":"Schraps","year":"2026","journal-title":"Cancer Med."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Brancato, L., Osok, D., Van den Bossche, L., Van Cutsem, E., Bates, S.E., Van den Bossche, J., and Bogers, J. (2025). CA19-9 as a Dynamic Biomarker for Continuous Monitoring of Therapeutic Efficacy in Pancreatic Adenocarcinoma. Cancers, 17.","DOI":"10.3390\/cancers17243902"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1332","DOI":"10.1038\/s41598-020-57930-x","article-title":"CA19-9 for detecting recurrence of pancreatic cancer","volume":"10","author":"Azizian","year":"2020","journal-title":"Sci. Rep."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"224","DOI":"10.1016\/j.hpb.2019.06.012","article-title":"Induction chemotherapy in pancreatic cancer: CA 19-9 may predict resectability and survival","volume":"22","author":"Heger","year":"2020","journal-title":"HPB"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"302","DOI":"10.1016\/j.pan.2019.01.023","article-title":"CA19-9 elevation as an indication to start salvage treatment in surveillance after pancreatic cancer resection","volume":"19","author":"Li","year":"2019","journal-title":"Pancreatology"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1016\/j.hpb.2015.10.004","article-title":"Indications for staging laparoscopy in pancreatic cancer","volume":"18","author":"Cameron","year":"2016","journal-title":"HPB"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"231","DOI":"10.21037\/jgo.2020.02.01","article-title":"Targeting CA 19-9 with a humanized monoclonal antibody at the time of surgery may decrease recurrence rates for patients undergoing resections for pancreatic cancer, cholangiocarcinoma and metastatic colorectal cancer","volume":"11","author":"Gupta","year":"2020","journal-title":"J. Gastrointest. Oncol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"738","DOI":"10.1016\/j.pan.2017.07.007","article-title":"Revisions of international consensus Fukuoka guidelines for the management of IPMN of the pancreas","volume":"17","author":"Tanaka","year":"2017","journal-title":"Pancreatology"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"881","DOI":"10.3892\/ol.2016.5501","article-title":"Patients with normal-range CA19-9 levels represent a distinct subgroup of pancreatic cancer patients","volume":"13","author":"Luo","year":"2017","journal-title":"Oncol. Lett."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Zhao, B., Cheng, Q., Cao, H., Zhou, X., Li, T., Dong, L., and Wang, W. (2021). Dynamic change of serum CA19\u20139 levels in benign and malignant patients with obstructive jaundice after biliary drainage and new correction formulas. BMC Cancer, 21.","DOI":"10.1186\/s12885-021-08204-w"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"630","DOI":"10.5306\/wjco.v13.i7.630","article-title":"Clinical characteristics and outcomes in carbohydrate antigen 19-9 negative pancreatic cancer","volume":"13","author":"Balaban","year":"2022","journal-title":"World J. Clin. Oncol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"188409","DOI":"10.1016\/j.bbcan.2020.188409","article-title":"Roles of CA19-9 in pancreatic cancer: Biomarker, predictor and promoter","volume":"1875","author":"Luo","year":"2021","journal-title":"Biochim. Biophys. Acta Rev. Cancer"},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Coppola, A., La Vaccara, V., and Farolfi, T. (2022). Role of CA 19.9 in the Management of Resectable Pancreatic Cancer: State of the Art and Future Perspectives. Biomedicines, 10.","DOI":"10.3390\/biomedicines10092091"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"14","DOI":"10.69734\/psc3br75","article-title":"3. SMART Medical Review: CA 19-9 and pancreatic ductal adenocarcinoma (PDAC).: CA 19-9 and Pancreatic Cancer","volume":"1","author":"Whitcomb","year":"2024","journal-title":"SMART-MD J. Precis. Med."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"778","DOI":"10.21037\/jgo.2017.07.04","article-title":"Prognostic impact of carbohydrate antigen 19-9 level at diagnosis in resected stage I\u2013III pancreatic adenocarcinoma: A U.S. population study","volume":"8","author":"Mirkin","year":"2017","journal-title":"J. Gastrointest. Oncol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1340","DOI":"10.1016\/j.pan.2024.11.011","article-title":"Characteristics and prognosis of patients with pancreatic adenocarcinoma not expressing CA19-9: Analysis of the National Cancer Database","volume":"24","author":"Sugawara","year":"2024","journal-title":"Pancreatology"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"8820","DOI":"10.1038\/s41598-020-65720-8","article-title":"Carbohydrate antigen 19-9 elevation without evidence of malignant or pancreatobiliary diseases","volume":"10","author":"Kim","year":"2020","journal-title":"Sci. Rep."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"410","DOI":"10.1159\/000448068","article-title":"Acute Cholecystitis with Significantly Elevated Levels of Serum Carbohydrate Antigen 19-9","volume":"10","author":"Akimoto","year":"2016","journal-title":"Case Rep. Gastroenterol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"18","DOI":"10.21037\/amj.2017.02.02","article-title":"An extremely increased CA19-9 level due to common bile duct stone: A case report","volume":"2","author":"Wang","year":"2017","journal-title":"AME Med. J."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1713","DOI":"10.2169\/internalmedicine.2597-23","article-title":"A Significant Increase in the Serum Carbohydrate Antigen 19-9 Level Accompanied by Acute Cholecystitis and Choledocholithiasis: A Case Report and Review of the Literature","volume":"63","author":"Kawaguchi","year":"2024","journal-title":"Intern. Med."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"3494971","DOI":"10.1155\/crgm\/3494971","article-title":"Markedly Elevated CA 19-9 in ANA\/ASMA-Negative IgG4-Related Autoimmune Hepatitis with Concomitant Pancreatitis: A Case Report","volume":"2026","author":"Scott","year":"2026","journal-title":"Case Rep. Gastrointest. Med."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Dhingra, S., Raman, P., Ramsaroop, T., Harrison, I., Bergsten, T., Nusbaum, E., and Feldman, L.E. (2024). Elevated serum CA 19-9 level mimicking pancreaticobiliary carcinoma from a hepatic abscess: Case report and literature review. Front. Med., 11.","DOI":"10.3389\/fmed.2024.1470046"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"e1687","DOI":"10.1590\/0102-672020220002e1687","article-title":"ELEVATED CA 19-9 IN AN ASYMPTOMATIC PATIENT: WHAT DOES IT MEAN?","volume":"35","author":"Costa","year":"2022","journal-title":"Abcd-Arq. Bras. Cir. Dig. Arch. Dig. Surg."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"123","DOI":"10.1016\/j.cca.2008.10.033","article-title":"Comparison of three immunoassays for CA 19-9","volume":"400","author":"Hotakainen","year":"2009","journal-title":"Clin. Chim. Acta"},{"key":"ref_40","first-page":"319","article-title":"Comparison of Two Different Methods for CA19-9 Antigen Determination","volume":"56","author":"Deinzer","year":"2010","journal-title":"Clin. Lab."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"235","DOI":"10.5455\/aim.2018.26.235-239","article-title":"The Comparison Between Different Immunoassays for Serum Carbohydrate Antigen (CA 19-9) Concentration Measurement","volume":"26","author":"Serdarevic","year":"2018","journal-title":"Acta Inform. Medica"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1309\/AJCPOPNPLLCYR07H","article-title":"The pitfalls of CA19-9: Routine testing and comparison of two automated immunoassays in a reference oncology center","volume":"138","author":"Passerini","year":"2012","journal-title":"Am. J. Clin. Pathol."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Liu, Y., Li, W., Tang, S., Wu, R., Wang, Y., and Shao, F. (2025). Comparative Study of Elevated CA19-9 Levels in Non-Gastrointestinal Tumors Patients: Evaluation of Different Immunoassay Methods and Analysis of Potential Interfering Factors. Biomedicines, 13.","DOI":"10.3390\/biomedicines13061386"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"749","DOI":"10.1016\/j.amjsurg.2006.07.019","article-title":"Pancreatic cysts: A proposed management algorithm based on current evidence","volume":"193","author":"Goh","year":"2007","journal-title":"Am. J. Surg."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"3142","DOI":"10.1097\/MS9.0000000000004919","article-title":"Predicting recurrence patterns and outcomes following resection of pancreatic ductal adenocarcinoma: A contemporary real-world data cohort study","volume":"88","author":"Mane","year":"2026","journal-title":"Ann. Med. Surg."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"987","DOI":"10.1111\/ans.14131","article-title":"Serum carbohydrate antigen 19-9 in pancreatic adenocarcinoma: A mini review for surgeons","volume":"87","author":"Goh","year":"2017","journal-title":"ANZ J. Surg."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"773","DOI":"10.1007\/s12672-024-01683-w","article-title":"The prognostic impact of preoperative CA19-9 on resectable cholangiocarcinoma: A comprehensive systematic review and meta-analysis","volume":"15","author":"Wang","year":"2024","journal-title":"Discov. Oncol."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"224","DOI":"10.4174\/astr.2025.109.4.224","article-title":"Combined CA19-9, CA125, and CEA to predict prognosis of patients with intrahepatic cholangiocarcinoma after radical surgery: A retrospective, multi-institutional study","volume":"109","author":"Wang","year":"2025","journal-title":"Ann. Surg. Treat. Res."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"2999","DOI":"10.1002\/cncr.34854","article-title":"The association of carbohydrate antigen 19-9 response with radiologic response and survival in intrahepatic cholangiocarcinoma: A prospective cohort study","volume":"129","author":"Cai","year":"2023","journal-title":"Cancer"},{"key":"ref_50","doi-asserted-by":"crossref","unstructured":"Lee, J.W., and Lee, J.H. (2021). Prognostic Impact of Perioperative CA19-9 Levels in Patients with Resected Perihilar Cholangiocarcinoma. J. Clin. Med., 10.","DOI":"10.3390\/jcm10071345"},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"731","DOI":"10.1007\/s00280-020-04165-2","article-title":"The prognostic value of CA19-9 response after neoadjuvant therapy in patients with pancreatic cancer: A systematic review and pooled analysis","volume":"86","author":"Ye","year":"2020","journal-title":"Cancer Chemother. Pharmacol."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"e22380","DOI":"10.1002\/jcla.22380","article-title":"Reference intervals of carbohydrate antigen 19-9 in the apparently healthy adult population","volume":"32","author":"Zhang","year":"2018","journal-title":"J. Clin. Lab. Anal."}],"container-title":["Diagnostics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2075-4418\/16\/16\/2638\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,19]],"date-time":"2026-08-19T11:19:34Z","timestamp":1787138374000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2075-4418\/16\/16\/2638"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,19]]},"references-count":52,"journal-issue":{"issue":"16","published-online":{"date-parts":[[2026,8]]}},"alternative-id":["diagnostics16162638"],"URL":"https:\/\/doi.org\/10.3390\/diagnostics16162638","relation":{},"ISSN":["2075-4418"],"issn-type":[{"value":"2075-4418","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,19]]}}}