Abstract
Objectives
This study assesses the clinical relevance of dipeptidyl peptidase 4 (DPP4) membrane exopeptidase as a biomarker of inflammatory bowel disease (IBD). A spike-and-recovery approach of DPP4 in fecal samples was used to compare two different methods for protein extraction, followed by a stability assessment.
Methods
Fecal samples of healthy volunteers spiked with known concentrations of recombinant DPP4 were processed using a standard manual extraction protocol and the CALEX® protocol. The two methods were compared by quantification of fecal DPP4 by ELISA, followed by Bland-Altman analysis. For the stability assays DPP4 was extracted from fecal samples and stored under different conditions of temperature and time after collection.
Results
In general, the levels of spiked DPP4 in stool samples were lower with the manual protocol than in those obtained with the CALEX® method; this trend was corroborated by Bland-Altman analysis. Nonetheless, variability was within the acceptable limits for both protocols. In the stability assessment, no statistically significant differences were found between the results obtained under the different storage conditions.
Conclusions
Both manual and CALEX® protocols provided equal extraction ability of DPP4 from stool samples. In addition, DPP4 provided flexibility in terms of sample storage enabling the accurate assessment of samples delivered up to a week before analysis.
Acknowledgments
The authors thank Paula Pinto, PharmD, PhD (PMA – Pharmaceutical Medicine Academy) for providing medical writing and editorial assistance.
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Research funding: This work was supported by the Portuguese Study Group of Inflammatory Bowel Disease (GEDII). Sandra F. Gomes is supported by funding from the Portuguese FCT under the grant UI/BD/150826/2021 (“The modulation of cytokines, toll-like receptors and adipose-derived cell secretome on intestinal epithelial cells and adipocytes upon dipeptidyl peptidase-4”). Francisco Jorge Melo is supported by funding from the Portuguese FCT under the grant 2021.06912.BD (“Looking 4WARD: The role of dipeptidyl peptidase 4 (DPP-4) in inflammatory bowel disease (IBD) as a novel biomarker for predicting disease activity and monitoring response to therapy in IBD patients”). The funding organizations played no role in the study design; in the collection, analysis, and interpretation of data; in the writing of the report; or in the decision to submit the report for publication.
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Author contributions: All authors have accepted responsibility for the entire content of this manuscript and approved its submission.
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Competing interests: Fernando Magro served as a speaker and received honoraria from Merck Sharp & Dohme, Abbvie, Vifor, Falk, Laboratórios Vitória, Ferring, Hospira, and Biogen; the other authors have no conflict of interests to disclose.
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Informed consent: Informed consent was obtained from all individuals included in this study.
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Ethical approval: Research involving human subjects complied with all relevant national regulations, institutional policies and is in accordance with the tenets of the Helsinki Declaration (as revised in 2013), and has been approved by the authors’ Institutional Review Board (Ethics Committee of University Hospital Center of São João, Porto, Portugal; approval number 492/2020).
References
1. Hoffmann, T, Faust, J, Neubert, K, Ansorge, S. Dipeptidyl peptidase IV (CD 26) and aminopeptidase N (CD 13) catalyzed hydrolysis of cytokines and peptides with N-terminal cytokine sequences. FEBS Lett 1993;336:61–4. https://doi.org/10.1016/0014-5793(93)81609-4.Search in Google Scholar PubMed
2. Klemann, C, Wagner, L, Stephan, M, von Hörsten, S. Cut to the chase: a review of CD26/dipeptidyl peptidase-4’s (DPP4) entanglement in the immune system. Clin Exp Immunol 2016;185:1–21. https://doi.org/10.1111/cei.12781.Search in Google Scholar PubMed PubMed Central
3. Nargis, T, Kumar, K, Ghosh, AR, Sharma, A, Rudra, D, Sen, D, et al.. KLK5 induces shedding of DPP4 from circulatory Th17 cells in type 2 diabetes. Mol Metabol 2017;6:1529–39. https://doi.org/10.1016/j.molmet.2017.09.004.Search in Google Scholar PubMed PubMed Central
4. Röhrborn, D, Eckel, J, Sell, H. Shedding of dipeptidyl peptidase 4 is mediated by metalloproteases and up-regulated by hypoxia in human adipocytes and smooth muscle cells. FEBS Lett 2014;588:3870–7. https://doi.org/10.1016/j.febslet.2014.08.029.Search in Google Scholar PubMed
5. Enz, N, Vliegen, G, De Meester, I, Jungraithmayr, W. CD26/DPP4 – a potential biomarker and target for cancer therapy. Pharmacol Ther 2019;198:135–59. https://doi.org/10.1016/j.pharmthera.2019.02.015.Search in Google Scholar PubMed
6. Cuchacovich, M, Gatica, H, Pizzo, SV, Gonzalez-Gronow, M. Characterization of human serum dipeptidyl peptidase IV (CD26) and analysis of its autoantibodies in patients with rheumatoid arthritis and other autoimmune diseases. Clin Exp Rheumatol 2001;19:673–80.Search in Google Scholar
7. Bank, U, Tadje, J, Helmuth, M, Stefin, S, Täger, M, Wolke, C, et al.. Dipeptidylpeptidase IV (DPIV) and alanyl-aminopeptidases (AAPs) as a new target complex for treatment of autoimmune and inflammatory diseases-proof of concept in a mouse model of colitis. Adv Exp Med Biol 2006;575:143–53. https://doi.org/10.1007/0-387-32824-6_15.Search in Google Scholar PubMed
8. Pinto-Lopes, P, Afonso, J, Pinto-Lopes, R, Rocha, C, Lago, P, Gonçalves, R, et al.. Serum dipeptidyl peptidase 4: a predictor of disease activity and prognosis in inflammatory bowel disease. Inflamm Bowel Dis 2020;26:1707–19. https://doi.org/10.1093/ibd/izz319.Search in Google Scholar PubMed
9. Melo, FJ, Pinto-Lopes, P, Estevinho, MM, Magro, F. The role of dipeptidyl peptidase 4 as a therapeutic target and serum biomarker in inflammatory bowel disease: a systematic review. Inflamm Bowel Dis 2021;27:1153–65. https://doi.org/10.1093/ibd/izaa324.Search in Google Scholar PubMed
10. Torres, J, Mehandru, S, Colombel, JF, Peyrin-Biroulet, L. Crohn’s disease. Lancet 2017;389:1741–55. https://doi.org/10.1016/s0140-6736(16)31711-1.Search in Google Scholar
11. Ordás, I, Eckmann, L, Talamini, M, Baumgart, DC, Sandborn, WJ. Ulcerative colitis. Lancet 2012;380:1606–19. https://doi.org/10.1016/s0140-6736(12)60150-0.Search in Google Scholar PubMed
12. Khaki-Khatibi, F, Qujeq, D, Kashifard, M, Moein, S, Maniati, M, Vaghari-Tabari, M. Calprotectin in inflammatory bowel disease. Clin Chim Acta 2020;510:556–65. https://doi.org/10.1016/j.cca.2020.08.025.Search in Google Scholar PubMed PubMed Central
13. Pinto-Lopes, P, Melo, F, Afonso, J, Pinto-Lopes, R, Rocha, C, Melo, D, et al.. Fecal dipeptidyl peptidase-4: an emergent biomarker in inflammatory bowel disease. Clin Transl Gastroenterol 2021;12:e00320. https://doi.org/10.14309/ctg.0000000000000320.Search in Google Scholar PubMed PubMed Central
14. Juricic, G, Brencic, T, Tesija-Kuna, A, Njegovan, M, Honovic, L. Faecal calprotectin determination: impact of preanalytical sample treatment and stool consistency on within- and between-method variability. Biochem Med (Zagreb) 2019;29:010707. https://doi.org/10.11613/bm.2019.010707.Search in Google Scholar PubMed PubMed Central
15. Kaur, S, Ford, C, Gama, R. BÜHLMANN Calex® Cap for the faecal extraction of calprotectin – fit for purpose? Ann Clin Biochem 2020;57:332–3. https://doi.org/10.1177/0004563220927056.Search in Google Scholar PubMed
Supplementary Material
This article contains supplementary material (https://doi.org/10.1515/cclm-2023-0139).
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