Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Jun 5.
doi: 10.1007/s00592-025-02537-9. Online ahead of print.

Proximity extension assay inflammatory profiling cannot distinguish the presence of residual C-peptide in patients with long-standing type 1 diabetes

Ebrahim Anvari  1 , Per Lundkvist  1 , Kailash Singh  2 , Daniel Espes  3   4   5
Affiliations

Proximity extension assay inflammatory profiling cannot distinguish the presence of residual C-peptide in patients with long-standing type 1 diabetes

Ebrahim Anvari et al. Acta Diabetol. .

Abstract

Objective: Many patients with long-standing type 1 diabetes (T1D) have remaining low levels of C-peptide, i.e. and indirect sign of remaining functional beta-cells. This study focused on identifying differences in immunological and inflammatory biomarkers in patients with longstanding T1D and remaining C-peptide.

Research design and methods: Adult patients (n = 120) with long-standing T1D (≥ 10 years) and healthy controls (HC) (n = 50) were recruited at Uppsala University Hospital. Residual beta-cell function was determined with an ultrasensitive C-peptide ELISA under fasting conditions. T1D patients were divided into two groups (C-peptide positive vs. C-peptide negative). Using the OLINK Explore Inflammation proximity extension assay (PEA), 368 circulating immunological and inflammatory biomarkers were analyzed in plasma.

Results: The three groups could not be distinguished by principal component analysis and when correcting for multiple testing we found no differences in circulating biomarkers. However, based on uncorrected p-values there were six biomarkers that were different when comparing all T1D patients with HC and eight markers that were different when comparing C-peptide positive vs. negative T1D patients.

Conclusion: A wide inflammatory assay analysis cannot distinguish patients with longstanding T1D and remaining C-peptide from patients with a complete loss of C-peptide nor from HC.

Keywords: Biomarkers; C-peptide; Proximity extension assay; Type 1 diabetes.

PubMed Disclaimer

Conflict of interest statement

Declarations. Conflict of interest: The authors declare that they have no conflict of interest.

Similar articles

See all similar articles

References

    1. Jones AG, Hattersley AT (2013) The clinical utility of C-peptide measurement in the care of patients with diabetes. Diabet Med 30(7):803–817 - PubMed - PMC - DOI
    1. Landin-Olsson M, Nilsson KO, Lernmark A, Sundkvist G (1990) Islet cell antibodies and fasting C-peptide predict insulin requirement at diagnosis of diabetes mellitus. Diabetologia 33(9):561–568 - PubMed - DOI
    1. Webb PG, Bonser AM (1981) Basal C-peptide in the discrimination of type I from type II diabetes. Diabetes Care 4(6):616–619 - PubMed - DOI
    1. Solimena M, Folli F, Denis-Donini S, Comi GC, Pozza G, De Camilli P et al (1988) Autoantibodies to glutamic acid decarboxylase in a patient with stiff-man syndrome, epilepsy, and type I diabetes mellitus. N Engl J Med 318(16):1012–1020 - PubMed - DOI
    1. Solimena M, Folli F, Aparisi R, Pozza G, De Camilli P (1990) Autoantibodies to GABA-ergic neurons and pancreatic beta cells in stiff-man syndrome. N Engl J Med 322(22):1555–1560 - PubMed - DOI

LinkOut - more resources