Following is the abstract of this presentation:
ACPA detection by haemagglutination using an antibody-based mediator
I.C. Kruis (1), A. van der Heijden (1), M. Salden (2), G.J.M. Pruijn (1)
1: Department of Biomolecular Chemistry, Institute for Molecules and Materials, Radboud University, Nijmegen, The Netherlands
2: Novio Catalpa, Nijmegen, The Netherlands
Anti-citrullinated protein/peptide antibodies (ACPA) are the most specific serological marker of rheumatoid arthritis (RA). The presence of ACPA early in the disease, even before onset of clinical symptoms, facilitates early diagnosis and ACPA is among the most prominent classification criteria for RA. Importantly, early diagnosis and immediate start of treatment is strongly correlated with improved outcomes. Several ACPA-detection assays are available for clinical use, but all are based on the same principle: ELISA with cyclic citrullinated peptides or citrullinated proteins, and variants thereof. While this technique can be automated in modern diagnostic laboratories, it is ill-suited for low volume laboratories or resource-poor environments.
Here, we explored the suitability of haemagglutination for ACPA detection. Haemagglutination is simpler, less time-consuming, has a visual readout and can efficiently be performed for single patient samples. To achieve haemagglutination in the presence of ACPA, we have generated a mediating molecule by protein engineering. It is based on a single-chain antibody fragment that binds to the glycophorin A receptor, which is ubiquitously present on the surface of erythrocytes, and is conjugated to a citrullinated peptide recognized by ACPA. As a result, when an (possibly autologous) erythrocyte suspension, ACPA-positive serum and the mediator molecule are mixed, agglutination of the erythrocytes is induced. We conclude that the use of these mediator molecules represents a promising approach to develop a haemagglutination-based assay for the detection of ACPA, and possibly other autoimmune biomarkers.
Dr Martin Salden, CEO of Novio Catalpa will represent the company and be available for marketing discussions on a new haemagglutination-based approach for autoimmune diagnostics. Please contact me by email: firstname.lastname@example.org
Dr Ilmar Kruis will discuss the scientific details of this agglutination approach for ACPA detection on September 8 during the afternoon in the “Systemic Autoimmune Disease “session.