AB1182 The stability of rheumatoid factor and anti-ccp antibody in archived samples of blood

Background Recently, there has been an increasing demand for analysing a large amount of specimen at the same time and for stably storing those specimens for clinical research. Therefore, the role of the biobank that collects and preserves the samples for research and supplies them stably is very important.1 Anti-CCP antibody and RF predated the onset of RA by several years, which indicates that citrullination and the production of anti-CCP and RF autoantibodies are early processes in RA.2 In addition, RA patients with anti-CCP antibody had more swollen joints and more severe radiological destruction.3 Objectives The purpose of this study is to evaluate the stability of RF and anti-CCP antibody after preserving the remaining samples for a long time and to determine the usefulness of the remaining samples that were kept for future research. Methods Serum samples used in this study were collected from 50 patients with RA in Eulji university hospital in 2011. The patients had baseline measurement at the time the samples were obtained and had more than one serum aliquots stored for archived samples. At baseline measurement, rheumatoid factor was quantified with turbid immunometry and anti-CCP was measured by an ELISA analyzer. all specimens were kept in a freezer where temperature monitoring was carried out for 24 hours to keep the temperature below −70°C. 6 years later, he samples were slowly thawed at 4°C and measured by the same method of the baseline measurement. Results The mean age for 50 patients from which the samples were collected is 51.22 years. It was an average of 6.0 years (range: 5.6–6.1 years) for the samples to be stored at the biobank. We observed a slight decrease in concentration of RF and anti-CCP. There were significantly difference in concentration of RF and anti-CCP (Z=−5.10, p-value<0.001; Z=−3.81, p-value<0.001). The correlation between baseline sample and archived sample is strong (RF: ρ=0.973, p-value<0.001; anti-CCP: ρ=0.938, p-value<0.001). Conclusions This study assessed the stability of RF and anti-CCP antibody in archived samples of blood. Our results showed that serum concentration of RF and anti CCP antibody remain stable for up to 5 years at −70°C. There was a slight decreased in the level overtime that was correlated with baseline value. These data indicated that the archived human samples in human cohorts could be used to examine for research and could be estimated according to the regression analysis. References [1] Shankar S, Uday Y. Biobanking: Basic concepts and role in rheumatology. Indian J Rheumatol. 2011;6(3):129–37. [2] Rantapää-Dahlqvist S, De Jong BAW, Berglin E, Hallmans G, Wadell G, Stenlund H, et al. Antibodies Against Cyclic Citrullinated Peptide and IgA Rheumatoid Factor Predict the Development of Rheumatoid Arthritis. Arthritis Rheum. 2003;48(10):2741–9. [3] van der Helm-van Mil AHM, Verpoort KN, Breedveld FC, Toes REM, Huizinga TWJ. Antibodies to citrullinated proteins and differences in clinical progression of rheumatoid arthritis. Arthritis Res Ther. 2005;7(5):R949–58. Acknowledgements none Disclosure of Interest None declared