AB1235 Clinical relevance of anti-citrullinated protein antibody for the detection of rheumatoid arthritis in hemodialysis patients
Authors: A. Nakashima, K. Yamada, M. Kawano
Journal: Annals of the Rheumatic Diseases (2013)

<h3>Background</h3> Hemodialysis (HD) patients are considered to be at increased risk for developing rheumatoid arthritis (RA), as a result of immunologic abnormalities caused by this treatment<sup>1)</sup>. Anti-cyclic citrullinated peptide (anti-CCP) antibody testing is particularly useful in the diagnosis of rheumatoid arthritis, with high specificity, especially early in the disease process<sup>2)</sup>. <h3>Objectives</h3> To determine this possibility, anti-CCP and other autoantibodies, such as rheumatoid factor (RF) and anti-nuclear antibody (ANA) were evaluated. <h3>Methods</h3> We examined 113 hemodialysis patients (64 males and 49 females; mean age 65.2±10.6 years). The duration of hemodialysis was 7.9±7.5 years. The etiologies of ESRD were: aortitis syndrome (n=1), glomerulonephritis (n=36), diabetes mellitus (n=36), benign glomerulosclerosis (n=14), polycystic kidney disease (n=6), drug induced renal failure (n=2), hyperparathyroidism (n=2), hypoplastic kidney (n=1), interstitial nephritis (n=1), pregnancy kidney (n=2), purpura nephritis (n=1), RA (n=1), rapidly progressive glomerulonephritis (n=1), and unknown (n=8). Anti-CCP was measured using enzyme-linked immunosorbent assay (ELISA) with the CCP Ab. ELISA "Cosmic" (Cosmic Corporation, Tokyo, Japan). The normal value for anti-CCP reported by the manufacturer is less than 4.5 U/mL. <h3>Results</h3> Mean serum value of Anti-CCP of HD patients was 4.8±24.3 U/ml, and five patients (4.4%) were positive for serum anti-CCP, three of whom showed high titers (64.3, 165.6, and 192.2 U/mL). Two of these patients developed RA after starting HD. Six patients (5.3%) were positive for ANA, and ten patients (8.8%) for RF. <h3>Conclusions</h3> Our results indicated that HD patients had increased values of anti-CCP more frequently than the normal population and some of them developed RA. Romic et al<sup>3)</sup> reported that anti-CCP and RF concentrations were not changed in HD patients, but increased values of anti-CCP were detected in four of fifty-seven HD patients. They did not describe any signs or symptoms in HD patients who showed increased values of anti-CCP and suggested that HD is not likely to be a trigger for development of RA. Contrary to these findings, our results suggested that HD might indeed trigger RA. Future prospective studies are needed to determine if anti-CCP is an early predictor of RA in HD patients who might be at greater risk of developing this condition. <h3>References</h3> Gagnon RF, Shuster J, Kaye M. Auto-immunity in patients with end-stage renal disease maintained on hemodialysis and continuous ambulatory peritoneal dialysis. J Clin Lab Immunol 1983; 11, 155-158. Niewold TB, Harrison MJ, Paget SA. Anti-CCP testing as a diagnostic and prognostic tool in rheumatoid arthritis. QJM 2007; 100, 193-201. Romic Z, Unic A, Derek L et al. Anti-citrullinated protein antibody and rheumatoid factor in patients with end-stage renal disease. Clin Chem Lab Med 2009; 47, 959-962. <h3>Disclosure of Interest</h3> None Declared