No abstract

HLA-DRB1*04 was associated with increased risk for RA and ACPA positivity, while HLA-DRB1*07 was associated with reduced risk for RA and RF synthesis in Algerian patients.

Aim: To describe the autoantibody profile in a cohort of Algerian patients with systemic sclerosis (SSc) and to determine clinical associations between SSc-related autoantibodies, disease subtypes and specific clinical features. Methods: Consecutive Algerian patients with SSc were included in the present study. In addition to clinical characterization, all subjects underwent autoantibody testing using indirect immunofluorescence, immunoenzymatic, and line immunoblot assays. Results: A total of 150 patients were included in this study, 103 (68.7%) had limited cutaneous SSc (lcSSc), 42 (28%) had diffuse cutaneous SSc (dcSSc) and 5 (3.3%) had sine cutaneous scleroderma. One hundred thirty-five (90.0%) patients were positive for SSc-related autoantibodies, including 63 (42%) with more than one autoantibody. The two most frequent autoantibodies were anti-topoisomerase I (ATA) (76; 50.7%) and anti-SSA/Ro (49; 32.7%). Only 23 (15.3%) patients were positive for anticentromere; 9 (6%) were positive for anti RNA polymerase III; 5 (3.3%) for anti-U3 RNP; 3 (2%) for anti Th/To; 25 (16.7%) for anti-U1 RNP; 11 (7.3%) for anti-PM/Scl and 4 (2.7%) for anti-Ku. Anti-topoisomerase I was associated with dcSSc (p <0.0001), interstitial lung disease (ILD) (p <0.0001) and digital ulcers (p <0.0001). Anti-U3 RNP was associated with pulmonary arterial hypertension (PAH) (p=0.031). Conclusion: Notable similarities and differences in the prevalence of SSc-related autoantibodies were found in our population when compared to other ethnic groups. ATA and anti-U3 RNP may be a reliable biomarker for ILD and PAH. Further studies should be conducted to better understand the ethnic influence on disease expression and autoantibody production.

Increasing evidence suggests that the rs6822844, within KIAA1109/TENR/IL2/IL21 gene cluster on 4q27, is strongly associated with rheumatoid arthritis (RA) in the Caucasian population. The aim of this study is to investigate the possible association between the SNP rs6822844 and susceptibility to RA in the Algerian Maghreb population, and to explore the association with the clinical and immunological features of RA. The polymorphism rs6822844 was genotyped in 323 RA patients and 323 healthy individuals using the TaqMan assay. A strong association of IL2/IL21 with RA susceptibility was detected in the Algerian population [odds ratio (OR) = 2.57 (95% confidence interval (CI) 1.74-3.83), P = 10(-4) ]. Our results revealed that IL2/IL21 predisposed to disease development in both autoantibody positive and negative disease. Meanwhile, the association was stronger in RA patients with anti-cyclic citrullinated peptides (ACPA) positive than those with ACPA negative [OR = 2.30 (95% CI 1.53-3.51), P = 10(-4) and OR = 1.98 (95% CI 1.01-4.22), P = 0.037, respectively]. Moreover, our findings showed a moderate association of the rs6822844 polymorphism with disease activity (P = 0.014). This study indicates for the first time that there is a strong association between IL2/IL21 rs6822844 variant and susceptibility to RA in the Algerian population, and that this association was independent from the autoantibodies status of RA patients.

Background Increasing evidence suggest that single nucleotide polymorphism (SNP) rs6822844, within KIAA1109-TENR-IL2-IL21 gene cluster, is strongly associated with autoimmune diseases in Caucasian population, including rheumatoid arthritis (RA) [1, 2, 3]. Objectives The aim of this study was to investigate possible association between this polymorphism, susceptibility to RA, auto-antibody profile and RA severity in Algerian population. Methods We investigated 289 Algerian patients with RA and 266 healthy subjects, for rs6822844 polymorphism, using Taqman allelic discrimination assays (Applied biosystems 7500). We recorded demographics, clinical, and laboratory data, including evidence of inflammatory activity and presence of autoantibodies (rheumatoid factor (RF) and cyclic citrullinated peptide antibodies (anti-CCP)). Results The allele G of IL-21 gene polymorphism (rs6822844) was associated significantly with susceptibility to RA (odds ratio (OR) =1.33 [95% CI 1.21 to 1.46], p=0.000). No significant association was observed between rs6822844 and ACPA+ or ACPA- RA groups. However, the major G allele frequency was significantly increased in the RF- RA group compared with RF+ RA group (96% vs 92%, OR=0.95 [95% CI 0.91 to 0.99], p =0.039). Concerning RA severity, the minor T allele was associated with (1) disease activity, assessed by HAQ score and DAS-28-CRP, and (2) ACPA serum levels (p =0.027, p =0.031 and p =0.005 respectively). Conclusions Our results indicate that there is a strong relationship between rs6822844, susceptibility and severity of RA in Algerian population. References Amit K. Maiti, Xana Kim-Howard, Parvathi Viswanathan, Laura Guillén, Adriana Rojas- Villarraga, Harshal Deshmukh, Haner Direskeneli, Güher Saruhan-Direskeneli, Carlos Cañas, Gabriel J. Tobόn, Amr H. Sawalha, Alejandra C. Cherñavsky, Juan-Manuel Anaya, Swapan K. Confirmation of an Association Between rs6822844 at the IL2–IL21 Region and Multiple Autoimmune Diseases: Evidence of a General Susceptibility Locus. Arthritis & rheumatism 2010; 62: 323–329. Hollis-Moffatt JE, Chen-Xu M, Topless R, Dalbeth N, Gow PJ, Harrison AA, Highton J, Jones PB, Nissen M, Smith MD, van Rij A, Jones GT, Stamp LK, Merriman TR. Only one independent genetic association with rheumatoid arthritis within the KIAA1109-TENR-IL2-IL21 locus in Caucasian sample sets: confirmation of association of rs6822844 with rheumatoid arthritis at a genome-wide level of significance. Arthritis Research & Therapy 2010; 12: R116. Nina A. Daha, Fina A. S. Kurreeman, Rute B. Marques, Gerrie Stoeken-Rijsbergen, Willem Verduijn, Tom W. J. Huizinga, René E. M. Toes. Confirmation of STAT4, IL2/IL21, and CTLA4 Polymorphisms in Rheumatoid Arthritis. Arthritis & rheumatism 2009; 60: 1255–1260. Disclosure of Interest None declared DOI 10.1136/annrheumdis-2014-eular.1950