Association Study of PTPN22 (rs2476601) and PADI4 (rs2240340) Polymorphisms with Rheumatoid Arthritis in Algerian Population Ines Allam , Merzak Gharnaout 2 , Soumia Louahchi 1 , Nabil Raaf 3 , Nawel Kheldoun 4 , Aicha Ladjouze 4 , Reda Djidjik 1 1 Department of Immunology, Beni Messous Teaching Hospital, University of Algiers 1, Algiers, Algeria; 2 Department of Pneumology, Rouiba Hospital, University of Algiers 1, Algiers, Algeria; 3 Department of Biology, Beni Messous Teaching Hospital, University of Algiers 1, Algiers, Algeria; 4 Department of Rheumatology, Ben Aknoun Hospital, University of Algiers 1, Algiers, Algeria ABSTRACT An association between protein tyrosine phosphatase 22 (PTPN22) and Peptidylarginine deiminase 4 (PADI4) genes with rheumatoid arthritis (RA) has been demonstrated in several populations. The present study investigated whether PTPN22 and PADI4 genes polymorphisms were involved in the genetic predisposition to RA in the Algerian patients. Materials and methods: The PADI4_94 (rs2240340) and the PTPN22 (rs2476601) Single Nucleotide Polymorphisms (SNPs) were genotyped in 300 RA patients and 306 healthy controls by real time polymerase chain reaction method (TaqMan Assays). The relationships between Anti-Citrullinated Peptide Antibody (ACPA) positivity, Rheumatoid Factor (RF) positivity and genotypes were statistically analyzed. Results: There was no significant association between the PTPN22, PADI4 SNP and RA susceptibility in our population (p>0.05). No association with ACPA profile with either PTPN22 or PADI4 was detected (p>0.05). However, our results showed a strong association of PTPN22 minor T allele with RF positive disease (OR=8.53 (95% CI 1.34-354.9), p=0.013); also, a significant association was shown between CT genotype of PTPN22 SNP and RF positive RA (OR=8.01 (95% CI 1.22-336.5), p=0.018). Conclusion: Our findings indicated that PTPN22 and PADI4 polymorphisms were unlikely to play an important role in the susceptibility to RA in Algerian population but PTPN22 polymorphism T allele may predispose individuals to RF positive RA. Keywords: PADI4; PTPN22; Rheumatoid arthritis INTRODUCTION Rheumatoid arthritis (RA) is a systemic inflammatory disease, characterized by chronic synovial inflammation which leads to joint destruction and disability. A genetic predisposition toward RA has been strongly supported by evidence from twin and sibling studies. Among siblings, the prevalence is 4%. In monozygotic twins, the concordance rate for RA is between 12.3% and 15.4% compared with 3.5% for dizygotic twins [1]. The sibling and twin pair studies demonstrate that genetic factors substantially affect RA susceptibility, resulting in an estimated genetic contribution to RA of approximately 50% to 60% [2,3]. The first genetic risk factor for RA consists of the human leucocyte antigen (HLA) class II molecules. There is extensive evidence showing that certain frequently occurring HLA-DRB1 alleles are associated with susceptibility to RA. The indicated alleles share a conserved amino acid sequence also called the shared epitope (SE) – at position 70 to 74 in the third hypervariable region of the DRβ1 chain [4,5]. Journal of Clinical & Cellular Immunology Research Article * Correspondence to: Ines Allam, Department of Immunology, Beni Messous Teaching Hospital, Algiers, Algieria, Tel: 213558239924; E-mail: i.allam@univ-alger.dz Received: January 20, 2019; Accepted: February 05, 2020; Published: February 12, 2020 Citation: Allam I, Gharnaout M, Louahchi S, Raaf N, Kheldoun N, Ladjouze A, et al. (2020) Association Study of PTPN22 (rs2476601) and PADI4 (rs2240340) Polymorphisms with Rheumatoid Arthritis in Algerian Population. J Clin Cell Immunol. 11:586. DOI: 10.35248/2155-9889.20.11:586. Copyright: © 2020 Allam I, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. J Clin Cell Immunol, Vol.11 Iss.1 No:1000586 1 J o u r n a l o f C l in i ca l & C e l lu l a r I m m u n o l o gy ISSN: 2155-9899 1*