title: HLA class II alleles influence rheumatoid arthritis susceptibility and autoantibody status in South Indian Tamil population.
abstract: Rheumatoid arthritis (RA) is a complex multifactorial autoimmune disease characterized by inflammatory arthritis. The precise etiology and pathogenesis of RA remains elusive but evidence points towards stochastic interactions between genetic and environmental factors. This study investigated the distribution of human leucocyte antigen (HLA)-DRB1/DQB1 alleles in South Indian patients with rheumatoid arthritis (RA) and their influence on RA susceptibility and clinical phenotype. Low resolution HLA-DRB1 and -DQB1 typing was performed in 271 RA patients and 233 healthy controls by polymerase chain reaction (PCR) using sequence-specific primers (SSP). HLA-DRB1*10 was found to be more frequent in patients (Pc= 0.004, OR = 2.23, 95% CI = 1.5-3.34) than controls. This difference persisted in RF positive (Pc= 9 × 10-6, OR = 2.45, 95% CI = 1.62-3.74), ACPA positive (Pc= 0.007, OR = 2.10, 95% CI = 1.35-3.29), ACPA negative (Pc= 0.001, OR = 2.45, 95% CI = 1.50-3.97) and both RF and ACPA positive subgroup of patients (Pc= 0.003, OR = 2.22, 95% CI = 1.41-3.51). On the contrary, the HLA-DRB1*13 (Pc= 0.01, OR = 0.43, 95% CI = 0.25-0.73) and HLA-DRB1*14 (Pc= 0.003, OR = 0.43, 95% CI = 0.26-0.69) alleles were over-represented in controls than patients. Further, distribution of the prominent Caucasian RA risk allele DRB1*04 did not differ between patients and controls in our study population. We did not find any association between DQB1 alleles and RA susceptibility or autoantibody status. The haplotypes DQB1*05-DRB1*10 (P = 6.8 × 10-6, OR = 2.46, 95% CI = 1.63-3.79) and DQB1*06-DRB1*15 (P = 0.03, OR = 1.41, 95% CI = 1.02-1.96) were more frequent in patients while DQB1*05-DRB1*14 (P = 8.4 × 10-4, OR = 0.44, 95% CI = 0.26-0.74) and DQB1*06-DRB1*13 (P = 9.5 × 10-4, OR = 0.40, 95% CI = 0.21-0.72) were higher in controls. To conclude, HLA-DRB1*10 is associated with RA while HLA-DRB1*13 and HLA-DRB1*14 alleles confer protection in south Indian Tamils.
authors.affiliation: Department of Clinical Immunology, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India.|INSERM, UMRS 1160, Saint Louis Hospital, Paris, France.
authors.forename: C M
authors.initials: CM
authors.lastname: Mariaselvam
authors.affiliation: Jean Dausset Laboratory of Immunology and Immunogenetics and LabExTransplantex, Saint Louis Hospital, Paris, France.
authors.forename: C
authors.initials: C
authors.lastname: Fortier
authors.affiliation: INSERM, UMRS 1160, Saint Louis Hospital, Paris, France.|Jean Dausset Laboratory of Immunology and Immunogenetics and LabExTransplantex, Saint Louis Hospital, Paris, France.
authors.forename: D
authors.initials: D
authors.lastname: Charron
authors.affiliation: INSERM, UMRS 1160, Saint Louis Hospital, Paris, France.
authors.forename: R
authors.initials: R
authors.lastname: Krishnamoorthy
authors.affiliation: INSERM, UMRS 1160, Saint Louis Hospital, Paris, France.|Jean Dausset Laboratory of Immunology and Immunogenetics and LabExTransplantex, Saint Louis Hospital, Paris, France.
authors.forename: R
authors.initials: R
authors.lastname: Tamouza
authors.affiliation: Department of Clinical Immunology, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India. vsnegi22@yahoo.co.in.
authors.forename: V S
authors.initials: VS
authors.lastname: Negi
mesh_terms: D000328:Adult; D000483:Alleles; D001172:Arthritis, Rheumatoid / Q000208:ethnology / Q000235:genetics* / Q000276:immunology / Q000473:pathology; D001323:Autoantibodies / Q000097:blood / Q000235:genetics; D016022:Case-Control Studies; D005006:Ethnicity; D005260:Female; D015870:Gene Expression; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D059866:HLA-DQ beta-Chains / Q000235:genetics* / Q000276:immunology; D059811:HLA-DRB1 Chains / Q000235:genetics* / Q000276:immunology; D006239:Haplotypes; D006650:Histocompatibility Testing; D006801:Humans; D007194:India; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide
chemical_list: D001323:Autoantibodies; D059866:HLA-DQ beta-Chains; C069051:HLA-DQB1 antigen; D059811:HLA-DRB1 Chains
keywords: HLA-DR/DQ polymorphism; autoantibodies; clinical phenotype; protection; rheumatoid arthritis; susceptibility