The variant of CD11b, rs1143679 within ITGAM, is associated with systemic lupus erythematosus and clinical manifestations in Brazilian patients

Background/aims: Immune responses mediated by complement receptors (CR) are impaired in patients with systemic lupus erythematosus (SLE). Regarding CR3 (CD11b/CD18), the CD11b subunit is encoded by the ITGAM gene and a single nucleotide polymorphism (G230A; rs1143679) in ITGAM changes an arginine to a histidine at position 77 (R77H). We assessed whether the variant R77H, rs1143679 within ITGAM, is associated with the risk to developing SLE and the clinical manifestations of Brazilian SLE patients. Methods: The rs1143679 was genotyped by SSP-PCR in 157 patients with SLE and 147 healthy individuals. Clinical and laboratorial manifestations were obtained from the official medical records according the criteria of the American College of Rheumatology. Results: The 77H variant was associated with susceptibility to SLE (OR = 1.8); the frequencies of the minor allele A were 0.25 (SLE) and 0.15 (healthy) (p < 0.01). In addition, the minor allele A was associated with lupus nephritis (p = 0.02) and antiphospholipid antibodies (p = 0.04). Conclusion: These results showed that the rs1143679 variant is also associated with the risk to SLE in our population and with the risk to specific clinical manifestations, as nephritis and presence of antiphospholipid antibodies. These results may have implications for discussing the association of this polymorphism with the IC deposition in SLE. (C) 2013 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.