ABSTRACT
Recently, different microRNA (miRNA) gene polymorphisms have been evaluated in patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and Graves' disease (GD). In the present study, we examined three single-nucleotide polymorphisms (SNPs) located in the pre-miR-146a (rs2910164G/C), pre-miR-196a-2 (rs11614913C/T), and pre-miR-499 (rs3746444A/G) genes. Our study population included 900 Mexican patients with RA, SLE, or GD, as well as 486 healthy control individuals with no family history of inflammatory or autoimmune diseases. Genotyping was performed using TaqMan probes and a 5' exonuclease assay. None of the investigated SNPs were associated with RA or GD susceptibility under any genetic model (co-dominant, recessive, or dominant). Genotype and allele frequencies of the miR-196a-2 rs11614913C/T polymorphism were similar between SLE cases and controls. In contrast, the miR-146a rs2910164G/C and miR-499 rs3746444A/G polymorphisms were associated with SLE susceptibility. These SNPs were not associated with lupus nephritis (LN). Our results suggest that polymorphisms in miR-146a, miR-196a-2, and miR-499 are not associated with RA or GD susceptibility. This is the first report documenting that the miR-146a rs2910164G/C and miR-499 rs3746444 polymorphisms are associated with SLE susceptibility but not with LN.
ABSTRACT
OBJECTIVE: The functional PTPN22 R620W polymorphism (rs2476601) is clearly associated with susceptibility to several autoimmune diseases (ADs). However, the PTPN22 R263Q polymorphism (rs33996649) has been scarcely explored in different ADs. Here we aimed to examine the associations of the PTPN22 R620W and R263Q polymorphisms with susceptibility to or protection against rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and Graves' disease (GD) among Mexican patients. METHODS: We conducted a case-control study including 876 patients (405 with SLE, 388 with RA, and 83 with GD) and 336 healthy control individuals. PTPN22 genotypes were determined using the TaqMan 5' allele discrimination assay. RESULTS: PTPN22 R620W was associated with GD susceptibility (OR 4.3, p = 0.004), but was not associated with SLE (OR 1.8, p = 0.19). We previously demonstrated that this polymorphism is associated with RA susceptibility (OR 4.17, p = 0.00036). Moreover, PTPN22 R263Q was associated with protection against SLE (OR 0.09, p = 004) and RA (OR 0.28, p = 0.045), but was not associated with GD. CONCLUSIONS: Our data provide the first demonstration that PTPN22 R620W confers GD susceptibility among Latin-American patients. Moreover, this is the second report documenting the association of PTPN22 R263Q with protection against SLE and RA.
