The present study aimed to investigate relationships between the CD94 and NKG2A gene polymorphisms and the risk of rheumatoid arthritis (RA) development as well as their association with the response to anti-TNF therapy.

A total of 284 patients with RA receiving anti-TNF therapy and 124 healthy subjects were enrolled to the study. Genotypings for CD94 (rs2302489) and NKG2A (rs7301582, rs2734440, rs2734414) polymorphisms were performed using a polymerase chain reaction (PCR) amplification employing LightSNiP assays (TIB-MolBiol, Berlin, Germany). Clinical response was evaluated at 12th and 24th week after initiation of the therapy according to the EULAR response criteria.

The frequency of the CD94 AA genotype was significantly decreased in RA patients compared to controls (OR=0.44; P=0.016). The CD94 AA homozygotes were also more common among patients negative to anti-cyclic citrullinated peptide (anti-CCP) antibodies (OR=11.28; P=0.001) as compared to anti-CCP-positive patients and the presence of the CD94 allele A was associated with lack of anti-CCP antibodies (OR=5.00; P=0.0005). The CD94 rs2302489 TT genotype was over-represented in patients exhibiting worse EULAR response at 12th week (OR=3.33; P=0.017). Furthermore, the lack of response after 12 weeks was more frequent among patients carrying the NKG2A rs7301582C allele (OR=3.68; P=0.019) or the CC genotype (OR=3.58; P=0.035) in comparison to allele T or CT/TT genotypes, respectively.

These results indicate that CD94 and NKG2A polymorphisms may contribute to genetic susceptibility to RA or affect the response to anti-TNF therapy in patients of Caucasian origin.