The CD244 rs3766379 variant showed no association with susceptibility to rheumatoid arthritis while soluble CD244 was associated with disease activity

Abstract

Cluster of differentiation 244 (CD244), a member of the signaling lymphocytic activation molecule (SLAM) family, is one of the major cell surface receptors of the SLAM family with activating and inhibitory signaling potentials that is involved in the functional regulation of inflammatory reactions. It has recently been suggested that soluble CD244 levels are dysregulated in patients with rheumatoid arthritis (RA), but the evidence is not conclusive. Furthermore, the CD244 rs3766379 variant showed conflicting results regarding association with disease susceptibility. In this cross-sectional case-control study, serum CD244 concentration was determined in 123 RA patients and 60 controls using an enzyme-linked immunosorbent assay kit. The CD244 rs3766379 variant was also genotyped using real-time polymerase chain reaction principles. Results revealed that Log10-transformed serum concentrations (mean ± standard error) of soluble CD244 were significantly elevated in RA patients compared to controls (0.53 ± 0.04 vs. 0.29 ± 0.02 ng/mL; probability = 0.003), especially in patients with high disease activity (0.73 ± 0.12 vs. 0.29 ± 0.02 ng/mL; probability = 0.003), where CD244 showed reliable discrimination between patients and controls (area under the curve = 0.698; probability = 0.023). The rs3766379 allele and genotype frequencies showed no significant differences between patients and controls. Furthermore, this variant did not affect CD244 concentration. In conclusion, CD244 levels were up-regulated in the serum of patients with RA, particularly those with high disease activity. The CD244 rs3766379 variant was not associated with susceptibility to RA and had no effect on serum CD244 concentration.