[Expression of plasma Dickkopf-1 in patients with rheumatoid arthritis and its correlation with peripheral blood T cell subsets].

OBJECTIVE

To detect the levels of Dickkopf-1 (DKK-1) in the plasma of patients with rheumatoid arthritis (RA), and to analyze their correlation with peripheral blood T cell subsets and clinical indicators.

METHODS

Enzyme-linked immunosorbent assay (ELISA) was used to detect plasma DKK-1 levels in 32 RA patients and 20 healthy controls, and to record the various clinical manifestations and laboratory indicators of the RA patients, and flow cytometry to detect peripheral blood T cell subsets in the RA patients (Including Treg, nTreg, aTreg, sTreg, Teff, Tfh, CD4CD161T, CD8T, CD8CD161T cells). The plasma DKK-1 levels between the two groups were ompared, and its correlation with peripheral blood T cell subsets and clinical indicators analyzed.

RESULTS

(1) The plasma DKK-1 concentration of the RA patients was (124.97±64.98) ng/L. The plasma DKK-1 concentration of the healthy control group was (84.95±13.74) ng/L. The plasma DKK-1 level of the RA patients was significantly higher than that of the healthy control group ( < 0.05), and the percentage of CD8CD161T cells in the peripheral blood of the RA patients was significantly higher than that of the healthy control group ( < 0.05). (2) The plasma DKK-1 level was positively correlated with erythrocyte sedimentation rate (=0.406, =0.021), DAS28 score (=0.372, =0.036), immunoglobulin G(=0.362, =0.042), immunoglobulin A(=0.377, =0.033); it had no correlation with age, course of disease, C-reactive protein, rheumatoid factor, anti-cyclic citrullinated peptide antibody, immunoglobulin M, complement C3, complement C4, white blood cell, neutrophil ratio. (3) The plasma DKK-1 level in the RA patients was positively correlated with the percentage of peripheral blood CD161CD8T cells (=0.413, =0.019);it had no correlation with Treg, nTreg, aTreg, sTreg, Teff, Tfh, CD4CD161T, CD8T cells. (4) The percentage of CD161CD8T cells was negatively correlated with erythrocyte sedimentation rate (=-0.415, =0.004), C-reactive protein (=-0.393, =0.007), DAS28 score(=-0.392, =0.007), rheumatoid factor (=-0.535, < 0.001), anti-citrullinated protein antibody (=-0.589, < 0.001), immunoglobulin G(=-0.368, =0.012) immunoglobulin M (=-0.311, =0.035); it had no correlation with age, disease course, immunoglobulin A, complement C3, complement C4, white blood cell, and neutrophil ratio.

CONCLUSION

RA patients' plasma DKK-1 levels and the percentage of CD8CD161T cells in T cell subsets in peripheral blood increase, which may be related to the secretion of proinflammatory cytokines in patients; DKK-1 is involved in the regulation of bone homeostasis and can be used as a marker of bone destruction in RA.