ABSTRACT
Objective To measure the serum levels of angiopoietin-like protein (ANGPTL) 3, ANGPTL4 and RANKL in patients with rheumatoid arthritis (RA), and the relationship between ANGPTL3/ANGPTL4 and clinical manifestations were analyzed. Methods Blood samples were drawn from 72 patients with RA and 28 healthy subjects. Serum levels of ANGPTL3, ANGPTL4 and RANKL were tested by enzyme linked immuno-sorbent assay (ELISA). Nonparametric rank sum test was used for the comparisons between groups and Spearmanˊs correlation test was used for correlation analysis. Results ① The serum level of ANGPTL3 was significantly increased in RA group compared to healthy group [800.325(577.477, 1 750.636) pg/ml vs 487.900 (382.340, 565.499) pg/ml, P<0.05, Z=-6.082]. ② The serum level of ANGPTL4 was significantly increased in RA group compared to healthy group [1 036.199(853.347, 1 746.677) pg/ml vs 706.095(558.571, 807.302) pg/ml, Z=-5.962, P<0.05].③ The serum levels of ANGPTL3 and ANGPTL4 in RA patients were increased with the rise of disease activity (DAS 28) [ANGPTL3 in the low disease activity groupwas 457.265 (373.709, 605.296) pg/ml, that of the moderate disease activity group was 785.815(679.156, 1 308.785) pg/ml, that of the high disease activity group was 1 502.038 (817.713, 1 960.493) pg/ml, P<0.05; ANGPTL4 in the low disease activity group was 737.604 (467.040, 918.222) pg/ml, that of the moderate disease activity group was 991.227 (819.456, 1 699.972) pg/ml, and that of the high disease activity group was 1 842.310 (1 252.023, 2 669.902) pg/ml, P<0.05].④ANGPTL3 and ANGPTL4 was positively correlated with RANKL (r=0.554, 0.619, P<0.01).⑤ The serum level of ANGPTL4 was significantly increased in patients with bone destruction, compared to those without bone destruction [1 624.071(949.432, 2 622.371) pg/ml vs 927.590(737.604, 1 409.798) pg/ml, Z=-2.483, P<0.05]. Conclusion The serum levels of ANGPTL3 and ANGPTL4 are increased in RA, and are both positively correlated with disease activity, moreover, ANGPTL4 is associated with pathological bone destruction.