OBJECTIVETo investigate the immunoregulation effects of umbilical cord mesenchymal stem cells (UC-MSCs) on the rats with collagen II induced arthritis (CIA).

METHODSThe rats were first immunized by intradermal injection of chicken collagen type II emulsified with complete Freund's adjuvant (CFA) to monitor their swelling of foot, hair color and action state. After injected UC-MSC by caudal vein, the rats were scored with the arthritis index (AI) once a week. Then, the concentration of interleukin (IL-6), tumor necrosis factor-α (TNF-α) in serum and D-dimer (D-D), antithrombin-III (AT-III), thrombomodulin (TM) in plasma were detected by ELISA.

RESULTSObvious swellings of the feet were found in the experiment group compared with normal one. ELISA analysis showed that the concentrations of IL-6, TNF-α, D-D and TM in plasma of the experiment group as of (200.48 ± 15.04) ng/L, (450.25 ± 45.39) ng/L, (274.26 ± 67.93) ng/L and (9.18 ± 0.84) µg/L, respectively were higher than of(167.62 ± 0.97) ng/L, (371.44 ± 21.26) ng/L, (193.95 ± 8.22) ng/L and (6.30 ± 0.32) µg/L respectively in normal group (P < 0.05), but the concentration of AT-III \[(89.57 ± 6.40) ng/L\] was lower than normal group \[(112.82 ± 1.74) ng/L\] (P < 0.05). The levels of cytokines through the UC-MSCs treatment were significantly different from the model group (P < 0.05). After 9 weeks, these cytokines in the UC-MSCs group were mostly the same as the normal group.

CONCLUSIONThe thrombophilia status of the CIA rats was caused by immune injury. The UC-MSCs reduced the production of inflammatory cytokines and regulated and repaired the balance of coagulation and anticoagulation system of the body to cure the immune-related thrombophilia.