Objective To observe the effect of fire-needle acupuncture of"Zusanli"(ST 36) and "Kunlun"(BL 60)on ankle-joint swelling and serum tumor necrosis factor-α(TNF-α)and anti-cyclic citrullinated peptide antibody(ACPA)contents in collagen-induced arthritis(CIA)rats

so as to study its mechanism underlying improvement of rheumatoid arthritis(RA).Methods Thirty-two male Wistar rats were randomized into control

model

medication(Methotrexate)and fire-needling groups(n=8 in each).The RA model was established by injecting typeⅡchicken collagen(0.1 mol/L)plus Freund's complete adjuvant(primary immunization)and Freund's incomplete adjuvant(immunization once more)into the subcutaneous tissues of the right foot bottom

back and tail root of rats.Fire-needling was applied to the left and right "Zusanli"(ST 36) and "Kunlun" (BL 60)alternatively for3 times in each acupoint

once daily for 10 days.For rats of the medication group

Methotrexate sodium chloride solution(0.1 mg/100 g)was administrated by gavage

once every 5 days

twice together.The rats' right hind ankle diameter was measured before and after the treatment.The X-ray film of the right ankle was taken

and the contents of serum TNF-αand ACPA were assayed by ELISA.Results The ankle diameter and serum concentrations of TNF-αand ACPA were significantly increased in the model group compared to the control group(P<0.05)

and X-ray film showed swollen and deformed tarsus joints

and narrowing of the joint space.After the intervention

the ankle diameter

serum TNF-αand ACPA levels were considerably decreased in both medication and fire-needle groups compared with the model group(P<0.05).Meanwhile

the joint swelling and bone deformity became relatively milder.There were no significant differences between the medication and fire-needling groups in the ankle diameter and the contents of serum TNF-αand ACPA(P>0.05).Conclusion Fire-needling stimulation of ST 36 and BL 60

similar to Methotrexate

can relieve the inflammatory reactions of hind-ankle joint in CIA rats

which may be related to its effect in down-regulating ACPA and TNF-αlevels.