RESUMEN
OBJECTIVE: To evaluate homocysteine levels in patients with Takayasu arteritis (TA) and in controls, and to analyze associations between homocysteine levels and paraoxonase 1 (PON1) activity, cysteine levels, methotrexate use, disease activity, extent of arterial involvement, and ischemic events in patients with TA. METHODS: A cross-sectional study was performed with 29 patients with TA and 30 controls who underwent clinical evaluation and blood sample collection in the fasting state. RESULTS: Among patients with TA, active disease was observed in 9 (31.0%) and previous arterial ischemic events in 10 (34.5%). Therapy with methotrexate was prescribed to 9 (31.0%) patients and it was associated with folic acid in 8 cases. Median homocysteine level was higher in patients with TA [10.9 µmol/l, interquartile range (IQR) 9.6-14.8] than in controls (6.9 µmol/l, IQR 5.1-11.9; p < 0.001). No difference was found regarding mean homocysteine levels between those using methotrexate and those under other therapies (12.8 ± 5.3 µmol/l vs 12.1 ± 3.2 µmol/l, respectively; p = 0.662). TA patients with active disease presented lower homocysteine levels (10.4 ± 2.1 µmol/l) compared to TA patients in remission (13.1 ± 4.2 µmol/l) (p = 0.034). A significant correlation was found between cysteine and homocysteine levels in patients with TA (ρ = 0.676, p < 0.0001), while there was no correlation between homocysteine and PON1 activity (ρ = 0.214, p = 0.265). Median homocysteine levels were higher in patients with ischemic events (13.2 µmol/l, IQR 10.9-17.5) compared to patients with no ischemic events (9.8 µmol/l, IQR 8.7-14.7; p = 0.027) and were associated with arterial ischemia in patients with TA (OR 1.31, 95% CI 1.01-1.71, p = 0.041). CONCLUSION: Patients with TA presented higher homocysteine levels than controls and homocysteine was associated with an increased risk of arterial ischemic events in TA.