The serum HMGB1 of the enrolled AS patients who had a history of recurrent episodes of anterior uveitis (13 positive versus 134 negative) or diarrhea (13 positive versus 134 negative) was not significantly higher than in those without these symptoms (103.77 ± 44.36 ng/mL versus 107.11 ± 29.46 ng/mL, 93.14 ± 22.31 ng/mL versus 108.14 ± 31.32 ng/mL). This evidence concerns the gene HMGB1 and anterior uveitis.