At T0, fetuin-A was significantly higher in non-smokers compared with smokers (237.1 (210.8–288.8) vs. 213.4 (182.1–223.1), respectively, p = 0.01); in patients with heel enthesitis compared with those without (232 (208.6–262.4) vs. 207.4 (182.1–214.8), respectively, p = 0.03) and with a family history of SpA compared with no family history (234.7 (215.5–287.6) vs. 211 (199.3–242.6), respectively p = 0.04). This evidence concerns the gene AHSG and enthesitis.