IL1B and alkaline phosphatase measurement: We found that haplotype IL1B-TGCT (N°5) was associated with an increased risk of AP in the unadjusted (OR 1.45; 95% CI 1.05–2.00; p = 0.02) and adjusted model (OR 1.40; 95% CI 0.98–2.00; p = 0.06) (Table 2).