IL1B and hematocrit: In the study of Phenekos et al., the level of IL-1β in the serum of patients with HT at different stages of disease (TSH > 8 μIU/mL; some participants were treated with L-T4 for up to 18 months) was significantly lower than in the group of healthy subjects (2.52 ± 0.14 vs. 3.6 ± 0.20 pg/mL) [29].