IL1B and aggressive systemic mastocytosis: Of note, the same pattern of alteration was observed for soluble IL1β, IL6, IL8 and TNFα (P ≤ 0.006) across the distinct diagnostic subtypes of SM, although ISM patients displayed higher IL8 levels than BMM cases (P = 0.05), and increased IL10 levels were restricted to ISM and ASM patients (P = 0.010 and P = 0.015 vs. HD, respectively) (Figure 2B).