Reduced IL-33 plasma levels in aplastic anemia

Background: In this study, we aim to evaluate the balance of interleukin (IL)-33 and its soluble receptor sST2 in patients with aplastic anemia (AA). Methods: Plasma IL-33, IL-17 and sST2 levels were measured in patients with active AA (n = 31), AA in remission (n = 29) and in healthy subjects (n = 30), using enzyme linked immunosorbent assays (ELISAs). Results: The results showed that sST2 and IL-17 levels were significantly elevated in patients with active AA when compared to control subjects, but IL-33 levels were significantly lower in AA patients, which resulted in elevated sST2/IL-33 ratios in patients with active disease. During remission stages, the levels of these cytokines were comparable to those of healthy controls. Conclusions: The elevated levels of sST2/IL-33 in the plasma during active stages of the disease suggest a possible role in the pathogenesis and course of AA.