The gene that encodes hepcidin expression (HAMP) is subject to regulation by proinflammatory cytokines, such as IL-6 and IL-1; excessive hepcidin production explains the relative deficiency of iron during inflammatory states, eventually resulting in the anaemia of inflammation.
We therefore studied the relationship between the circulating levels of interleukin-1beta (IL-1beta) and interleukin-18 (IL-18), a new member of the IL-1 complex, as well as polymorphisms within the IL-1 cluster with the occurrence of anaemia in patients with AA amyloidosis.
Since cytokines are of crucial significance in this process, we decided to examine the role of stem cell factor (SCF), granulocyte macrophage colony stimulating factor (GM-CSF), interleukin 3 (IL-3), granulocyte colony stimulating factor (G-CSF), and interleukin 1 alpha (IL-1 alpha), known for their stimulatory effects on in vitro hematopoiesis; and transforming growth factor beta (TGF beta), interferon gamma (IFN gamma) and tumor necrosis factor alpha (TNF-alpha), known for their inhibitory effect, in the anemia of GCA.