Tuesday, August 09, 2011

Anemia of chronic disorders: the effect of EPO

Reduced EPO production

Under normal physiological conditions, levels of EPO are inversely correlated with hemoglobin levels and tissue oxygenation, but in chronic inflammatory conditions the EPO response is blunted, leading to inadequate levels of EPO for the degree of anemia, and this is thought to be mediated via inflammatory cytokines such as IL-1 and TNF-alpha, though not all studies confirm this.

Reduced erythroid responsiveness

In ACD, the proliferation and differentiation of erythroid progenitor cells is reduced. Early studies showed that macrophages from patients with ACD could suppress erythroid colony formation in vitro. Subsequent studies showed this effect to be due to inhibitory effects of inflammatory cytokines, especially interferon-gamma, on growth of BFU-E and CFU-E, and that this effect could be overcome by addition of high concentrations of EPO to the culture systems. Hepcidin itself has an inhibitory effect on erythropoiesis in vitro at low EPO concentrations.

It has been demonstrated that bone marrow cultures from patients with active rheumatoid arthritis showed defective growth when compared to normal controls, and that there was an inverse correlation between colony growth and levels of TNF-alpha in the culture supernatant. Moreover, these effects were reversed both in vitro and in vivo following treatment with infliximab, an antibody against TNF-alpha.


Anonymous said...

There is a trial of hydroxychloroquine going on at Glasgow Uni albeit it is for CML. They say a cure is on the horizon using this anti-malarial drug. In leukaemia it enters the white blood cells and interrupts the way cancer cells remove their damaged products and recycle their building blocks. It neutralises the acidic environment and the cancer cells die.Would it work for CLL?

Terry Hamblin said...

No. It has been tried.