[Pattern of blood levels of erythropoietin and proinflammatory cytokines in patients with anemia of chronic disorders secondary to infection].

OBJECTIVE

To evaluate the pattern of erythropoietin (EPO) and some proinflammatory cytokines in the anemia of chronic disorders (ACD) secondary to infection.

METHODS

Sequential determination in serum of interleukin-1 beta (IL-1 beta), necrosis tumoral factor alpha (TNF-alpha), gamma interferon (IFN-gamma), interleukin-6 (IL-6), and erythropoietin (EPO) in 25 patients with chronic bacterial infectious diseases and ACD criteria. We evaluated the relationship of these mediators with the anemia and the iron metabolism.

RESULTS

Serum EPO levels significatively decreased compared with initial values, and the last control was in normal rank (18.04 +/- 19.10 vs. 8.56 +/- 4.72 UI/mL; p < 0.001; normal rank: 4-15 mUI/mL). In the first control, there was a negative and non significative correlation between the EPO levels and the hemoglobin concentration (r = -0.115, NS), reaching significance in the last control (r = -0.446; p < 0.05). There was negative correlation between the hematocrit and TNF-alpha levels (r = 0.467; p < 0.05) and between the haemoglobin values and the log of serum TNF-alpha (r = 0.424; p < 0.001). An inverse correlation between the IL-6 levels and both, the hemoglobin concentration and the serum iron was found, and there was a direct correlation between this cytokine values and the EPO levels.

CONCLUSIONS

Blunted response of erythropoietin and the action of TNF may contribute to the pathogenesis of ACD secondary to infection. Positive correlation between IL-6 and EPO suggest a proerythropoietic action of IL-6 in response to the anemia.