Background: The cause of the anemia of patients in surgical intensive care units (SICU) is not completely clear but is likely to be multifactorial. This study investigated a possible role for immune activation in the anemia of SICU patients.
Methods: Neopterin plasma levels, as a measure of T-cell-macrophage-axis activation, RBC-counts, Hb, Hct, MCV, MCH, MCHC, RDW, HDW, red cell morphology and iron status were determined in a group of 47 SICU patients.
Results: The study confirms the presence of a moderate anemia (Hb = 10.38 +/- 13 g/dL) in SICU patients. Abnormal red blood cell morphology was observed in 82% of all patients over at least part of their ICU-stay. Markedly enhanced T-cell-macrophage-axis activity was evidenced by a significant increase in the plasma neopterin levels of the patient group (44 +/- 79.6 nmol/L) compared to that of the control group (3.38 +/- 4.9 nmol/L). Iron metabolism was found to be disturbed.
Conclusions: The red cell distribution width, the morphological results, the enhanced macrophage activation state, as well as the results of the iron status, point towards a contribution of an immune-associated functional iron deficiency to the anemia of SICU patients.