Anemia of inflammatory disease in the dog: ferrokinetics of adjuvant-induced anemia.

Anemia of inflammatory disease induced by injection of adjuvant was characterized by decreases in hematocrit (mean +/- 1 SD, 37.5 +/- 2.7%, as compared with base-line values of 49.8 +/- 2.4%) and hemoglobin (12.54 +/- 1.22 g/dl, as compared with base line of 16.87 +/- 0.96 g/dl) and was classified as unresponsive, normocytic, and normochromic. Disordered iron metabolism was manifest by decreases in serum iron (62.3 +/- 13.6 g/dl, as compared with base line or 113.0 +/- 8.2 g/dl) and shortened mean radioiron clearance half-times (50.0 +/- 12.6 minutes, as compared with base line of 74.0 +/- 13.6 minutes) in the presence of increased bone marrow reticuloendothelial iron. Shortened radioiron clearance half-times reflected maximal extraction of iron from the plasma by the erythroid marrow due to suboptimal iron supply, since extraction of iron by other tissues is minor. Shortened mean marrow transit times (2.79 +/- 0.46 days, as compared with base line of 5.4 +/- 0.64 days) were indicative of adequate erythropoietin stimulation in the anemia of inflammatory disease. Increases in plasma iron turnover rate over base line (1.73 +/- 0.33 mg/dl/day to 1.51 +/- 0.34 mg/dl/day), erythron iron turnover rate (1.50 +/- 0.27 mg/dl/day, as compared with base line of 0.99 +/- 0.27 mg/dl/day), and RBC iron utilization (86 +/- 8.3%, as compared with base-line utilization of 65 +/- 9.3%) indicated erythroid marrow proliferation was effective. The magnitude of erythroid response appeared to be limited mainly by iron supply.