Prediction of bone marrow iron findings from tests performed on peripheral blood.

After evaluating multiple tests, the authors have devised a scheme to predict bone marrow iron findings from tests performed on peripheral blood. They examined bone marrows from 97 consecutive patients with anemia who were divided into five marrow morphologic groups: (1) iron deficiency; (2) anemia of chronic disease; (3) abnormal sideroblasts; (4) ring sideroblasts; and (5) other. Tests of peripheral blood included hemoglobin, hematocrit, red blood cell count and red blood cell indices, reticulocyte count, sedimentation rate or zetacrit, ferritin, iron, iron binding capacity, free erythrocyte protoporphyrin, and tests of hepatic and renal function. Cluster analysis, multidimensional scaling, and logistic discriminant analysis were used to derive a graph of serum ferritin with the sedimentation rate, allowing accurate confirmation or exclusion of iron deficiency in most patients. Percent saturation of serum transferrin and serum ferritin allowed identification of only 50 percent of patients with abnormal or ring sideroblasts while excluding 100 percent of patients without abnormal or ring sideroblasts. In three years of follow-up, two of 19 patients with abnormal or ring sideroblast have developed the dysmyelopoietic syndrome or ANLL, respectively. With the aid of the two parameter graphs described, the authors believe the differential diagnosis of the hypoproliferative anemias relating to iron metabolism can frequently be made without examination of the bone marrow.