In 26 patients with severe iron deficiency and microcytic anemia (MCV less than 70 fl), serial red cell size distribution histograms (erythrograms) were taken before and during iron therapy. Initially all patients had a single population of red cells, all microcytes. With the first reticulocytosis after iron therapy, a new population of cells appeared, larger in volume than the original. In 23 of 26 patients the new population of cells was of normal size (82-96 fl). In 3 of 26, the new population was macrocytic (MCV greater than 98 fl). Of these 3, 1 had folate deficiency; after folate was given, normocytes were produced. The other 2, both taking phenytoin and 1 a heavy alcohol using, had persistent macrocytosis despite folate administration. Erythrograms allowed quantitative, rapid evaluation of erythropoietic response to iron repletion. Abnormal macrocytic responses could be identified and seemed to occur with some frequency.

Anemia, Hypochromic↗

PubMed1977

Erythropoiesis during recovery from macrocytic anemia: macrocytes, normocytes, and microcytes.

In seven patients with marked megaloblastic anemia (MCV greater than 110 fl), red cell size distribution curves (erythrograms) demonstrated the size of red cells produced after therapy. In six, the new red cells were normocytic throughout recovery. In the seventh patient, folate repletion along produced a new population of microcytes, due to unsuspected iron deficiency; after iron repletion normocytes were produced. Three patients with autoimmune hemolytic anemia had macrocytosis (MCV greater than 110 fl) without folate or vitamin B12 deficiency. During recovery with predisone therapy, instead of a discrete new normocytic population appearing, the entire population progressively returned to normal size. Normal rather than "stress" reticulocytes, and remodeled stress reticulocytes remaining, may explain this different pattern of recovery. Two patients initially had minor subpopulations of smaller red cells that disappeared soon after therapy. These probably reflected the dyserythropoiesis of severe megaloblastic anemia.

Anemia, Hemolytic, Autoimmune↗