The following conclusions can be made concerning the cause of anemia in patients with untreated chronic lymphatic leukemia excluding the rare case with an autoimmune hemolytic anemia:
1. Early in the natural history of the disease there is a normal amount of erythroblastic tissue which produces red cells at a normal rate. The rate of red cell destruction is also normal.
2. With progression of the disease the erythroblastic tissue is gradually replaced by lymphatic tissue, leading to a decrease in red cell production. The rate of red cell destruction is still normal.
3. Only late in the disease may decreased rate of red cell production be aggravated by an increased rate of red cell destruction.