The effect of transfusions of erythrocytes on untreated pernicious anemia.

EXAMINATIOX of the bomie issart’ow imi umitreated perniciotts aneliiia reveals that. erythmopoiesis is megaloblastic imi type.’ ‘ Either spomitaneous remission,’ or the administratiomi of liver extract,3 folic acid,4 or vitamin B125 causes a disappearamice of the characteristic miiegaioblasts amid the appearance of miormol)lastic niaturat iou . This change begi mis a few hours after specific therapy is started and is complete withimi a few tlays.3 During the first. w’eek after treatment is started reticulocytosis occstrs amid reaches a maximum value in 5 to 10 days. These changes occur as a result of the correction of a deficiemicy of a specific substamice that is necessary for normoblastic maturatiomi.t Imi 1946, Davidson, iVEurphy, \Vatsomi, amid Castle reporte(i the effects of givitig muassive transfusions of whole blood and packed erythrocytes to 5 patielits with pertucious anemia imi relapse.6 The authors reported that tramisfusiomis had no effect on the low lestkocyte amid platelet counts amid did not produce striking clinical improvement imi the patients evemi whets the erythrocyte level was brought to normal. They also reported that. the “megaloblasts characteristic of perniicious amiemia” disappeared from the bomie marrow within 4 to 12 days after transfusions were started. Imi 2 patiemits this occurred whemi the erythrocyte coumtt was raised to levels of omily 3.2 amid 4 muilliomi. Their data did miot indicate that amsy further chamige imi the morphology of the erythrocyte precursors in the marrow was produced by the adtninistratioti of liver extract after tramisfusions were given, although a small reticulocyte response occurred in all but omie case. These observations suggested to them that the miutritional deficiency state that was manifested by a rnegaloblastic marrow’ was relative rather thami absolute amid that it could be affected by ami artificial decrease imi the bomie marrow anoxia. In the conclusions of the paper of Davidson et al.6 it was stated that “Following the blood tramisfusions, but prior to liver extract therapy, the bone marrow megaloblasts characteristic of pernicious anemia disappeared.” This important observation has been quoted widely but it would appear that the statement is opemi to two imiterpretations that do not have the same significance. One possible imiterpretatiomi would meams that multiple blood tramisfusiotis produce a change iii the erythrocyte precursors in the marrow of patietits with pernicious anemia in relapse that is similar to that seen after specific therapy with vitamin B,2 or liver extract. Simice the transfitsiomis did not supply an effective amount of vitamin B,2,7 this interpretatiomi would meami that with the samue amount of available vitamin B12, erythropoiesis may be normoblastic in type during reduced erythrocyte production amid become muegaloblastic (vitamin B12 deficient) when erythrocyte production is rapid emiough to deplete the available supply of vitamin B,2. A differemit conclusiomi is suggested if the term “normoblast” as