The significance of Howell-Jolly bodies in red cell precursors.

During the routine examination of sternal marrow smears it was observed that the presence of nuclear fragments in red cell precursors, commonly known as Howell-Jolly bodies, was usually associated with clear evidence of vitamin B12 or folic acid deficiency. Moreover, this seemed to be so even when the megaloblastic transformation of erythropoiesis was not well developed. With further experience the presence of Howell-Jolly bodies does appear to be a finding of diagnostic value even in doubtful cases. In order to test the validity of this impression a series of sternal marrow films examined for HowellJolly bodies has been reviewed. In this the incidence in iron deficiency and other states where B12 or folic acid deficiency could clearly be excluded has been compared with the incidence in conditions known to be associated with B12 or folic acid deficiency. The results of this investigation are presented here.