Electron Microscopy of the Red Cells in Erythropoietic Porphyria

I N 1955 Schmid et al.1 noted the presence of intranuclear heme inclusions in the fluorescing normoblastic nuclei of several patients with ( congenital) erythropoietic porphyria. With a routine Romanovsky stain they were able to demonstrate incompletely stained areas in the nuclei. In addition, these inclusions stained positively with benzidine2 and showed a strong absorption at 400 ITIJL, clearly establishing the presence of hemoglobin. Gross, in 1964, confirmed these findings in an additional case of erythropoietic porphyria with a severe hemolytic component, hyperferremia, and a bizarre peripheral smear characterized mainly by hypochromia and poikihocytosis. In the latter instance, a combination Wright’s and benzidine-nitroprusside stain was employed which clearly distinguished the nonnucleated target forms from the abnormal nuclear inclusions. In all of the cases studied, erythropoietic cells without red fluorescence exhibited the usual nuclear structures. On the basis of the cumuhative data supporting the existence of 2 red cell lines in erythropoietic porphyria,4 electron microscopic studies were carried out on the erythroid precursors in order to determine their morphologic characteristics and signify, if possible, differences relative to the porphyrin laden cells.