Significance for the diagnosis of iron overload of histochemical and chemical iron in the liver of control subjects.

Storage iron was examined in surgical liver biopsy specimens in 43 haematologically normal and otherwise healthy adult individuals. These patients had no history of unphysiological iron losses nor of unphysiological iron intake. Histochemical iron was estimated in parenchymal and Kupffer cells and graded from 0 to 4+. Stainable iron of grade 1+ or more was present in parenchymal cells in 23 of the 27 men. Six of them had a 3+ grade. In nine cases iron was also visible in Kupffer cells. Visible iron was absent in most of the menstruating women. The mean total nonhaemin iron concentration for the male group was 80.2 (19.4 to 227.0), for the postmenopausal women 50.7 (19.3 to 106.6), and for the menstruating women 23.5 (5.5 to 65.9) mg./100 g. dry weight. The mean value for the women was significantly lower than the mean value for the men. There was a significant correlation between the histochemical grades of iron and chemically determined nonhaemin iron, but the degree of overlapping was considerable. The presence of stainable iron in the parenchymal liver cells is a normal finding. The significance of the present results with reference to familial studies of haemochromatosis is discussed.