Iron overload in urban Africans in the 1990s

Background-In a previously described model, heterozygotes for an African ir on loading locus develop iron overload only when dietary iron is high, but homozygotes may do so with normal dietary iron. If an iron loading gene is common, then homozygotes with iron overload will be found even in an urban population where traditional beer, the source of iron, is uncommon. Aims-To determine whether iron overload and the C282Y mutation characterist ic of hereditary haemochromatosis are readily identifiable in an urban Afri can population. Methods-Histological assessment, hepatocellular iron grading, and dry weigh t non-haem iron concentration were determined in post mortem tissue from li ver, spleen, heart, lungs, and skin. DNA of subjects with elevated hepatic iron indexes was analysed for the C282Y mutation. Iron concentrations in ot her tissues were compared. Results-A moderate increase (>30 mu mol/g) in hepatic iron concentrations w as found in 31 subjects (23%; 95% confidence interval 15.9 to 30.1%), and t hey were considerably elevated (>180 mu mol/g) in seven subjects (5.2%; 95% confidence interval 1.5 to 8.9%). Appreciably elevated hepatic iron concen trations were associated with heavy iron deposition in both hepatocytes and macrophages, and either portal fibrosis or cirrhosis. All were negative fo r the C282Y mutation. Very high concentrations were uncommon in subjects dy ing in hospital. Concentrations of iron in spleen, heart, lung, and skin we re significantly higher in subjects with elevated hepatic iron. Conclusions-Iron overload is readily identified among urban Africans and is associated with hepatic damage and iron loading of several tissues. The co ndition is unrelated to the genetic mutation found in hereditary haemochrom atosis.