Ultrastructural localisation of iron in the jejunum of black children withpellagra

Objective. To elucidate the pathogenesis of iron overload in the jejunum of black children with pellagra by means of comparative ultrastructural studi es of iron deposition in the jejunal enterocytes of these children and adul t blacks with dietary iron overload (DIO). Design. Retrospective study of jejunal biopsies from 10 black children (age 4 - 10 years) with pellagra. Methods. Jejunal biopsies were subjected to routine transmission electron m icroscopy, which enables reliable structural identification of ferritin and haemosiderin. Results. In all the pellagra patients, deposits of ferritin and/or haemosid erin were found in the jejunal absorptive cells in 4 intracellular localisa tions, viz, apical vesicles, dense bodies (siderosomes), Golgi complex and basolateral areas of the cell. This pattern of iron deposition in enterocyt es of black children with pellagra was similar to that previously found in adult blacks with DIG. However, in sharp contrast to DIG, no excessive iron deposition could be demonstrated in the intercellular space and lamina pro pria of the malnourished children. Conclusion. These results suggest that the iron overload in the jejunal abs orptive cells of black children with pellagra may be due to a defect in the release of iron from these cells.