Limited value of serum ferritin in evaluating iron status in children with protein-energy malnutrition.

26 of 46 Nigerian children with protein-energy malnutrition (PEM) had elevated S-Ferritin levels; the geometric mean value in the entire group of children with PEM was 146 micrograms/l and the observed range 11-7000 micrograms/l. There was no statistically significant correlation between the logarithm of the S-Ferritin level and the amount of stainable iron in marrow fragments (r = 0.23; p greater than 0.2). A stepwise multiple linear regression analysis in which the logarithm of the S-Ferritin level was used as the dependent variable and a total of 17 clinical, biochemical and haematological parameters were used as the independent variables showed that 34.8% of the variability in S-Ferritin could be accounted for by variations in the percentage of lymphocytes in the bone marrow. We speculate that the latter parameter may be an index of previous infection and that the elevated S-Ferritin levels may, therefore, be at least partly caused by infections. Increased serum aspartate transaminase activities were also encountered in PEM, suggesting that hepatocellular damage may contribute to the high S-Ferritin levels in this condition. Our data indicate that S-Ferritin has a limited value as an indicator of iron status in subjects with PEM, presumably because of the frequency of infections and of hepatocellular damage in such subjects.