SOLUBLE TRANSFERRIN RECEPTOR AS AN INDEX OF IRON STATUS IN ZAIRIAN CHILDREN WITH MALARIA

This study was designed to evaluate soluble transferrin receptor (sTfR ) as an index of iron status in 0.5-16-year-old Zairian children: 17 w ith symptomatic malaria, 8 with asymptomatic malaria, and 15 controls. sTfR was also measured in 20 plasma samples obtained from iron suffic ient laboratory employees. sTfR, haemoglobin and ferritin were measure d by enzyme-immunoassay, cyanmethaemoglobin method, and radioimmunoass ay respectively. Mean haemoglobin levels were lower and ferritin highe r (P<0.001) in children with clinical symptoms of malaria than in thos e without malaria, and they were intermediate in those with asymptomat ic malaria. Mean sTfR concentrations were similar among the three grou ps of children and laboratory controls. There was a considerable overl ap in sTfR concentrations between the three groups of children (1.8-10 .2, 2.9-11.6 and 2.97-8.95 mg l(-1) in symptomatic malaria, asymptomat ic malaria and control groups, respectively) as well as laboratory con trols (1.2-7.30 mg l(-1)). Despite the overlap, 6 children with malari a (24%) and one control child (6.7%) had sTfR concentrations above the highest concentration found in laboratory controls. No child had seru m ferritin <12 mu g l(-1) (suggestive of iron deficiency). As expected , sTfR negatively correlated with ferritin (r=-0.230) in the overall s tudy population of children, and with haemoglobin in children with asy mptomatic malaria (r=-0.943, P<0.05), as well as in control children ( r=-0.363). All children with sTfR above normal were also anaemic. Alth ough the upper limit of normal sTfR concentration in healthy children is unknown, using the cut-off value of adults, we conclude that sTfR m ight be a more sensitive index of iron deficiency than serum ferritin in patients with malaria.