Serum transferrin receptor levels are increased in asymptomatic and mild Plasmodium falciparum-infection

Background and Objectives. The serum transferrin receptor (sTfR) concentrat ion in an individual reflects the extent of erythropoietic activity and is considered a useful marker of iron deficiency independent of concurrent inf lammation or infection. However, data on the impact of malaria on this para meter are ambiguous. We examined potential associations of asymptomatic and mild Plasmodium falciparum-infections and of several erythrocyte variants with sTfR values in South West Nigeria. Design and Methods. In a cross-sectional study among 161 non-hospitalized c hildren, sTfR concentrations and P. falciparum parasitemia were assessed. I n addition, hemoglobin (Hb) and serum ferritin values, Hb-types, glucose-6- phosphate dehydrogenase (G6PD) deficiency and alpha-globin genotypes were d etermined and the effects of these factors on sTfR levels were analyzed by univariate and multivariate statistical methods. Results. P. falciparum-infection was present in 77% of the children. Mean s TfR levels were higher in infected than In non-infected children (geometric mean, 3.68, 95% confidence interval [3.5-3.9] vs. 2.99 [2.7-3.3] mg/L; p = 0.0009). There was a significant trend for higher sTfR values with increas ing parasite density, sTfR values decreased continuously with age. Hb-types , G6PD-, and alpha-globin genotypes did not correlate with sTfR levels. In the multivariate analysis, age, Hb and log ferritin values, and parasite de nsity of P, falciparum were independently associated with log sTfR values. Interpretation and Conclusions. sTfR concentrations are increased in asympt omatic and mild P. falciparum-infections suggesting adequate bone marrow re sponse in this condition. The diagnostic value of sTfR levels for iron defi ciency may be impaired in areas where stable malaria occurs. (C)1999, Ferra ta Storti Foundation.