Transferrin Types, Iron-Binding Capacity and Body Iron Stores

Abstract

Increased body iron stores and transferrin (TF) variants have been found to be associated with adverse health effects believed to be caused by oxygen free radicals. Previous attempts to establish a relationship between TF types, serum TF concentrations and iron-binding have been inconclusive. We have studied serum iron, total iron-binding capacity (TIBC), TF saturation and serum ferritin in relation to genetic TF types in a population sample (691 females and 639 males) from northern Sweden in an attempt to elucidate whether individuals with TF variants associated with adverse somatic and reproductive effects (TFC2 and C3) have increased body iron stores. As expected there was a highly significant sex difference, males manifesting increased body iron stores viz. increased levels of serum iron, TF saturation and serum ferritin, and a lower TIBC. There was no consistent and statistically significant association between the TFC2 variant and the parameters that indicate iron binding and storage. Thus the associations between TFC2 and somatic and reproductive damage appear to be independent of iron binding and body iron stores. TIBC (and TF levels) showed significant differences between TF types in females (p = 0.0015) but not in males. In females the TFC3 variant was associated with a significantly lower (p = 0.002) TIBC value. This decreased TIBC value was, however, not accompanied by an increased ferritin value, thus there was no unequivocal evidence for an association between TFC3 and increased body iron stores.

Association study between iron-related genes polymorphisms and Parkinson's disease

“…Although the functional significance of the G258S transferrin polymorphism is unclear, the A allele, which encodes a serine at position 258 of the mature protein,is specific for the C3 isoform [1],an electrophoretic variant that has been associated with a decreased plasma total iron binding capacity [15]. The present results suggest that genetic variations in the control of iron metabolism may be involved in the pathogenesis of PD by contributing to disturbances of iron metabolism in the brain.…”

Sex- and age-dependent association of SLC11A1polymorphisms with tuberculosis in Chinese: a case control study

“…This finding remains to be explained in biological terms. It is also interesting to note that, due to menstruation, females tend to have a lower body iron stores [59][60][61]. This might lead to a limited supply of iron ions in phagosomes for generating enough hydroxyl radical for bactericidal activity.…”

Effect modification by transferrin C2 polymorphism on lead exposure, hemoglobin levels, and IQ

“…Although partial changes in TF glycosylation do not affect its receptor binding, they may speed its degradation (van Rensburg et al, 2004; Hoefkens et al, 1997). Total iron-binding capacity in blood may be marginally lower in C2 homozygotes, although a significant difference was observed in only one study (Cleve et al, 1988; Sikström et al, 1993; Wong and Saha, 1986). In a subset of subjects in the OPTIMA study, TF saturation was higher in non-demented elderly with both HFE 282Y and TF C2, although neither variant alone had any effect (Lehmann et al, 2006).…”