Insulin-like growth factors and their binding proteins in the circulation of patients with echinococcosis, trichinellosis and toxoplasmosis.

BACKGROUND

Insulin-like growth factors (IGFs) are polypeptide hormones that play anabolic roles in cellular growth and metabolism. Their activity is regulated by binding proteins (IGFBPs) and degradation mechanisms. The liver is regarded as the main source of circulating forms and the levels change in various disease states. The aim of the study was to explore the effects of parasitic infections on the circulating IGFs and IGFBPs.

METHODS

Peptide concentrations in sera of patients with echinococcosis, trichinellosis and toxoplasmosis were measured by radioimmunoassay, while IGFBP patterns were characterised by ligand-affinity blotting and gel chromatography.

RESULTS

IGF-I levels were reduced in trichinellosis (p=0.016), with the increased relative amounts of IGFBP-1, -2 and -4. The significantly reduced levels of IGF-I (p<0.001), IGF-II (p=0.017) and IGFBP-3 and the increased presence of IGFBP-2 were found in patients with echinococcosis.

CONCLUSIONS

In subjects with trichinellosis probably the combined effects of inadequate nutrition and the immunological response occurred. A possible explanation for the changes found in patients with echinococcosis is that the liver is a frequent target organ for Echinococcus granulosus. Since liver cysts were present in these patients, it can be expected that hepatic injury may affect liver metabolism leading to altered IGF/IGFBP profiles.