Endocrine Abstracts

Insulin-like growth factors (IGFs) and their binding proteins (IGFBPs) have important metabolic roles in the human body. IGFBP-3 (40 and 45 kD glycoforms) is the most abundant in serum, whereas IGFBP-2 (34 kD) and IGFBP-1 (29 kD) are present at lower concentrations.

Most inflammatory diseases of the gastrointestinal tract are characterised by a cytokine- mediated inflammatory reaction, malnutrition and catabolism. The aim of this work was to detect possible changes in the circulating IGF/IGFBP system in patients with gastrointestinal inflammations of various etiology: Crohn's disease (n=17), colitis ulcerosa (n=16), gastritis (n=13), duodenitis errosiva (n=2), gastrointestinal candidiasis (n=2), rotaviral enteritis (n=19), adenoviral infection (n=21) and inflammations of unknown cause (n=2). Most patients in the first four groups were positive when tested for Helicobacter pylori.

Serum concentrations of IGF-I and IGF-II were determined by radioimmunoassay. IGFBPs were analysed by ligand-affinity blotting and immunoblotting using anti-IGFBP-3 or anti-IGFBP-2 antibodies.

Serum levels of IGF-I and IGF-II in patients were significantly lower than in healthy people (p< 0.05). The IGFBP pattern, detected by ligand-affinity blotting, in most cases demonstrated decreased IGFBP-3 and increased IGFBP-2. IGFBP-1 and IGFBP-4 were increased in some patients. Immunoblotting with the anti-IGFBP-3 antibody confirmed a reduced amount of intact IGFBP-3 in sera from the majority of the patients together with an increased presence of immunoreactive IGFBP-3 fragments (30, 20 and 15 kD in size). Immunoblotting with an anti-IGFBP-2 antibody indicated increased amounts of both native IGFBP-2 and a fragment (20 kD in size) in most patients' sera.

The results indicate that patients with inflammatory gastrointestinal disease exhibit a serious disbalance in their circulating IGF system. These observed alterations may help in the understanding of the metabolic consequences of the inflammation and perhaps in predicting the efficiency of recovery.