Endocrine Abstracts

Background: HIV-infected paediatric patients usually show impaired growth. Data reporting abnormalities in GH–IGF–IGFBPs system are scarce and inconclusive.

Aim: To analyse blood concentration of the major components of IGF–IGFBPs system in these children and compare them to growth parameters and to cytokines levels.

Methods: prepubertal HIV-infected children, aged 8.2±1.7 years, were evaluated every 6 months during 1 year when anthropometric data and blood samples were collected for IGFs, IGFBPs, cytokines and viral load (VL) determinations. Thirty healthy prepurbetal children were studied as controls. IGF1, IGF2, IGFBP3 and IGFBP1 were determined by ELISA and IGFBP2 and IGFBP4 by western-ligand blotting (WLB). Interleukin 6 (IL6) and tumoral necrosis factor α (TNFα) were determined by Luminex. We defined VL <5.000 and VL >5.000 copies/ml as good (GC) and poor (PC) disease control respectively.

Results: BMI in HIV-infected children was similar to controls. Height was lower in HIV-children than in controls (P<0.001). Serum IGF1, IGF2 and IGFBP3 were similar in PC and in GC but lower than in controls. IGFBP1 and IGFBP4 levels were similar among PC, GC and controls. IGFBP2 levels were higher in PC than in GC. IL6 and TNFa concentrations were similar in PC and in GC but higher than in controls, indicating a permanent chronic inflammatory process in HIV-infected children. No significant correlation was observed between IL6 or TNFα and IGF1, IGF2 or IGFBP3. However, IGFBP1 levels were significantly lower (<58 ng/ml) in samples with TNFα >24 pg/ml (P=0.0006) or IL6 >3.8 pg/ml (P=0.05).

Conclusion: HIV-children present poor growth comparatively to healthy children. The poor growth may be explained by alterations in IGF-IGFBPs system that reduces IGF bioavailability/activity during good or poor disease control. The permanent and chronic inflammatory process may contribute to IGF–IGFBPs alterations.