Changes and relationships of IGFS and IGFBPS and cytokines in coeliac disease at diagnosis and on gluten-free diet.

OBJECTIVE: To evaluate changes and relationships of IGFs and IGFBPs, serum interleukin 6 (IL-6) and tumour necrosis factor (TNF)-alpha, and auxological parameters at diagnosis of coeliac disease (CD) and at 6 months and 12 months after starting a gluten-free diet (GFD), compared with a control population.

PATIENTS: Twenty patients were enrolled at diagnosis (9 male, 11 female; age 9.6 +/- 0.8 years). A healthy population of 18 subjects (5 male, 13 female; age 11.3 +/- 0.6 years) comparable for age, sex and pubertal status served as controls at baseline.

MEASUREMENTS: Blood samples were taken at diagnosis, and at 6 months and 12 months after starting the GFD. Serum IGF-I, IGF-II, IGFBP-1, IGFBP-2, IGFBP-3, IL-6 and TNF-alpha were measured using commercial kits. Height (Ht) standard deviation score (SDS), body mass index (BMI) SDS and Ht velocity SDS were evaluated at diagnosis and at 6 months and 12 months after starting GFD.

RESULTS: In CD patients, both Ht SDS and BMI SDS increased during the first year of treatment, and Ht velocity SDS increased during the second 6 months of follow-up (P < 0.05). At diagnosis, IGF-I, IGF-II and IGFBP-3 were lower compared with controls, IGFBP-1 was similar, IGFBP-2, IL-6 and TNF-alpha were higher (P < 0.05). When on GFD, all peptides normalized and IGFBP-1 decreased. The IGF-I/IGFBP-2 and IGF-I/IGFBP-3 molar ratios were significantly reduced at diagnosis compared with those of controls, but were increased for both groups when on GFD. Although there was no apparent abnormality at diagnosis, the IGF-II/IGFBP-2 molar ratio increased significantly on GFD. Ht velocity SDS was positively correlated with IGFBP-3 (P < 0.05) and with the IGF-I/IGFBP-2 molar ratio (P < 0.05). Serum IL-6 was negatively correlated with IGF-I and positively with IGFBP-1 (P < 0.05).

CONCLUSIONS: The data obtained from this study confirm changes in the IGF and cytokine systems at diagnosis of CD which tend to normalize on the gluten-free diet. The two systems show relationships with each other and with linear growth.