Plasma thrombospondin 1 as a predictor of postoperative liver dysfunction.

BACKGROUND: Liver regeneration following liver resection involves a complex interplay of growth factors and their antagonists. Thrombospondin 1 has recently been identified as a critical inhibitor of liver regeneration by the activation of transforming growth factor ß1 in mice, and preliminary data seem to confirm its relevance in humans. This study aimed to confirm these observations in an independent validation cohort. METHODS: Perioperative circulating levels of thrombospondin 1 were measured in patients undergoing liver resection between January 2012 and September 2013. Postoperative liver dysfunction was defined according to the International Study Group of Liver Surgery and classification of morbidity was based on the criteria by Dindo et al. RESULTS: In 85 patients (44 major and 41 minor liver resections), plasma levels of thrombospondin 1 increased 1 day after liver resection (mean 51·6 ng/ml before surgery and 68·3 ng/ml on postoperative day 1; P = 0·001). Circulating thrombospondin 1 concentration on the first postoperative day specifically predicted liver dysfunction (area under the receiver operating characteristic (ROC) curve 0·818, P = 0·003) and was confirmed as a significant predictor in multivariable analysis (Exp(B) 1·020, 95 per cent c.i. 1·005 to 1·035; P = 0·009). Patients with a high thrombospondin 1 concentration (over 80 ng/ml) on postoperative day 1 more frequently had postoperative liver dysfunction than those with a lower level (28 versus 2 per cent) and severe morbidity (44 versus 15 per cent), and their length of hospital stay was more than doubled (19·7 versus 9·9 days). CONCLUSION: Thrombospondin 1 may prove a helpful clinical marker to predict postoperative liver dysfunction as early as postoperative day 1.

Serum levels of insulin-like growth factor binding proteins in Ecuadorean children with growth hormone insensitivity.

Although insulin-like growth factor binding proteins (IGFBPs) are known to be important modulators of the action of insulin-like growth factors (IGFs), regulation of their production in vivo is not completely understood. Serum concentrations of IGFBP-3, -4 and -5 and acid-labile subunit (ALS) were therefore examined in 20 children with growth hormone (GH) insensitivity before and after 6 months of therapy with recombinant human IGF-I (80 or 120 micrograms/kg twice daily). The IGFBP concentrations in these children were compared with those in 62 GH-deficient children receiving GH therapy for 3 months. Serum levels of IGFBP-3, -4 and -5 and ALS all increased significantly (p < 0.0001) in GH-deficient children in response to GH therapy, whereas no significant increases occurred in the children with GH insensitivity. These findings indicate that GH is responsible for the regulation of serum levels of IGFBP-3, -4 and -5 and ALS, and that IGF-I does not directly regulate the concentrations of these circulating IGFBPs.