Serum insulin-like growth factor (IGF)-II is more closely associated with liver dysfunction than is IGF-I in patients with cirrhosis

Insulin-Like Growth Factor 2 and Incidence of Liver Cancer in a Nested Case-Control Study

BACKGROUND

Insulin-like growth factor (IGF)2 is a potent mitogen. To elucidate the relationship between IGF2 and risk of tumorigenesis, we analyzed associations between serum levels of IGF2 and incidence of liver cancer in a prospective case-control study nested in the Japan Collaborative Cohort study.

METHODS

A baseline survey was conducted from 1988 using blood samples from 39,242 subjects. Those who had been diagnosed with liver cancer by 1997 were regarded as cases. For each case, we randomly selected two or three controls matched for sex, age, and residential area. Conditional logistic regression was used to estimate ORs for cancer incidence associated with IGF2.

RESULTS

This analysis included 86 cases and 294 controls. Low IGF2 was associated with risk of future liver cancer (P trend <0.001). After controlling for alcohol intake, body mass index, smoking, hepatitis viral infection, IGF1, and IGF-binding protein-3, participants with low IGF2 displayed a higher risk of liver cancer (P trend < 0.001). Individuals in quintiles 2 to 5 showed lower risk compared with quintile 1 (OR range, 0.05-0.16). In both sexes and in both nonelderly and elderly groups, subjects in the lowest quintiles showed higher risks of liver cancer. Limiting subjects to those followed for 3 years, low IGF2 was associated with cancer risk (P trend < 0.001).

CONCLUSIONS

Our findings suggest that low serum IGF2 level, especially below 460 ng/mL, is related to future risk of liver cancer.

IMPACT

Our findings highlight this important biomarker for further analysis in large prospective cohorts and pooled investigation with other cohorts.

Insulin-like growth factor-related components and the risk of liver cancer in a nested case-control study

Insulin-like growth factor-1 (IGF1) is a potent mitogen. IGF-binding protein-3 (IGFBP3) binds and inhibits IGF1. High circulating IGF1 levels and low IGFBP3 levels are associated with increased risk of several cancers. We examined relationships between serum levels of these factors and hepatoma risk in a case-control study nested in a prospective cohort study (the Japan Collaborative Cohort Study (JACC Study)). A baseline survey was conducted from 1988 to 1990, and 39,242 subjects donated blood samples. Participants diagnosed with hepatoma by 1997 were considered cases for nested case-control studies. Ninety-one cases and 263 sex- and age-matched controls were analyzed. A conditional logistic model was used to estimate odds ratios (ORs) for the incidence of hepatoma associated with serum IGF1 and IGFBP3 levels. Neither IGF1 nor the molar ratio of IGF1/IGFBP3 was correlated with hepatoma risk. After adjustment for hepatitis viral infection, body mass index, smoking, and alcohol intake, a higher molar difference of (IGFBP3 - IGF1) was associated with a decreased hepatoma risk more than IGFBP3 alone (p for trend <0.001 and = 0.003, respectively). People in the highest quartile had a lower risk (OR = 0.098; 95 % confidence interval = 0.026-0.368). In subgroup analyses of males and females, the molar difference was associated with a decreased hepatoma risk (p for trend <0.05). In non-elderly individuals, the difference was inversely correlated with the incidence of hepatoma (p for trend <0.01). The molar difference of (IGFBP3 - IGF1) may be inversely associated with the incidence of hepatoma.

Postoperative Insulin-Like Growth Factor 1 Levels Reflect the Graft's Function and Predict Survival after Liver Transplantation

BACKGROUND

The reduction of insulin-like growth factor 1 (IGF-1) plasma levels is associated with the degree of liver dysfunction and mortality in cirrhotic patients. However, little research is available on the recovery of the IGF-1 level and its prognostic role after liver transplantation (LT).

METHODS

From April 2010 to May 2011, 31 patients were prospectively enrolled (25/6 M/F; mean age±SEM: 55.2±1.4 years), and IGF-1 serum levels were assessed preoperatively and at 15, 30, 90, 180 and 365 days after transplantation. The influence of the donor and recipient characteristics (age, use of extended criteria donor grafts, D-MELD and incidence of early allograft dysfunction) on hormonal concentration was analyzed. The prognostic role of IGF-1 level on patient survival and its correlation with routine liver function tests were also investigated.

RESULTS

All patients showed low preoperative IGF-1 levels (mean±SEM: 29.5±2.1), and on postoperative day 15, a significant increase in the IGF-1 plasma level was observed (102.7±11.7 ng/ml; p<0.0001). During the first year after LT, the IGF-1 concentration remained significantly lower in recipients transplanted with older donors (>65 years) or extended criteria donor grafts. An inverse correlation between IGF-1 and bilirubin serum levels at day 15 (r = -0.3924, p = 0.0320) and 30 (r = -0.3894, p = 0.0368) was found. After multivariate analysis, early (within 15 days) IGF-1 normalization [Exp(b) = 3.913; p = 0.0484] was the only prognostic factor associated with an increased 3-year survival rate.

CONCLUSION

IGF-1 postoperative levels are correlated with the graft's quality and reflect liver function. Early IGF-1 recovery is associated with a higher 3-year survival rate after LT.

The GH-IGF-SST system in hepatocellular carcinoma: biological and molecular pathogenetic mechanisms and therapeutic targets

Hepatocellular carcinoma (HCC) is the sixth most common malignancy worldwide. Different signalling pathways have been identified to be implicated in the pathogenesis of HCC; among these, GH, IGF and somatostatin (SST) pathways have emerged as some of the major pathways implicated in the development of HCC. Physiologically, GH-IGF-SST system plays a crucial role in liver growth and development since GH induces IGF1 and IGF2 secretion and the expression of their receptors, involved in hepatocytes cell proliferation, differentiation and metabolism. On the other hand, somatostatin receptors (SSTRs) are exclusively present on the biliary tract. Importantly, the GH-IGF-SST system components have been indicated as regulators of hepatocarcinogenesis. Reduction of GH binding affinity to GH receptor, decreased serum IGF1 and increased serum IGF2 production, overexpression of IGF1 receptor, loss of function of IGF2 receptor and appearance of SSTRs are frequently observed in human HCC. In particular, recently, many studies have evaluated the correlation between increased levels of IGF1 receptors and liver diseases and the oncogenic role of IGF2 and its involvement in angiogenesis, migration and, consequently, in tumour progression. SST directly or indirectly influences tumour growth and development through the inhibition of cell proliferation and secretion and induction of apoptosis, even though SST role in hepatocarcinogenesis is still opened to argument. This review addresses the present evidences suggesting a role of the GH-IGF-SST system in the development and progression of HCC, and describes the therapeutic perspectives, based on the targeting of GH-IGF-SST system, which have been hypothesised and experimented in HCC.

IGF2 and cancer

Insulin-like growth factor 2 (IGF2) is a 7.5  kDa mitogenic peptide hormone expressed by liver and many other tissues. It is three times more abundant in serum than IGF1, but our understanding of its physiological and pathological roles has lagged behind that of IGF1. Expression of the IGF2 gene is strictly regulated. Over-expression occurs in many cancers and is associated with a poor prognosis. Elevated serum IGF2 is also associated with increased risk of developing various cancers including colorectal, breast, prostate and lung. There is established clinical utility for IGF2 measurement in the diagnosis of non-islet cell tumour hypoglycaemia, a condition characterised by a molar IGF2:IGF1 ratio >10. Recent advances in understanding of the pathophysiology of IGF2 in cancer have suggested much novel clinical utility for its measurement. Measurement of IGF2 in blood and genetic and epigenetic tests of the IGF2 gene may help assess cancer risk and prognosis. Further studies will determine whether these tests enter clinical practice. New therapeutic approaches are being developed to target IGF2 action. This review provides a clinical perspective on IGF2 and an update on recent research findings.

The insulin-like growth factor-1 and expression of its binding protein‑3 in chronic hepatitis C and hepatocellular carcinoma

The role of growth factors produced by the liver, including insulin-like growth factor-1 (IGF-1) and its main binding protein, IGF binding protein-3 (IGFBP-3), in hepatitis C virus (HCV)-associated carcinogenesis has only partially been recognized and there is not much data available on the local expression of IGF-1 and IGFBP-3 in chronic hepatitis C (CH‑C). Therefore, the aim of the present study was to evaluate the IGF‑1 and IGFBP‑3 serum levels and tissue expression in liver biopsies of CH‑C patients (n=37) and hepatocellular carcinoma (HCC) samples (n=61) as related to age- and gender-matched control serum samples (n=15) and healthy liver samples (n=10). Serum concentrations of IGF-1 (S-IGF-1) and IGFBP‑3 (S-IGFBP‑3) were measured by the ELISA method. Tissue expression of proteins was detected using ABC immunocytochemistry and evaluated applying a spatial visualization technique. Concentrations of S-IGF-1 and hepatic expression of IGF-1 (H-IGF-1) proved to be lower in CH-C compared to the controls. No significant differences were detected in the concentration of S-IGFBP-3 between the studied groups but the S-IGF-1/IGFBP-3 ratio in the CH-C group was significantly lower compared to the control. H-IGFBP-3 was higher in CH-C compared to those in the control and HCC. In HCC, lower expression of H-IGF-1 was detected compared to the control and a higher H-IGF-1/IGFBP-3 ratio compared to CH-C. A negative correlation was detected between S-IGF-1 and S-IGF-1/IGFBP-3 ratio, on the one hand, and age, grading and concentration of α-fetoprotein (AFP) on the other, while H-IGFBP-3 was negatively correlated with BMI in the CH‑C group. In patients with CH‑C, the H‑IGF‑1/IGFBP‑3 ratio was higher compared to that of the S‑IGF‑1/IGFBP‑3 ratio. The studies documented a disturbed H‑IGF‑1 and H‑IGFBP‑3 in CH‑C, which may be of significance in carcinogenesis. Examination of serum concentration and tissue expression of the two proteins and, first of all, estimation of the IGF‑1/IGFBP‑3 ratio may provide additional (to the estimation of IGF‑1 and AFP) non-invasive markers in HCV‑related liver injury.

The insulin-like growth factor (IGF) signaling axis and hepatitis C virus-associated carcinogenesis (review)

Insulin-like growth factor (IGF) signaling plays an important autocrine, paracrine and endocrine role in growth promotion involving various tissues and organs. Synthesis of both IGFs (IGF-1 and IGF-2) in normal conditions takes place mainly in the liver even if the proteins can be produced in every cell of the human body. The alterations in the IGF signaling axis in human hepatocarcinogenesis are described, but mechanisms of the interactions between expression of oncogenic hepatitis C virus (HCV) proteins and components of the IGF system in progression of chronic hepatitis C to primary hepatocellular carcinoma (HCC) have been poorly recognised. In advanced stages of liver diseases, lowered serum levels of IGF-1 and IGF-2 have been documented. This was supposed to reflect significant damage to liver parenchyma, a decreased number of growth hormone receptors and a decreased genomic expression of IGF binding proteins (IGF BPs). In HCC, a decreased tissue expression of IGF-1, and an increased expression of IGF-1 receptor (IGF-1R) were noted, compared to the control. Potential mechanisms of augmented IGF-2 expression in HCC were also described and dysregulation of IGF signaling in HCC was concluded to occur predominantly at the level of IGF-2 bioavailability. The review aimed at presentation of involvement of IGF-1, IGF-1R and IGF BPs (mostly IGF BP-3 and IGF BP-6) in HCV-related hepatocarcinogenesis. Manifestation of various mRNA transcripts and IGF-1 proteins and their potential involvement in carcinogenesis are also discussed.

Alterations of insulin-like growth factor I (IGF-I) and estradiol serum levels in chronic hepatitis C

Aim of the study

Deregulation of insulin-like growth factor I (IGF-I) production and decreased hepatic estrogen levels were associated with development of hepatocellular carcinoma (HCC) in hepatitis C virus (HCV) infected cirrhotic patients. The aim of our study was to determine serum levels of IGF-I, insulin and 17-β estradiol (17-βE) in relation to other markers of liver injury in chronic hepatitis C (CHC) patients.

Material and methods

Thirty anti-viral treatment-naïve CHC patients and 10 healthy subjects were examined. HCV infection was confirmed by presence of anti-HCV and HCV-RNA in serum. Serum levels of IGF-I, insulin and of 17-βE were evaluated using ELISA methods.

Results

Serum levels of IGF-I and 17-βE were significantly lower in CHC patients than in controls while insulin levels were similar in both groups. A lower IGF-I level (but not the level of 17-βE) was observed in cirrhotic CHC patients in comparison to non-cirrhotic ones. Decreased serum level of IGF-I was associated with more advanced staging and liver steatosis, higher levels of alpha-fetoprotein (AFP) and gamma globulin levels, and higher aspartate transaminase (AST) activity in CHC patients. Insulin and 17-βE levels positively correlated with patient's age. A positive correlation was observed between insulin level on one hand and staging, liver steatosis and levels of gamma globulins in CHC patients on the other. A negative correlation between IGF-I and insulin levels was noted only in HCV infected patients.

Conclusions

Decreased IGF-I levels and increased levels of insulin better than estradiol serum levels characterize staging and liver steatosis in CHC patients. The lower serum level of 17-βE in the CHC group than in control patients suggests that CHC patients carry higher risk of liver injury and of HCC development.

Serum insulinlike growth factor-1 and its binding protein-3 levels in children with cirrhosis waiting for a liver transplant

OBJECTIVES

Investigate the prognostic value of serum insulinlike growth factor-1 (IGF-1) and its binding protein 3 (IGFBP-3) in pediatric patients with liver cirrhosis, and investigate the correlation between these parameters and other available prognostic factors including Child-Pugh scoring, Pediatric End-Stage Liver Disease, and Mayo End-Stage Liver Disease scoring.

MATERIALS AND METHODS

This prospective, case-controlled study was done at the Nemazee hospital for 12 months from August 2009 to August 2010. It included 45 pediatric patients (< 18 years) diagnosed with liver cirrhosis and 38 healthy age and sex-matched controls. The extent and severity of the liver disease was evaluated by the Child-Pugh classification and Pediatric End-Stage Liver Disease/Mayo End-Stage Liver Disease scores. Serum levels of IGF-1 and IGFBP-3 were determined and were compared to controls and their correlation with Child-Pugh and Pediatric End-Stage Liver Disease/Mayo End-Stage Liver Disease scores were investigated.

RESULTS

The most-common cause of liver cirrhosis was biliary atresia being found in 11 patients (24.4%) followed by tyrosinemia in 8 (17.8%). IGF-1 serum levels were significantly lower in cirrhotic patients compared with controls (3.85 ± 3.69 nmol/L vs 41.79 ± 16.03 nmol/L; P < .001). Serum levels of IGFBP-3 also were significantly lower in patients with liver cirrhosis compared with healthy controls (46.66 ± 30.57 nmol/L vs 205.63 ± 25.52 nmol/L; P < .001). Serum levels of IGF-1 were significantly lower in patients with stage B (P = .047) and C (P = .036) of Child-Pugh classification compared with stage A. Serum levels of IGF-1 (r ≈ 0.227; P = .034) and IGFBP-3 (r ≈ 0.389; P = .008) were negatively correlated with Pediatric End-stage Liver Disease / Mayo End-stage Liver Disease scores.

CONCLUSIONS

The serum levels of IGF-1 and IGFBP-3 are decreased in children with liver cirrhosis. The stage of liver dysfunction is correlated to serum levels of IGF-1 and IGFBP-3 in children. Thus, these 2 factors can be used for assessing the prognosis and outcome in those children with liver cirrhosis.

Relation of serum insulin-like growth factor-1 (IGF-1) levels with hepatitis C virus infection and insulin resistance

The prospect of the growing worldwide epidemic of hepatitis C virus (HCV) infection and type 2 diabetes mellitus certainly merits attention toward their controversial relationship. Insulin-like growth factor-1 (IGF-1) plays an important role in glucose homeostasis. This study is a cross-sectional study considered as an initial investigation aimed to evaluate the effect of HCV infection on serum IGF-1, as well as to find out whether IGF-1 has a role in development of insulin resistance (IR) in HCV infection. A total of 45 subjects divided into 3 groups were included in the study: chronic HCV-infected patients (15 patients), chronic HCV-infected diabetic patients (15 patients), and diabetic patients without HCV infection (15 patients), along with 15 healthy controls. HCV RNA was quantified using real-time polymerase chain reaction (PCR). Serum IGF-1 levels were measured by enzyme-linked immunosorbent assay (ELISA). Homeostasis model assessment of insulin resistance [HOMA-IR], insulin sensitivity [HOMA-S], and β-cell function [HOMA-β] were determined by previously validated mathematic indexes. Fasting blood glucose, insulin levels, and liver parameters including alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were determined. IGF-1 levels were significantly lower in the 3 patient groups compared with controls (P = 0.001). The HCV group demonstrated high HOMA-IR and HOMA-β with a positive correlation between HOMA-IR and either HOMA-β or fasting insulin (P < 0.001). In addition, a negative correlation was found between IGF-1 levels and both AST and ALT, and HOMA-IR was correlated positively with AST activity (P < 0.05). In HCV patients with detectable viremia, IGF-1 levels were correlated negatively with HOMA-β (P < 0.01) and with HOMA-IR. However, this correlation did not reach statistical significance (P = 0.074). No significant correlation was found between HCV viral load and the studied parameters. In conclusion, low IGF-I levels might have a role in IR among HCV viremic patients.

Insulin-like growth factor II in hepatocellular carcinoma

Hepatocellular carcinoma is one of the most common malignant human tumors. Hepatocarcinogenesis is a multistep process with a multifactorial etiology. Chronic hepatitis B and hepatitis C virus infection, alcohol drinking and cirrhosis of any etiology are the major risk factors for hepatocellular carcinoma. Growth factors, their receptors and related proteins are involved in the process of malignant transformation. The IGF axis is involved in the proliferation and differentiation of normal, transformed and malignant hepatocytes. In the context of hepatocarcinogenesis, IGF-II has, in particular, been investigated thoroughly. Increased IGF-II bioavailability, protease activity of IGF-binding proteins and IGF-I receptor expression, decreased expression of IGF-II receptor and IGF-binding proteins are thought to contribute to hepatocellular carcinoma genesis. This review will first focus on the role of the IGF axis in hepatocarcinogenesis. In the second part it will emphasize circulating IGF-II levels in chronic liver disease and hepatocellular carcinoma, and diagnostic application of serum IGF-II level in both small and larger hepatocellular carcinoma.

Association of Elevated IGFBP-1 with Increased IGF-II Concentration in Patients with Carcinoma of the Liver

Insulin-like growth factors (IGFs) are mitogens for numerous types of cells including cancer cells. The aim of this work was to analyze some of the components of the IGF system to assess which could be potential clinical biomarkers for monitoring patients diagnosed with liver cancer. Compared to healthy persons, patients with liver cancer had a lower concentration of IGF-I and a higher concentration of IGFBP-1, whereas the concentrations of IGF-II and IGFBP-3 remained unchanged. The IGF-I:IGFBP-3 ratio decreased in patients with cancer, while the IGF-II:IGFBP-1 ratio was not altered. Patients with primary carcinoma and those scheduled for surgery had lower IGF-I and higher IGF-II and IGFBP-1 concentrations than patients with secondary carcinoma and those not eligible for surgery. It may be postulated that a liver with primary cancer is induced to increase IGF-II and IGFBP-1 synthesis more than a liver involved in metastatic response. Similarly, in patients eligible for liver surgery an increase in IGF-II may reflect a gradual change in the concentration associated with a different stage of disease. As increased synthesis of certain IGFBPs is necessary to compensate decreased production of the others or increased IGF production, determination of serum IGF-II, IGFBP-1 and their ratio may aid in estimating the compensatory capacity of the liver affected by cancer.

Hepatitis-C patients have reduced growth hormone (GH) secretion which improves during long-term therapy with pegylated interferon-alpha

OBJECTIVES

In vitro and in vivo data indicate multiple, but contradictory effects of interferon on pituitary hormone secretion. We therefore investigated prospectively basal and stimulated pituitary hormone secretion in 21 patients with chronic hepatitis C virus (HCV) infection before and during antiviral therapy.

METHODS

Twenty-one patients received pegylated interferon-alpha plus either ribavirin or levovirin. Baseline and stimulated growth hormone (GH), cortisol, luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin (PRL), and thyroid-stimulating hormone (TSH) responses were measured using standard pituitary function tests, before therapy in all and during therapy in 17 out of the 21 patients.

RESULTS

Before therapy 17 patients (81%) had severe GH insufficiency and 9 of these had low insulin-like growth factor-1 (IGF-1) concentrations. Basal and stimulated GH concentrations increased significantly during therapy, reducing the number of patients with severe GH insufficiency to four, but IGF-1 remained low. Basal PRL and TSH concentrations were normal before and during therapy, while thyroid-releasing hormone (TRH)-stimulated concentrations increased significantly during therapy. The adrenocorticotropic hormone (ACTH)/cortisol axis, basal and stimulated gonadotropin, and testosterone concentrations were normal throughout. Neither the HCV RNA level nor transaminases correlated with hormone concentrations before or during therapy.

CONCLUSIONS

GH insufficiency is common in patients with chronic HCV infection. While GH secretion improves during antiviral therapy, IGF-1 remains low, indicating persistent GH resistance of hepatocytes. Whether improvement in GH secretion during treatment is due to a direct drug effect or related to the suppression of viral load could not be differentiated, as most patients demonstrated a positive virologic response.

Differential influence of open surgery and sepsis on the circulating insulin-like growth factors and their binding proteins as representative metabolic markers

OBJECTIVES

In critical illnesses and stress conditions many endocrine systems are disturbed. In the current study we determined the influence of open surgery, post-operative sepsis and its early therapy on the components of the insulin-like growth factor (IGF) system in patients with malignant gastric or pancreatic tumors.

DESIGN AND METHODS

Twenty-one patients and eighty-one age- and sex-matched healthy subjects were included in this study. IGF-I, IGF-II, IGF binding proteins (IGFBPs), cortisol, insulin and protein concentrations (total, albumin and IgG) were determined pre-operatively, post-operatively, when sepsis was diagnosed and 48 h after initiating therapy.

RESULTS

The concentrations of circulating IGF-I, IGF-II and IGFBP-3 were significantly lower in pre-operative patients compared to healthy subjects. Sepsis caused a further decrease in IGF-I and IGFBP-3 but an increase in IGFBP-1, IGFBP-2 and IGFBP-4 resulting in a redistribution of IGF molecules from ternary to binary complexes.

CONCLUSIONS

The presence of malignant gastric or pancreatic tumors followed by post-operative sepsis caused a serious misbalance in components of the IGF system which failed to recover during the time of our longitudinal study.

Body composition, muscle function, and energy expenditure in patients with liver cirrhosis: a comprehensive study

BACKGROUND

Data describing the nutritional status of patients with liver cirrhosis of diverse origin, as assessed by direct body-composition methods, are limited.

OBJECTIVE

We sought to provide a comprehensive assessment of nutritional status and metabolic activity in patients with liver cirrhosis by using the most accurate direct methods available.

DESIGN

Two hundred sixty-eight patients (179 M, 89 F; x +/- SEM age: 50.1 +/- 0.6 y) with liver cirrhosis underwent measurements of total body protein by neutron activation analysis, of total body fat and bone mineral by dual-energy X-ray absorptiometry, of resting energy expenditure by indirect calorimetry, of grip strength by dynamometry, and of respiratory muscle strength by using a pressure transducer. Dietary intakes of energy and protein were assessed and indexed to resting energy expenditure and energy intake, respectively.

RESULTS

Significant protein depletion, seen in 51% of patients, was significantly (P<0.0001) more prevalent in men (63%) than in women (28%). This sex difference occurred irrespective of disease severity or origin. The prevalence of protein depletion increased significantly (P<0.0001) with disease severity. Protein depletion was associated with decreased muscle function but not with lower energy and protein intake. Energy intake was significantly (P=0.002) higher in men than in women, whereas protein intakes did not differ significantly (P=0.12). Hypermetabolism, seen in 15% of patients, was not associated with sex, origin or severity of disease, protein depletion, ascites, or presence of tumor.

CONCLUSIONS

Poor nutritional status with protein depletion and reduced muscle function was a common finding, particularly in men, and was not related to the presence of hypermetabolism or reduced energy and protein intakes. The greater conservation of protein stores in women than in men warrants further investigation.

Possible contribution of serum activin A and IGF-1 in the development of hepatocellular carcinoma in Egyptian patients suffering from combined hepatitis C virus infection and hepatic schistosomiasis

OBJECTIVES

The present study evaluated the role of activin A, insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein 3 (IGFBP-3) in Egyptian patients suffering from combined hepatitis C virus (HCV) infection and hepatic schistosomiasis.

DESIGN AND METHODS

Four groups were included in the present study. Group I: 30 healthy subjects were included as controls; Group II (HCV): 30 patients with chronic liver disease due to HCV infection without evidence of schistosomiasis; Group III (SHF + HCV): 30 patients with combined disease, chronic schistosomal hepatic fibrosis (SHF) and chronic hepatitis C infection; Group IV (HCC): 30 patients with hepatocellular carcinoma associated with chronic hepatitis C virus and schistosomal infection.

RESULTS

Patients with HCV, HCV + SHF and those with HCC had a significantly higher serum activin A compared with the control group (P < 0.001). Serum activin A level (mean +/- SD) was 5.7 +/- 2.76, 10.59 +/- 3.59, 15.39 +/- 4.61 and 19.93 +/- 5.43 ng/mL in controls, HCV patients, HCV + SHF patients and HCC patients, respectively. Serum IGF-1 was significantly lower in HCV patients, HCV + SHF patients and HCC patients compared to the control group (P < 0.001). Serum IGF-1 was 121.7 +/- 73.4, 76.7 +/- 23.5, 35.7 +/- 17.6 and 39.9 +/- 25.9 ng/mL in controls, HCV patients, HCV + SHF patients and HCC patients, respectively. Similarly, serum IGFBP-3 was significantly lower in HCV patients, HCV + SHF patients and HCC patients compared to the control group (P < 0.001). Furthermore, serum insulin-like growth factor binding protein 3 (IGFBP-3) was significantly lower in patients with HCC compared to patients with HCV or those with HCV + SHF (P < 0.01 and P = 0.024, respectively). The median (range) of serum IGFBP-3 was 4452 (352.2-8965), 3457 (1114-6000), 2114 (867-5901) and 1202 (576-3994) ng/mL in controls, HCV patients, HCV + SHF patients and HCC patients, respectively. Serum activin A correlated positively with Child-Pugh scoring in patients with HCV, HCV + SHF and those with HCC. The correlation coefficient was significant, at 0.001, in total cases.

CONCLUSIONS

We conclude that patients with HCV, HCV + SHF and those with HCC have a significantly higher serum activin A when compared with controls. Serum activin A level was significantly higher in patients with HCV + SHF compared to those with HCV alone (P < 0.01) with a significant positive correlation between the serum activin A level and Child-Pugh scoring in patients with HCV, HCV + SHF and those with HCC. Furthermore, serum IGF-1 and IGFBP-3 levels were significantly reduced in patients with HCV, HCV + SHF and those with HCC compared to the control group. We suggest that this pattern (high activin A and low IGF-1 and its binding protein 3) may play a role in development of HCC in Egyptian patients suffering from combined hepatitis C virus infection and hepatic schistosomiasis.

Caffeic acid phenethyl ester ameliorates changes in IGFs secretion and gene expression in streptozotocin-induced diabetic rats

The protective effect of caffeic acid phenethyl ester (CAPE) against diabetes-induced alteration of IGFs protein and gene expression was investigated in serum, liver, heart, and kidney. In the present study, diabetic rats exhibited the decrease of IGF-I content in serum, liver and heart but the increase of that in kidney and CAPE blocked them. Diabetic rats also manifested the increase of IGF-II content in serum, liver, heart, and kidney and CAPE prevented them. CAPE prevented the diabetes-induced decrease of liver IGF-I mRNA and IGF-II mRNA, which is similar to pattern of IGFs mRNA in kidney. Moreover, diabetic rats exhibited the decrease of heart IGF-I mRNA but the increase of IGF-II mRNA and CAPE blocked them. In conclusion, CAPE, in part, prevented diabetes-induced alteration of IGF-I and IGF-II protein and gene expression in liver, heart, and kidney in rats.

Clinical significance of serum IGF-I, IGF-II and IGFBP-3 in liver cirrhosis

AIM: To investigate the relationship between insulin-like growth factor-I, -II (IGF-I and IGF-II), IGF-binding protein 3 (IGFBP-3) and Child-Pugh score in patients with liver cirrhosis, and to search for potential clinical markers of liver function.

METHODS: Forty-four patients with advanced liver cirrhosis of viral origin were divided into 3 groups according to severity of cirrhosis (Child-Pugh score) and 38 healthy subjects served as controls. Serum levels of IGF-I, IGF-II and IGFBP-3 were measured by immunoradiometric assay.

RESULTS: Serum IGF-I, IGF-II and IGFBP-3 levels were significantly lower in patients with cirrhosis than in controls, and serum concentrations of IGF-I, IGF-II and IGFBP-3 were associated with the severity of liver dysfunction, and dropped sharply during the progression of liver failure. Among these 3 parameters, serum IGF-II was the most sensitive and effective indicator for liver dysfunction. Concentrations of IGF-I < 30 ng/mL, IGF-II < 200 ng/mL and IGFBP-3 < 6 ng/mL implied a negative prognosis for patients with liver cirrhosis.

CONCLUSION: Serum IGF-I, IGF-II and IGFBP-3 may provide a new dimension in the assessment of liver dysfunction. Combined detection of serum IGF-I, IGF-II and IGFBP-3 with Child-Pugh score is more effective in predicting prognosis than Child-Pugh score alone.

Insulin-like growth factors in patients with liver cysts

Insulin-like growth factors (IGFs) play an important role in cell growth and differentiation, and the liver is the main source of IGFs and IGF-binding proteins (IGFBPs) that appear in the circulation. The effect of liver cysts on the circulating IGF system was studied in this work. Serum concentrations of IGF-I and -II were measured by radioimmunoassay, IGFBP patterns were characterised by ligand-affinity and immunoblotting, and a lectin-binding assay was used to investigate the glyco component of IGFBP-3 complexes. IGF-I and -II concentrations in patients with cysts were significantly lower compared to those in healthy individuals (P<0.0001 and P<0.01, respectively), and the decrease was related to age but not sex. The overall mean concentrations of IGF-I and -II were not significantly different whether the cysts were caused by Echinococcus granulosus, cross-reactive pathologies, or some other factor. IGFBP profiles correlated with the amount of IGF present: patients with lower IGF-I concentrations expressed decreased IGFBP-3 and elevated IGFBP-2 levels. Increased IGFBP-3 proteolytic activity in the patients' blood was not detected by immunoblotting. In the lectin-binding assay, IGFBP-3 complexes in the circulation of patients demonstrated reactivity similar to that in healthy persons, suggesting that the overall structure of the saccharide moieties of the IGFBP-3 complexes was not significantly altered due to liver cyst formation.

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.

Ghrelin in chronic liver disease

BACKGROUND/AIMS

Ghrelin is a novel endogenous ligand for the growth hormone (GH) secretagogue receptor involved in energy metabolism, glucose homeostasis and food intake. We investigated the role of ghrelin and insulin-like growth factor-1 (IGF-1), the mediator of the GH axis, in patients with chronic liver diseases (CLD).

METHODS

Ghrelin and IGF-1 serum levels were determined in 105 CLD patients and 97 healthy controls and correlated with clinical and biochemical parameters.

RESULTS

Ghrelin was significantly elevated and IGF-1 reduced in CLD patients compared with healthy controls. IGF-1 serum levels inversely correlated with Child's classification. Ghrelin levels were significantly elevated in Child C cirrhosis patients independent of the aetiology of liver disease. Ghrelin levels did not correlate with liver function. In contrast, there was a correlation of ghrelin with clinical (gastrointestinal bleeding, ascites, encephalopathy) and biochemical (anaemia, inflammatory markers, hypoglycaemia, renal dysfunction) parameters. In a subgroup of patients with CLD and hepatocellular carcinoma (HCC), we observed a strong inverse correlation between alpha-fetoprotein (AFP) and ghrelin levels.

CONCLUSIONS

Unlike IGF-1, ghrelin is not correlated with liver function, but increases in Child C cirrhosis and with complications of CLD. The inverse correlation with AFP in HCC patients requires further studies on the potential impact of ghrelin on the pathogenesis of anorexia-cachexia syndrome.

Reactivity of IGF binding protein-3 isoforms towards concanavalin A in healthy adults and subjects with cirrhosis

The capacity of the liver to synthesize insulin-like growth factors (IGFs) and their binding proteins (IGFBPs) may be compromised by alcohol. The characteristics of IGFBP-3 variants obtained from healthy individuals and patients with alcoholic cirrhosis (ALC) were compared. Concanavalin A (Con A) affinity electrophoresis and ligand blotting demonstrated that there was a gradual change in carbohydrate properties of putative IGFBP-3 with progression of ALC from stages A to C. As many as 12 ionic species of IGFBP-3 could be distinguished, corresponding probably to variously glycosylated and/or phosphorylated isoforms of the core protein. Three of them reacted significantly with the immobilized Con A, the pattern being altered in patients with ALC. Patients with ALC in stage B exhibited the presence of clearly differentiated IGFBP-3 variants less and more Con A reactive, suggesting this stage to be a turning point with the most intensive changes in the IGF - IGFBP system. Because the glycosylation pattern is tissue specific, pathological post-translational modifications found for one glycoprotein (IGFBP-3) are probably shared by others of the same tissue origin. This may affect their susceptibility to proteolysis and subsequently their function.

GH/IGF system, cirrhosis and liver transplantation

The GH-related effects are primarily mediated by insulin-like growth factor I (IGF-I), a peptide hormone almost completely produced by the liver. Liver cirrhosis is usually accompanied by a fall in protein turnover. Furthermore, an important consequence of chronic liver disease (CLD) is growth hormone/insulin-like growth factor (GH/IGF) axis modification and growth failure. Nutritional status also suffers in this condition, and IGF-I has been proposed as a marker of hepatocellular dysfunction, malnutrition and survival. CLD is characterised by alterations of various clinical biochemistry laboratory parameters. Aminotransferases, bilirubin, plasma proteins, together with prothrombin time and gamma globulins, are usually examined for laboratory diagnostic and/or monitoring purposes. These traditional parameters are also used in the perioperative liver transplantation, but an early signal of graft functioning has still not been established. The aim of the present work is a review of the possibility offered by the clinical biochemistry laboratory GH/IGF investigation in the outcome of liver transplantation.

Alterations of IGF-binding proteins in patients with alcoholic liver cirrhosis

The protein synthetic activity of the liver is diminished in cirrhosis. The aim of this study was to investigate possible changes in the serum IGF-IGFBP system among patients with alcoholic liver cirrhosis (ALC). The results obtained demonstrated that serum IGF-I and IGF-II concentrations were significantly lower in patients with ALC than in healthy persons (P=0.0008 for IGF-I and 0.0002 for IGF-II). The IGFBP profile was markedly altered and the 34 kDa IGFBP from patients had higher affinity towards 125I-IGF-II compared to the 34 kDa IGFBP of control individuals. Moreover, the 40-45 kDa IGFBP (in isolated complex with 125I-IGF-II) exhibited diminished interaction with concanavalin A, wheat germ, and breadfruit lectins. Modification of the glyco-component of the 40-45 kDa IGFBP seems to be an early event in ALC since change in reactivity towards lectins was noticed in patients with ALC classified as Child score A, whose serum IGF-I and IGF-II levels were within reference limits (the existence of carbohydrate microheterogeneity of this IGFBP was also assessed by lectin-affinity electrophoresis). It is possible that these biochemical alterations may affect the functional activity of the IGFs by changing the dynamics and distribution of these growth factors in the organism.