Congreso Americano 2013-2

Study of hepatic leptin and insulin signaling during non-alcoholic fatty liver disease (NAFLD) progression in morbid obesity



NAFLD is considered the hepatic exponent of metabolic syndrome, in which insulin resistance is the most important factor. Accordingly, hepatic and systemic insulin resistance have been reported in patients with NAFLD. Moreover, many arguments suggest that obese patients with NAFLD also develop hepatic leptin resistance. However, the molecular mechanisms that lead to liver leptin resistance have yet to be described. The main objective of this study is to analyze the relation between NAFLD progression during morbid obesity and the expression level of genes related to hepatic leptin and insulin signaling.


The patient cohort included 87 morbidly obese subjects who underwent bariatric surgery. Liver biopsies were obtained at the moment of surgery. NAFLD was diagnosed by anatomopathological evaluation of liver biopsies using the Kleiner score. Hepatic gene expression level was estimated by measuring mRNA concentration using a methodology based on Real Time PCR (including normalization of mRNA concentration by three housekeeping genes). Seven expression levels were analyzed: long and short leptin receptor isoforms (OB-Rb and OB-Ra), insulin receptor (INS-R), ISR-1, IRS-2 (Insulin Receptor Substrate 1 and 2), SOCS-1 and SOCS-3 (Suppressor of Cytokine Signaling 1 and 3).


The patients were classified into three groups: 10 without NAFLD (group 1); 33 with liver steatosis but without steatohepatitis (group 2, Kleiner score<3) and 44 with probable or confirmed steatohepatitis (group 3, Kleiner score≥3). Comparison of the average gene expression levels in obese patients without NAFLD (group 1) and in those with NAFLD (groups 2 and 3) revealed a non-significant tendency toward a decrease in leptin and insulin receptors, IRS-1 and SOCS-3 (P<0.1), and a non-significant tendency toward an increase in SOCS-1 (P<0.1). Moreover, the patients without NAFLD presented a marked degree of correlation between the expression of leptin and insulin signaling-related genes (above 0.8 in all combinations and a maximum of 0.986 for both leptin receptor isoforms). Interestingly, all these genetic correlation levels decreased or disappeared as NAFLD progressed.


In morbidly obese patients without NAFLD, high levels of correlation between leptin and insulin signaling-related genes suggest that hepatic leptin and insulin signaling pathways share key expression factors. Moreover, the reduction in these correlations as NAFLD progresses suggests that liver endocrine homeostasis is affected by NAFLD development. This study presents new perspectives on the mechanism that gives rise to leptin and insulin hepatic resistance during NAFLD origin and progression.


Congreso Americano 2013-1

Ribavirin priming pegylated-Interferon combination therapy in chronic hepatitis C patients: study of plasma Ribavirin trough concentrations, anaemia, viral kinetic and genetic variability

Paloma Muñoz-de-Rueda, PhD, Alicia Martín-Lagos1, MD,  Rosa Quiles, PhD, Ana Gila, MDPhD, Ana Martín, BS, Esther Pavón, PhD, Elena Ruiz-Escolano, MD, Angeles Ruiz-Extremera, MDPhD, Javier Salmerón, MDPhD.

 1Unidad de Ap. Digestivo y 2Servicio de Pediatría H. U. San Cecilio de Granada and3CIBEREHD, Spain.

 Aim: Ribavirin (RBV) remains essential to chronic hepatitis C (CHC) treatment. We aimed to investigate the influence of RBV priming to steady state before combined pegylated-Interferon/RBV (pegIFN/RBV) treatment on viral kinetics, alanine aminotransferase (ALT) levels, anaemia, RBV trough concentrations (RBV Ctrough), genetic variability within HCV–core, -NS5B and –NS5A (ISDR, PKRbd), and response to antiviral therapy.

Methods: Prospective cohort study. 27 chronic hepatitis C genotype 1 naïve patients received 4 weeks of RBV monotherapy followed by pegIFN-α-2a and RBV for 48 weeks (group A). The results were compared with a control/historical group (group B) of 27 patients undergoing treatment with pegIFN α-2a and RBV for 48 weeks. The study of mutations being done in the majority sequence of core, NS5B and NS5A (ISDR and PKRbd).

Results: No differences in main baseline characteristics were found between the treatment arms. Rapid, early and sustained virological response values were 44%, 89% and 52%, respectively, in group A, and 41%, 89% and 48% in group B, with no statistically significant differences. However, in the 4-week combined treatment, group A patients showed a greater decrease in HCV-RNA (2.3 log10 IU/mL vs 1.2 log10IU/mL; P=0.04), lower levels of Hb (12.48±1.7 g/dL vs 13.6±1.9 g/dL; P=0.039), lower levels of ALT (23.5±1.3 U/L vs 60.11±18 U/L; P<0.001) and higher mean RBV Ctrough (3.28±1.26 mg/L vs 1.76±0.69 mg/L; P=0.001). Did not observe variation, with respect to the baseline, in the number of mutations after RBV monotherapy, nor in the NS5B, ISDR, or PKRbd, however we observe a decrease of silent mutations in core (P=0.04) (Table 1).

Conclusions: A 4-week course of induction therapy, priming with RBV, does not improve SVR rates in HCV genotype 1 naïve infected patients. However, the greater reductions in viral load, Hb and ALT, and higher RBV Ctrough values at week 4 of combined treatment could reflect the greater effectiveness of the treatment. RBV monotherapy does not cause an increase in the number of mutations in the majority sequence of the regions core, NS5B and NS5A (ISDR and PKRbd).