Transforming growth factor-beta 1 in chronic hepatitis C

Circulating transforming growth factor beta(1) as an indicator of hepatic function impairment in liver cirrhosis

In the liver, transforming growth factor (TGF) -beta(1)is primarily responsible for activation of fat-storing cells, which are the main source of extracellular matrix proteins. Their deposition play a key role in the development of liver cirrhosis. The aim of this study was to evaluate plasma TGF-beta(1)in patients with different stages of liver cirrhosis and its possible use as an indicator of liver function impairment. TGF-beta(1)was measured in the plasma of 40 patients with liver cirrhosis. To estimate possible effect of liver insufficiency on plasma TGF-beta(1), patients were divided into three groups: A, B and C, univocal with Child-Pugh classes. Normal values were collected from 13 healthy volunteers. Liver cirrhosis resulted in a significant increase of plasma concentration of TGF-beta(1)(39.3+/-3.8 ng/ml), which doubled normal values (18.3+/-1.6 ng/ml). The highest concentrations were observed in alcoholic patients (44.4+/-4.7 ng/ml). TGF-beta(1)level increased depending on the degree of liver insufficiency, demonstrated by a significant positive correlation with Child-Pugh score (r=0.591). Values in group A were similar to normal, but were significantly elevated in groups B and C. These findings suggest possible use of plasma TGF-beta(1)measurement as an indicator of liver function impairment and possible marker of hepatic fibrosis progression in cirrhotic patients.

Pathologic features of chronic hepatitis. A review and update

The general histopathologic changes of chronic hepatitis and those related to the various causes are reviewed. Consideration also is given to underlying or associated diseases and to mixed infections in chronic viral hepatitis. Changes occurring in exacerbations or relapses are described. Selected histopathologic changes are illustrated. The nomenclature is reviewed briefly, with emphasis on separation of activity from stage of disease.

TGF-beta in infections and infectious diseases

Since it was first described as having the ability to inhibit macrophage activation, transforming growth factor-beta (TGF-beta) has been analyzed for its role in regulating immune responses to a variety of pathogens, including viruses, bacteria, yeast, and protozoa. Most of the studies have involved organisms that infect macrophages, and this discussion will attempt to highlight these findings. Perhaps the most work has been performed with protozoan pathogens, including Trypanosoma cruzi and a variety of Leishmania species, so the discussion will begin with these organisms. Other studies have focused on mycobacteria and viruses, including human immunodeficiency virus, so these areas will also be emphasized in the discussion. For the most part, investigators have reported that TGF-beta has, as expected, a negative influence on host responses and a beneficial effect on the survival and growth of intracellular pathogens. However, other studies have found that TGF-beta may have a positive or beneficial effect in some models of infection. This review will attempt to highlight studies and conclusions on the roles of TGF-beta in infection.

The significance of apoptosis in the liver

Apoptosis is a form of cell death which occurs in normal as well as in pathological tissues. We provide a description of the morphological changes during apoptosis and an overview of the role of apoptosis dysregulation in the pathogenesis of non-neoplastic liver diseases.

Viruses, host responses, and autoimmunity

Conceptually, the initiation of autoimmune disease can be described as a three-stage process involving both genetic and environmental influences. This process begins with the development of an autoimmune cellular repertoire, followed by activation of these autoreactive cells in response to a localized target and, finally, the immune system's failure to regulate these self-reactive constituents. Viruses have long been associated with inciting autoimmune disorders. Two mechanisms have been proposed to explain how a viral infection can overcome immunological tolerance to self-components and initiate an organ-specific autoreactive process; these mechanisms are molecular mimicry and bystander activation. Both pathways, as discussed here, could play pivotal roles in the development of autoimmunity without necessarily excluding each other. Transgene technology has allowed us and others to examine more closely the roles of these mechanisms in mice and to dissect the requirements for initiating disease. These results demonstrate that bystander activation is the most likely explanation for disease development. Additional evidence suggests a further role for viruses in the reactivation and chronicity of autoimmune diseases. In this scenario, a second invasion by a previously infecting virus may restimulate already existing autoreactive lymphocytes, and thereby contribute to the diversity of the immune response.

Hepatocyte proliferative activity in human liver cirrhosis

BACKGROUND/AIMS

The objective of this study was to validate, with an independent prospective cohort of patients, our previous data indicating that the proliferating cell nuclear antigen-labeling index (PCNA-LI) reflects the liver functional reserve in human cirrhosis and might have prognostic significance for patient survival. We also examined how this proliferative index is related to the expression of transforming growth factor beta1 (TGFbeta1) as a possible correlate of hepatocyte proliferative activity.

METHODS

The present group (n=70 patients) was similar in composition to our previous group regarding age, sex and severity of liver cirrhosis. PCNA and TGFbeta1 immunostaining were analyzed on methanol-fixed, paraffin-embedded liver biopsies.

RESULTS

Our data show that PCNA-LI declined significantly with worsening Child class and was negatively correlated with the Pugh score. Twenty-five patients died and 10 underwent liver transplantation during the observation period. Liver function, hepatic venous pressure gradient and hepatocyte PCNA-LI were significantly different in survivors and non-survivors. At a mean follow-up of 356 days, the patients with a PCNA-LI higher than 4.4% (the previously determined best cut-off value) had a significantly higher probability of survival than those with a PCNA-LI < or = 4.4% (0.87 vs 0.48, p=0.0009). TGFbeta1 expression in liver parenchyma correlated negatively with PCNA-LI, suggesting that this cytokine could be involved in the impaired regeneration observed in worsened liver cirrhosis.

CONCLUSIONS

This prospective study strengthens our previous observation that, in cirrhosis, hepatocyte proliferative activity, as evaluated by the PCNA-LI, provides information on liver functional reserve as well as on the patient's prognosis.

Effects of chocolate cyst fluid on endometrioma cell growth in culture

OBJECTIVE

To evaluate the effect of chocolate cyst fluid on the proliferation of cultured human endometrioma cells and to assay the concentration of transforming growth factor-B1 in this fluid.

DESIGN

Controlled in vitro study.

SETTING

Department of Obstetrics and Gynecology, State University of New York Health Science Center.

PATIENT(S)

Five women with ovarian endometriomas.

INTERVENTION(S)

Endometrioma tissue and chocolate fluid from five different patients were entered in this study.

MAIN OUTCOME MEASURE(S)

Endometrioma cell proliferation in culture with and without chocolate cyst fluid.

RESULT(S)

Chocolate cyst fluid increased the proliferation of endometrioma cells compared with controls. Also, high concentrations of transforming growth factor-B1 were found in cysts' fluid.

CONCLUSIONS

Chocolate cyst fluid has a growth-enhancing effect on endometrioma cells. One promoting growth factor is transforming growth factor-B1.