Non-invasive scores, such as the non-alcoholic fatty liver disease (NAFLD) Fibrosis Score (NFS), are increasingly used for liver fibrosis assessment in patients with NAFLD. The aim of this study was to assess the applicability and reliability of non-invasive fibrosis scores in NAFLD patients with and without morbid obesity.

Three hundred sixty-eight patients with biopsy-proven NAFLD identified between January 2012 and December 2015 were studied; 225 with morbid obesity (biopsy obtained during bariatric surgery) and 143 patients without (termed as "conventional").

Median age was 47 years, 57% were female. Median body mass index (BMI) was 42.9 kg/m² with significant differences between our conventional and morbidly obese patients (BMI 29.0 vs. 50.8 kg/m², p < 0.001). Overall, 42% displayed mild/moderate and 16% advanced liver fibrosis (stage III/IV). All tested scores were significantly linked to fibrosis stage (p < 0.001 for all). FIB-4 (AUROC 0.904), APRI (AUROC 0.848), and NFS (AUROC 0.750) were identified as potent predictors of advanced fibrosis, although NFS overestimated fibrosis stage in morbid obesity. Limiting BMI to a maximum of 40 kg/m² improved NFS' overall performance (AUROC 0.838). FIB-4 > 1.0 indicated high probability of advanced fibrosis (OR = 29.1). FIB-4 predicted advanced fibrosis independently from age, sex, BMI, and presence of morbid obesity.

Our data suggest that FIB-4 score is an accurate predictor of advanced fibrosis in NAFLD throughout all BMI stages. Without adjustment, NFS tends to overestimate fibrosis in morbidly obese NAFLD patients. This problem may be solved by implementation of an upper BMI limit (for NFS) or adjustment of diagnostic thresholds.

To examine whether the biopsy method could affect histological evaluation, the volumetric ratio of human liver parenchyma was estimated in specimens from subcapsular and intralobar areas, and also in specimens obtained by needle biopsy (Tru-Cut needle). A new method of morphometric analysis was performed using a computer-aided color image analyzer. Eighteen cirrhotic, 7 fibrotic, and 4 normal liver biopsies were taken during hepatic resection and analyzed. The parenchymal cell volume ratio in the intralobar area was significantly correlated with that in the subcapsular area, and less significantly with needle biopsy samples (r = 0.844, p < 0.001; r = 0.577, p < 0.01, respectively). Both showed one-to-one correspondence. These results suggest that both wedged and needle biopsy samples are appropriate for assessing the degree of fibrosis or cirrhosis, although the sampling variability of the latter is greater than the former.

During experimental CCl4 cirrhosis, an increase of membrane-associated factor stimulating 3T3 cell proliferation in vitro was observed. This stimulator is a 150-kD protein similar to one previously described. In situ perfusion released growth stimulatory activity, suggesting a peripheral plasma membrane protein localizing on basolateral surfaces. The activity increased with increasing number of CCl4 treatments, reaching a maximum at the 14th intoxication. It was faster than the proliferation of connective tissues determined histologically. Cessation of treatment caused a decrease in activity to that of the level of untreated liver, although the number of fibroblastlike cells remained large. This data, taken with the results of experiments with enriched hepatocyte fraction, may serve as an evidence in favor of hepatocyte origin of the factor. A factor inhibiting fibroblast proliferation was measured in detergent extracts from membranes, suggesting an integral membrane protein. The activity of the inhibitory factor increased in acute liver lesions, but at the stage of maximal fibrogenesis this factor is reduced to levels comparable to those of the intact liver. Therefore it is unlikely that this factor is involved in CCl4-induced fibrogenesis at the final stages. These factors may be common controls for various hepatic lesions causing fibrosis, both in clinical and experimental modeling.

A simple morphometrical method was developed using a color image analyzing system, which allowed quantitative evaluation of parenchymal liver cell volume and total hepatocyte number in cirrhotic patients. With this method, we estimated these values in 29 cirrhotic patients who underwent hepatic resection (nine cases) or nonshunting operation (20 cases). Liver volume, calculated from computed tomographic images, was 976 +/- 196 cm3 (range = 602 to 1,376 cm3); the parenchymal cell volume ratio, obtained based on liver histological appearance with silver stain, was 0.665 +/- 0.092 (range = 0.510 to 0.881); and the parenchymal cell volume, calculated by multiplying the liver volume with the parenchymal cell volume ratio, was 645 +/- 140 cm3 (range = 403 to 936 cm3). The total hepatocyte number obtained in a similar manner using hematoxylin-stained specimens was 1.72 +/- 0.56 x 10(11) (range = 0.74 to 2.94 x 10(11)). The validity and applicability of the method is discussed, and the data are compared with those reported in other studies.

Most liver diseases lead to a pathobiochemical reaction termed liver fibrosis. This is a dynamic process implying different rates of progression or regression. Thus, histological examination of a liver biopsy is essential for a diagnosis but biochemical tests are necessary for assessing the activity of the process and monitoring its evolution. We review the most important constituents of liver connective tissue and the biochemical tests developed for evaluating liver fibrosis. The aminopeptide of type III procollagen is the most widely used parameter: two different radioimmunoassays have been developed with different affinities for the two circulating forms of the molecule. The determination of serum P3P reveals an elevation of blood levels both in acute and chronic liver diseases. In the first, serum P3P is an index of hepatic necrosis and inflammation which correlates with other biochemical parameters. In the second it is an index of active fibrogenesis. Moreover, in primary biliary cirrhosis this parameter is an independent prognostic variable and an important predictor of survival. Other immunoassays exist for different collagen cleavage products, but their clinical value is not established. Laminin and fibronectin are the principal structural glycoproteins in liver. Fibronectin determination does not seem to be of clinical value in liver disease. In contrast, serum laminin correlates with the severity of portal venous pressure in advanced liver disease. Its concentration parallels the severity of varices and may indicate the risk of bleeding. Hyaluronate is a high molecular weight polysaccharide, raised serum concentrations reflect both its increased synthesis by activated fibroblasts and its impaired catabolism by the liver. Thus, it may be useful for evaluating and monitoring the progression of chronic liver disease. The measurement of the activity of prolyl 4-hydroxylase as well as that of lysine oxidase and other enzymes has been proposed, but their clinical value is not sufficiently demonstrated. A panel of tests (e.g., laminin, hyaluronate and the aminopeptide of type III procollagen) seems to be recommended for a biochemical assessment of liver fibrosis in clinical practice.

In the course of experimental CCl4-induced cirrhosis, an increase of the membrane-associated factor stimulating 3T3 cells' proliferation in vitro was observed. Gel filtration showed an approximate molecular mass of 150 kDa. Extraction of growth stimulatory activity by liver perfusion in situ demonstrated a peripheral plasma membrane protein localization. The activity increased with an increasing number of CCl4 treatments, reaching a maximum at the tenth intoxication, faster than the proliferation of connective tissues. Cessation of treatment caused a decrease in activity to the level of untreated liver, although the amount of fibroblast-like cells remained large, which is evidence in favour of an hepatocyte origin of the factor.

Sera from 64 patients with HBsAg-negative chronic liver disease with or without cirrhosis were investigated for aminoterminal peptide of type III procollagen (sP-III-P) as a suitable marker of hepatic fibrosis; 244 healthy control subjects were included in the study. A close correlation (p less than 0.01) between sP-III-P levels and histological activity was observed; on the contrary, no correlation was found between the same serum marker of liver fibroplasia and biochemical activity or clinical severity of the disease. We conclude that sP-III-P as a suitable marker of liver overload of collagen fibers is strongly correlated with the histological activity of the disease. Local immune reactions produce soluble substances that might stimulate fibroblastic activity. The test has a significant sensitivity and a very high specificity as a marker of chronic liver disease with histological activity.

The cellular distribution and temporal expression of transcripts from transforming growth factor-beta 1 (TGF-beta 1) and procollagen alpha 1(I), alpha 1(III), and alpha 1(IV) genes were studied in carbon tetrachloride (CCl4)-induced rat liver fibrosis by using in situ hybridization technique. During the fibrotic process, TGF-beta 1 and procollagen genes were similarly and predominantly expressed in Desmin-positive perisinusoidal cells (e.g., fat-storing cells and myofibroblasts) and fibroblasts and their expression continued to be higher than those observed in control rats. These transcripts were also observed in inflammatory cells mainly granulocytes and macrophage-like cells at the early stages of liver fibrosis. The production of extracellular matrix along small blood vessels and fibrous septa coincided with the expression of these genes. Expression of TGF-beta 1 and procollagen genes were not detected in hepatocytes throughout the experiment. No significant differences in cellular distribution or time course of gene expression among procollagen alpha 1(I), alpha 1(III), and alpha 1(IV) were observed. Desmin-positive perisinusoidal cells and fibroblasts appeared to play the principal role in synthesis of collagens in CCl4-induced hepatic fibrosis. The simultaneous expression of TGF-beta 1 and procollagen genes in mesenchymal cells, including Desmin-positive perisinusoidal cells, during hepatic fibrosis suggests the possibility that TGF-beta 1 may have an important role in the production of fibrosis.

To evaluate the significance of natural killer (NK) cell activity in the clinical assessment of patients with hepatocellular carcinoma (HCC), 32 patients combined with liver cirrhosis (LC) and HCC, and 29 LC patients were studied. The NK cell activity was markedly decreased in HCC patients and the LC group as compared with the control group, but there was no statistical difference between the NK cell activity of the HCC group and the LC group. The depression of NK cell activity in HCC patients was inversely correlated with the patient's age, and the HCC patients with venous invasion or with both lobes involved had lower NK cell activity. These results suggest that the decreased NK cell activity in HCC patients might be related to the coexistent liver disease, and marked decrease in NK cell activity might be one of the causes for the early development and invasion of HCC.

The intralobar and subcapsular areas of human liver were compared in terms of morphometry and morphology, and a correlation was made between the thickness of liver capsules and the amount of intralobar non-parenchyma in normal and diseased livers. Tissue was systematically sampled from 16 normal and 26 fibrotic livers taken at necropsy. The volume fraction of subcapsular and intralobar non-parenchyma and the capsule thickness were determined by morphometry on histological sections. The volume fraction of intralobar non-parenchyma not only correlated well (tau = 0.7, p less than 0.001) with but was also equivalent in each case to the actual volume fraction of subcapsular non-parenchyma. Morphologically, the intralobar and subcapsular areas were remarkably similar. The volume fraction of intralobar non-parenchyma also correlated well (tau = 0.5, p less than 0.001) with capsule thickness. These results show that pathological changes in liver architecture were essentially similar in the intralobar and subcapsular areas and that capsule thickness reflected intralobar non-parenchymal changes.