Non-invasive assessment of chronic liver and gastric diseases.

BACKGROUND: In patients with both chronic liver diseases and dyspepsia there is the need for non-invasive, inexpensive and effective laboratory tests. These tests should not substitute but complement and integrate the information derived from invasive techniques such as liver biopsy and esofagogastroduodenoscopy. Natural history studies indicate that advanced fibrosis and cirrhosis develop in about 20%-40% of patients with chronic hepatitis B or C, and in a similar proportion of those with alcoholic or non-alcoholic steatohepatitis. In these patients, precise definition of the hepatic fibrosis stage is the most important parameter to assess the risk of disease progression and to decide for an immediate and appropriate antiviral therapy.
METHODS: Liver biopsy represents the gold standard for evaluating the presence, type and stage of liver fibrosis but a body of evidence has been accumulated to demonstrate the limitations of this technique, including inter- and intra-observer variations, sampling errors and variability. In recent years there has been an increasing interest in the possibility of identifying and describing liver fibrosis by using non-invasive, surrogate markers measurable in blood. Many studies have been dedicated to the evaluation of "direct" markers of fibrogenesis, while a second approach is based on the evaluation of single or combined biochemical parameters that reflect the stage of liver disease. Upper gastrointestinal symptoms are common in developed countries and this makes impossible the use of esofagogastroduodenoscopy in all patients with dyspepsia. The Maastricht 2-2000 Consensus meeting has suggested screening and treating Helicobacter pylori infection in dyspeptic patients in primary health care as the first line of therapy for newly onset dyspepsia.
CONCLUSIONS: Combination panels of biomarkers have been demonstrated to improve the accuracy of the single tests and with the use of algorithms based on sequential combination of non-invasive biomarkers a high diagnostic accuracy has been achieved for liver fibrosis. This, in turn, translates in a reduction by >50% in the need of taking liver biopsies. A biochemical panel which includes the measurement of serum pepsinogen I and II, gastrin G-17 and anti-H. pylori antibodies for patients with gastric disease, due to its high negative predictive value, appears to be a valuable approach to screen patients <55 years and with no alarm features, assuring safety and cost-effectiveness.