Lymph node enlargement within the hepatoduodenal ligament in patients with chronic hepatitis C reflects the immunological cellular response of the host.

BACKGROUND/AIMS: Lymph nodes in the hepatoduodenal ligament seem to be a common ultrasonographic finding in patients with chronic hepatitis C. Lymphadenopathic enlargement is associated with the histological hepatic features reflecting the immunological response of the host, but the correlation between lymphadenopathy, liver histology and the cellular immunoreactivity of the host has never been studied. AIM: (1) To specify the prevalence of lymph nodes within the hepatoduodenal ligament; and (2) to investigate whether lymphadenopathies might reflect the immunological response of the host. METHODS: One hundred and eleven patients were enrolled in this study. Eleven chronic hepatitis B patients and 34 healthy volunteers served as controls. RESULTS: Lymph nodes were detectable in 90 out of the 104 chronic hepatitis C patients studied. After logistic regression, a high CD8 level and the absence of post hepatitis C cirrhosis were associated with lymph node enlargement. The total lymph node volume was correlated with transaminase levels, inflammatory activity, and stage of fibrosis. CONCLUSIONS: (1) The prevalence of lymph nodes within the hepatoduodenal ligament is high; (2) lymph node enlargement is correlated with the immunological cellular response of the host; and (3) the total lymph node volume is correlated with hepatic necroinflammatory markers and the stage of fibrosis.

Physiological study of pH stability and sensitivity to pepsin of human gastric lipase.

BACKGROUND/AIMS: The aim of this study was to exactly determine the pH stability of human gastric lipase (HGL) and to investigate the mechanism underlying the inactivation of HGL which occurs in gastric juice. METHODS: Samples of human gastric juice and purified HGL were incubated at various pH values ranging from 0.5 to 8.0, and the residual HGL activity was measured as a function of time using the pHstat technique. Samples of purified HGL were also incubated in the presence of human pepsin. Electrophoresis and Western blot analysis were performed on all the samples in which HGL was inactivated. RESULTS: HGL was found to be stable in gastric juice at pH values ranging from 2.0 to 7.0, especially between pH 3.0 and 5.0 (half-inactivation time >24 h). HGL activity decreased rapidly below pH 2.0 and above pH 7.0. The inactivation half times were only 43 +/- 9 and 24 +/- 18 min at pH 1 and pH 8, respectively. The pH stability of purified HGL was much lower than that of HGL in gastric juice. Acid or alkaline inactivation of HGL could occur without any prior proteolytic degradation, and this inactivation was irreversible. However, proteolytic degradation of HGL by pepsin also occurred at very low pH values, probably because the acid-denatured HGL is more sensitive to proteolytic cleavage by pepsin. An ex vivo study of HGL activity in several gastric juice samples showed that the HGL activity decreased with the pH of the sample, in both basal and pentagastrin-stimulated gastric juice. CONCLUSION: Although HGL is not as stable as it was previously thought to be under acidic conditions, it is nevertheless the most stable acid lipase and constitutes a good candidate tool for enzyme substitution therapy.