Activated liver macrophages in human liver diseases

Macrophages and progressive tubulointerstitial disease

Macrophages and progressive tubulointerstitial disease. In chronic renal disease, tubulointerstitial inflammation and injury is associated with infiltrating macrophages. As a consequence of primary injury, proteinuria, chronic hypoxia, and glomerular-derived cytokines may all differentially modulate the expression of factors that promote macrophage recruitment. In addition to adhesion molecules and chemokines, products of complement system and renin-angiotensin system activation may direct this process. Once present at interstitial sites, macrophages interact with resident cells and extracellular matrix to generate a proinflammatory microenvironment that amplifies tissues injury and promotes scarring. There is now increasing evidence for the efficacy of interventions directed against factors that recruit, activate, or are produced by macrophages. A detailed understanding of the biology of this area may lead to the further development of therapies that will improve the outcome of renal disease.

Fcgamma receptor expression on hepatic macrophages and histological activity of chronic hepatitis

AIMS/BACKGROUND

Activated liver macrophages in chronic hepatitis express a high affinity receptor for IgG named FcgammaRI. This study was performed to find the difference in FcgammaRI expression between chronic hepatitis B (CHB) and C (CHC) with reference to histological activity.

METHODS

Consecutive patients with CHB (20 cases) and CHC (25 cases) were enrolled in the study. Inflammatory activity was evaluated using the modified histological activity index (HAI). FcgammaRI-positive macrophages were quantitatively measured by computer assisted morphometry.

RESULTS

Total HAI score was significantly higher in CHB than in CHC. Confluent necrosis was observed in significantly higher frequency in CHB at Stages 3 5 than in CHC. The percentage area of FcgammaRI-positive macrophages was significantly higher in CHB than in CHC. In CHB, the percentage area of FcgammaRI-positive macrophages correlated with total HAI (<0.01) as well as the degree of confluent necrosis (<0.01), interface hepatitis (<0.05) and portal inflammation (<0.05). FcgammaRI-positive macrophages accumulated mainly at the site of confluent necrosis. In CHC, no correlation was observed between activated macrophages and any histological categories.

CONCLUSION

These results suggest that FcgammaRI-positive macrophages are associated with confluent necrosis in CHB, which is more common in CHB patients than in CHC.