Novel syngeneic liver hapten protein compounds play different roles in pathogenesis of autoimmune hepatitis in the C57BL/6 mouse.

BACKGROUND/AIMS: The autoimmune hepatitis (AIH) model in C57BL/6 mice with syngeneic hapten S100 and adjuvant injected intraperitoneally has been designed to elucidate the pathogenesis of AIH. Three separate hapten peak proteins, peak I, peak II and peak III, could be derived from S100, but little is understood their roles on the development of AIH. This study aims to learn more about these roles on pathogenesis of AIH. METHODOLOGY: Novel AIH C57BL/6 mouse models were developed by weekly immunization by intraperitoneal injection with syngeneic S100 liver proteins and the three separated hapten peak proteins emulsified covalently in complete Freund's adjuvant (CFA) for 4 weeks and sacrificed for liver histopathological study. Additionally, TNF-α and INF-γ in culture supernatants of spleen lymphocytes of healthy C57BL/6 mice cultured together with S100 plus CFA for 48 hours were detected, and the T-lymphocytes proliferative response after stimulation with crude S100, peak I, II or III proteins were also assessed. RESULTS: Data showed that hepatitis induced by CFA+S100 was accompanied with more severe inflammation characterized by diffusely distributed liver necrosis and enhanced lymphocyte infiltration in portal tracts, while hepatitis induced by peak I+CFA was characterized by mass lymphocyte infiltration, occasional isolated liver necrosis and many acidophilic bodies, which was more similar to autoimmune hepatitis; hepatitis induced by peak II+CFA was characterized by massive liver necrosis and mild lymphocyte infiltration; hepatitis induced by peak III+CFA was characterized by mild inflammation with isolated acidophilic bodies or dotted hepatocellular necrosis. TNF-α, INF-γ from culture supernatants were increased, and T-lymphocyte proliferative response stimulated with peak I protein significantly increased compared with those stimulated with crude S100, peak II or III proteins. CONCLUSIONS: Syngenic S100 liver protein and its three separated hapten proteins have different roles in the pathogenesis of AIH, and peak I protein may be important in its development.

Clinical and immunopathological features of patients with lupus hepatitis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Lupus hepatitis is yet to be characterized based on its clinical features and is often difficult to differentially diagnose from other liver diseases. We aimed to elucidate clinical, histopathological and immunopathological features of lupus hepatitis and to evaluate primarily the effectiveness of liver immunopathological manifestations on differential diagnosis of lupus hepatitis from other liver diseases.</p><p><b>METHODS</b>A retrospective study was performed to analyze clinical features of lupus hepatitis in 47 patients out of 504 inpatients with systemic lupus erythematosus (SLE) in First Affiliated Hospital of Sun Yat-sen University, China from May 2006 to July 2009, and to evaluate the association between lupus hepatitis and SLE activity. Additionally, liver histopathological changes by hematoxylin and eosin (HE) staining and immunopathological changes by direct immunofluorescence test in 10 lupus hepatitis cases were analyzed and compared to those in 16 patients with other liver diseases in a prospective study.</p><p><b>RESULTS</b>Of 504 SLE patients, 47 patients (9.3%) were diagnosed to have lupus hepatitis. The prevalence of lupus hepatitis in patients with active SLE was higher than that in those with inactive SLE (11.8% vs. 3.2%, P < 0.05). The incidence of hematological abnormalities in patients with lupus hepatitis was higher than that in those without lupus hepatitis (40.4% vs. 21.7%, P < 0.05), such as leucocytes count (2.92×10(9)/L vs. 5.48×10(9)/L), platelets count (151×10(9)/L vs. 190×10(9)/L), serum C3 and C4 (0.34 g/L vs. 0.53 g/L; 0.06 g/L vs. 0.09 g/L) (P < 0.05); 45 of 47 (95.7%) lupus hepatitis patients showed 1 upper limit of normal (ULN) < serum ALT level < 5 ULN. The liver histopathological features in patients with lupus hepatitis were miscellaneous and non-specific, similar to those in other liver diseases, but liver immunopathological features showed positive intense deposits of complement 1q in 7/10 patients with lupus hepatitis and negative complement 1q deposits in all patients with other liver diseases (Fisher's exact test, P = 0.011).</p><p><b>CONCLUSIONS</b>Lupus hepatitis was not infrequent in active SLE patients which would be one of the indices indicating SLE activity. Positive intense deposit of complement 1q in liver may be a characteristic immunopathological feature of lupus hepatitis, which provides a new way to differentially diagnose lupus hepatitis from other liver diseases.</p>