Background: 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.
Methods: 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.
Results: 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).
Conclusions: 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.