Centrilobular zonal necrosis is a unique subtype of autoimmune hepatitis: A cohort study

BACKGROUNDS

Centrilobular zonal necrosis (CZN) is described as a histological feature present in a small number of autoimmune hepatitis (CZN-AIH) patients. CZN may be detected in the absence of significant interface hepatitis, which is the most important histological finding of AIH. The clinical and histopathological spectra of CZN-AIH were not homogeneous, and the concept of CZN-AIH as a distinctive subtype of AIH remains controversial, due to the rarity of CZN-AIH and the ambiguous definition of CZN.

METHODS

To elucidate the clinical and immunogenetic features of CZN-AIH, a total of 102 biopsy samples of AIH, obtained at The Jikei University Katsushika Medical Center and Jikei University Hospital from 2000 to 2018, were reviewed. The 32 patients whose biopsies showed CZN were selected as the CZN-AIH group, and the remaining 70 were grouped as the non-CZN-AIH controls (control AIH). Data on clinical, histopathologic, and immunogenetic features were statistically compared between the CZN-AIH and the control AIH group. Additionally, the impact of the onset pattern (acute or chronic) and coexistent significant interface hepatitis in CZN-AIH was determined.

RESULTS

In CZN-AIH, the frequency of acute-onset cases was significantly higher than that in control AIH (56.2% vs 32.9%; P < .05), and the number of cases with moderate-to-severe interface hepatitis in liver histology was significantly lower (37.5% vs 87.1%; P < .001). Compared to the control AIH, cases of CZN-AIH had lower immunoglobulin G level (P < .001), lower antinuclear antibodies titer (P < .001), and lower AIH score (P < .001). The immunogenetic disproportionate distribution of HLA-DR phenotypes in control AIH (increased HLA-DR4 and decreased HLA-DR9) was not found in CZN-AIH. Moreover, CZN-AIH was less frequently relapsed (P < .05). For the acute-onset CZN-AIH cases, the clinical features were hardly indistinguishable from the chronic CZN-AIH cases. Similarly, the existence of interface hepatitis did not influence on the pathophysiology of CZN-AIH. Moreover, the acute-onset CZN-AIH cases is clinically distinguishable from acute-onset control AIH.

CONCLUSION

CZN can characterize as a distinct AIH subtype, regardless of onset-pattern or coexistence of significant interface hepatitis. To further strengthen this hypothesis, collection of more CZN-AIH cases is needed.

The Acute Onset of Autoimmune Hepatitis During Pregnancy in the Absence of Hypergammaglobulinemia and Autoantibodies

The onset of autoimmune hepatitis (AIH) during pregnancy is rare and often poses a diagnostic challenge. A 29-year-old Japanese woman experienced epigastric pain and nausea during the third trimester of her third pregnancy. Three days after the symptom onset, an emergency Caesarean section was performed because of suspected acute fatty liver of pregnancy; however, the patient's liver dysfunction worsened afterward. Despite normal serum IgG concentration and absence of autoantibodies, biopsy-proven severe hepatitis with centrilobular zonal necrosis and good biochemical response to corticosteroids led to a diagnosis of AIH. Therefore, AIH should be included in the differential diagnosis of liver dysfunction during pregnancy.

Autoimmune hepatitis: current challenges and future prospects

Autoimmune hepatitis (AIH) is a chronic progressive liver disease characterized by high levels of aminotransferases and autoantibodies, hypergammaglobulinemia, and interface hepatitis. AIH affects all races and all ages worldwide, regardless of sex, although a preponderance of females is a constant finding. The etiology of AIH has not been completely elucidated, but immunogenetic background and environmental parameters may contribute to its development. The most important genetic factor is human leukocyte antigens (HLAs), especially HLA-DR, whereas the role of environmental factors is not completely understood. Immunologically, disruption of the immune tolerance to autologous liver antigens may be a trigger of AIH. The diagnosis of classical AIH is fairly easy, though not without pitfalls. In contrast, the diagnosis of atypical AIH poses great challenges. There is confusion as to the definition of the disease entity and its boundaries in the diagnosis of overlap syndrome, drug-induced autoimmune hepatitis, and AIH with concomitant nonalcoholic fatty liver disease (NAFLD) or chronic hepatitis C. Centrilobular zonal necrosis is now included in the histological spectrum of AIH. However, the definition and the significance of AIH presenting with centrilobular zonal necrosis have not been examined extensively. In ~20% of AIH patients who are treated for the first time with standard therapy, remission is not achieved. The development of more effective and better tolerated novel therapies is an urgent need. In this review, we discuss the current challenges and the future prospects in relation to the diagnosis and treatment of AIH, which have been attracting considerable recent attention.

Centrilobular zonal necrosis as a hallmark of a distinctive subtype of autoimmune hepatitis

BACKGROUND AND AIM

Centrilobular zonal necrosis (CZN) is a known histological variant of autoimmune hepatitis (AIH). However, the significance of CZN is yet to be fully elucidated. This study aimed to determine whether CZN is a hallmark of a distinctive subtype of AIH.

METHODS

Histological changes in the centrilobular zones of liver biopsies from 113 AIH patients were assessed by a single pathologist and classified into three categories: typical zonal necrosis defined as CZN (15 patients); other necroinflammatory change (NIC; 24 patients); and absence of necrosis (non-NIC; 74 patients). The clinicopathological features and immunogenetic background of CZN patients were then assessed.

RESULTS

The clinicopathological features of AIH with CZN were distinct from other types of AIH, including a higher frequency of acute onset, lower frequency of antinuclear antibodies, lower antinuclear antibody titers, lower serum immunoglobulin G levels, lower grade interface hepatitis, less prominent lymphoplasmacytic infiltration, and lower AIH score. Increased and decreased frequencies of HLA-DR9 and HLA-DR4, respectively, were identified as immunogenetic features of AIH with CZN. Conversely, the clinicopathological characteristics of AIH with NIC were similar to those of non-NIC AIH, including the majority of the AIH patients. The therapeutic outcomes of AIH with CZN were excellent when precise diagnoses were made without delay.

CONCLUSION

The clinicopathological features and immunogenetic background of AIH with CZN differed from AIH without CZN. CZN may be a hallmark of a distinct subtype of AIH.