Spectrum of Autoimmune Liver Disease and Real-World Treatment Experience from a Tertiary Care Hospital

Background and aims

Autoimmune liver disease (AILD) comprises of autoimmune hepatitis (AIH), primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) with a spectrum of overlap amongst the three. We analyzed the spectrum and treatment outcomes of patients with AILD presenting to a tertiary care center in India.

Methods

A retrospective analysis of AILD patients from June 2008 to April 2021 was performed. The diagnosis was based on clinical, biochemical, imaging, serological, and histological characteristics. Eligible patients received treatment depending on the disease stage. Biochemical response to treatment was defined as normalization of AST, ALT, bilirubin, and immunoglobulin G levels at 6 months in AIH, normalization of total bilirubin and/or albumin at 1 year in PBC and decrease in alkaline phosphatase (ALP) levels by 40% in PSC.

Results

Two hundred seventy-five patients were analyzed. AIH (58.54%) was most common, followed by an overlap of AIH-PBC (24%) and AIH-PSC (6.54%), PSC (6.18%), and PBC (4.72%). Most patients presented in 3rd or 4th decade, except PBC which occurred predominantly in 5th decade. The majority of patients were females (72.72%). Jaundice was the most common presentation seen in 60% of patients. Cirrhosis was present in 57.47% of patients. Patients with overlap had more pruritus (54.76 vs 6.83%), fatigue (63.1% vs 49.7%), hepatomegaly (52.4% vs 25.5%), and higher ALP (80.9% vs 37.7%) than patients with AIH alone. Acute presentation was seen in 33 patients (13.5%) with most having AIH flare. Five patients had acute liver failure (ALF) and 9 had acute-on-chronic liver failure (ACLF). ALF was associated with 80% mortality while 55.56% of patients with ACLF had a complete biochemical response to immunosuppression. Among patients with AIH and/or overlap who received immunosuppression, a complete biochemical response to immunosuppression was seen in 60.69% of patients. High ALT (OR 1.001 [1.000-1.003], P = 0.034), high albumin (OR 1.91 [1.05-3.48], P = 0.034) and low fibrosis on biopsy (OR 0.54 [0.33-0.91], P = 0.020) predicted complete response.

Conclusion

AIH is the most common AILD followed by overlap syndromes, PSC and PBC in our cohort. Biochemical response to immunosuppression is seen in 60% of patients with AIH & low fibrosis score on histopathology predicts a complete response.

Features and outcome of AIH patients without elevation of IgG

Background & Aims

High IgG levels are considered a hallmark of autoimmune hepatitis (AIH). A subgroup of patients with AIH has IgG within the normal range despite evidence of clinical disease activity. The clinical significance of this biomarker has not been explored.

Methods

In a European multicentre study we compared biochemical, clinical and histological features from patients with AIH and normal IgG-values at diagnosis to an age- and sex-matched control group of patients with typical AIH presenting with elevated IgG. Data were assessed at diagnosis, after 12 months of therapy and at last follow-up.

Results

Out of 1,318 patients with AIH, 130 (10%) had normal IgG at presentation. Histological and biochemical parameters at diagnosis, as well as treatment response, showed no difference between groups. Stable remission off treatment was achieved more commonly in the normal IgG group than in the typical AIH group (24 vs. 8%; p = 0.0012). Patients of the control group not only had higher IgG levels (29.5 ± 5.8 vs. 12.5 ± 3.2 g/L; p <0.0001), but also a higher IgG/IgA ratio (9.3 ± 6.9 vs. 5.4 ± 2.4; p <0.0001) at diagnosis. The IgG/IgA ratio only declined in patients with typical AIH and was no longer different between groups after 12 months (6.3 ± 4.3 vs. 5.5 ± 2.2; p = 0.1), indicating a selective increase of IgG in typical AIH and its suppression by immunosuppression. Autoantibody titres were higher in the typical AIH group, but not when controlled for IgG levels.

Conclusions

Compared to AIH with typical biochemical features, patients with normal IgG levels at diagnosis (i) show similar biochemical, serological and histological features and comparable treatment response, (ii) appear to lack the selective elevation of serum IgG levels observed in typical active AIH disease, (iii) may represent a subgroup with a higher chance of successful drug withdrawal.

Lay summary

A characteristic feature of autoimmune hepatitis (AIH) is an elevation of immunoglobulin G (IgG), which is therefore used as a major diagnostic criterion, as well as to monitor treatment response. Nevertheless, normal IgG does not preclude the diagnosis of AIH. Therefore, we herein assessed the features of patients with AIH and normal IgG in a large multicentre study. This study demonstrates that about 10% of all patients with AIH have normal IgG; these patients are indistinguishable from other patients with AIH with respect to biochemical markers, liver histology, disease severity and treatment response, but might represent a subgroup with a higher chance of remission after drug withdrawal.

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Patients with AIH and normal IgG comprise around 10% of all patients with AIH.

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These patients are indistinguishable from patients with typical AIH by biochemical markers or liver histology.

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They have no selective IgG elevation, with lower IgG and IgA levels than patients with typical AIH.

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These patients might represent a subgroup in whom there is a high chance of successful drug withdrawal.