Biliary features in liver histology of children with autoimmune liver disease

Biliary disease progression in childhood onset autoimmune liver disease: A 30-year follow-up into adulthood

Background & Aims

Long-term follow-up studies of paediatric onset autoimmune liver disease (AILD) are invaluable in helping better understand the clinical course of disease. In day-to-day practice clinicians struggle with disease definitions whilst patients and parents lack clear prognostic information.

Methods

The clinical progression of 159 patients with childhood onset AILD between June 1990 and December 2013 was reviewed, capturing data up to adulthood (ending May 2021).

Results

Presentation with autoimmune hepatitis (AIH) was dominant (n = 119); biliary presentations accounted for 25%. During follow up, biliary disease progression confirmed by cholangiography and/or liver histology was observed frequently: 19.8% (20/101) patients with childhood onset AIH type 1 (AIH-1) developed biliary features by adulthood and of these 50% phenotypically transitioned to primary sclerosing cholangitis (PSC); the remaining transitioned to an overlap disease phenotype. No patients with AIH type 2 developed biliary progression. Two-thirds of patients with overlap features (14/21) in childhood had phenotypically progressed to PSC by adulthood. Approximately 43% (6/14) of AIH-1 patients requiring a liver transplant in adulthood had explant evidence of biliary disease compared with 11% (1/9) in childhood, whereas 35.7% (5/14) of patients had histology diagnostic of PSC in their explant liver and 7.1% (1/14) had overlap features. All patients with biliary phenotypes (PSC, autoimmune sclerosing cholangitis, overlap) who required a transplant (n = 18) were found to have explant histology consistent with PSC. Twelve of 14 patients with biliary progression developed ulcerative colitis during follow-up with 92% progressing to PSC.

Conclusions

Three decades of follow-up demonstrated how children presenting with AILD had a significant risk of clinical transformation to PSC. Biliary progression was significantly associated with the development of inflammatory bowel disease.

Impact and implications

Childhood onset autoimmune liver disease remains very impactful for patients and families. Disease nomenclature can however be confusing. Long-term follow up studies as children become adults is important to help understand how and why disease behaves over time. Understanding more about the long-term course of childhood autoimmune liver disease will help patients, families and doctors striving to improve care and reduce poor clinical outcomes. We followed over 150 patients with childhood onset autoimmune liver diseases into adulthood. We found that amongst patients with classical autoimmune hepatitis, 1 in 5 developed biliary disease over time, mostly consisting of primary sclerosing cholangitis. This was associated with developing inflammatory bowel disease. Our study design was retrospective and has relevant limitations. Defining phenotypes of autoimmune liver diseases is difficult and there is insufficient consensus, especially between adult and childhood physicians. Our data confirms the critical importance of careful long-term follow-up of patients, including safe transition to adult care, as well as robustly demonstrates, using real-world data, how disease nature can change over time. Our study affirms the need for investment in prospective cohort studies.

Expression of IL-37 Correlates With Immune Cell Infiltrate and Fibrosis in Pediatric Autoimmune Liver Diseases

OBJECTIVES

The activation of innate immune mechanisms is key for chronic liver injury. Interleukin-37 (IL-37) is a profound inhibitor of innate and adaptive immune responses, and its overexpression protects mice from liver inflammation and fibrosis. Here, we characterize the hepatic inflammatory infiltrate and expression of IL-37 in children with autoimmune liver diseases.

METHODS

We compared the inflammatory microenvironment of the liver in a retrospective cohort of children with primary sclerosing cholangitis (PSC), autoimmune sclerosing cholangitis (ASC) and autoimmune hepatitis (AIH) by immunohistochemistry. The expression of IL-37 was quantified in liver parenchyma and portal tracts. Double immunofluorescence was used for detection of IL-37 in specific cell types and colocalization with Smad3.

RESULTS

AIH is characterized by a dense lymphoplasmacytic infiltrate whereas ASC shows high numbers of granulocytes in portal tracts. IL-37 expression correlates positively with liver inflammation and fibrosis, the number of infiltrating immune cells and serum markers for hepatic inflammation. IL-37 is mainly expressed in hepatocytes, cholangiocytes and infiltrating immune cells. Double staining revealed IL-37 positivity in T helper and regulatory T cells (Treg), Kupffer (KC) and hepatic stellate cells (HSC). IL-37 colocalizes with intranuclear pSmad3L in areas of liver inflammation.

CONCLUSIONS

Pediatric ASC separates from PSC and AIH by a granulocyte-rich portal infiltrate. Upregulation of IL-37 with liver injury, the expression in Treg as well as KC and HSC and the colocalization of IL-37 with pSmad3L in cholangiocytes and hepatocytes suggest a modulating role to limit hepatic inflammation and fibrosis in pediatric autoimmune liver diseases.

Cutting edge issues in juvenile sclerosing cholangitis

Sclerosing cholangitis (SC) is a rare chronic disorder characterised by inflammation and progressive obliterative fibrosis of the intrahepatic and/or extrahepatic bile ducts. Diagnosis is based on cholangiogram showing bile duct dilatation, narrowing and obliteration of the biliary tree, and histologically, on the presence of inflammatory bile duct damage leading to periductal fibrosis. In children the most common SC is associated with strong autoimmune features, overlapping with those of autoimmune hepatitis (AIH); this form is known as autoimmune sclerosing cholangitis, ASC. Conversely, primary SC (PSC), a condition in which the term "primary" indicates that aetiology and pathogenesis are unknown, is rare in paediatrics. Secondary SC (SSC) defines a cholangiopathy associated with an identifiable aetiology such as immunodeficiencies, infections or haematological disorders. ASC and PSC are strongly associated with inflammatory bowel disease (IBD). ASC responds biochemically well to immunosuppressive drugs and ursodeoxycholic acid (UDCA). Primary forms are exclusively managed with oral UDCA, while in the secondary forms the medical treatment depends on the underlying aetiology. Despite treatment, SC often progresses to biliary cirrhosis and end-stage liver disease requiring liver transplantation. The disease can recur after transplant. Better understanding of pathogenic mechanisms and better treatment modalities are needed to improve the prognosis of this invalidating hepatic disorder.

Autoimmmune hepatitis

Autoimmune hepatitis (AIH) is a T-cell mediated, inflammatory liver disease affecting all ages and characterized by female preponderance, elevated serum transaminase and immunoglobulin G levels, positive circulating autoantibodies, and presence of interface hepatitis at liver histology. AIH type 1, affecting both adults and children, is defined by positive anti-nuclear and/or anti-smooth muscle antibodies, while type 2 AIH, affecting mostly children, is defined by positive anti-liver-kidney microsomal type 1 and/or anti-liver cytosol type 1 antibody. While the autoantigens of type 2 AIH are well defined, being the cytochrome P4502D6 (CYP2D6) and the formiminotransferase cyclodeaminase (FTCD), in type 1 AIH they remain to be identified. AIH-1 predisposition is conferred by possession of the MHC class II HLA DRB1*03 at all ages, while DRB1*04 predisposes to late onset disease; AIH-2 is associated with possession of DRB1*07 and DRB1*03. The majority of patients responds well to standard immunosuppressive treatment, based on steroid and azathioprine; second- and third-line drugs should be considered in case of intolerance or insufficient response. This review offers a comprehensive overview of pathophysiological and clinical aspects of AIH.

Associations Between Quantitative MRI Metrics and Clinical Risk Scores in Children and Young Adults With Autoimmune Liver Disease

Background: The Mayo risk score and SCOPE (Sclerosing Cholangitis Outcomes in Pediatrics) Index are clinical risk scores for monitoring progression of primary sclerosing cholangitis (PSC) and predict clinically important endpoints. Objective: To evaluate relationships of quantitative MRI measures of liver disease with clinical risk scores in children and young adults with autoimmune liver disease (AILD). Methods: This prospective study included 58 patients (35 male, 23 female; mean age, 15 years; range, 6-24 years) with AILD [PSC (n=16), autoimmune hepatitis (n=30), autoimmune sclerosing cholangitis (n=12)] who underwent research liver MRI examinations including: MR elastography (MRE), T2*-corrected T1 (cT1), and quantitative MRCP measurements. Associations between quantitative MRI metrics and clinical risk scores were evaluated using Spearman rank-order correlation coefficients and multivariable regression analyses. Results: Mean Mayo risk score was -1.1±0.9 (range: -2.9-1.1); mean SCOPE Index was 2.7±2.2 (range: 0-9). Mean liver stiffness was 2.8±1.1 kPa, mean whole-liver mean cT1 was 875±78 ms, and mean cT1 interquartile range (IQR) was 151±56 ms. Mayo risk score was significantly correlated with liver stiffness (r=0.56; p<.001), cT1 IQR (r=0.58; p<.001), whole-liver mean cT1 (r=0.31; p=.02), and multiple quantitative MRCP measures (r=0.36-0.45, p<.001). SCOPE Index was significantly correlated with liver stiffness (r=0.68; p<.001), cT1 IQR (r=0.51; p<.001), and multiple quantitative MRCP measures (r=0.47-0.49, p<.001). Multivariable linear regression analyses identified liver stiffness, cT1 IQR, and left hepatic duct maximum diameter as significant independent predictors of Mayo risk score (adjusted R2=0.45), and liver stiffness, cT1 IQR, common bile duct maximum (CBD) diameter, and CBD median diameter as significant independent predictors of SCOPE Index (adjusted R2=0.69). On logistic regression analysis, greater than low risk by SCOPE Index was best predicted by liver stiffness [odds ratio (OR)=49.6; 95% CI: 3.1-793.6) and CBD maximum diameter (OR=2.5; 95% CI: 1.3-4.7). Conclusion: Increased liver stiffness, increased cT1 IQR, and larger bile duct diameters are independently associated with higher (worse) Mayo risk score and SCOPE Index in children and young adults with AILD and may be surrogate markers of clinically meaningful endpoints. Clinical Impact: Multiparametric liver MRI incorporating quantitative metrics may serve as a noninvasive diagnostic and prognostic tool in pediatric AILD.

Use of oral vancomycin in children with autoimmune liver disease: A single centre experience

BACKGROUND

Previous reports showed some beneficial effect of oral vancomycin treatment (OVT) in children with primary sclerosing cholangitis; conversely, the experience in patients with other autoimmune liver diseases (AILD), including autoimmune hepatitis (AIH) and autoimmune sclerosing cholangitis (ASC), is scant.

AIM

To assess the response to immunosuppressive treatment (IS) and to OVT in children diagnosed with AILD.

METHODS

Retrospective study of children diagnosed with AIH (normal biliary tree at cholangiography) and ASC (abnormal biliary tree at cholangiography) in the last 10 years. All underwent standard immunosuppressive therapy (IS), but non-responders received also OVT. Biochemical remission [normal aspartate aminotransferase (AST)] and immunological remission (normal IgG and negative autoantibodies) rates and Sclerosing Cholangitis Outcomes in Pediatrics (SCOPE) index were assessed and compared during the follow up.

RESULTS

75 children were included [69% female, median age 10.5 years (5.6-13.4 years), AIH = 54, ASC= 21]. Sixty-three patients (84%, AIH = 52, ASC = 11) were treated with standard IS and 61 achieved biochemical remission, whereas 12 not responding to IS [16%, F = 75%, median age 13.5 years, (12.2-15.7), 10 with ASC] required OVT and 8 achieved biochemical remission. Overall OVT increased the biochemical remission rate of the whole group of AILD patients from 81% (61/75) to 92% (69/75). Median values of AST, alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT) decreased significantly after OVT start (P < 0.05). Complete normalization of livers enzymes (AST, ALT and GGT) was observed in 6/12 patients (50%). Decrease in SCOPE index score was reported in 5/12 patients (42%). At last follow up (median of 4.4 years, range 0.6-13.8 years) all 75 patients are alive, 6 (8%, 1 with ASC) successfully discontinued medications, 1 (with ASC) required liver transplantation.

CONCLUSION

Children with AIH and ASC respond well to IS treatment. OVT may represent a valuable treatment option to achieve biochemical remission in patients not responding to standard IS. These promising preliminary results suggest that a prospective study is indicated to define the efficacy of OVT in AILD.

Subclinical biliary strictures as a cause of long-term allograft dysfunction in children who underwent liver transplantation

We aimed to evaluate the role of liver biopsy to predict subclinical biliary strictures (BS) and assess the impact of BS on long-term allograft dysfunction following liver transplantation in children (LT). We reviewed all liver biopsies performed from 2012-2018. Percutaneous transhepatic cholangiography (PTC) was performed in patients presenting cholangiolar proliferation on cytokeratin-7 stained sections. We performed 271 biopsies in 161 children (86% with a left lateral segment); 44/161 (27%) presented with diffuse or multifocal cholangiolar proliferation. Among them, a tight BS was confirmed in 38/44 (86%, 24% of total) and it was managed by balloon dilatation. Cholangiolar proliferation showed a positive predictive value (PPV) for BS of 86.4%. Levels of alkaline phosphatase >325 IU/L predicted BS (P = .007). Dilatation of intrahepatic bile ducts on ultrasound was found only in 44% of patients with BS. Following a median follow-up of 9.2 years, only 15/38 (39%) patients resolved the BS. In conclusion subclinical BS is very common and probably underdiagnosed in these patients. Histological evidence of cholangiolar proliferation detectable by cytokeratin-7 immunostain should be preferred to liver function tests and ultrasound to suspect BS. BS in this setting should be regarded as a main cause of long-term allograft dysfunction.

Seroprevalence of AIH-related autoantibodies in patients with acute hepatitis E viral infection: a prospective case-control study in China

The seroprevalenc of autoimmune hepatitis (AIH)-related antibodies in patients, particularly Asians, with acute hepatitis E (AHE) is unclear. In this study, we investigated whether acute hepatitis E virus (HEV) infection is associated with the seroprevalence of AIH-related autoantibodies and assessed their impact on the disease characteristics. AIH-related autoantibodies were detected by indirect immunofluorescence in 198 AHE patients and 50 type 1 AIH patients. The positivity rates of against nuclear antigen (ANA) and smooth muscles antibody (SMA) in AHE patients were 37.4% and 22.7%, and the total positivity rate was 50%. Compared to those in AIH patients, the positivity rates of ANA-H and SMA-AA were significantly lower (35.1% vs. 82.1% and 4.4% vs. 88.4%). Female gender and the ALT level, but not immunosuppressive or antiviral drugs, were independently predictive of the presence of AIH-related autoantibodies in AHE patients. Fifty-two patients positive for AIH-related autoantibodies were followed up for 12 months. During this period, 33 of them became negative and 19 remained positive, albeit with significantly decreased titres. In conclusions, the seroprevalence of AIH-related autoantibodies in AHE patients was elevated, particularly in females, but their subspecificities and titres differed from those of type 1 AIH. Acute HEV infection may be related to AIH.

Abbreviations: AIH: autoimmune hepatitis; AHE: acute hepatitis E; ANA: against nuclear antigen; SMA: smooth muscles antibody; ANA-H: ANA with homogeneous pattern; SMA-AA: SMA with anti-actin pattern; Anti-LKM1: anti- liver-kidney microsomes-1 antibody; ANCA: anti-neutrophil cytoplasmic antibody; AMA: anti-mitochondrial antibody; Anti-SLA: anti-soluble liver antigen; Anti-LC1: anti-liver cytoplasmic type 1 antibody; pANCA: perinuclear antineutrophil cytoplasmic antibody