Pediatric Autoimmune Hepatitis.

Pediatric autoimmune hepatitis (PAIH) is a rare necro-inflammatory disease of the liver of unknown etiology thought to derive from the dysregulation of the immune response upon exposure to environmental triggers in genetically predisposed individuals [...].

Silencing of aryl hydrocarbon receptor repressor restrains Th17 cell immunity in autoimmune hepatitis.

Th17-cells play a key role in the pathogenesis of autoimmune hepatitis (AIH). Dysregulation of Th17-cells in AIH is linked to defective response to aryl-hydrocarbon-receptor (AhR) activation. AhR modulates adaptive immunity and is regulated by aryl-hydrocarbon-receptor-repressor (AHRR), which inhibits AhR transcriptional activity. In this study, we investigated whether defective Th17-cell response to AhR derives from aberrant AHRR regulation in AIH. Th17-cells, obtained from the peripheral blood of AIH patients (n = 30) and healthy controls (n = 30) were exposed to AhR endogenous ligands, and their response assessed in the absence or presence of AHRR silencing. Therapeutic effects of AHRR blockade were tested in a model of Concanavalin-A (Con-A)-induced liver injury in humanized mice. AHRR was markedly upregulated in AIH Th17-cells, following exposure to l-kynurenine, an AhR endogenous ligand. In patients, silencing of AHRR boosted Th17-cell response to l-kynurenine, as reflected by increased levels of CYP1A1, the main gene controlled by AhR; and decreased IL17A expression. Blockade of AHRR limited the differentiation of naïve CD4-cells into Th17 lymphocytes; and modulated Th17-cell metabolic profile by increasing the levels of uridine via ATP depletion or pyrimidine salvage. Treatment with 2'-deoxy-2'-fluoro-d-arabinonucleic acid (FANA) oligonucleotides to silence human AHRR in vivo, reduced ALT levels, attenuated lymphocyte infiltration on histology, and heightened frequencies of regulatory immune subsets in NOD/scid/gamma mice, reconstituted with human CD4 cells, and exposed to Con-A. In conclusion, blockade of AHRR in AIH restores Th17-cell response to AHR, and limits Th17-cell differentiation through generation of uridine. In vivo, silencing of AHRR attenuates liver damage in NOD/scid/gamma mice. Blockade of AHRR might therefore represent a novel therapeutic strategy to modulate effector Th17-cell immunity and restore homeostasis in AIH.

Juvenile Autoimmune Hepatitis: Recent Advances in Diagnosis, Management and Long-Term Outcome.

Juvenile autoimmune hepatitis (JAIH) is severe immune-mediated necro-inflammatory disease of the liver with spontaneous progression to cirrhosis and liver failure if left untreated. The diagnosis is based on the combination of clinical, laboratory and histological findings. Prothrombin ratio is a useful prognostic factor to identify patients who will most likely require a liver transplant by adolescence or early adulthood. JAIH treatment consists of immune suppression and should be started promptly at diagnosis to halt inflammatory liver damage and ultimately prevent fibrosis and progression to end-stage liver disease. The risk of relapse is high especially in the setting of poor treatment compliance. Recent evidence however suggests that treatment discontinuation is possible after a prolonged period of normal aminotransferase activity without the need for liver biopsy prior to withdrawal.

Natural history of liver disease in a large international cohort of children with Alagille syndrome: Results from the GALA study.

BACKGROUND AND AIMS: Alagille syndrome (ALGS) is a multisystem disorder, characterized by cholestasis. Existing outcome data are largely derived from tertiary centers, and real-world data are lacking. This study aimed to elucidate the natural history of liver disease in a contemporary, international cohort of children with ALGS. APPROACH AND RESULTS: This was a multicenter retrospective study of children with a clinically and/or genetically confirmed ALGS diagnosis, born between January 1997 and August 2019. Native liver survival (NLS) and event-free survival rates were assessed. Cox models were constructed to identify early biochemical predictors of clinically evident portal hypertension (CEPH) and NLS. In total, 1433 children (57% male) from 67 centers in 29 countries were included. The 10 and 18-year NLS rates were 54.4% and 40.3%. By 10 and 18 years, 51.5% and 66.0% of children with ALGS experienced ≥1 adverse liver-related event (CEPH, transplant, or death). Children (>6 and ≤12 months) with median total bilirubin (TB) levels between ≥5.0 and <10.0 mg/dl had a 4.1-fold (95% confidence interval [CI], 1.6-10.8), and those ≥10.0 mg/dl had an 8.0-fold (95% CI, 3.4-18.4) increased risk of developing CEPH compared with those <5.0 mg/dl. Median TB levels between ≥5.0 and <10.0 mg/dl and >10.0 mg/dl were associated with a 4.8 (95% CI, 2.4-9.7) and 15.6 (95% CI, 8.7-28.2) increased risk of transplantation relative to <5.0 mg/dl. Median TB <5.0 mg/dl were associated with higher NLS rates relative to ≥5.0 mg/dl, with 79% reaching adulthood with native liver ( p < 0.001). CONCLUSIONS: In this large international cohort of ALGS, only 40.3% of children reach adulthood with their native liver. A TB <5.0 mg/dl between 6 and 12 months of age is associated with better hepatic outcomes. These thresholds provide clinicians with an objective tool to assist with clinical decision-making and in the evaluation of therapies.

Pregnancy outcome in women with childhood onset autoimmune hepatitis and autoimmune sclerosing cholangitis on long-term immunosuppressive treatment.

INTRODUCTION: Autoimmune hepatitis and autoimmune sclerosing cholangitis may lead to maternal and fetal complications in pregnant women diagnosed during childhood and treated long-term with immunosuppressive drugs. Immunosuppressive treatment with azathioprine is usually employed during pregnancy to maintain remission but his safety is still controversial. The aim of our study is to investigate pregnancy outcomes after maternal long-term immunosuppressive treatment for autoimmune hepatitis/sclerosing cholangitis. METHODS: We conducted a retrospective cohort study including all pregnant women who received a diagnosis of autoimmune hepatitis or autoimmune sclerosing cholangitis during childhood and followed-up from 1989 to 2021. RESULTS: Fifteen pregnancies in 12 women were observed. The median follow-up from disease onset was 26.7 years. All patients had been treated with prednisone and azathioprine (AZA) as first line therapy. At the beginning of the pregnancy, 11/12 (91.6%) patients were in spontaneous or pharmacologically induced clinical and biochemical remission and one had received a liver transplant. During pregnancy, 8 patients continued azathioprine. No relapse during pregnancy occurred in any patient. One woman presented a flare five months after delivery and a second one, one year after delivery when AZA was discontinued. The 15 pregnancies resulted in 13 livebirths (86.6%) with 9 (69.2%) full-term healthy neonates. Two miscarriages (13.3%) were recorded and cesarean section was performed in 3 women (23%). No congenital malformations were observed. CONCLUSIONS: Pregnancy in women diagnosed during pediatric age with autoimmune hepatitis or autoimmune sclerosing cholangitis and treated long-term with immunosuppressants is possible with good maternal and neonatal outcomes. Azathioprine allows, in most cases, to maintain remission with a good safety profile. Careful monitoring of these patients during pregnancy is, however, mandatory.

Giant cell hepatitis associated with autoimmune hemolytic anemia: an update.

Giant cell hepatitis associated with autoimmune hemolytic anemia (GCH-AHA) is a rare and severe disease characterized by autoimmune hemolysis associated with acute liver injury, histologically defined by widespread giant cell transformation. It occurs after the neonatal period, most commonly in the first year of life and uniquely affects pediatric patients. It is still poorly understood and likely underdiagnosed, although in recent years there have been advances in the understanding of its pathogenesis and the liver injury is now hypothesized to be secondary to a humoral immune mechanism. Although no laboratory test specific for the diagnosis currently exists, given its severity, it is fundamental to rule out GCH-AHA when evaluating a patient in the first year of life presenting with AHA and/or with acute liver disease of unknown etiology. While GCH-AHA is progressive in nature as other autoimmune liver disorders, it differs significantly from juvenile autoimmune hepatitis (JAIH) in that a cure can be achieved after several years of intensive treatment in a portion of patients. Conventional first line therapy consist of prednisone/prednisolone combined with azathioprine, however, several immunosuppressive drugs, commonly used in the treatment of JAIH have been tried as second line therapy, including cyclosporine, cyclophosphamide, mycophenolate mofetil, 6-mercaptopurine, calcineurin inhibitors, and sirolimus. Intravenous immunoglobulins have also been used in cases of severe liver dysfunction and/or severe anemia allowing for transitory remission. More recently treatment with B-cell depletion has been attempted in some patients and encouraging results have been reported in refractory cases. Although what constitutes optimal treatment has yet to be determined, the recent progress in the understanding of the pathogenetic mechanisms of GCH-AHA have made positive strides, cautiously pointing toward a hopeful prognosis for some of these patients.

Transient elastography assessment of liver allograft fibrosis in pediatric transplant recipients.

TE measures liver stiffness to assess fibrosis. Its use in post-transplant patients was reported in few small pediatric studies. We evaluated TE ability to predict liver graft fibrosis in a large cohort while comparing it to the performance of APRI and FIB-4. We also investigated the effect of graft type on LSMs. Patients at Boston Children's Hospital who underwent LT and LSM ≤ 1 year from biopsy (2007-2018) were eligible. Ninety-four patients (45%M) aged 1-21 years (89% < 18 years; 13% < 2 years) were eligible. Median time between transplant/biopsy and LSM was 5.1 years and 52 days, respectively. Thirty-nine percent received whole-liver grafts, 54% TV grafts, and 6% as part of MV. At LSM, median ALT was 25 [IQR 16-33] IU/L. Twenty-one percent had METAVIR ≥ F2. LSM was statistically higher among those with significant fibrosis (METAVIR ≥ F2) compared to those with METAVIR F0/F1 (median [IQR] 7.5 [4.6, 13.6] vs 5.1 [4.0, 6.4] kPa, respectively) (P = .005 by Wilcoxon rank-sum test). APRI and FIB-4 distributions were not different across METAVIR stages. The AUROC for LSM was 0.71 (95% CI 0.56-0.85) with an optimal cut-point of 6.5 kPa. Graft type had no influence on the AUROC for LSM. TE is useful for assessing significant graft fibrosis in children and young adult LT recipients and performs better than APRI and FIB-4. TV grafts demonstrate similar correlation with histology as whole-liver grafts.

B-cell depletion induces prolonged remission in patients with giant cell hepatitis and autoimmune hemolytic anemia.

BACKGROUND: Giant cell hepatitis with autoimmune hemolytic anemia (GCH-AHA) is a rare and severe immune-mediated disorder. Despite aggressive immunosuppressive treatments, the mortality is high. Prednisone has been effectively employed to achieve remission, but with a risk of relapse, if discontinued, and with severe side effects. A possible causative role of humoral immune response has paved the way to anti CD-20 monoclonal antibody (rituximab; RTX). Nevertheless, data about timing of remission and long-term side effects are sparse. METHODS AND MATHERIALS: We have retrospectively evaluated 3 refractory GCH-AHA patients in whom a prolonged remission has been achieved with RTX. In all patients, response to first and second line therapy was incomplete or transitory and severe steroid side effects occurred. RESULTS: A stable and sustained remission was achieved after multiple doses of RTX allowing withdrawing all the other treatments. No life-threatening infections have been recorded, however two patients developed persistent, paucisymptomatic hypogammaglobulinaemia. The only patient who did not develop hypogammaglobulinemia received IgG replacement during RTX. CONCLUSION: RTX induced complete and long-lasting remission allowing discontinuing all the other immunosuppressive drugs. A persistent, paucisymptomatic hypogammaglobulinaemia has been the unique side effect. Although further studies need to replicate our data, RTX can be considered as an effective and safe therapy for sustained remission in patients with severe refractory GCH-AHA.

Novel Diagnostic and Therapeutic Strategies in Juvenile Autoimmune Hepatitis.

Juvenile autoimmune hepatitis (JAIH) is a rare, chronic, inflammatory disease of the liver characterized by a complex interaction between genetic, immunological, and environmental factors leading to loss of immunotolerance to hepatic antigens. It affects both children and adolescents, most commonly females, and its clinical manifestations are quite variable. JAIH is progressive in nature and if left untreated may lead to cirrhosis and terminal liver failure. Although JAIH was first described almost 50 years ago, there have been few significant advances in the clinical management of these patients, both in terms of available diagnostic tools and therapeutic options. Aminotransferase activity, class G immunoglobulins and autoantibodies are the biomarkers used to diagnose AIH and monitor treatment response alongside clinical and histological findings. Despite their utility and cost-effectiveness, these biomarkers are neither an accurate expression of AIH pathogenic mechanism nor a precise measure of treatment response. Current standard of care is mainly based on the administration of steroids and azathioprine. This combination of drugs has been proven effective in inducing remission of disease in the majority of patients dramatically improving their survival; however, it not only fails to restore tolerance to hepatic autoantigens, but it also does not halt disease progression in some patients, it is often needed life-long and finally, it has deleterious side-effects. The ideal therapy should be enough selective to contrast immune-mediated live damage while preserving or potentiating the ability to develop permanent tolerance vs. pathogenic autoantigens. By reviewing the state of the art literature, this article highlights novel diagnostic and therapeutic strategies for managing pediatric AIH with a special focus on new strategies of immunotherapy. These promising tools could improve the diagnostic algorithm, more accurately predict disease prognosis, and provide targeted, individualized treatment.

Long-term follow-up of children and young adults with autoimmune hepatitis treated with cyclosporine.

BACKGROUND: Cyclosporine (CSA) is an alternative treatment for autoimmune hepatitis (AIH), however, its unknown long-term safety and efficacy have limited its use. AIMS: Examine the long-term outcome of children and young adults with AIH treated with CSA for at least 4 years. METHODS: Twenty patients were included in this retrospective study: 15 with classical AIH and 5 with autoimmune hepatitis/autoimmune sclerosing cholangitis overlap syndrome (ASC). CSA was administered as first (12 patients) or second-line (8 patients) treatment, alone or in combination with azathioprine or mycophenolate mofetil and/or prednisone. RESULTS: CSA determined initial clinical and biochemical remission in all patients. At the end of follow-up (median 8.6; range 4-20.4 years), all patients are alive with their native liver; 15 in complete remission (75%), 2 with incomplete response to treatment and 3 listed for liver transplant. Side effects were mild and transitory after dose tapering or, in 1 case, after CSA withdrawal. Hypertrichosis and moderate gingival hyperplasia were the most frequent. Two patients presented mild transient glomerular filtration rate (GFR) reduction. Median GFR at the beginning and end of treatment was not statistically different for all patients. CONCLUSIONS: CSA was effective and safe in the long-term treatment of our cohort of patients with AIH, tailoring the treatment remains key-points during CSA administration.

Old and New Treatments for Pediatric Autoimmune Hepatitis.

BACKGROUND: Autoimmune hepatitis is a rare inflammatory disease of the liver that most frequently affects children and young adults. It is a multifactorial disease of unknown etiology, characteristically progressive in nature, and if left untreated, may lead to cirrhosis and terminal liver failure. It has been known for several decades now that immunosuppressive treatment convincingly alters the outcome of most patients with autoimmune hepatitis and as such it should be started as soon as diagnosis is made. Primary goals of treatment are: normalization of hepatocellular function, extinction of the hepatic necroinflammatory process, and maintenance of a stable remission, thus preventing progression to cirrhosis and its complications. This article aims to review old and new treatments for this rare chronic disorder, from the oldest and most frequently used treatment consisting of the association of prednisone and azathioprine, to alternative medical treatments, liver transplant and promising medical strategies currently under investigation. RESULT AND CONCLUSION: The review will focus on the efficacy and safety profile of each drug, as well as on the published clinical experience with them in pediatric patients with autoimmune hepatitis.

Seronegative autoimmune hepatitis in children: Spectrum of disorders.

BACKGROUND: A few children with acute or chronic liver disease display histological features compatible with autoimmune hepatitis, but lack specific serological markers. AIM: To describe features, management and outcome of childhood seronegative autoimmune hepatitis. METHODS: From 1988 to 2010, 38 children were included under the following criteria: negative virological studies, no serum autoantibodies, exclusion of other causes of liver diseases, and liver histology compatible with autoimmune hepatitis. RESULTS: Four groups were identified: (1) 12 with increased serum gamma globulin concentrations; (2) 10 with normal or low serum gamma globulins and no combined blood disease; (3) 10 with combined aplastic anemia; and (4) 6 with peripheral thrombocytopenia with/without neutropenia. Immunosuppressive treatment was associated with aminotransferases normalization in all but one child who required liver transplantation. Relapses occurred in 10 children. Lymphocytopenia was found at the time of the diagnosis of hepatitis in 13 children, 12 in groups 3 or 4. All 38 children are alive after 4-17 years, 18 still under immunosuppression. CONCLUSIONS: Childhood seronegative autoimmune hepatitis includes a spectrum of disorders. Early liver histology is recommended and, if compatible with autoimmune hepatitis, immunosuppressive treatment should be started. Initial lymphocytopenia may indicate future hematological complication.

Efficacy of intravenous immunoglobulin therapy in giant cell hepatitis with autoimmune hemolytic anemia: A multicenter study.

BACKGROUND AND OBJECTIVE: Giant cell hepatitis with autoimmune hemolytic anemia (GCH-AHA) is a rare disease of infancy, of possible autoimmune mechanism with poor prognosis due to its scarce response to immunosuppressive drugs. The aim of this retrospective multicenter study was to evaluate the efficacy and safety of intravenous immunoglobulin (IVIg) treatment in inducing and maintaining remission of the liver disease, in patients with GCH-AHA. METHODS: Seven children with GCH-AHA, four newly diagnosed, and three in relapse, being treated with different therapies, received one to three IVIg infusions (0.5 to 2g/kg) in association with other immunosuppressive drugs. Subsequently five of them received monthly sequential IVIg infusions (mean 13.4, range 7-24). RESULTS: IVIg infusions as first-line therapy associated with prednisone and other immunosuppressive drugs significantly (P=0.04) reduced the aminotransferase activity in all patients and normalized prothrombin activity in the only patient with severe liver dysfunction. Sequential monthly IVIg infusions determined a steroid-sparing effect and allowed a complete or partial remission in all patients, although with temporary efficacy, since relapse of the hemolytic anemia and/or of liver disease occurred in all patients. IVIg infusions were associated with mild side effects in two patients. CONCLUSIONS: IVIg infusion can be safely and effectively administered in patients with severe GCH-AHA at diagnosis, or in case of relapse, in association with other immunosuppressive drugs. Repeated IVIg infusions may help maintain remission, however, due to their temporary efficacy, they should not be routinely employed.