A molecular marker of disease activity in autoimmune liver diseases with histopathological correlation; FoXp3/RORγt ratio

Integrating Molecular Testing With Clinical Criteria and Histopathology Improves Diagnostic Precision in Immune-Mediated Liver Diseases

Autoimmune hepatitis (AIH) and primary biliary cholangitis (PBC) are immune-mediated liver diseases (IMLDs) that are diagnosed by a combination of clinical, serologic, and histologic features. Diagnosis may be challenging, particularly when patients have mixed features of both AIH and PBC, a disease often called overlap syndrome (OS). In addition, many patients have refractory disease. We hypothesized that adding molecular testing to the current diagnostic criteria would provide an additional tool that could assist in correctly classifying patients. RNA was isolated from liver biopsies from patients with AIH (n = 16), PBC (n = 13), OS (n = 8), drug-induced/serology-negative AIH (AIH DI/Ser-neg, n = 6), or controls (n = 10). Gene expression was determined using an nCounter Sprint Profiler, and principal component analysis delineated distinct clusters for patients with an inflammatory profile due to AIH, PBC, and AIH DI/Ser-neg. Two patients with minimal histologic features of PBC clustered with the control group, and 2 patients with predominantly AIH and minimal PBC features clustered with the PBC group. A patient with OS who received treatment for both conditions showed no disease progression, whereas a patient with OS treated solely for AIH failed to respond. Conversely, one of the gene signatures from a patient diagnosed with PBC fell within the AIH group. This patient did not respond to treatment with ursodiol and ultimately required liver replacement. These findings suggest that the IMLD initially diagnosed in these patients may have been incorrectly classified. As expected, molecular analysis could not identify a distinct cluster for patients diagnosed with OS, and these had variable gene signatures that fell throughout the identified AIH or PBC groups. Cluster analysis was also able to distinguish patients with disease progression from non-progressors with mild disease who responded to treatment. In summary, gene expression analysis may assist in confirming the type of IMLD, especially when the diagnosis is unclear. Combining molecular testing with existing criteria could provide an additional diagnostic tool, improving patient care and response to treatment.

Mechanisms of Tolerance Induction in Liver Transplantation: Lessons Learned from Fetomaternal Tolerance, Autoimmunity and Tumor Immunity

Since the first published report of experimental kidney transplantation in dogs in 1902, there were many experimental and clinical trials of organ transplantation, with many sacrifices. After the establishment of the surgical technique and the discovery of immunosuppressive drugs, transplantation became the definitive treatment strategy for patients with terminal organ failure. However, this is not a common therapy method due to the difficulty of solving the fundamental issues behind organ transplantation, including the shortage of donor graft, potential risks of transplant surgery and economic capability. The pre- and post-transplant management of recipients is another critical issue that may affect transplant outcome. Most liver transplant recipients experience post-transplant complications, including infection, acute/chronic rejection, metabolic syndrome and the recurrence of hepatocellular carcinoma. Therefore, the early prediction and diagnosis of these complications may improve overall and disease-free survival. Furthermore, how to induce operational tolerance is the key to achieving the ultimate goal of transplantation. In this review, we focus on liver transplantation, which is known to achieve operational tolerance in some circumstances, and the mechanical similarities and differences between liver transplant immunology and fetomaternal tolerance, autoimmunity or tumor immunity are discussed.

Role of the type 3 cytokines IL-17 and IL-22 in modulating metabolic dysfunction-associated steatotic liver disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) comprises a spectrum of liver diseases that span simple steatosis, metabolic dysfunction-associated steatohepatitis (MASH) and fibrosis and may progress to cirrhosis and cancer. The pathogenesis of MASLD is multifactorial and is driven by environmental, genetic, metabolic and immune factors. This review will focus on the role of the type 3 cytokines IL-17 and IL-22 in MASLD pathogenesis and progression. IL-17 and IL-22 are produced by similar adaptive and innate immune cells such as Th17 and innate lymphoid cells, respectively. IL-17-related signaling is upregulated during MASLD resulting in increased chemokines and proinflammatory cytokines in the liver microenvironment, enhanced recruitment of myeloid cells and T cells leading to exacerbation of inflammation and liver disease progression. IL-17 may also act directly by activating hepatic stellate cells resulting in increased fibrosis. In contrast, IL-22 is a pleiotropic cytokine with a dominantly protective signature in MASLD and is currently being tested as a therapeutic strategy. IL-22 also exhibits beneficial metabolic effects and abrogates MASH-related inflammation and fibrosis development via inducing the production of anti-oxidants and anti-apoptotic factors. A sex-dependent effect has been attributed to both cytokines, most importantly to IL-22 in MASLD or related conditions. Altogether, IL-17 and IL-22 are key effectors in MASLD pathogenesis and progression. We will review the role of these two cytokines and cells that produce them in the development of MASLD, their interaction with host factors driving MASLD including sexual dimorphism, and their potential therapeutic benefits.

Ursodeoxycholic acid and 18β-glycyrrhetinic acid alleviate ethinylestradiol-induced cholestasis via downregulating RORγt and CXCR3 signaling pathway in iNKT cells

Estrogen-induced intrahepatic cholestasis (IHC) is a mild but potentially serious risk and urges for new therapeutic targets and effective treatment. Our previous study demonstrated that RORγt and CXCR3 signaling pathway of invariant natural killer T (iNKT) 17 cells play pathogenic roles in 17α-ethinylestradiol (EE)-induced IHC. Ursodeoxycholic acid (UDCA) and 18β-glycyrrhetinic acid (GA) present a protective effect on IHC partially due to their immunomodulatory properties. Hence in present study, we aim to investigate the effectiveness of UDCA and 18β-GA in vitro and verify the accessibility of the above targets. Biochemical index measurement indicated that UDCA and 18β-GA presented efficacy to alleviate EE-induced cholestatic cytotoxicity. Both UDCA and 18β-GA exhibited suppression on the CXCL9/10-CXCR3 axis, and significantly restrained the expression of RORγt in vitro. In conclusion, our observations provide new therapeutic targets of UDCA and 18β-GA, and 18β-GA as an alternative treatment for EE-induced cholestasis.

Autoimmune Hepatitis: Pathophysiology

Genome-wide association analyses suggest that HLA genes including HLA-DRB*0301, HLA-DRB*0401, and HLA-B*3501 as well as non-HLA genes including CD28/CTLA4/ICOS and SYNPR increased AIH susceptibility. The destruction of hepatocytes is the result of the imbalance between proinflammatory cells and immunosuppressive cells, especially the imbalance between Tregs and Th17 cells. The microbiome in patients with AIH is decreased in diversity with a specific decline in Bifidobacterium and enrichment in Veillonella and Faecalibacterium. Recent evidence has demonstrated the pathogenic role of E. gallinarum and L.reuteri in inducing autoimmunity in the liver.

Noninvasive biomarkers for the diagnosis and management of autoimmune hepatitis

Autoimmune hepatitis (AIH) is a rare disease of unclear etiology characterized by loss of self-tolerance that can lead to liver injury, cirrhosis, and acute liver failure. First-line treatment consists of systemic corticosteroids, or budesonide, and azathioprine, to which most patients are initially responsive, although predictors of response are lacking. Relapses are very common, correlate with histological activity despite normal serum transaminases, and increase hepatic fibrosis. Furthermore, current regimens lead to adverse effects and reduced quality of life, whereas medication titration is imprecise. Biomarkers that can predict the clinical course of disease, identify patients at elevated risk for relapse, and improve monitoring and medication dosing beyond current practice would have high clinical value. Herein, we review novel candidate biomarkers in adult and pediatric AIH based on prespecified criteria, including gene expression profiles, proteins, metabolites, and immune cell phenotypes in different stages of AIH. We also discuss biomarkers relevant to AIH from other immune diseases. We conclude with proposed future directions in which biomarker implementation into clinical practice could lead to advances in personalized therapeutic management of AIH.

Disturbance in Serum Levels of IL-17 and TGF-β1 and in Gene Expression of ROR-γt and FOX-P3 Is Associated with Pathogenicity of Systematic Lupus Erythematosus

To investigate the disturbance in serum levels of interleukin-17 (IL-17) and transforming growth factor-beta1 (TGF-β1) and gene expression of retinoic acid-related orphan receptor-gamma t (ROR-γt) and forkhead box-P3 (FOX-P3) in patients with systemic lupus erythematosus (SLE) and to study their association with disease pathogenicity and activity. Newly diagnosed active patients with SLE (n=88) and healthy volunteers (n=70) were included. Serum IL-17 and TGF-β1 were measured using enzyme-linked immunosorbent assay. Gene-expression profiles of ROR-γt and FOX-P3 were screened using real-time polymerase chain reaction. The IL-17/TGF-β1 and ROR-γt/FOX-P3 levels were also calculated. The mean age of the patients was 30.96±8.25 years; they were 82 women and 6 men. Of the patients, 11.4% manifested mild disease while 88.6% had severe disease. The serum level of TGF-β1 was significantly lower (70.2±34.9 vs. 200.23±124.77 pg/ml), while both IL-17 (614.7±317.5 vs. 279.76±110.65 pg/ml) and IL-17/TGF-β1 (18.5±30.1 vs. 1.66±0.9) levels were significantly higher, in patients than in controls (p<0.0001). The gene-expression level of FOX-P3 (0.6±0.8 vs. 13.68±39.35) was reported to be lower, while ROR-γt (3.9±3.5 vs. 1.99±2.09) and ROR-γt/FOX-P3 (18.6±21.1 vs. 7.63±17.19) levels were significantly higher, in patients than in controls (p<0.0001). Disturbance in serum levels of IL-17 and TGF-β1 in T helper-17 and T-regulatory cells proliferation was highlighted through an imbalance in the gene expression of FOX-P3 and ROR-γt, as both are signature genes for the two cell types, respectively. These findings underscore the critical role of IL-17 and TGF-β1 in SLE development, rendering them potential targets for developing novel immunotherapeutic strategies.

T-Regulatory Cells in Erythema Nodosum Leprosum: An Immunohistochemical and Image Morphometric Study

ABSTRACT

Erythema nodosum leprosum (ENL) occurs as an immune-inflammatory complication of multibacillary leprosy (MBL), precipitated by an interaction between the host, bacilli, and the environment. This complication often causes significant morbidity due to systemic involvement and needs to be treated aggressively. T-regulatory cells (T-regs) are the immunomodulatory subset of T cells that are hypothesized to play a role in ENL. We have performed immunohistochemistry for FoxP3 (T-reg), CD3 (pan-T), CD4 (helper T), and CD8 (cytotoxic T) on 50 biopsy-proven cases of ENL along with 84 biopsy-proven cases of paucibacillary leprosy (PBL) (n = 49) and MBL (n = 35). Image morphometry was applied to objectively assess the relative preponderance of these subsets of T cells. The area fraction of T-regs showed a trend of reduction from PBL to MBL to ENL (P = 0.068), whereas the FoxP3:CD3 (T-reg: pan-T) ratio showed a significant reduction across these groups (P = 0.023). However, there was no significant difference of T-regs or FoxP3:CD3 ratio between MBL and ENL. The T-regs showed a significant positive correlation (P = 0.007) with the cytotoxic T cells in the skin biopsy. The presence of dermal eosinophils in ENL showed a trend association with the FoxP3:CD3 ratio (P = 0.05). Various histopathological parameters including epidermal spongiosis, dermal stromal edema, dermal ill-formed granuloma, and the presence of bacilli within the endothelium and vascular smooth muscle correlated with various T-cell subsets. Our study, one of the largest on this topic, objectively assessed the role of T-regs in the spectrum of leprosy. Nevertheless, the precipitation of ENL from MBL is probably not associated with the T-reg subset alone.

Enhanced Th17 Responses in Patients with Autoimmune Hepatitis

BACKGROUND

T cells are major players in chronic inflammatory diseases such as autoimmune hepatitis (AIH). However, it is not clear which subset of T cells participates in the pathophysiology of the disease. The aim of this study was to assess the expression profile of signature transcription factor and cytokines of T helper 17 (Th17) cells in patients with AIH.

METHODS

A total of 24 patients with AIH and 24 normal subjects were recruited in the study. Comparison of gene expression patterns between the patients and normal subjects was done by quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR).

RESULTS

The results showed that retinoic acid receptor-related orphan receptors gamma (RORɣt), interleukin-17A (IL-17A), and interleukin-22 (IL-22) mRNA expression were increased greatly in the patients group compared with the normal controls group (p < 0.05).

CONCLUSION

Deregulated production of Th17-related molecules may be associated with the pathogenesis of AIH.

Dual effect of T helper cell 17 (Th17) and regulatory T cell (Treg) in liver pathological process: From occurrence to end stage of disease

Liver disease is a complicated pathological status with acute or chronic progressions, causing a series of damages to liver and massive burden to public health and society. Th17 and Treg, two subsets of CD4⁺ T helper cells, seem to keep a subtle balance in the maintenance of organic immune homeostasis including liver. The dysfunction of Th17/Treg balance in liver has been proved associated with hepatic injury and disease. Herein, we summarized the research advance of Th17 and Treg cells in different phenotypes of liver diseases in the past decade. It is known to all that hepatic diseases start from stimulations or infections like virus, autoimmune, alcohol and so on in the early stage, which would cause inflammation. With the disease consistently existed, severe outcomes like cirrhosis and hepatocellular carcinoma appear finally. In conclusion, it is found that Th17 and Treg cells serve as an important role in the immune response imbalance of liver diseases from the beginning to the end stage. However, the effect of these two subsets of CD4⁺ T helper cells is not a stereotype. Pathological role which exacerbates the disease and protective character which inhibits damage to liver are co-existed in the effect of Th17 and Treg cells. Still, more studies should be carried out to enrich the understandings of liver disease and Th17/Treg immune balance in the future.

Immunity and Fibrogenesis: The Role of Th17/IL-17 Axis in HBV and HCV-induced Chronic Hepatitis and Progression to Cirrhosis

Cirrhosis is a common final pathway for most chronic liver diseases; representing an increasing burden worldwide and is associated with increased morbidity and mortality. Current evidence has shown that, after an initial injury, the immune response has a significant participation in the ongoing damage, and progression from chronic viral hepatitis (CVH) to cirrhosis, driving the activation and maintenance of main fibrogenic pathways. Among immune deregulations, those related to the subtype 17 of T helper lymphocytes (Th17)/interleukin-17 (IL-17) axis have been recognized as key immunopathological and prognostic elements in patients with CVH. The Th17/IL-17 axis has been found involved in several points of fibrogenesis chain from the activation of stellate cells, increased expression of profibrotic factors as TGF-β, promotion of the myofibroblastic or epithelial–mesenchymal transition, stimulation of the synthesis of collagen, and induction of imbalance between matrix metalloproteinases and tissue inhibitors of metalloproteinases (TIMPs). It also promotes the recruitment of inflammatory cells and increases the expression of proinflammatory cytokines such as IL-6 and IL-23. So, the Th17/IL-17 axis is simultaneously the fuel and the flame of a sustained proinflammatory and profibrotic environment. This work aims to present the immunopathologic and prognostic role of the Th17/IL-17 axis and related pathways in fibrogenesis and progression to cirrhosis in patients with liver disease due to hepatitis B virus (HBV) and hepatitis C virus (HCV).

Deranged regulatory T-cells and transforming growth factor-β1 levels in type 1 diabetes patients with associated autoimmune diseases

Aim:

This study was designed to enumerate regulatory T-cells (Tregs) and estimate transforming growth factor-β1 (TGF-β1) levels in type 1 diabetic (T1D) patients with respect to disease duration and associated autoimmune diseases.

Methods:

One hundred and fifty patients and twenty healthy controls were recruited in the study. The patients were subcategorized into eight categories on the basis of disease duration (new onset [NO] and long standing [LS]) and associated diseases, i.e., celiac disease (CD) and autoimmune thyroid disease (AiTD). Treg cells were assessed as CD4⁺ CD25^hi+, FOXP3⁺ cells and serum TGF-β1 levels were assessed by ELISA.

Results:

The frequency of Tregs and levels of TGF-β1 were significantly increased in the patients compared to the healthy controls. Among the different categories of the patients, no significant differences were seen for TGF- β1 levels, but for Tregs in patients with T1D and AiTD (P = 0.035). A significant correlation was also found between percentage count of Tregs and TGF-β1 levels in NO cases in all disease subcategories, but not in LS patients.

Conclusion:

Thus, there was an increased percentage of Tregs and serum levels of TGF-β1 in T1D patients, irrespective of the disease duration and associated autoimmune diseases. The significant correlation in these two parameters at the onset of the disease, but not in LS disease, indicates that the immunological milieu in LS autoimmune diseases is more complicated with disease-associated conditions such as prolonged hyperglycemia, insulin therapy, and/or continued gluten in diet. Treatment and modulation of these long-term complications for improving immunological parameters require further research.

Clinical significance of changes in the Th17/Treg ratio in autoimmune liver disease

AIM

To investigate the levels, ratios, and clinical significance of T helper 17 (Th17) cells and regulatory T (Treg) cells in the peripheral blood of patients with autoimmune liver disease (AILD).

METHODS

Forty-two AILD patients were included in the experimental group (group E), and 11 healthy subjects were recruited as the control group (group C). Flow cytometry was performed to determine the percentages of Th17 and Treg cells in peripheral blood lymphocytes. Furthermore, a range of biochemical indices was measured simultaneously in the blood of group E patients.

RESULTS

The percentage of Th17 cells and the Th17/Treg ratio were higher in group E than in group C (P < 0.01), whereas the percentage of Tregs was lower in the group E patients (P < 0.05). Patients in group E who were admitted with AILD in the active stage showed significantly higher Th17 percentages and Th17/Treg ratios than those measured in patients with AILD in remission (P < 0.05). In addition, among patients with AILD in the active stage, individuals that remained unhealed after hospitalization showed significantly higher baseline values of the Th17 percentage and the Th17/Treg ratio than those detected in patients who improved after treatment (P < 0.05). The results suggested that imbalance in the Th17/Treg ratio plays an important role in the pathogenesis and development of AILD.

CONCLUSION

A high Th17/Treg ratio appears to predict poor short-term prognosis in patients with AILD in the active stage.