Autoimmune liver diseases and SARS-CoV-2.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), causing coronavirus disease 2019 (COVID-19), can trigger autoimmunity in genetically predisposed individuals through hyperstimulation of immune response and molecular mimicry. Here we summarise the current knowledge about auto-immune liver diseases (AILDs) and SARS-CoV-2, focusing on: (1) The risk of SARS-CoV-2 infection and the course of COVID-19 in patients affected by AILDs; (2) the role of SARS-CoV-2 in inducing liver damage and triggering AILDs; and (3) the ability of vaccines against SARS-CoV-2 to induce autoimmune responses in the liver. Data derived from the literature suggest that patients with AILDs do not carry an increased risk of SARS-Cov-2 infection but may develop a more severe course of COVID-19 if on treatment with steroids or thiopurine. Although SARS-CoV-2 infection can lead to the development of several autoimmune diseases, few reports correlate it to the appearance of de novo manifestation of immune-mediated liver diseases such as autoimmune hepatitis (AIH), primary biliary cholangitis (PBC) or AIH/PBC overlap syndrome. Different case series of an AIH-like syndrome with a good prognosis after SARS-CoV-2 vaccination have been described. Although the causal link between SARS-CoV-2 vaccines and AIH cannot be definitively established, these reports suggest that this association could be more than coincidental.

Concurrence of Guillain-Barré syndrome and primary biliary cholangitis not related to SARS-CoV-2: Case report. / Concurrencia de síndrome de Guillain-Barré y colangitis biliar primaria no vinculado a SARS-CoV-2: reporte de caso.

Introduction: Guillain-Barré syndrome is a polyradiculoneuropathy of autoimmune origin, considered the most frequent cause of acute flaccid paralysis. Various associations of Guillain-Barré syndrome with other non-neurological autoimmune diseases have been reported, some of them extremely rare, such as that which occurs with primary biliary cholangitis, a chronic disease of autoimmune etiology whose diagnosis is also supported by the clinical picture. , in the alteration of liver enzymes and the presence of anti-mitochondrial antibodies. Clinical case: A 38-year-old male patient, with no history of previous comorbidities, who, after presenting with diarrheal disease two weeks prior, developed subacute onset ascending weakness associated with paresthesias in four extremities that progressed to quadriplegia and respiratory distress. Cerebrospinal fluid cytochemistry was performed, which showed albuminocytological dissociation and electromyography, which showed findings compatible with acute motor axonal neuropathy, for which he received treatment with intravenous immunoglobulin at 0.4g/kg/day, achieving improvement in the neurological condition. Since admission and during hospitalization, he presented persistent changes in liver enzymes which followed a cholestatic pattern, in addition to mild abdominal pain and generalized itching, for which he was evaluated by gastroenterology, who requested anti-mitochondrial antibodies that were positive. Concluding in the diagnosis of primary biliary cholangitis. Conclusion: The present case shows an extremely rare association of two autoimmune diseases Guillain-Barré syndrome and primary biliary cholangitis, so much so that it represents the first case reported, not linked to SARS-CoV-2.

Introducción: El síndrome de Guillain-Barré es una polirradiculoneuropatia de origen autoinmune, considerada la causa más frecuente de parálisis flácida aguda. Se han reportado diversas asociaciones del síndrome de Guillain-Barré con otras enfermedades autoinmunes no neurológicas, algunas de ellas extremadamente raras, como la que ocurre con la colangitis biliar primaria, una enfermedad crónica de etiología autoinmune cuyo diagnóstico se sustenta, además del cuadro clínico, en la alteración de las enzimas hepáticas y la presencia de anticuerpos anti-mitocondriales. Caso clínico: Paciente varón de 38 años, sin antecedente de comorbilidades previas, quien luego de presentar enfermedad diarreica dos semanas antes, desarrolló debilidad ascendente de inicio subagudo asociado a parestesias en cuatro extremidades que progresó hasta generar cuadriplejia y dificultad respiratoria. Se le realizó examen citoquímico de líquido cefalorraquídeo que evidenció disociación albumino-citológica y electromiografía que mostró hallazgos compatibles con neuropatía axonal motora aguda. Recibió tratamiento con inmunoglobulina intravenosa a dosis de 0,4 gramos por kilogramo al día, logrando mejoría del cuadro neurológico. Desde su ingreso y durante la hospitalización, presentó alteración persistente de las enzimas hepáticas que seguía un patrón colestásico. Además, se agregó dolor abdominal de leve intensidad y prurito generalizado, por lo cual fue evaluado por gastroenterología, quienes solicitaron anticuerpos anti-mitocondriales que resultaron positivos. Con esta prueba, se comprobó el diagnóstico de colangitis biliar primaria. Conclusión: El presente caso muestra una asociación extremadamente rara de dos enfermedades autoinmunes; síndrome de Guillain-Barré y colangitis biliar primaria, tanto así que representa el primer caso reportado, no vinculado a SARS-CoV-2.

The Genetics of Primary Biliary Cholangitis: A GWAS and Post-GWAS Update.

Primary biliary cholangitis (PBC) is a chronic, progressive cholestatic liver disease in which the small intrahepatic bile ducts are destroyed by autoimmune reactions. Among autoimmune diseases, which are polygenic complex traits caused by the combined contribution of genetic and environmental factors, PBC exhibits the strongest involvement of genetic heritability in disease development. As at December 2022, genome-wide association studies (GWASs) and associated meta-analyses identified approximately 70 PBC susceptibility gene loci in various populations, including those of European and East Asian descent. However, the molecular mechanisms through which these susceptibility loci affect the pathogenesis of PBC are not fully understood. This study provides an overview of current data regarding the genetic factors of PBC as well as post-GWAS approaches to identifying primary functional variants and effector genes in disease-susceptibility loci. Possible mechanisms of these genetic factors in the development of PBC are also discussed, focusing on four major disease pathways identified by in silico gene set analyses, namely, (1) antigen presentation by human leukocyte antigens, (2) interleukin-12-related pathways, (3) cellular responses to tumor necrosis factor, and (4) B cell activation, maturation, and differentiation pathways.

Ursodeoxycholic acid is associated with a reduction in SARS-CoV-2 infection and reduced severity of COVID-19 in patients with cirrhosis.

BACKGROUND AND AIMS: Studies have demonstrated that reducing farnesoid X receptor activity with ursodeoxycholic acid (UDCA) downregulates angiotensin-converting enzyme in human lung, intestinal and cholangiocytes organoids in vitro, in human lungs and livers perfused ex situ, reducing internalization of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) into the host cell. This offers a potential novel target against coronavirus disease 2019 (COVID-19). The objective of our study was to compare the association between UDCA exposure and SARS-CoV-2 infection, as well as varying severities of COVID-19, in a large national cohort of participants with cirrhosis. METHODS: In this retrospective cohort study among participants with cirrhosis in the Veterans Outcomes and Costs Associated with Liver cohort, we compared participants with exposure to UDCA, with a propensity score (PS) matched group of participants without UDCA exposure, matched for clinical characteristics, and vaccination status. The outcomes included SARS-CoV-2 infection, symptomatic, at least moderate, severe, or critical COVID-19, and COVID-19-related death. RESULTS: We compared 1607 participants with cirrhosis who were on UDCA, with 1607 PS-matched controls. On multivariable logistic regression, UDCA exposure was associated with reduced odds of developing SARS-CoV-2 infection (adjusted odds ratio [aOR] 0.54, 95% confidence interval [CI] 0.41-0.71, p < 0.0001). Among patients who developed COVID-19, UDCA use was associated with reduced disease severity, including symptomatic COVID-19 (aOR 0.54, 95% CI 0.39-0.73, p < 0.0001), at least moderate COVID-19 (aOR 0.51, 95% CI 0.32-0.81, p = 0.005), and severe or critical COVID-19 (aOR 0.48, 95% CI 0.25-0.94, p = 0.03). CONCLUSIONS: In participants with cirrhosis, UDCA exposure was associated with both a decrease in SARS-CoV-2 infection, and reduction in symptomatic, at least moderate, and severe/critical COVID-19.

Antimitochondrial Antibodies: from Bench to Bedside.

Anti-mitochondrial antibodies (AMA) are directed against the E2 subunits of the 2-oxo acid dehydrogenase complexes (PDC-E2) and are the typical biomarkers of primary biliary cholangitis (PBC), being present in 90-95% of patients, with increasing sensitivity at increasing titers. Albeit being highly specific for PBC diagnosis, AMA can be detected in less than 1% of healthy subjects, and thus the management subjects with no sign or symptom of liver disease is still a challenge and data concerning clinical risk of developing PBC in this subgroup of patients are controversial. Moreover, AMA can also be detected in patients affected by overlap syndrome, as well as hepatic diseases (i.e., NASH and viral hepatitis), while the association with autoimmune diseases, in particular Sjögren's syndrome, systemic sclerosis, and systemic lupus erythematosus, is well established. Furthermore, new associations are being identified with inflammatory myositis and heart disease. AMA are directed towards the pyruvate dehydrogenase multi enzyme complex (PDC-E2) subunit, which represents an epithelial specific autoantigen for PBC. This review focuses on the main characteristics of AMA, their association with autoimmune diseases and liver diseases.

Predictors of serious adverse events and non-response in cirrhotic patients with primary biliary cholangitis treated with obeticholic acid.

BACKGROUND & AIMS: Obeticholic acid (OCA) has recently been restricted in patients with primary biliary cholangitis (PBC) with "advanced cirrhosis" because of its narrow therapeutic index. We aimed to better define the predicting factors of hepatic serious adverse events (SAEs) and non-response in cirrhotic patients undergoing OCA therapy. METHODS: Safety and efficacy of treatment were evaluated in a cohort of consecutive PBC cirrhotic patients started with OCA. OCA response was evaluated according to the Poise criteria. Risk factors for hepatic SAEs and non-response were reported as risk ratios (RR) with 95% confidence intervals (CIs). RESULTS: One hundred PBC cirrhotics were included, 97 Child-Pugh class A and 3 class B. Thirty-one had oesophageal varices and 5 had a history of ascites. Thirty-three per cent and 32% of patients achieved a biochemical response at 6 and 12 months respectively. Male sex (adjusted-RR 1.75, 95%CI 1.42-2.12), INR (1.37, 1.00-1.87), Child-Pugh score (1.79, 1.28-2.50), MELD (1.17, 1.04-1.30) and bilirubin (1.83, 1.11-3.01) were independently associated with non-response to OCA. Twenty-two patients discontinued OCA within 12 months: 10 for pruritus, 9 for hepatic SAEs (5 for jaundice and/or ascitic decompensation; 4 for upper digestive bleeding). INR (adjusted-RR 1.91, 95%CI 1.10-3.36), lower albumin levels (0.18, 0.06-0.51), Child-Pugh score (2.43, 1.50-4.04), history of ascites (3.5, 1.85-6.5) and bilirubin (1.30, 1.05-1.56), were associated with hepatic SAEs. A total bilirubin≥1.4 mg/dl at baseline was the most accurate biochemical predictor of hepatic SAEs under OCA. CONCLUSIONS: An accurate baseline assessment is crucial to select cirrhotic patients who can benefit from OCA. Although OCA is effective in one third of cirrhotics, bilirubin level ≥1.4 mg/dl should discourage from its use.

SARS-CoV-2 vaccine, a new autoimmune hepatitis trigger?

SARS-CoV2 infection and vaccination against this virus have been related to the development of autoimmune diseases. We report a case of autoimmune hepatitis (AIH) after SARS-COV2 vaccine. Male, 76 years old, with a history of hepatic cirrhosis secondary to primary biliary cholangitis (PBC), compensated, treated with ursodeoxycholic acid and obeticholic acid. The patient received the third dose of the SARS-CoV2 vaccine (BioNTech/Pfizer) in December 2021. In subsequent analytical control, the patient presented altered liver test, with elevation of ALT and AST. Ultrasound was performed, without alterations, and viral causes were ruled out. IgG elevation and positive antinuclear antibodies were observed. A liver biopsy was performed, with findings of intense interface and lobular hepatitis and areas of centrilobular necrosis. The inflammation was predominantly lymphoplasmacytic. The patient was diagnosed with AIH and initiated therapy with steroids and azathioprine, currently with an adequate response. AIH is an immune-mediated disease of uncertain etiology. Cases of AIH with SARS-CoV2 vaccination as a possible trigger have recently been published, with characteristics similar to ours. Some of them had a history of autoimmune pathology, such as this case (PBC). Therefore, it is suggested that vaccination can induce the development of autoimmune pathology in patients at risk. Our reported case reinforces the hypothesis of an association between AIH and the SARS-CoV2 vaccine.

SARS-CoV-2 vaccination response in patients with autoimmune hepatitis and autoimmune cholestatic liver disease.

BACKGROUND/AIMS: In this observational study, we explored the humoral and cellular immune response to SARS-CoV-2 vaccination in patients with autoimmune hepatitis (AIH) and patients with cholestatic autoimmune liver disease (primary sclerosing cholangitis [PSC] and primary biliary cholangitis [PBC]). METHODS: Anti-SARS-CoV-2 antibody titers were determined using the DiaSorin LIAISON and Roche immunoassays in 103 AIH, 64 PSC, and 61 PBC patients and 95 healthy controls >14 days after the second COVID-19 vaccination. The spike-specific T-cell response was assessed using an activation-induced marker assay (AIM) in a subset of individuals. RESULTS: Previous SARS-CoV-2 infection was frequently detected in AIH but not in PBC/PSC (10/112 (9%), versus 4/144 (2.7%), p = 0.03). In the remaining patients, seroconversion was measurable in 97% of AIH and 99% of PBC/PSC patients, respectively. However, in 13/94 AIH patients antibody levels were lower than in any healthy control, which contributed to lower antibody levels of the total AIH cohort when compared to PBC/PSC or controls (641 vs. 1020 vs. 1200 BAU/ml, respectively). Notably, antibody levels were comparably low in AIH patients with (n = 85) and without immunosuppression (n = 9). Also, antibody titers significantly declined within 7 months after the second vaccination. In the AIM assay of 20 AIH patients, a spike-specific T-cell response was undetectable in 45% despite a positive serology, while 87% (13/15) of the PBC/PSC demonstrated a spike-specific T-cell response. CONCLUSION: Patients with AIH show an increased SARS-CoV-2 infection rate as well as an impaired B- and T-cell response to SARS-CoV-2 vaccine compared to PBC and PSC patients, even in the absence of immunosuppression. Thus, antibody responses to vaccination in AIH patients need to be monitored and early booster immunizations considered in low responders.

A comparison of COVID-19 secondary attack rate in household and close contacts compared to current risk stratification guidelines of the Kerala government.

COVID-19 has been found to be highly infectious with a high secondary attack rate with a R0 of 3.3. However, the secondary attack rate based on risk stratification is sparsely reported, if ever. We studied the contact tracing data for two index cases of COVID-19 with some overlap of contacts. We found that 60% of high-risk contacts and 0% of low-risk contacts of symptomatic COVID-19 patients contracted the infection, in keeping with the Kerala government contact risk stratification guidelines.