Vitamin D supplementation for autoimmune hepatitis: A need for further investigation

Autoimmune Hepatitis and Vitamin D Deficiency: A Nationwide Perspective

BACKGROUND

Vitamin D deficiency is linked to worse outcomes in patients with chronic liver diseases (CLD). However, data in patients with autoimmune hepatitis (AIH) remain limited.

AIMS

We aimed to assess the impact of vitamin D deficiency on the outcomes of individuals with AIH.

METHODS

This retrospective cohort study used the TriNetX research network to identify patients with AIH. Patients were matched using propensity score matching and stratified to sufficient vitamin D levels (e.g., 25 (OH) D3 ≥ 30 ng/mL), vitamin D insufficiency (25 (OH) D3: 20-29.9 ng/mL) and vitamin D deficiency (e.g., 25 (OH) D3 < 20 ng/mL). The primary outcome was the all-cause mortality among adult patients with AIH. Secondary outcomes included decompensated liver cirrhosis, acute hepatic failure, liver transplantation (LT), all-cause hospitalizations and all-cause critical care admissions.

RESULTS

A total of 1288 AIH patients with vitamin D deficiency were identified and propensity matched with 1288 patients with normal vitamin D levels. Patients with vitamin D deficiency had significantly increased odds for all-cause mortality compared to those with normal levels (adjusted odds ratio (aOR) = 3.2, 95%CI: 2.3-4.48). Patients with vitamin D deficiency were at increased odds of all-cause hospitalizations (aOR = 2.37, 95%CI: 1.97-2.84), critical care unit admissions (aOR = 2.8, 95%CI: 2.21-3.71), decompensated liver cirrhosis (aOR = 2.74, 95%CI: 2.13-3.54), acute hepatic failure (aOR = 3.11, 95%CI: 2.09-4.62) and LT (aOR = 3.47, 95%CI: 1.71-7.04), as compared to those with normal vitamin D levels.

CONCLUSION

This cohort study showed significantly increased odds for all-cause mortality in AIH patients with vitamin D deficiency. Vitamin D deficiency in patients with AIH was associated with increased likelihood of hospitalisation, decompensated liver cirrhosis, acute liver failure and LT.

L-lysine supplementation attenuates experimental autoimmune hepatitis in a chronic murine model

The incidence of autoimmune hepatitis (AIH) has increased significantly worldwide. The present study aims to explore the protective effect of L-lysine supplementation against AIH and to investigate its potential underlying mechanisms. A chronic experimental AIH mouse model was established by repeated tail vein injection of human cytochrome P450 2D6 (CYP2D6) plasmid. Starting from day 14 of the modeling, mice in the CYP2D6-AIH +L-lysine group were given 200 µl of purified water containing 10 mg/kg L-lysine by gavage until day27, once a day, and mice in the healthy control group and model group were given an equal volume of purified water by gavage. Our results showed that L-lysine supplementation partially reversed the liver injury mediated by CYP2D6 overexpression. These effects were consistent with the restraining impacts of L-lysine supplementation on decreasing pro-inflammatory cytokines expression level and CD4+ and CD8+ T lymphocytes infiltration, as well as curbing hepatic oxidative stress. Furthermore, L-lysine supplement relieved liver fibrosis in the context of AIH. In conclusion, L-lysine supplementation attenuates CYP2D6-induced immune liver injury in mice, which may serve as a novel nutrition support approach for AIH.

COVID-19 vaccination-related autoimmune hepatitis-a perspective

Autoimmune hepatitis (AIH) is the inflammation of the liver with clear-cut interface hepatitis and piecemeal necrosis located at the boundary between portal areas and periportal hepatocytes, and characterized by autoimmunity to hepatocytes with an increase in the antinuclear antibody. After the disastrous SARS-CoV-2 pandemic flagellated several countries, several vaccines have been commercialized and have become a ground for social responsibility. The mRNA vaccines, issued by Pfizer-BioNTech (BNT162b2) and Moderna (mRNA-1273), do not use prebuilt viruses to supply the antigen in the subject's body and are not perfect but have been useful in tackling the pandemic. Nevertheless, both myocarditis and AIH have been reported as side effects of the vaccination programs in addition to thromboembolic events. Here, we explore this topic and give a data-based perspective, gathering a comparison between the titin protein of the sarcomere and myocarditis. The isolation of a Drosophila gene using the serum from a patient with autoimmune scleroderma recognized an epitope on chromosomes (condensed mitotic form) in both human cultured cells and early Drosophila embryos. It revealed that this gene encodes a Drosophila homolog of the vertebrate titin (D-Titin). Moreover, anti-titin antibodies have been found in a subset of patients with myasthenia gravis, a neuromuscular junction disease that is mostly associated with autoimmune antibodies, such as the anti-acetylcholine receptor antibody. The co-existence of myasthenia gravis and autoimmune hepatitis is rare, and a cohort of patients with myasthenia gravis anti-titin antibodies seems to be highly relevant. In consideration of these data and the number of patients who may not be symptomatic, we postulated that autoimmune phenomena may not be exceedingly rare, following the administration of mRNA technology-based vaccines, and a balance between pros and cons in administrating boosters is critical.

Vitamin D–VDR Novel Anti-Inflammatory Molecules—New Insights into Their Effects on Liver Diseases

There is consistent evidence that vitamin D deficiency is strongly associated with liver dysfunction, disease severity, and poor prognosis in patients with liver disease. Vitamin D and its receptor (VDR) contribute to the regulation of innate and adaptive immune responses. The presence of genetic variants of vitamin D- and VDR-associated genes has been associated with liver disease progression. In our recent work, we summarized the progress in understanding the molecular mechanisms involved in vitamin D–VDR signaling and discussed the functional significance of VDR signaling in specific cell populations in liver disease. The current review focuses on the complex interaction between immune and liver cells in the maintenance of liver homeostasis and the development of liver injury, the interplay of vitamin D and VDR in the development and outcome of liver disease, the role of vitamin D- and VDR-associated genetic variants in modulating the occurrence and severity of liver disease, and the therapeutic value of vitamin D supplementation in various liver diseases. The association of the vitamin D–VDR complex with liver dysfunction shows great potential for clinical application and supports its use as a prognostic index and diagnostic tool.