# Leptin, vitamin D, and APRI values during the six months post-liver transplantation

## TL;DR

This study explores how leptin, vitamin D, and APRI values change after liver transplantation and their role in liver fibrosis progression.

## Contribution

The study identifies leptin and vitamin D as potential biomarkers for liver fibrosis and explores their relationship with extracellular matrix proteins.

## Key findings

- Serum leptin and APRI values decreased significantly after liver transplantation.
- Serum vitamin D levels increased significantly after liver transplantation.
- Leptin and vitamin D are linked to extracellular matrix proteins involved in liver fibrosis.

## Abstract

Liver fibrosis is a common outcome of chronic liver disease, characterized by accumulating extracellular matrix proteins. Aims: While the gold standard in the assessment of liver fibrosis remains liver biopsy, non-invasive methods have been increasingly used for estimating liver fibrosis. This study aims at contributing to our understanding of the role of leptin,vitamin D, APRI, and FIB-4 in the progression of liver disease. For this purpose, we evaluate the clinical significance of leptin, vitamin D, APRI, and FIB-4 in cirrhotic patients with different ratios of steatosis and in cirrhotic pateints with different grades of hepatocellular carcinoma. We compare the performance of simple biochemical scores (FIB-4 and APRI) with leptin and vitamin D. Also, We identified the proteins in the serum of liver fibrosis and showed the role of these proteins in the pathogenesis of liver fibrosis. Also, we identified the relationship between leptin and vitamin D with extracellular matrix proteins using bioinformatics analysis.

The current study included 50 liver fibrosis patients who underwent liver transplantation. We measured the levels of serum vitamin D and leptin in these patients at pre-LT and three- and six-months post-LT using enzyme-linked immunosorbent assay. We performed qualitative proteomic analysis to identify the proteins in the sera from patients with liver fibrosis. Among these proteins, there are extracellular matrix proteins. One-way ANOVA test was used.

We found that serum leptin levels and APRI values were significantly higher in liver fibrosis patients than in controls, after three- and six-months following LT serum leptin levels and APRI values significantly decreased. While serum vitamin D levels were significantly lower in liver fibrosis patients than in controls, after three- and six-months following LT, serum vitamin D levels significantly increased. ROC curves analysis showed that the area under the curve (AUC) of vitamin D and leptin was 1 and 0.997, respectively. Gene ontology analysis demonstrated that the proteins participate in a diverse array of biological processes, emphasizing the systemic effects of liver fibrosis disease. From the STRING database, the proteins are at least partially biologically connected, as a group with leptin and vitamin D explaining the promiscuous nature of leptin and vitamin D. This emphasized the role of leptin and vitamin D in accumulation and increased synthesis of extracellular matrix proteins that incorporated in the pathogenesis of liver fibrosis, and showed that the leptin and vitamin D are involved in the pathogenesis process where the total proteins are involved.

In summary, serum vitamin D and leptin could serve as a valuable supplemental biomarker for predicting the liver fibrosis.