To quantitatively detect CD44 expression in patients with nonalcoholic fatty liver disease (NAFLD) for comparative analysis.

Patients with chronic liver diseases accompanied with or without NAFLD, including chronic hepatitis B, cirrhosis and hepatocellular carcinoma after chronic hepatitis B, and healthy blood donors as normal controls who admitted to the Affiliated Hospital of Nantong University from May to October 2018 were selected. The proportion of CD44 positive cells was analyzed by flow cytometry. CD44 level was quantified by an enzyme-linked immunosorbent assay, and the biochemical indicators such as serum aspartate aminotransferase, alanine aminotransferase activity, total cholesterol and triglyceride were routinely analyzed. The cancerous and adjacent cancerous tissues of patients accompanied with or without NAFLD were collected by self-matching method and analyzed by immunoblotting and histochemistry and compared by CD44 integrated optical density. Image-Pro Plus version 6.0, Image J, GraphPad Prism 5.0, Photoshop, Microsoft Excel and IBM SPSS statistics 23 were used to analyze and draw pictures. An independent sample t-test was used to compare the differences between groups.

Patients accompanied with NAFLD had hepatocyte injury and dyslipidemia. NAFLD and chronic liver disease patients had significantly elevated serum CD44 levels than normal control group (P < 0.01). CD44 positive lymphocyte ratio was 78.19 % ± 16.33 % in NAFLD patients and 68.47% ± 20.91% in chronic hepatitis B group, which was higher than the control group (46.51% ± 20.52%). Chronic hepatitis B group with steatosis had significantly higher CD44 concentration (181.42 ± 49.36) ng/ml than chronic hepatitis B group (142.52 ± 53.87) ng/ml and normal control group (99.47 ± 15.23) ng/ml. CD44/GAPDH ratio in the liver cancer group (1.306 ± 0.614) was significantly higher than paracancerous group (0.477 ± 0.291) and the difference between the two groups was statistically significant ( t = 3.451, P = 0.004). The integrated optical density of CD44 in the NAFLD-related liver cancer and paracancerous group were 25.721 ± 5.881 and 14.155 ± 4.001 and the difference between the groups was statistically significant (t = 14.544, P < 0.001). The pathological features of high expression of CD44 in patients with hepatocellular carcinoma were significantly correlated with HBV infection, tumor size, single/multi-center, and lymph node metastasis, degree of differentiation, TNM grade, Child-Pugh score, portal vein tumor thrombus and extrahepatic metastasis. HCC patients with NAFLD had significantly higher serum CD44 (234.62 ± 69.40) ng/ml than patients without NAFLD (186.49 ± 58.89) ng/ml ( t = -3.191, P = 0.002), but there was no statistically significant difference in the clinicopathological characteristics between the high/low CD44 groups of HCC patients with NAFLD.

The results suggest that CD44 is abnormally activated and its mechanism may play an important role in the progression of NAFLD.

Fatty liver, alcoholic; Liver diseases; Signal molecule