Abstract:

Objective To explore the expression of T cell immunoglobulin and mucin domain protein 3 （Tim-3） on CD56+ NK cells in peripheral blood and its correlation with liver fibrosis indicators in patients with advanced schistosomiasis. Methods Tim-3 expression on CD56+ NK cells from 28 patients with advanced schistosomiasis and 30 healthy controls was determined by flow cytometry. The serum levels of IFN-γ and IL-4 were detected by enzyme-linked immunosorbent assay （ELISA）. Fibroscan analyzer was used for liver stiffness measurement （LSM）to determine the extent of liver fibrosis. Four serological indicators of liver fibrosis, collagen type III N-peptide （PIIIP N-P), Laminin （LN）, collagen IV （CIV） and hyaluronic acid （HA） were measured by the Automated Chemiluminescence Immunoassay Analyzer. Results Flow cytometry analysis showed that Tim-3 expression on CD56+ NK cells in advanced schistosomiasis patients was （62.3±11.4）%, significantly higher than that （52.1±6.5）% （P<0.01）. In patients with advanced schistosomiasis and the healthy controls, the levels of PIIIP N-P were （86.5±29.5） ng/mL and （22.0±7.8） ng/mL, LN （49.3±21.5） ng/mL and （20.4±6.3） ng/mL, CIV （67.5±22.3） ng/mL and （22.0±3.9） ng/mL, HA （645.9±483.1） ng/mL and （54.7± 27.7） ng/mL, respectively. There were significant differences in all these indicators between the two groups （P<0.05）. The levels of IFN-γ were （93.9±20.1） ng/L and （107.7±24.6） ng/L, and those of IL-4 were （46.6±11.8） ng/L and （28.9±8.9） ng/L respectively in patients with advanced schisto-somiasis and the healthy controls, both with significant differences （P<0.05）. Spearman nonparametric correlation analysis showed that Tim-3 expression on CD56+ NK cells in patients was positively correlated with the levels of LSM, PIIIP N-P, LN, CIV and IL-4 （r=0.528-0.834, P<0.01）, but negatively with serum IFN-γ （r=-0.501, P<0.01）. No correlation was found with the HA level （r=0.352, P>0.05）. Conclusion The expression of Tim-3 on peripheral CD56+ NK cells increases in patients with advanced schistosomiasis compared with the healthy controls, and it positively correlates with the levels of LSM, PIIIP N-P, LN, CIV and IL-4, four indicators of liver fibrosis.

Key words: T cell immunoglobulin and mucin domain protein 3, Advanced schistosomiasis, CD56+NK cell, Liver fibrosis