Value of microparticles in the diagnosis of nonalcoholic steatohepatitis

Objective To investigate the value of plasma levels of microparticles ( MPs) derived from CD14+cells and invariant natural killer T ( iNKT) cells in the diagnosis of nonalcoholic steatohepatitis ( NASH) . Methods A total of 36 patients with nonalcoholic fatty liver disease ( NAFLD) who underwent liver biopsy in Department of Gastroenterology and Department of Hepatobiliary Surgery, Sichuan Provincial People's Hospital, from March to November 2015, were enrolled, and according to the activity score of NAFLD and fibrosis stage, the patients were divided into NASH group with 22 patients and non-NASH group with 14 patients. A total of 15 individuals, matched for age and sex, who underwent physical examination were enrolled as control group. Flow cytometry was used to measure the plasma levels of MPs derived from CD14+cells and iNKT cells in all subjects. The t-test was used for comparison of normally distributed continuous data between groups; the t-test was used for comparison of non-normally distributed continuous data which became normally distributed after logarithmic transformation between groups, and the Mann-Whitney U test was used for comparison of non-normally distributed continuous data between groups. The chi-square test was used for comparison of categorical data between two groups. An analysis of variance was used for comparison of normally distributed continuous data between multiple groups, and the least significant difference t-test was used for further comparison between two groups. The Pearson correlation analysis was used to investigate the correlation between two variables, and the receiver operating characteristic ( ROC) curve was used to evaluate the diagnostic value of MP. Results Compared with the control group, the NAFLD group had significantly higher plasma levels of MPs from CD14+cells ( 5. 92 ± 0. 62 cells/μl vs 4. 52 ± 0. 42 cells/μl, t =7. 160, P < 0. 001) and MPs from iNKT cells ( 4. 38 ± 0. 51 cells/μl vs 3. 79 ± 0. 28 cells/μl, t = 3. 966, P < 0. 001) . Compared with thenon-NASH group, the NASH group had significantly higher plasma levels of MPs from CD14+cells ( 6. 25 ± 0. 48 cells/μl vs 5. 44 ± 0. 49 cells/μl, t = 4. 773, P < 0. 001) and MPs from iNKT cells ( 4. 70 ± 0. 39 cells/μl vs 3. 96 ± 0. 26 cells/μl, t = 6. 544, P < 0. 001) . There were significant differences in the plasma levels of MPs from CD14+cells and iNKT cells between the three groups ( F = 61. 039 and42. 285, both P < 0. 05) ; the NASH group had significantly higher plasma levels of MPs than the non-NASH group and the control group, and the non-NASH group had significantly higher plasma levels of MPs than the control group ( all P < 0. 05) . The plasma levels of MPs from CD14+cells and iNKT cells were positively correlated with NAFLD activity score ( r = 0. 697 and 0. 793, both P < 0. 001) . MPs from CD14+cells had an area under the ROC curve ( AUC) of 0. 886 ( 95% confidence interval [CI]: 0. 750-1. 000, P < 0. 001) in the diagnosis of NASH, with a sensitivity of 90. 9% and a specificity of 85. 6%; MPs from iNKT cells had an AUC of 0. 935 ( 95% CI: 0. 822-1. 000, P < 0. 001) , with a sensitivity of 81. 8% and a specificity of 92. 9%. Conclusion There are increases in the plasma levels of MPs from CD14+cells and iNKT cells in patients with NASH, which are positively correlated with the degree of liver inflammation, and therefore, they can be used as potential noninvasive indices for liver inflammation.