关键词: 丙氨酸转氨酶, 乙型肝炎, 肝纤维化, FibroTouch, 肝脏硬度值

Abstract: Background　A number of studies have shown that elevated alanine aminotransferase（ALT）level may result in increase of liver stiffness measurements，but few studies have explored the association of liver stiffness measurements with elevated ALT，especially mildly elevated ALT，in patients with chronic hepatitis B（CHB）. Objective　To explore the impact of ALT level on liver stiffness measured by FibroTouch in patients with CHB. Methods　A total of 145 CHB patients were recruited from Inpatient Ward of Infectious Disease Department，the Second Hospital of Dalian Medical University during May 2016 to March 2019. All of them performed ALT blood test，measured liver stiffness by FibroTouch，and assessed liver fibrosisby liver biopsy. Liver stiffness measured by FibroTouch was compared by ALT level〔ALT<1×ULN（upper limit of normal）（group A，n=46），1×ULN≤ALT<2×ULN（ group B，n=64），2×ULN≤ALT<5×ULN（group C，n=35）〕and by liver fibrosis assessed by liver biopsy using the METAVIR scoring system〔score F1（mild liver fibrosis），score F2-F3（obvious liver fibrosis）and score F4（cirrhosis）〕. ROC analysis was used to assess the accuracy of FibroTouch in measuring liver stiffness，with the results of liver biopsy serving as the gold standard of reference. Results　Groups A and B had lower mean liver stiffness measured by FibroTouch than group C（P<0.05）. Patients with mild liver fibrosis（n=16）in group A had lower mean liver stiffness measured by FibroTouch than those（n=6）in group C，so did those（n=14）in group B（P<0.05）. Patients with obvious liver fibrosis（n=22）in group A showed lower mean liver stiffness measured by FibroTouch than those（n=22）in group C，so did those（n=44）in group B（P<0.05）. Patients with cirrhosis（n=8）in group A demonstrated lower mean liver stiffness measured by FibroTouch than those（n=7）in group C，so did those（n=6）in group B（P<0.05）. In groups A，B and C，the mean liver stiffness measured by FibroTouch successively increased with the aggravation of liver fibrosis severity assessed by liver biopsy（P<0.05）. Spearman rank correlation analysis found that，liver stiffness measured by FibroTouchwas positively correlated with degree of liver fibrosis assessed by liver biopsy in groups A，B and C，respectively（rs=0.81，0.71，and 0.73，respectively，P<0.001）. ROC analysis showed that，the AUC of FibroTouch in staging F2-F3 in all participants，and groups A，B and C was 0.904，0.933，0.914 and 0.897，respectively，and the AUC of which in staging F4 in all participants，and groups A，B and C was 0.942，0.954，0.989 and 0.949，respectively（P<0.001）. Conclusion　Liver stiffness measured by FibroTouch may not be affected in CHB patients with ALT<2×ULN，but it may be overestimated in those with ALT≥2×ULN，which may not be the real degree of liver fibrosis.

Key words: Alanine transaminase, Hepatitis B, Liver fibroses, FibroTouch, Liver stiffness measurements