Factors associated with liver stiffness in chronic liver disease

Abstract

Background/Aims: Transient elastography is a new noninvasive tool for measuring liver stiffness that accurately predicts significant fibrosis and cirrhosis. However, several studies have indicated that liver stiffness can be significantly influenced by major changes in aminotransferase in patients with chronic viral hepatitis. The aim of this study was to determine the factors influencing liver stiffness in patients with chronic liver disease.

Methods: We studied 158 patients with chronic liver disease who underwent transient elastography and liver biopsy sampling. Histologic findings on fibrosis and necroinflammatory activity in the biopsy specimens were evaluated according to the Korean Society of Pathologists Scoring System. Routine biochemical tests were performed according to standard methods.

Results: Liver stiffness was strongly correlated with liver fibrosis stage (Spearman coefficient=0.636, P<0.001), lobular activity (Spearman coefficient=0.359, P<0.001), and portoperiportal activity grade (Spearman coefficient=0.448, P<0.001). Liver stiffness was significantly associated with serum levels of total bilirubin (P=0.025), direct bilirubin (P=0.049), gamma-glutamyl transpeptidase (P=0.014), platelet count (P=0.004), albumin (P<0.001), and international normalized ratio (P<0.001). Multivariate analysis showed that fibrosis stage (B 3.50, P=0.009) and lobular activity grade (B 3.25, P=0.047) were independently associated with liver stiffness.

Conclusions: Liver stiffness as measured by transient elastography is associated with the grade of necroinflammatory activity and the stage of fibrosis, irrespective of serum ALT levels.

목적: 본 논문은 만성 간질환 환자를 대상으로 간탄성률 측정에 영향을 미치는 요인을 알아보기 위해 연구를 시행하였다.

대상과 방법: Transient elastography와 간조직검사를 시행한 만성 간질환 환자 158명을 대상으로 혈액검사 및 간조직 소견을 분석하였으며, 간조직검사 결과는 대한병리학회 기준에 따라 0～4단계로 분류하였다.

결과: 간탄성률은 간조직생검으로 확인한 간섬유화 정도와 유의한 상관관계를 보였다(P=0.636. P<0.001). 간염의 소엽 내 활성도 및 문맥역/문맥주변부 활성도가 높아질수록 간탄성률 측정치도 증가하였으며, spearman 상관계수가 각각 0.359(P<0.001), 0.448(P<0.001)로 유의하였다. 또한 간탄성률은 혈청 총 빌리루빈치, 직접 빌리루빈치, GGT 수치, INR 등과 양의 상관관계가 있었으며, 혈청 알부민치 및 혈소판치와는 음의 상관관계가 있었다. 다변량 회귀분석에서는 간섬유화(B 3.50, P=0.009) 및 간염의 소엽 내 활성도(B 3.25, P=0.047)만이 간탄성률과 관련이 있는 것으로 나타났다.

결론: 만성 간질환 환자에서 간탄성률은 간섬유화뿐만 아니라 간내 염증 활성도에 의해서도 영향을 받음을 확인하였으며, 간탄성률의 해석에 간섬유화뿐만 아니라 간내 염증 정도도 고려해야 할 것이다.