Enhanced liver fibrosis (ELF) score: Analytical performance and distribution range in a large cohort of blood donors.

Background: The Enhanced Liver Fibrosis (ELF) is a serological score that includes hyaluronic acid (HA), tissue inhibitor of matrix metalloproteinases-1(TIMP-1), and aminoterminal propeptide of type III procollagen (PIIINP) and shows good performance for detecting liver fibrosis. There are few studies evaluating ELF's intra and inter-assay variation and stability of the samples. The influence of host variables, such as age, gender and body mass index (BMI) is also not well known. We determined ELF's analytical performance and possible influences of gender, age and BMI.

Methods: The study included 958 healthy blood donors evaluated for age, gender, and BMI.

Results: Mean ELF scores were significantly different between female (8.53±0.75) and male groups (8.76±0.76) and also according to age strata (p<0.001). For both genders, ELF significantly varied in individuals with BMI under 25 (p<0.001). Analytes remained stable after freezing/thawing cycles and intra- and inter-assay coefficients of variation were low.

Conclusions: ELF has appropriate precision and is quite robust, due to the high stability of the analytes in fresh and frozen samples. ELF's results are influenced by gender, age and BMI which should be taken into account when analyzing its results.