Z Gastroenterol 2009; 47 - P5_07
DOI: 10.1055/s-0029-1191969

Questioning the value of a possible non-invasive assessement of fibrogenic liver diseases as exemplified by serum based Fibrotest/Actitest

OA Gressner 1, N Beer 1, S Stanzel 2, AM Gressner 1
  • 1Institut für Klinische Chemie und Pathobiochemie, Universitätsklinikum der RWTH Aachen
  • 2Institut für Medizinische Statistik, Universitätsklinikum der RWTH Aachen

Introduction: Non-invasive, i.e. serum-based assessment of liver fibrosis is still an important challenge although multiple single and multiparametric panels of biomarkers have been proposed (1).

Aim and Methods: (i) Haptoglobin, ALT, gammaGT, alpha 2-macroglobulin, apolipoprotein A1 and bilirubin in sera of 4 patients with histological proven fibrosis (F1-F4, A1-A3) were determined in 6 different quality-controlled laboratories. Inter-laboratory variations of the calculated Fibrotest Score for staging and Actitest Score for grading (both BioPredictiveTM), and their error ratios compared to the results obtained by biopsy were calculated. (ii) The variability of obtained Fibrotest/Actitest Scores depending on 64 differential combinations of the allowed analyt-specific maximum/minimum permissible values as determined by the external quality control of the German Association of Clinical Chemistry and Laboratory Medicine (DGKL) was determined and the frequency distribution of the results calculated.

Results: (i): Fibrotest and Actitest Scores were largely reproducible among the different laboratories. However, the error ratio was 77% for all results calculated by both, Fibrotest and Actitest when compared to the histological findings. (ii): Calculated scores varied among F2 (9%), F3 (31%), F3-F4 (6%), and F4 (54%) (Fibrotest), as well as A1/A2 (48%), A2 (9%), A2-A3 (5%), and A3 (38%) (Actitest).

Conclusion: Despite reproducibility of Fibro- and Actitest results among the six laboratories, large scale investigation (n=64) displayed increasing variability of the results depending on interlaboratory differences that were still in a quality controlled, analytically acceptable range. Furthermore, calculated scores coincided with histological findings only in less than 25% of all cases. Thus, the diagnostic accuracy of these tests must be considered as low, if histology is accepted as gold standard.

Literatur: (1) Gressner, O. A. et al. Clin Chim Acta 381 (2007) 107-113