*2.4. Serological Scoring of Fibrosis*

Haematological analyses and subsequent serological scoring algorithms, such as our recently developed PRTA-score [17] and the clinical algorithms Fib-4, APRI, and the AST/ALT ratio, were used to validate the elastography-based fibrosis scoring. The PRTA-score, Fib-4, and APRI were calculated using following formulae:

Fib-4 <sup>=</sup> age <sup>×</sup> AST[IU/L]/(thrombocytes[109/L] <sup>×</sup> (ALT[IU/L])1/2);

APRI = (AST[IU/L]/ULN)/thrombocytes[109/L];

PRTA-score <sup>=</sup> (sPDGFRβ[pg/mL] <sup>×</sup> 100)/(albumin[g/L] <sup>×</sup> (thrombocytes[/mm3]/100)).
