Histological activity in non-alcoholic fatty liver disease (NASH CRN system).
The NAFLD Activity Score (NAS) is a GI & Liver scoring tool used in paediatric practice. Histological activity in non-alcoholic fatty liver disease (NASH CRN system). It scores 3 criteria and interprets the total across 3 bands, so the number always arrives with the severity it implies rather than on its own. In PediAid each criterion is shown as a labelled option with the weight it carries, so the total can be checked rather than taken on trust.
3. They are Steatosis (% of hepatocytes involved); Lobular inflammation (foci per 200× field); Hepatocyte ballooning.
The total is interpreted as: any score - Not diagnostic of NASH: nAS 0-2 - largely not diagnostic of steatohepatitis; 3 points or more - Borderline: nAS 3-4 - borderline; correlate with the overall histological pattern rather than the score alone; 5 points or more - Consistent with NASH: nAS ≥5 - mostly diagnosed as steatohepatitis. Fibrosis is staged SEPARATELY (F0-F4) and is the strongest predictor of long-term outcome.
No. It is a structured way to record and communicate severity. A clinician concerned about a child should act on that concern regardless of the total.
Total range 0-8. NAS was designed to measure disease ACTIVITY for trials, not to replace a diagnostic pathology assessment. Paediatric NAFLD often shows a portal (type 2) pattern.
Yes. Score definitions are bundled with the PediAid app, so the score computes without a connection.