Nicht-alkoholische Fettlebererkrankung (NAFLE) – Was leistet die Labordiagnostik?

Die nicht-alkoholische Fettkleberkrankung (NAFLE) ist die hepatische Manifestation des metabolischen Syndroms. Diese kann über eine Fibrose zur Leberzirrhose und letztendlich zur Entstehung eines hepatozellulären Karzinoms führen. Die Diagnostik der NAFLE erfolgt durch Anamnese, klinische Symptome und bildgebende Verfahren. Die invasive Leberbiopsie gilt als Goldstandard der Beurteilung von Lebererkrankungen, ist jedoch komplikationsträchtig und kostenintensiv. Als nicht-invasives Verfahren ist die Verwendung von serologischen Biomarkern eine wegweisende Möglichkeit, eine einfache und reproduzierbare Beurteilung der Lebererkrankung zu erlangen. Zytokeratin-18 (CK-18) ist ein Intermediärfilamentprotein, welches während der hepatischen Schädigung von den Zellen sezerniert wird und im Serum nachweisbar ist. Für die NAFLE lässt sich mittels CK-18 zwischen der simplen Steatose und der nicht-alkoholischen Steatohepatitis (NASH) unterscheiden, da NASH-Patienten signifikant höhere Werte aufweisen. Die Bestimmung von CK-18 lässt Aussagen über die Aktivität und das Ausmaß der Lebererkrankung zu und kann zukünftig im klinischen Alltag zur Therapieentscheidung und zum Monitoring beitragen.

Non-alcoholic fatty Liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome. NAFLD may cause liver fibrosis and proceed to cirrhosis that eventually leads to hepatocellular carcinoma. The diagnosis is based on anamnesis (exclusion of extensive alcohol ingestion), clinical symptoms, imaging techniques, and liver biopsy, which is still the gold standard though associated with complications and sampling errors. As a non-invasive method, the use of serological biomarkers seems to be a good opportunity to gain a simple and reproducible assessment of ongoing liver injury. Cytokeratin-18 (CK-18) is an intermediate filament protein which is secreted during hepatic injury and detectable in patients' sera. Recent data indicate that CK-18 levels may differentiate between simple steatosis and non-alcoholic steatohepatitis (NASH). Furthermore the determination of CK-18 allows conclusions about the type and severity of liver disease and can potentially contribute to clinical diagnosis and management in clinical practice.

Key words

NAFLD - NASH - biomarker - Cytokeratin-18 - apoptosis

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