Hepatotoxicity
& Liver Disease
Assays
Validated ELISA kits for DILI monitoring, NAFLD progression staging, and NASH assessment ALT, AST, Albumin for Hy's Law compliance; CK-18, TGF- 1, FGF-21 for NASH staging; NIBSC-calibrated TNF-a and IL-6 for hepatic inflammation. Human, rat, and mouse validated.
Browse Liver Injury Assays Disease BiologyLiver Disease: Biomarker Landscape
Hepatotoxicity research spans three interconnected areas requiring distinct biomarker panels. Drug-induced liver injury (DILI) is the leading cause of acute liver failure and drug withdrawal in clinical development requiring ALT/AST/Albumin monitoring to satisfy Hy's Law criteria. Non-alcoholic fatty liver disease (NAFLD) affects ~25% of the global population, with 20 30% progressing to non-alcoholic steatohepatitis (NASH) requiring a staged biomarker panel beyond transaminases. GLP-1 agonists (Semaglutide, Tirzepatide) are now in Phase III NASH trials, making hepatic biomarker-drug PK co-monitoring increasingly important.
The spectrum of hepatic disease steatosis NAFLD NASH fibrosis cirrhosis requires different biomarkers at each stage. Standard liver function tests (ALT, AST, Albumin) detect hepatocellular injury but cannot distinguish steatosis from steatohepatitis or quantify fibrosis. Next-generation NASH biomarkers (CK-18 for apoptosis, TGF- 1 for fibrogenesis, FGF-21 for steatosis) address this gap and are now incorporated into clinical trial endpoints.
Drug-Induced Liver Injury Biomarker Panel
The standard DILI monitoring panel ALT, AST, and Albumin provides regulatory-compliant hepatocellular injury and liver function assessment. All three markers together satisfy Hy's Law criteria. Validated in human, rat, and mouse for both clinical study monitoring and preclinical safety pharmacology.
The most sensitive and specific biomarker for hepatocellular injury. ALT (SGPT) catalyses transamination of alanine and is found predominantly in hepatocyte cytoplasm. Released into circulation upon hepatocyte membrane disruption elevation is specific to liver injury with minimal cardiac contribution (unlike AST).
Hy's Law criterion 1: ALT >3 ULN. Normal serum ALT: 7 35 U/L (women) / 7 40 U/L (men). Krishgen ALT ELISA quantifies absolute enzyme protein concentration rather than activity, providing matrix-independent measurement valid across species. Validated in serum, plasma, tissue lysate.
AST (SGOT) is present in hepatocytes (mitochondrial and cytoplasmic), skeletal muscle, cardiac muscle, and kidney. Less liver-specific than ALT AST elevation occurs in both hepatic and muscular injury. Used alongside ALT: AST/ALT ratio >2:1 suggests alcoholic hepatitis or cirrhosis; ratio <1 suggests NAFLD or viral hepatitis.
In DILI assessment, ALT is the primary marker but AST elevation confirms and grades hepatocellular injury severity. Both markers required for Hy's Law compliance. Krishgen AST ELISA validated in serum, plasma, liver lysate.
Albumin is the major serum protein, synthesised exclusively by hepatocytes. Hypoalbuminaemia (<35 g/L) reflects impaired hepatic synthetic function and is evidence of significant parenchymal damage or chronic liver disease. Half-life ~20 days albumin falls slowly, making it a marker of sustained liver dysfunction rather than acute injury.
In Hy's Law assessment, low albumin alongside ALT/AST elevation and elevated bilirubin constitutes strong evidence of severe hepatotoxicity. Also used as a marker of disease severity in cirrhosis (Child-Pugh score). Validated in serum, plasma, urine, and CSF.
Next-Generation NASH Biomarker Panel
Distinguishing NAFLD from NASH, and quantifying fibrosis stage, requires biomarkers beyond ALT and AST. The three markers below address apoptosis (CK-18), fibrogenesis (TGF- 1), and steatosis/hepatic metabolic stress (FGF-21) together covering the key pathogenic mechanisms of NASH progression.
Cytokeratin-18 is released from hepatocytes undergoing apoptosis (caspase-cleaved CK-18 fragments M30 epitope) and necrosis (full-length CK-18 M65 epitope). CK-18 is the most validated non-invasive biomarker for distinguishing NASH from simple steatosis elevated in NASH patients vs NAFLD with AUROCs of 0.75 0.83 in clinical studies. The M30:M65 ratio provides an apoptosis:necrosis balance index.
GLP-1 agonist trials (Semaglutide PILOT-NASH, Tirzepatide SYNERGY-NASH) use CK-18 as a primary or secondary efficacy endpoint. Krishgen CK-18 ELISA detects total CK-18 in serum and plasma; request M30-specific ELISA for apoptosis-specific measurement.
The master fibrogenic cytokine in the liver. TGF- 1 secreted by Kupffer cells, injured hepatocytes, and activated stellate cells drives hepatic stellate cell (HSC) activation the central event in hepatic fibrosis. Activated HSCs become myofibroblasts producing type I collagen and extracellular matrix. TGF- 1 is elevated in NASH fibrosis stages F2 F4 and is a therapeutic target for anti-fibrotic drugs in NASH clinical trials.
Serum TGF- 1 measurement requires acid activation (latent TGF- 1 predominates in serum) Krishgen ELISA kits are supplied with acid activation protocol. Validated in human serum, plasma, liver lysate, cell culture supernatant.
FGF-21 secreted by the liver in response to fasting, carbohydrate excess, and fatty acid overload. Acts on adipose tissue via FGFR1c/KLB to promote adipose browning and thermogenesis. Circulating FGF-21 is elevated 2 3 in NAFLD and 4 5 in NASH vs healthy controls reflecting the degree of hepatic metabolic stress. FGF-21 is now a validated NASH biomarker in clinical trials.
Importantly, FGF-21 is also a drug target pegozafermin and efruxifermin (FGF-21 analogs) are in NASH Phase III trials, and GLP-1/GIP/FGF-21 triple agonists are in development. Krishgen FGF-21 ELISA validated in human serum, plasma; rat/mouse also available.
Inflammatory Mediators in Liver Disease
Kupffer cell activation and hepatic macrophage infiltration drive the transition from steatosis to steatohepatitis. The inflammatory cytokines below are measurable in serum and liver tissue and provide mechanistic readouts of hepatic inflammatory activity. Krishgen TNF-a and IL-6 are calibrated against NIBSC/WHO International Reference Standards.
Kupffer cells are the primary hepatic source of TNF-a. In NAFLD/NASH, activated Kupffer cells release TNF-a in response to lipopolysaccharide (LPS) from gut dysbiosis and saturated fatty acids via TLR4. Hepatocyte TNF-a signalling via TNFR1 drives apoptosis (caspase-8 CK-18 release) and NF- B-dependent inflammatory gene expression. Elevated serum TNF-a correlates with NASH severity and fibrosis stage. Krishgen TNF-a ELISA calibrated to NIBSC 88/786 for standardised reporting.
IL-6 is the principal inducer of hepatic acute-phase protein synthesis (CRP, fibrinogen, serum amyloid A). In NASH, IL-6 secreted by Kupffer cells and infiltrating macrophages drives hepatocyte JAK-STAT3 activation promoting lipogenesis, impairing insulin signalling (IRS-1 serine phosphorylation), and inducing the inflammatory gene programme. IL-6 also stimulates hepatic stellate cell activation contributing to fibrogenesis. Krishgen IL-6 ELISA calibrated to NIBSC 89/548. Validated in serum, plasma, liver lysate.
The terminal effector caspase of the apoptotic cascade. Activated by both intrinsic (mitochondrial, relevant to fatty acid lipotoxicity) and extrinsic (TNF-a/TRAIL via TNFR1) pathways. Active caspase-3 cleaves CK-18 generating the M30 epitope mechanistically linking TNF-a inflammation to CK-18 release. Caspase-3 ELISA in liver lysate provides a direct apoptosis readout complementary to serum CK-18.
Kupffer cell polarisation from pro-inflammatory M1 (CD11b+, TNF-a high, IL-6 high) to anti-inflammatory M2 (CD163+, IL-10 high, TGF- 1 high) state is a key determinant of NASH progression vs resolution. GLP-1 agonists promote M2 polarisation in preclinical models. CD163 (M2 marker) and IL-10 (anti-inflammatory) ELISA are available contact Krishgen technical team for panel design.
Hepatotoxicity Assay Reference Table
All validated Krishgen ELISA kits for liver injury, NAFLD/NASH, and hepatic inflammation research. CV <15%, recovery 85 115%. CoA and full validation reports on request.
| Biomarker | Disease Context | Regulatory / Clinical Relevance | Format | Species | Link |
|---|---|---|---|---|---|
ALT (Alanine Transaminase)Standard DILI marker | DILI acute hepatocellular injury | Hy's Law criterion 1FDA required | Sandwich ELISA | Human / Rat / Mouse | Search |
AST (Aspartate Transaminase)Standard DILI marker | DILI AST/ALT ratio for staging | Hy's Law supportFibrosis ratio | Sandwich ELISA | Human / Rat / Mouse | Search |
AlbuminSynthetic function marker | DILI cirrhosis staging Child-Pugh | Hy's Law supportSynthetic function | Sandwich ELISA | Human / Rat / Mouse | Search |
CK-18 (Cytokeratin-18)Hepatocyte apoptosis / NASH marker | NAFLD vs NASH differentiation | NASH stagingClinical trial endpoint | Sandwich ELISA | Human / Rat / Mouse | Search |
TGF- 1Hepatic fibrogenesis marker | NASH fibrosis stages F2 F4 | FibrosisHSC activation | Sandwich ELISA (acid activation) | Human / Rat / Mouse | Search |
FGF-21Hepatokine steatosis marker | NAFLD / NASH GLP-1 drug response | NASH biomarkerFGF-21 drug target | Sandwich ELISA | Human / Rat / Mouse | Search |
TNF-aKupffer cell output hepatic inflammation | NASH hepatic macrophage activation | NIBSC-calibratedInflammatory | Sandwich ELISA (NIBSC) | Human / Rat / Mouse | View |
IL-6Acute-phase inducer hepatic cytokine | NASH hepatic acute-phase response | NIBSC-calibratedInflammatory | Sandwich ELISA (NIBSC) | Human / Rat / Mouse | View |
GGT (Gamma-Glutamyl Transferase)Cholestasis / bile duct injury | Cholestatic DILI alcohol-related liver disease | Cholestatic pattern | Sandwich ELISA | Human / Rat | Enquire |
Frequently Asked Questions
Hy's Law requires: (1) ALT or AST >3 ULN AND (2) Total Bilirubin >2 ULN, with (3) no predominant cholestatic pattern (ALP <2 ULN). At minimum, you need ALT/AST + Bilirubin. Albumin is highly recommended as evidence of hepatic synthetic function impairment. Krishgen provides validated ELISA for ALT, AST, and Albumin contact team for Bilirubin ELISA availability.
Simple steatosis (NAFLD) is characterised by fat accumulation without significant hepatocyte injury or inflammation. NASH adds apoptosis, inflammation, and early fibrosis reflected in elevated CK-18 (hepatocyte apoptosis marker). CK-18 is the most validated non-invasive NASH-specific biomarker, with AUROC 0.75 0.83 in published clinical studies. ALT alone cannot distinguish the two conditions.
Build Your Hepatotoxicity Panel
Our scientific team can help design a DILI or NASH biomarker panel for your specific study design, matrix requirements, and regulatory context.
You were not leaving your cart just like that, right?
Enter your details below to save your shopping cart for later. And, who knows, maybe we will even send you a sweet discount code :)