Steatohepatitis is the one indication in the inflammatory catalogue where the diagnostic method varies enough to change what a cohort means. A biopsy-confirmed cohort and an imaging-defined cohort carry the same label and are not the same population. Given that fibrosis stage, not steatosis, is what drives outcome, the distinction determines whether a study can say anything about the thing that matters.
Nomenclature moved, and the literature is split across both terms
The field has moved from non-alcoholic fatty liver disease and non-alcoholic steatohepatitis toward metabolic dysfunction associated terminology, with steatotic liver disease and metabolic dysfunction associated steatohepatitis now in common use. The definitions are not identical, since the newer framing requires positive metabolic criteria rather than exclusion of alcohol alone.
For a research cohort this matters in two directions. Older material and older literature use the exclusion-based definition, and cohorts assembled under each are not perfectly interchangeable. Recording which definition was applied, and the alcohol history, keeps the cohort interpretable against both bodies of work.
Biopsy, elastography and imaging define different populations
Liver biopsy remains the reference for distinguishing simple steatosis from steatohepatitis and for staging fibrosis, and it is invasive, so it is not performed on everyone. Non-invasive methods including transient elastography and serum fibrosis scores estimate fibrosis without confirming inflammation.
A cohort described as steatohepatitis without histology may contain donors with simple steatosis and no significant inflammation at all. Where the study concerns inflammatory mechanism, that distinction is the study. Ask what the diagnosis rests on rather than accepting the label.
| Diagnostic basis | Confirms inflammation | Stages fibrosis | Cohort meaning |
|---|---|---|---|
| Liver biopsy | Yes | Yes | The only basis that separates steatohepatitis from steatosis |
| Transient elastography | No | Estimates | Fibrosis-oriented; inflammation unconfirmed |
| Serum fibrosis score | No | Estimates | Screening grade; wide confidence intervals |
| Imaging steatosis only | No | No | Fatty liver, not necessarily steatohepatitis |
Related product
Disease-state PBMCs. PBMCs from donors with a documented diagnosis, across 24 autoimmune and inflammatory indications.
Metabolic comorbidity is the population, not a confounder to remove
Type 2 diabetes, obesity, dyslipidaemia and hypertension are so closely associated with this disease that a cohort without them would not represent the condition. That creates an unusual comparator problem, because a lean metabolically healthy control differs from the disease cohort on many axes at once.
The more informative comparator is often metabolically matched: donors with similar body mass index and glycaemic status but without steatohepatitis. That isolates the liver-specific component instead of re-measuring metabolic syndrome. Both body mass index and type 2 diabetes are available as selection parameters, and type 2 diabetes is itself one of the 24 indications, which makes assembling that comparator arm practical.
The immune biology that peripheral blood can report
Monocyte and macrophage biology sits at the center of the described pathology, with circulating monocyte subsets and their activation state being the most directly relevant peripheral readout. Circulating cytokine profiles, gut-derived endotoxin responsiveness and T cell subset distribution including mucosal associated invariant T cells are also documented areas of interest.
What peripheral blood cannot do is stage fibrosis or confirm inflammation in the liver. Those remain properties of the tissue and of the diagnostic work-up, which is precisely why the annotation matters more here than the assay does.
Fibrosis stage is the axis that predicts outcome
The consistent finding across the outcome literature is that fibrosis stage, rather than the degree of steatosis or the inflammatory grade alone, predicts liver-related outcomes. A cohort stratified by fibrosis stage is therefore aligned with the variable the field cares about, and one stratified only by the presence of steatohepatitis is not.
Where fibrosis stage is unavailable, a non-invasive estimate with its method recorded is far better than nothing, provided the analysis treats it as an estimate rather than as a stage.
Specifying a steatohepatitis cohort
OrganaBio supplies disease-state donor material across 24 autoimmune and inflammatory indications for research use, covering discovery, drug screening and biomarker work, with a post-thaw viability specification above 80 percent. Donor-matched plasma, serum and PBMCs from the same donor are available, which most suppliers cannot provide. Donor selection can be scoped by disease state, HLA genotype, age, sex, ethnicity, blood type, CMV and EBV status, BMI and smoking status, all subject to availability.
For this indication the parameters worth naming are the diagnostic basis and whether biopsy was performed, fibrosis stage or non-invasive estimate with method, body mass index, type 2 diabetes status, alcohol history, and which diagnostic definition was applied.
High-resolution NGS HLA genotyping is performed across HLA-A, HLA-B, HLA-C, HLA-DR, HLA-DQ and HLA-DP, and KIR genotyping is included in donor characterization. Where a design needs the same donor sampled more than once, the repeat-collection program covers eligible donors and is not a blanket guarantee for every donor or request.
Because type 2 diabetes is itself one of the 24 indications, a metabolically matched comparator arm can be assembled from the same catalogue rather than approximated from a healthy pool.
Related material: what a mononuclear cell preparation contains, how HLA typing resolution is reported, and the cryopreserved PBMC format.
Frequently asked questions
Why does the diagnostic basis matter so much?
Because only liver biopsy separates steatohepatitis from simple steatosis and stages fibrosis directly. A cohort defined by imaging or serum scores may contain donors without significant inflammation, which undermines any inflammatory endpoint.
Has the terminology changed?
Yes. The field has moved toward metabolic dysfunction associated terminology, which requires positive metabolic criteria rather than exclusion of alcohol alone. Record which definition was applied and the alcohol history so the cohort stays interpretable against both bodies of literature.
What is the right comparator group?
Often a metabolically matched one, meaning donors with similar body mass index and glycaemic status but without steatohepatitis. A lean healthy control differs on so many axes that the comparison re-measures metabolic syndrome rather than liver disease.
Can peripheral blood stage fibrosis?
No. Fibrosis stage is a property of the tissue and the diagnostic work-up. Peripheral blood supports monocyte subset and activation work, circulating cytokine profiling and T cell distribution, all of which should be interpreted against a recorded stage.
Why is fibrosis stage the preferred stratifier?
Because it is the variable that predicts liver-related outcomes in the outcome literature, more than steatosis degree or inflammatory grade alone. A cohort stratified by fibrosis stage aligns with what the field is trying to change.
Is metabolic comorbidity a reason to exclude donors?
No. Type 2 diabetes, obesity and dyslipidaemia are so closely associated that a cohort without them would not represent the disease. Record them and use them for matching rather than exclusion.
What viability specification applies to this material?
Disease-state donor material carries a post-thaw viability specification above 80 percent. That figure applies to the disease-state line specifically and is not carried across from healthy donor products.
Can this material be used for clinical manufacturing?
No. Disease-state donor material is supplied for research use covering discovery, drug screening and biomarker work. Material intended for further manufacturing is a separate cGMP scope with its own agreement and documentation requirements.
Talk to OrganaBio
Sourcing a steatohepatitis cohort?
Donor selection can be scoped by disease state, HLA genotype and donor characteristics, subject to availability, and donor-matched plasma, serum and PBMCs are available from the same donor. Tell us the parameters your protocol needs and the scientific team will confirm what can be supplied.
