Table 6.
Comparison of methods to measure fibrosis
| Technique | Routine Slide | Ease (Minutes per Assay) | Interassay Reproducibility (R2 for Duplicate Slides) | Interobserver Reproducibility (R2) | Dynamic Range (% Min-Max Observed) | Correlation with Functiona |
|---|---|---|---|---|---|---|
| Sirius Red polarized | No | 60 | High (0.94) | n.d.b | Low (4 to 22) | − |
| Sirius Red unpolarized | No | 45 | High (0.96) | n.d. | Moderate (12 to 53) | +++ |
| Collagen III | No | 20 | Moderate (0.83) | High (0.99) | High (24 to 74) | +++ |
| Trichrome-PAS | Yes | 40 | Moderate (0.69) | High (0.96) | Moderate (38 to 82) | + |
| Visual % fibrous tissue | Yes | 5 | Moderate to high (0.75 to 0.90) | Moderate to high (0.75 to 0.99) | High (3 to 90) | +++ |
| Visual % fibrotic cortex | Yes | 5 | Moderate to high (0.62 to 0.88) | Moderate to high (0.75 to 0.93) | High (3 to 100) | ++++ |
aOne + for each functional correlation, P < 0.02.
bn.d., not done.