A (percentage of positive cells) | B (intensity of staining) | IRS score (multiplication of A and B) |
---|---|---|
0 = no positive cells | 0 = no color reaction | 0-1 = negative |
1 = <10% of positive cells | 1 = mild reaction | 2-3 = mild |
2 = 10-50% positive cells | 2 = moderate reaction | 4-8 = moderate |
3 = 51-80% positive cells | 3 = intense reaction | 9-12 = strongly positive |
4 = >80% positive cells | Final IRS score (A × B): 0-12 |