Table 1

The operative link on gastritis assessment staging system (OLGA)

ATROPHY SCORE Score 0 = no atrophy in any of the specimens obtained from the same compartment Score 1 = atrophy involving 1–30% of the specimens obtained from the same compartment		CORPUS BIOPSY SPECIMENS Overall score of atrophy as assessed in 2 biopsy samples obtained from oxyntic mucosa
Score 2 = atrophy involving 31–60% of the specimens obtained from the same compartment
Score 3 = atrophy involving >60% of the specimens obtained from the same compartment		Score 0	Score 1	Score 2	Score 3
	Score 0	Stage 0	Stage I	Stage II	Stage II
ANTRUM BIOPSY SPECIMENS Overall score of atrophy as assessed in the 3 biopsy samples obtained from the antrum (2) and from the angularis incisura (1)	Score 1	Stage I	Stage I	Stage II	Stage III
	Score 2	Stage II	Stage II	Stage III	Stage IV
	score 3	Stage III	Stage III	Stage IV	Stage IV

Gastritis is staged by combining the atrophy scores obtained for the distal stomach with those obtained for the proximal gastric mucosa. While the OLGA system requires a global scoring of the mucosal atrophy, the OLGIM system only refers to IM score.