Kyoto classification of gastritis: Advances and future perspectives in endoscopic diagnosis of gastritis

Table 1 Kyoto classification score

Endoscopic findings	Kyoto score
	0	1	2
Atrophy1	None, C1	C2, C3	O1-O3
Intestinal metaplasia	None	Antrum	Corpus and antrum
Enlarged folds	Absence	Presence	-
Nodularity	Absence	Presence	-
Diffuse redness	None	Mild with RAC	Severe without RAC

¹According to the Kimura-Takemoto classification[80].

RAC: Regular arrangement of collecting venules.

Table 2 Diagnostic performance of Kyoto classification for Helicobacter pylori infection

	Ref.	Country	No. of patients	Sensitivity	Specificity	Accuracy
Non-infection
RAC	Garcés-Durán et al[22], 2019	Spain	140	100	49.0	65.0
	Yoshii et al[17], 2020	Japan	485	89.1	79.8	85.6
	Zhao et al[19], 2020	China	583	62.4	73.7	69.3
	Ebigbo et al[23], 2021	Germany	200	80.8	57.4	-
	Fiuza et al[20], 2021	Brazil	187	70.7	87.2	74.9
	Glover et al[24], 2021	UK	153	78.4	64.3	75.8
	Yuan et al[21], 2021	China	165	51.4	96.7	76.4
	Hirai et al[18], 2021	Japan	1761	93.2	83.2	90.6
Current infection
Atrophy	Toyoshima et al[27], 2018	Japan	136	82.6	85.8	85.3
	Zhao et al[19], 2020	China	583	54.9	61.1	58.5
	Ebigbo et al[23], 2021	Germany	200	80.4	69.7	-
Intestinal metaplasia	Toyoshima et al[27], 2018	Japan	136	39.1	95.6	86.0
Enlarged folds	Toyoshima et al[27], 2018	Japan	136	17.4	99.1	85.3
	Yoshii et al[17], 2020	Japan	494	23.1	96.6	85.0
Nodularity	Toyoshima et al[27], 2018	Japan	136	8.7	100	84.6
	Yoshii et al[17], 2020	Japan	494	6.4	98.3	83.8
	Toyoshima et al[28], 2020	Japan	265	33.3	99.6	89.1
	Fiuza et al[20], 2021	Brazil	187	10.6	98.6	76.5
Diffuse redness	Toyoshima et al[27], 2018	Japan	136	52.2	93.8	86.8
	Yoshii et al[17], 2020	Japan	485	60.0	94.7	89.7
	Zhao et al[19], 2020	China	583	20.3	97.6	65.0
	Fiuza et al[20], 2021	Brazil	187	80.9	73.6	75.4
Total Kyoto score	Toyoshima et al[27], 20181	Japan	136	78.3	92.0	89.7
	Sumi et al[30], 20222	Japan	561	98.7	98.4	98.6

¹The total Kyoto score ≥ 2 is defined as current infection.

²The total Kyoto score ≥ 1 is defined as current infection.

RAC: Regular arrangement of collecting venules.

Table 3 Gastric cancer incidence based on endoscopic atrophy

Ref.	Population	No. of subjects	No. of cancers	Duration, yr	Gastric cancer incidence, %/yr
					Atrophy (mild)	Atrophy (moderate)	Atrophy (severe)
Shichijo et al[39], 20161,2	Post eradication	573	21	6.2 ± 4.8	0.07	0.34	1.60
Kaji et al[40], 20193	Screening	12941	63	3.7 ± 0.8	0.10	0.16	0.31
	Post eradication	2571	20	3.7 ± 0.8	0.06	0.12	0.42
Take et al[41], 20201	Post eradication	2737	68	7.1 ± 5.4	0.15	0.29	0.67

¹Mild, moderate, and severe atrophy represent Kimura-Takemoto’s C1-2, C3-O1, and O2-3, respectively.

²Incidence was divided the incidence per 10 years by 10.

³Mild, moderate, and severe atrophy represent Kyoto atrophy scores 0, 1, and 2, respectively.

Table 4 Odds ratio for histological subtype of gastric cancer based on the Kyoto classification

	Ref.	H. pylori status	No. of subjects	No. of GC	No. of diffuse-type GC	No. of intestinal-type GC	OR for GC	OR for diffuse-type GC	OR for intestinal-type GC
Atrophy	Sekikawa et al[43], 2016	Current, past, and no infection	1823	29	3	26	7.41
	Toyoshima et al[44], 2021	Current infection	499	132	39	93	2.8	2.3	6.2
	Kawamura et al[45], 2022	Current, past, and no infection	380	115	19	96	2.51
Intestinal metaplasia	Shichijo et al[48], 2017	Current, past, and no infection	3392	107	22	85		0.22
	Toyoshima et al[44], 2021	Current infection	499	132	39	93	1.6		1.7
Enlarged folds	Nishibayashi et al[81], 2003	Current infection	276	135	69	66	5.0
	Toyoshima et al[44], 2021	Current infection	499	132	39	93			0.5
Nodularity	Nishikawa et al[53], 2018	Current infection	674	25	9	16		10.0
	Toyoshima et al[44], 2021	Current infection	499	132	39	93	0.5		0.3
RAC	Kawamura et al[45], 2022	Current, past, and no infection	380	115	19	96	0.23
Total Kyoto score	Toyoshima et al[44], 2021	Current infection	499	132	39	93	1.6	1.3	1.7
	Lin et al[61], 2022	Current, past, and no infection	1848	37	-	-	1.5

¹Odds ratio for Kyoto score 2 vs Kyoto scores 0 + 1.

²Odds ratio for Kyoto scores 1 + 2 vs Kyoto score 0.

³Odds ratio for regular arrangement of collecting venules presence vs absence.

Odds ratios were calculated per 1 rank of Kyoto score. H. pylori: Helicobacter pylori; GC: Gastric cancer; OR: Odds ratio; RAC: Regular arrangement of collecting venules.

Table 5 Odds ratio of gastric cancer after Helicobacter pylori eradication based on the Kyoto classification

	Ref.	No. of subjects	No. of GC	Odds ratio
Atrophy	Yan et al[57], 2021	1961	132	8.11
Map-like redness	Moribata et al[55], 2016	1222	223	5.3
	Majima et al[56], 2019	194	109	2.1
	Yan et al[57], 2021	1961	132	1.8
RAC	Majima et al[56], 2019	194	109	0.4
	Ohno et al[58], 2020	162	43	0.3

¹Odds ratio for Kyoto atrophy score 2.

²Patients after endoscopic resection of gastric cancer.

³Metachronous gastric cancer.

GC: Gastric cancer; RAC: Regular arrangement of collecting venules.