. 2023 Jun 7;160(2):113–125. doi: 10.1007/s00418-023-02202-8

Table 2.

Comprehensive table showing, for both biopsy series and their matched resection specimens, categorization, quality, patchiness and central artefact for MMR immunoreactions with MLH1, PMS2, MSH2 and MSH6 antibodies

		Category			Staining intensity		Patchiness				Central artefact
	Lost	Preserved	Indeterminate	Inadequate	Strong	Weak	0	1	2	3	0	1	2
pMMR BIOPSY SERIES 86 (prospective)
MLH1	0	85	1	0	85	1	69	17	0	0	86	0	0
PMS2	0	84	1	1^a	70	15	66	14	4	1	86	0	0
MSH2	0	86	0	0	86	0	86	0	0	0	86	0	0
MSH6	0	86	0	0	86	0	86	0	0	0	86	0	0
dMMR BIOPSY SERIES - 55 (17 prospective and 38 retrospective)
MLH1	20	3	31	1^a	44	10	53	1	1	0	55	0	0
PMS2	46	2	1	6^a	38	11	55	0	0	0	55	0	0
MSH2	1	54	0	0	50	5	55	0	0	0	55	0	0
MSH6	3	52	0	0	50	5	55^b	0	0	0	55	0	0
pMMR SURGICAL RESECTION SERIES - 48 (prospective)
MLH1	0	48	0	0	44	4	13	17	12	6	32	4	12
PMS2	0	48	0	0	39	9	13	11	14	10	36	2	10
MSH2	0	48	0	0	47	1	38	5	2	3	45	0	3
MSH6	0	48	0	0	47	1	35	8	2	3	43	2	3
dMMR SURGICAL RESECTION SERIES - 49 (11 prospective and 38 retrospective)
MLH1	44	3	1	1^a	33	15	25	9	8	6	38	1	9
PMS2	45	3	0	1^a	38	10	30	4	9	5	40	3	5
MSH2	1	48^c	0	0	44	5	25	7	8	9	39	3	7
MSH6	2	47^d	0	0	48	1	29	5	7	8	42	2	5

pMMR proficient MMR; dMMR deficient

^aInadequate cases were not evaluated for other variables

^bOne biopsy case showed loss of MLH1/PMS2 with sub-clonal loss of MSH6 on biopsy (confirmed on the resection specimen)

^c Two cases showed sub-clonal loss

^d Three cases showed sub-clonal loss