Extended Data Table 2. Clinical characteristics of evaluated patients.

Synovial tissue samples from patients 1-6 were used for mass and flow cytometry phenotyping. Samples from patients 7-10 were also included in flow cytometry phenotyping. Average ± SD shown. Parentheses indicate percentage of patients. Other biologics include abatacept, rituximab, tocilizumab, and tofacitinib.

	Patient	#1	#2	#3	#4	#5	#6	#7	#8	#9	#10
Synovial Tissue Donors	Age	57	54	76	46	46	79	62	63	52	43
	Sex	F	F	F	F	F	F	M	M	F	F
	Disease
	Duration (years)	13	17	4	8	19	0.5	19	8	N/A	N/A
	CDAI	14	9	17	15	21	25	5	9	N/A	N/A
	CRP (mg/L)	25	8	8	11	17	19	13	66	76	0.8
	Methotrexate	No	Yes	No	No	No	No	No	Yes	No	No
	Biologic therapy	Yes	Yes	Yes	Yes	Yes	No	No	No	No	Yes
	Other synthetic
	DMARD	Yes	No	Yes	No	Yes	No	No	No	Yes	No
	Samples from patients 1-6 were used for mass and flow cytometry phenotyping.
	Samples from patients 7-10 were also included in flow cytometry phenotyping.
			Control	Seropositive RA		Seronegative RA		Spondyloarthropathy
Blood Cross-sectional cohort	Number		35	42		16		11
	Age		61 ± 13	58 ± 14		58 ± 13		48 ± 12
	Female		22 (63)	33 (78)		11 (69)		5 (45)
	Disease Duration (years)		N/A	13 ± 9		14 ± 10		10 ± 6
	CRP (mg/L)		ND	9.3 ± 17.4		6.3 ± 8.5		3.9 ± 4.2
	CDAI		ND	13.7 ± 8.1		9.8 ± 7.6		ND
	Methotrexate		0	19 (45)		8 (50)		2 (18)
	Anti-TNF		0	16 (38)		6 (38)		10 (90)
	Other biologics		0	10 (24)		5 (31)		0
	Other synthetic DMARD		0	4 (10)		1 (6)		0
	Average ± SD shown. Parentheses indicate percentage of patients. Other biologics include abatacept, rituximab, tocilizumab, tofacitinib.
			Improved	Not Improved
Blood Longitudinal cohort	Number		18	5
	Age		49 ± 17	57 ± 10
	Female		17 (94)	4 (80)
	CDAI Before		17.6 ± 9.3	21.7 ± 8.9
	CDAI After		6.3 ± 4.2	25.6 ± 10.2
	Started methotrexate		7	4
	Started anti-TNF		4	0
	Started other biologic		7	1
	Average ± SD shown. Parentheses indicate percentage of patients.