Table 2.

Baseline Demographics of AS Subjects

Variable	Number (%) or Mean ± SD where appropriate
	BWH Cohort (n=13)	UPMC Cohort (n=12)	Total AS Subjects (n=25)
Age (years) at time of RTX	51 ± 10	47 ± 14	49 ± 12
Gender (female)	12 (92%)	8 (67%)	20 (80%)
Race (white)	4 (31%)	6 (50%)	10 (40%)
BMI	27.5 ± 9.6	31.4 ± 7.6	29.1 ± 8.9
Ever smoker	4 (31%)	4 (33%)	8 (32%)
Current smoker	0 (0%)	2 (17%)	2 (8%)
Antisynthetase Ab
Jo-1	6 (46%)	10 (83%)	16 (64%)
PL-12	4 (31%)	2 (17%)	6 (24%)
PL-7	3 (23%)	0 (0%)	3 (12%)
Anti-SSA	1 (8%)	3 (25%)	4 (16%)
Symptoms
Myositis	12 (92%)	7 (58%)	19 (76%)
Arthritis	9 (69%)	3 (25%)	12 (48%)
Mechanic’s hands	9 (69%)	3 (25%)	12 (48%)
Skin rashes	8 (62%)	4 (33%)	12 (48%)
Raynaud’s	7 (54%)	7 (58%)	14 (56%)
Fever	4 (31%)	2 (17%)	6 (24%)
Medications (Prior to RTX/Concurrent with RTX initiation)
Azathioprine	9 (69%)/1 (8%)	7 (58%)/0 (0%)	16 (64%)/1 (4%)
Mycophenolate Mofetil	8 (62%)/4 (31%)	8 (67%)/4 (33%)	16 (64%)/8 (32%)
Cyclophosphamide	6 (46%)/0 (0%)	5 (42%)/1 (8%)	11 (44%)/1 (4%)
Tacrolimus	2 (15%)/0 (0%)	7 (58%)/1 (8%)	9 (36%)/1 (4%)
Methotrexate	4 (31%)/0 (0%)	7 (58%)/1 (8%)	11 (44%)/1 (4%)
IVIG	4 (31%)/0 (0%)	3 (25%)/1 (8%)	6 (24%)/1 (4%)
Leflunomide	3 (23%)/0 (0%)	0 (0%)/0 (0%)	3 (12%)/0 (0%)
Etanercept	1 (8%)/0 (0%)	0 (0%)/0 (0%)	1 (4%)/0 (0%)
Baseline laboratory values
CK	872 ± 1537	3744 ± 7273	2308 ± 5337
Aldolase	18 ± 16	54 ± 72	29 ± 42
ESR	24 ± 17	36 ± 41	28 ± 28
CRP	6.2 ± 4.7	30.8 ± 36.2	10.1 ± 14.6

Number missing: Race (n=3), BMI (n=3), Ever smoke (n=1), Anti-SSA (n=6), Myositis (n=2), Mechanics (n=7), Raynaud (n=6), Fever (n=9), Arthritis (n=4), Rash (n=9), CK (n=2), Aldolase (n11), ESR (n=8), CRP (n=11)

Abbreviations: AS – Antisynthetase syndrome, SD – Standard deviation, RTX – Rituximab, BWH - Brigham and Women’s Hospital, UPMC – University of Pittsburgh Medical Center, CK – Creatinine kinase, ESR - Erythrocyte sedimentation rate, CRP – C-reactive protein