High titers of both rheumatoid factor and anti-CCP antibodies at baseline in patients with rheumatoid arthritis are associated with increased circulating baseline TNF level, low drug levels, and reduced clinical responses: a post hoc analysis of the RISING study

Table 1 Characteristics of patients at baseline and clinical response at week 54 in each dosing group

	3 mg/kg	6 mg/kg	10 mg/kg	p Value
At baseline (week 0)	(n = 99)	(n = 104)	(n = 104)
Age, years	49.7 (11.7)	48.8 (11.8)	50.4 (12.5)	0.5370
Female sex	78 (79%)	86 (83%)	89 (86%)	0.4446^a
Disease duration, years	8.3 (7.8)	7.2 (7.1)	8.4 (7.7)	0.4114
MTX dose, mg/week	7.8 (1.6)	7.9 (1.9)	7.7 (1.7)	0.6510
DAS28-CRP	5.59 (4.89, 6.31)	5.38 (4.85, 6.36)	5.50 (5.10, 6.11)	0.8026
TNF, pg/ml	0.92 (< 0.55, 1.29)	0.97 (0.70, 1.31)	0.89 (< 0.55, 1.24)	0.1320
RF
Median (IQR), IU/ml	128 (27, 280)	82 (37, 273)	89 (43, 187)	0.6361
Range (minimum, maximum), IU/ml	< 3, 1700	< 3, 2340	< 3, 1950
Negative (≤ 15 IU/ml)	19 (19%)	14 (13%)	8 (8%)	0.0551^a
Anti-CCP
Median (interquartile range), U/ml	≥ 100 (26, ≥ 100)	≥ 100 (23, ≥ 100)	≥ 100 (37, ≥ 100)	0.1308
Range (minimum, maximum), U/ml	< 0.6, ≥ 100	< 0.6, ≥ 100	< 0.6, ≥ 100
Negative (≤ 5.0 U/ml)	9 (9%)	12 (12%)	4 (4%)	0.1171^a
At week 54	(n = 99)	(n = 104)	(n = 104)
DAS28-CRP at week 54	3.02 (2.13, 4.25)	2.72 (1.59, 3.99)	2.52 (1.69, 3.65)	0.0394
REM/LDA/MDA/HDA	30 (30%)/11 (11%)/27 (27%)/31 (31%)	41 (39%)/10 (10%)/29 (28%)/24 (23%)	47 (45%)/9 (9%)/31 (30%)/17 (16%)	0.0384
RF, IU/ml	61 (6, 152)	38 (8, 91)	42 (9, 76)	0.3386
Anti-CCP, U/ml	≥ 100 (12, ≥ 100)	47 (12, ≥ 100)	≥ 100 (24, ≥ 100)	0.1079

Abbreviations: CCP, Cyclic citrullinated peptide antibodies, DAS28-CRP Disease Activity Score in 28 joints based on C-reactive protein, HDA high disease activity, LDA Low disease activity without clinical remission, MDA Moderate disease activity, MTX Methotrexate, REM Clinical remission, RF Rheumatoid factor, TNF Tumor necrosis factor
Data are mean (SD), median (interquartile range), or number (%), unless otherwise described. The Kruskal-Wallis test was used to evaluate the differences among three dosing groups, except where indicated otherwise. Disease activity, RF, and anti-CCP at Week 54 were evaluated using the last observation carried forward approach. Cutoff values for DAS28-CRP were as follows: REM, <2.3; LDA, ≥2.3– < 2.7; MDA, ≥2.7– ≤ 4.1; HDA, > 4.1 [22]
^aChi-square test was used to evaluate the differences among three dosing-groups

ISSN: 1478-6362