Rheumatoid Factor Positivity Is Associated with Increased Joint Destruction and Upregulation of Matrix Metalloproteinase 9 and Cathepsin K Gene Expression in the Peripheral Blood in Rheumatoid Arthritic Patients Treated with Methotrexate

Table 3

Clinical, immunological, and radiological parameters and therapeutic response in seropositive rheumatoid arthritic patients.

	Baseline 𝑛=21	24 months 𝑛=21	𝑃 (Wilcoxon matched pairs 𝑡-test)
IgM RF, mU/mL	83.1 [58.5; 304.5]	76.7 [26.9; 250.1]	0.24
ACPA, U/mL	100 [20.3; 100]	100 [68.7; 100]	0.03
C-reactive protein, mg/L	13.8 [3.7; 20.8]	6.2 [4.4; 11.4]	0.03
DAS28	5.56 [4.7; 6.4]	3.5 [2.4; 4.1]	0.0002
DAS28 < 2.6	0	5 (24%)	—
2.6 < DAS28 < 3.2	1 (5%)	2 (9%)	0.30
3.2 < DAS28 < 5.1	5 (24%)	11 (52%)	0.34
DAS28 > 5.1	15 (72%)	3 (14%)	0.002
Morning stiffness, min	60 [30; 180]	16.5 [0; 27]	0.002
Swollen joints	8 [5.5; 13]	2 [0; 6]	0.001
Tender joints	9 [3; 18.5]	2.5 [0; 8]	0.006
Number of patients with erosions, %	23.8% (5/21)	47.6% (10/21)	0.05
Erosion score	0 [0; 0.5]	1.5 [0; 5]	0.003
Joint space narrowing score	13 [7; 24]	23 [15.5; 31.5]	0.001