Session Information
Date: Sunday, November 8, 2015
Title: Rheumatoid Arthritis - Small Molecules, Biologics and Gene Therapy Poster I
Session Type: ACR Poster Session A
Session Time: 9:00AM-11:00AM
Background/Purpose:
The mechanism of methotrexate in rheumatoid arthritis (RA) is complex.
It may increase adenosine levels by blocking conversion to of xanthine to uric
acid (UA). This study was done to determine if methotrexate lowers UA in early
RA (ERA).
Methods:
Data were obtained from CATCH (Canadian Early Arthritis Cohort), an incident
ERA cohort. All ERA patients with serial UA measurements were included
comparing those with methotrexate use vs. no methotrexate (controls). Analyses
were exploratory. Patients with concomitant gout or taking uric acid lowering
therapies were excluded.
Results:
Forty-nine of 2524 ERA patients were identified with data available for
both pre-methotrexate UA levels vs. post-methotrexate UA levels (300 μmol/L vs. 273 μmol/L respectively
(p=0.035)). The control group not taking methotrexate had a mean baseline uric
acid level of 280 μmol/L and a follow-up level
of 282 μmol/L (p=0.448); mean change in UA with methotrexate
was -26.8 μmol/L, vs. 2.3 μmol/L
in no methotrexate group (p=0.042). Methotrexate users with a decrease in UA had
a mean lower DAS28 score of 2.37 vs. controls (3.26) at 18 months (p=0.042). Methotrexate
users who decreased UA had a lower SJC of 0.9 at 18 months vs. methotrexate
users without lowering of UA who had a SJC of 4.5 (p=0.035). Other analyses
were not significant.
Conclusion:
Methotrexate response is associated with lowering of uric acid in ERA
compared to non-users, and may be due to changes in adenosine levels.
Methotrexate response is associated with lower UA and fewer swollen joints
compared to non-responders.
|
|
Included Methotrexate Users with UA Decrease
|
Included Methotrexate Users with UA Increase
|
Methotrexate Non-Users (Controls)
|
p-value
|
|
Number of Patients (%)
|
32 (1.3) |
17 (0.7) |
40 (1.6) |
(N/A) |
|
Meeting 2010 ACR/EULAR Classification Criteria for Rheumatoid Arthritis, no. (%) |
29 (91) |
17 (100) |
29 (72) |
0.316 |
|
Positive Rheumatoid Factor (RF) serology at baseline, no. (%) |
22 (69) |
12 (71) |
26 (65) |
0.270 |
|
Positive Anti-CCP at baseline, no. (%) |
27 (84) |
14 (82) |
21 (53) |
0.006
|
|
Symptom duration at baseline, mean ± SD (Days) |
181.44 ± 86.67 |
227.71 ± 149.10
|
144.25 ± 71.25 |
0.011
|
|
Number of DMARDs, mean ± SD |
2.9 ± 0.9 |
3.2 ± 0.9 |
1.2 ± 0.7 |
< 0.001
|
|
Swollen joint count (28), mean ± SEM Baseline 12 months 18 Months 24 Months |
8.00 ± 6.61 3.45 ± 4.59 0.89 ± 2.02 0.82 ± 1.61 |
8.53 ± 5.69 3.87 ± 4.09 4.47 ± 6.30 2.36 ± 2.65 |
5.95 ± 4.99 2.03 ± 3.24 2.30 ± 3.63 1.18 ± 1.81
|
0.192 0.199 0.017 0.054 |
|
DAS28, mean ± SD Baseline 12 months 18 Months 24 Months |
4.93 ± 1.37 2.93 ± 1.52 2.37 ± 1.37 2.43 ± 1.29 |
4.96 ± 1.53 3.43 ±1.60 3.19 ± 1.66 3.26 ± 1.75
|
4.61 ± 1.49 2.86 ± 1.36 3.26 ± 1.70 2.97 ± 1.35 |
0.572 0.445 0.096 0.174 |
To cite this abstract in AMA style:
Lee J, Bykerk V, Dresser G, Boire G, Haraoui B, Hitchon C, Thorne JC, Tin D, Jamal S, Keystone EC, Pope JE. A Reduction in Serum Uric Acid Levels May be Related to Methotrexate Efficacy in Early Rheumatoid Arthritis: Data from a Canadian Arthritis Cohort [abstract]. Arthritis Rheumatol. 2015; 67 (suppl 10). https://acrabstracts.org/abstract/a-reduction-in-serum-uric-acid-levels-may-be-related-to-methotrexate-efficacy-in-early-rheumatoid-arthritis-data-from-a-canadian-arthritis-cohort/. Accessed .« Back to 2015 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/a-reduction-in-serum-uric-acid-levels-may-be-related-to-methotrexate-efficacy-in-early-rheumatoid-arthritis-data-from-a-canadian-arthritis-cohort/