Disease Activity Score 28 (DAS28) using C-reactive protein underestimates disease activity and overestimates EULAR response criteria compared with DAS28 using erythrocyte sedimentation rate in a large observational cohort of rheumatoid arthritis patients in Japan.
OBJECTIVE
To compare disease activity and the improvement of disease activity evaluated between by Disease Activity Score 28 using erythrocyte sedimentation rate (DAS28-ESR) and by DAS28 using C-reactive protein (DAS28-CRP) in Japanese patients with rheumatoid arthritis (RA).


METHODS
Data from 3073 RA patients registered in the large cohort database (NinJa: National Database of Rheumatic Diseases by iR-net in Japan) of 2003 was used to calculate DAS28-ESR and DAS28-CRP and disease activities were evaluated. Improvements in disease activities were also evaluated according to the European League Against Rheumatism (EULAR) response criteria in 1482 RA patients whose DAS28-ESR and DAS28-CRP could be calculated from data for both 2002 and 2003.


RESULTS
The mean value of DAS28-CRP (3.59, SD 1.25) was significantly smaller than that of mean DAS28-ESR (4.31, SD 1.32) (p < 0.0001). The number of patients who satisfied the criteria of remission was 297 (9.7%) in DAS28-ESR versus 705 (22.9%) in DAS28-CRP and the number of patients with high disease activity was 842 (27.4%) versus 357 (11.6%) for DAS28-ESR and DAS28-CRP, respectively; there was a significant difference between the two (p < 0.0001). Change of respective DAS28 was significantly correlated (DeltaDAS28-ESR -0.05, SD 1.14 versus DeltaDAS28-CRP -0.10, SD 1.10) (p < 0.0001); however, the number of "good response" patients was significantly different (p < 0.03) between DAS28-ESR (97 patients, 6.5%) and DAS28-CRP (136 patients, 9.2%).


CONCLUSIONS
DAS28-CRP significantly underestimated disease activity and overestimated the improvement in disease activity compared with DAS28-ESR. DAS28-CRP should be evaluated using different criteria from that for DAS28-ESR.
Matsui
Toshihiro
T
Department of Rheumatology, Sagamihara National Hospital, National Hospital Organization 18-1, Sakuradai Sagamihara-city, Kanagawa, 228-8522, Japan. t-matsui@sagamihara-hosp.gr.jp
Kuga
Yoshiaki
Y
Kaneko
Atsushi
A
Nishino
Jinju
J
Eto
Yoshito
Y
Chiba
Noriyuki
N
Yasuda
Masayuki
M
Saisho
Koichiro
K
Shimada
Kota
K
Tohma
Shigeto
S
D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D018501:Antirheumatic Agents / Q000627:therapeutic use; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000188:drug therapy; D015415:Biomarkers / Q000097:blood; D001799:Blood Sedimentation; D002097:C-Reactive Protein / Q000032:analysis*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005260:Female; D005938:Glucocorticoids / Q000627:therapeutic use; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D016896:Treatment Outcome
D000894:Anti-Inflammatory Agents, Non-Steroidal; D018501:Antirheumatic Agents; D015415:Biomarkers; D005938:Glucocorticoids; D002097:C-Reactive Protein