High sensitivity C-reactive protein as a disease activity marker in rheumatoid arthritis.
OBJECTIVE
To elucidate the potential contribution of high sensitivity C-reactive protein (hs-CRP) testing in the assessment of disease activity in rheumatoid arthritis (RA).


METHODS
We recorded clinical and psychological variables, the hs-CRP, and erythrocyte sedimentation rate (ESR) in 146 consecutive patients with RA. We analyzed the associations between the ESR and hs-CRP versus the other recorded variables.


RESULTS
The median (interquartile range) ESR (mm/h) and hs-CRP (mg/l) were 15 (7-36) and 5 (2.3-13.9), respectively. Thirty-two (22%) patients had an hs-CRP < 2 mg/l, 61 (42%) an hs-CRP of 2-8 mg/l and 53 (36%) an hs-CRP > 8 mg/l. In patients with an hs-CRP of 2-8 mg/l, the swollen joint counts and the physician disease activity scales were higher, and remission rates were lower than in patients with an hs-CRP of < 2 mg/l. The hs-CRP was consistently more closely associated with disease activity, depression, and helplessness than was the ESR.


CONCLUSIONS
High sensitivity CRP testing reveals systemic inflammation that is generally not detectable with routine CRP assays and that is associated with disease activity in RA.
Dessein
Patrick H
PH
Department of Rheumatology, Johannesburg Hospital, Johannesburg, South Africa. Dessein@lancet.co.za
Joffe
Barry I
BI
Stanwix
Anne E
AE
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000175:diagnosis* / Q000276:immunology*; D015415:Biomarkers / Q000097:blood*; D001799:Blood Sedimentation; D002097:C-Reactive Protein / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity
D015415:Biomarkers; D002097:C-Reactive Protein