Systemic lupus erythematosus in a multiethnic US cohort (LUMINA): LXI. Value of C-reactive protein as a marker of disease activity and damage.
OBJECTIVE
To determine whether C-reactive protein (CRP) measured by a high sensitivity (hs) assay is a surrogate marker of disease activity and damage in systemic lupus erythematosus (SLE).


METHODS
Five hundred eighty-eight patients with SLE participating in a multiethnic cohort (Hispanic, African American, and Caucasian) were studied. Disease activity was measured with the Systemic Lupus Activity Measure-Revised (SLAM-R) and damage with the Systemic Lupus International Collaborating Clinics (SLICC) Damage Index (SDI). hs-CRP was measured by immunometric assay. Disease activity and hs-CRP were measured at enrollment and damage accrual at last visit. The association of hs-CRP with the SLAM-R and SDI was examined by univariable (Pearson's correlation) and multivariable (linear regression) analyses. The association of hs-CRP and each individual domain of the SLAM-R and SDI was examined by Spearman's correlation.


RESULTS
hs-CRP was associated with the SLAM-R in the univariable (r = 0.35, p < 0.001) and multivariable (t = 7.11, coefficient beta = 0.27, p < 0.001) analyses. It also correlated with the constitutional, eye, pulmonary, gastrointestinal, neuromotor, and laboratory domains of the SLAM-R. hs-CRP was associated with the SDI (r = 0.12, p = 0.004) in the univariable analysis but not in the multivariable analysis. When the individual domains of the SDI were analyzed, hs-CRP correlated with the renal, pulmonary, cardiovascular, musculoskeletal, and diabetes domains.


CONCLUSIONS
hs-CRP was associated with disease activity but not with overall damage accrual; however, it correlated with specific domains of the damage index. hs-CRP may be useful to monitor the course of the disease and predict its intermediate outcome, but longitudinal studies with serial hs-CRP measurements are necessary to define its clinical value.
Bertoli
Ana M
AM
Department of Medicine, Division of Rheumatology, The University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico.
Vilá
Luis M
LM
Reveille
John D
JD
Alarcón
Graciela S
GS
D000328:Adult; D001741:Black or African American; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis*; D015331:Cohort Studies; D005260:Female; D006630:Hispanic or Latino; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000097:blood* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D044465:White People; D055815:Young Adult
D015415:Biomarkers; D002097:C-Reactive Protein