Prognostic laboratory markers of joint damage in rheumatoid arthritis.
OBJECTIVE
To investigate whether determination of a set of laboratory markers at baseline provides prognostic information on joint damage in hands and feet in rheumatoid arthritis.


METHODS
183 patients with early rheumatoid arthritis included in a prospective study were examined. Radiographic changes in hands and feet at 5 and 10 years after inclusion were evaluated (Larsen). The markers analysed were: erythrocyte sedimentation rate (ESR); HLA-DRB alleles typed by restriction fragment length polymorphism; and C reactive protein, cartilage oligomeric matrix protein (COMP), rheumatoid factor (RF) (IgG, IgA, and IgM subtypes), antibodies against cyclic citrullinated peptide (anti-CCP), and antibodies against interleukin 1alpha (anti-IL1alpha), analysed by immunoassays. Multiple linear regression with backward elimination was used to determine the prognostic value of the variables.


RESULTS
117/176 patients were positive for IgG RF, 138/176 for IgA RF, 139/176 for IgM RF, 140/176 for anti-CCP, and 40/182 for anti-IL1alpha. After five years, ESR, the presence of IgA RF, serum COMP, and the presence of anti-CCP were significantly associated with more severe joint damage, and the presence of anti-IL1alpha with less severe joint damage. Baseline C reactive protein and anti-CCP predicted radiographic outcome after 10 years. A stronger prediction was obtained by combining the prognostic factors.


CONCLUSIONS
Early determination of anti-CCP, IgA RF, anti-IL-1alpha, ESR, C reactive protein, and COMP predicted the development of joint damage in hands and feet in this cohort. A combination of these measures reflecting different aspects of the disease process should be useful for evaluating prognosis in individual patients with early rheumatoid arthritis.
Department of Rheumatology, Lund University Hospital, S-221 85 Lund, Sweden. elisabet.lindqvist@reum.lu.se
E
E
Lindqvist
K
K
Eberhardt
K
K
Bendtzen
D
D
Heinegård
T
T
Saxne
D000328:Adult; D001172:Arthritis, Rheumatoid / Q000175:diagnosis* / Q000000981:diagnostic imaging; D001323:Autoantibodies / Q000097:blood; D015415:Biomarkers / Q000097:blood*; D001799:Blood Sedimentation; D002097:C-Reactive Protein / Q000032:analysis; D064236:Cartilage Oligomeric Matrix Protein; D018450:Disease Progression; D016326:Extracellular Matrix Proteins / Q000097:blood; D005260:Female; D005528:Foot / Q000000981:diagnostic imaging; D006023:Glycoproteins / Q000097:blood; D006225:Hand / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D064235:Matrilin Proteins; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D011859:Radiography; D012044:Regression Analysis; D012217:Rheumatoid Factor / Q000097:blood
D001323:Autoantibodies; D015415:Biomarkers; D064236:Cartilage Oligomeric Matrix Protein; D016326:Extracellular Matrix Proteins; D006023:Glycoproteins; D064235:Matrilin Proteins; C577553:TSP5 protein, human; D002097:C-Reactive Protein; D012217:Rheumatoid Factor