Native, oxidized lipoprotein(a) and lipoprotein(a) immune complex in patients with active and inactive rheumatoid arthritis: plasma concentrations and relationship to inflammation.
BACKGROUND
Several studies suggest that lipoprotein (a) [Lp(a)] act as acute phase reactant and be associated with early atherosclerosis in rheumatoid arthritis (RA). Oxidized Lp(a) [ox-Lp(a)] and Lp(a) immune complex (IC) concentrations both increased in patients with coronary heart disease. We investigated Lp(a), ox-Lp(a) and Lp(a)-IC concentrations in RA patients and to explore the relationships with inflammatory disease activity markers.


METHODS
Plasma Lp(a), ox-Lp(a) and Lp(a)-IC concentrations, and inflammatory markers were analyzed in 54 patients with RA, including 23 active and 21 inactive RA, and 60 control subjects.


RESULTS
Lp(a) and ox-Lp(a) concentrations in active RA were higher than those in both inactive RA and control; Lp(a)-IC concentrations in active RA were also higher than inactive RA, while no difference was found in Lp(a), ox-Lp(a) and Lp(a)-IC concentrations between inactive RA and control. Lp(a) concentrations were found positively correlated with ox-Lp(a) and Lp(a)-IC concentrations, respectively; ox-Lp(a) concentrations were also related with Lp(a)-IC. Lp(a), ox-Lp(a) and Lp(a)-IC were all found positively related with C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), respectively.


CONCLUSIONS
Native, oxidized Lp(a) and Lp(a)-IC concentrations increased in active RA patients. Inflammation may induce the changes of Lp(a), resulting in increased ox-Lp(a) and Lp(a)-IC, and may play an important role in atherosclerosis.
Wang
Junjun
J
Department of Biochemistry, Jinling Hospital, Clinical School of Medical College, Nanjing University, 305#, East Zhong Shan Road, Nanjing, 210002, China.
Hu
Bing
B
Kong
Lingtao
L
Cai
Hui
H
Zhang
Chunni
C
D000328:Adult; D000368:Aged; D000936:Antigen-Antibody Complex / Q000097:blood*; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000276:immunology*; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D017270:Lipoprotein(a) / Q000097:blood / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D010084:Oxidation-Reduction
D000936:Antigen-Antibody Complex; D017270:Lipoprotein(a)