BUDAPEST, HUNGARY — Chloroquine therapy for patients with rheumatoid arthritis may lower levels of antibodies to oxidized low-density lipoprotein, and thus reduce the risk of cardiovascular disease, C.L.P. Mangueira, M.D., reported at the 4th International Congress on Autoimmunity.
Oxidized low-density lipoprotein (oxLDL) induces antibody production and the inflammatory process.
These antibodies (anti-oxLDL) are also considered risk factors for cardiovascular disease.
In a study of 66 rheumatoid arthritis (RA) patients and 66 age-matched healthy controls, “we found an apparent association between the use of chloroquine and low levels of the antibodies to oxidized LDL,” said Dr. Mangueira of Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo, Brazil.
This association is compelling because almost 50% of deaths among RA patients are due to cardiovascular causes and the onset of heart disease in RA patients has also been shown to start a decade earlier compared with those without RA.
The researchers evaluated the levels of anti-oxLDL by two different methods and compared them with those of the controls.
Anti-oxLDL was measured by an immunoassay that uses copper-oxidized LDL as antigen and another immunoassay that uses synthetic peptides derived from the fragmentation of apolipoprotein B as antigen. Both assays were developed by Dr. Mangueira's group.
RA patients were using methotrexate, prednisone, sulfasalazine, chloroquine, and leflunomide.
“We found higher levels of anti-oxLDL in rheumatoid patients compared with the control group,” using both methods, Dr. Mangueira said. There was no statistical correlation between anti-oxLDL levels and disease severity, which was assessed using the Modified Disease Activity Score system, the erythrocyte sedimentation rate, and C-reactive protein.
The 22 chloroquine patients had lower levels of anti-ox-LDL than did RA patients with no chloroquine use. In addition, the RA patients taking chloroquine had lower levels of anti-apolipoprotein B peptides than did those not taking the drug.
“We know that chloroquine has a cholesterol-lowering effect,” he said. In fact, chloroquine use has been suggested to reduce lipoprotein synthesis induced by corticosteroids in rheumatoid and lupus patients.