Autoantibodies in patients with psoriatic arthritis on anti-TNFα therapy.
BACKGROUND
Anti-TNFα therapy has been effective in the treatment of patients with refractory psoriatic arthritis (PSA). However, the risk of developing autoantibodies commonly found in rheumatic diseases in PSA patients undergoing this therapy is not clear.


OBJECTIVE
To evaluate the induction of specific autoantibodies after anti-TNFα therapy in PSA patients.


METHODS
Serum samples from 23 PSA patients (women: 61%, age: 45.04 ± 12.68 years, polyarticular: 69.6%, disease duration: 13.3 ± 7.7 years, infliximab: 82.60%) obtained immediately before (baseline) and approximately one year after the introduction of anti-TNF therapy (last sample) (385 ± 131.45 days), were analyzed. The analysis included detection of antinuclear antibodies (ANA) and anti-dsDNA antibodies (indirect immunofluorescence on Hep-2 cells and Crithidia luciliae, respectively); anti-RNP and anti-Sm (passive hemagglutination); and anti-Ro/ SS-A and/or anti-La/SS-B, anti-chromatin, anti-histones, anti-citrullinated peptide (CCP), and anti-cardiolipin (ELISA) antibodies.


RESULTS
At baseline, ANA was positive in 47.8% of patients, with predominance of homogeneous nuclear pattern (81.8%). All baseline serum samples were negative for rheumatoid factor and antibodies to cardiolipin, RNP, Sm, Ro/SS-A, anti-La/SS-B, anti-histone, and anti-dsDNA antibodies, while two patients were positive for anti-chromatin and one for anti-CCP. All ANA-positive samples at baseline, except for one, remained positive after the introduction of anti-TNF therapy; however, de novo ANA reactivity was observed in four originally negative patients (33.3%). Anti-Ro/SS-A, La/SS-B, cardiolipin, histones, dsDNA, and rheumatoid factor antibodies remained negative in all final serum samples tested, and anti-chromatin positivity was detected in three other patients.


CONCLUSIONS
Our findings have shown that anti-TNF therapy induced ANA positivity in one third of PSA patients. The concomitant use of methotrexate did not interfere with this finding. In addition, all serum samples were systematically negative for specific rheumatic autoantibodies tested after the introduction of the biological treatment.
High-Cost Drug Dispensation Center, Hospital das Clínicas, Medical School of Universidade de São Paulo (HCFMUSP), Rheumatology Department of FMUSP, Brazil. visatv@usp.br
Vilma S Trindade
VS
Viana
Jozélio Freire
JF
de Carvalho
Júlio César Bertacini
JC
de Moraes
Carla Gonçalves Schain
CG
Saad
Ana Cristina de Medeiros
AC
Ribeiro
Célio
C
Gonçalves
Cleonice
C
Bueno
Margarete B
MB
Vendramini
Eloísa
E
Bonfá
D000911:Antibodies, Monoclonal / Q000009:adverse effects*; D015535:Arthritis, Psoriatic / Q000097:blood* / Q000188:drug therapy*; D001323:Autoantibodies / Q000097:blood*; D005260:Female; D006801:Humans; D000069285:Infliximab; D008297:Male; D008875:Middle Aged; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors*
D000911:Antibodies, Monoclonal; D001323:Autoantibodies; D014409:Tumor Necrosis Factor-alpha; D000069285:Infliximab