ACPA-positive primary Sjögren's syndrome: true primary or rheumatoid arthritis-associated Sjögren's syndrome?
OBJECTIVE
Anticyclic citrullinated protein antibodies (ACPA) are highly specific of rheumatoid arthritis (RA). However, they have also been detected in 5-10% of primary Sjögren's syndrome (pSS). We compared ACPA-positive and negative patients with pSS and assessed the risk of evolution to RA.


METHODS
ACPA-positive and negative patients with pSS were included in this study. For ACPA-positive patients, clinical and radiological re-evaluation was systematically performed after at least 5 years of follow-up. Diagnosis was reassessed at the end of the follow-up to identify patients that developed RA according to the American College of Rheumatology 1987 classification criteria.


RESULTS
At inclusion in the cohort 16 patients with pSS were ACPA positive and 278 were ACPA negative. ACPA-positive patients, had more frequently arthritis (43.7% vs 12.2%; p=0.003) but not arthralgias. They also had more frequent lung involvement (25% vs 8.1%; p=0.05). After median follow-up of 8 (5-10) years, 7/16 (43.8%) patients developed RA including 5 (31.25%) with typical RA erosions. Elevation of acute phase reactants at inclusion was the only parameter associated with progression to erosive RA.


CONCLUSIONS
Median term follow-up of ACPA-positive patients with pSS showed that almost half of them developed RA, particularly in the presence of elevation of acute phase reactants. These results support the usefulness of a close radiological monitoring of these patients for early detection of erosive change not to delay initiation of effective treatment. Indeed, number of these patients with ACPA-positive pSS may actually have RA and associated SS.
Department of Rheumatology , Hôpitaux Universitaires Paris-Sud, Assistance Publique-Hopitaux de Paris (AP-HP), Université Paris-Sud, INSERM U1184 , Le Kremlin Bicêtre , France.
J
J
Payet
Department of Rheumatology , Hôpitaux Universitaires Paris-Sud, Assistance Publique-Hopitaux de Paris (AP-HP), Université Paris-Sud, INSERM U1184 , Le Kremlin Bicêtre , France.
R
R
Belkhir
Department of Rheumatology , Centre National de Référence des Maladies Auto-Immunes Rares, INSERM UMRS_1109, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Strasbourg University Hospital, Université de Strasbourg , Strasbourg , France.
J E
JE
Gottenberg
Department of Rheumatology , Hôpitaux Universitaires Paris-Sud, Assistance Publique-Hopitaux de Paris (AP-HP), Université Paris-Sud, INSERM U1184 , Le Kremlin Bicêtre , France.
E
E
Bergé
Department of Rheumatology , Hôpitaux Universitaires Paris-Sud, Assistance Publique-Hopitaux de Paris (AP-HP), Université Paris-Sud, INSERM U1184 , Le Kremlin Bicêtre , France.
F
F
Desmoulins
Department of Rheumatology , Assistance Publique-Hopitaux de Paris, Bichat Hospital , Paris , France.
O
O
Meyer
Department of Rheumatology , Hôpitaux Universitaires Paris-Sud, Assistance Publique-Hopitaux de Paris (AP-HP), Université Paris-Sud, INSERM U1184 , Le Kremlin Bicêtre , France.
X
X
Mariette
Department of Rheumatology , Hôpitaux Universitaires Paris-Sud, Assistance Publique-Hopitaux de Paris (AP-HP), Université Paris-Sud, INSERM U1184 , Le Kremlin Bicêtre , France.
R
R
Seror
Ant-CCP; Rheumatoid Arthritis; Sjøgren's Syndrome