Background Autoantibodies against SS-A/Ro include two specificities (anti-Ro52 and anti-Ro60). These are directed against different antigens. Sera with reactivity against Ro52 are usually precipitin negative and cannot be detected by SS-A/Ro native based ELISAs. This fact has generated a bias to the detection of Ro60 when classifying SS-A/Ro positive patients. Currently the idea that anti-Ro52 and anti-Ro60 should be considered as independent markers in connective tissue diseases (CTD) is gaining ground.
Objectives To correlate the detection of antibodies against Ro52 and/or Ro60 and the development of an organ specific clinical pattern in patients with CTD
Methods Design retrospective (1999-2012). Type of center: University academic center with a referral area of 800.000 inhabitants (HUGTiP). Sera from patients with CTD from HUGTiP where tested for SS-A/Ro specificities by ELISA (Orgentec) and inmunoblot (Innolia). Medical records of all the patients with positivity for one of the specificities in at least one occasion were analyzed. In addition demographic, immunological and clinical data of the patients with systemic lupus erythematosus (SLE), Sjögren syndrome (SS), systemic sclerosis (SSc) or poly-dermatomyositis (PM-DM) were recorded.
Results Data from 347 patients (299 women and 48 men) with positive serum were collected. Mean follow up 7.1 year (0-12.8 years). Of those, 151 presented reactivity only against Ro52 (Ro52+), 34 against Ro60 (Ro60+) and 162 against bothspecificities (Ro52+Ro60+). The associated diagnoses were: SLE (n=99), SS (n=57), PM-DM (n=15), SSc (n=20), undifferentiated connective tissue diseases (n=12), inflammatory arthropathy (n=20; rheumatoid arthritis=9) and liver diseases (n=34; VHC=21 and autoimmune liver diseases=13). Finally, 30 patients wereunclassified.
Ro 52+ patients included SLE (16%, n=24), SS (11%, n=17), SSc (12%, n=18) and PM-DM (10%, n=15). While Ro52+Ro60+ included mainly SLE (37%, n=60) and SS (27%, n=43) but also SSc (2%, n=3) and PM-DM (0.5%, n=1). Finally Ro60+ included only SLE (44%, n=15) and SS (6%, n=2).
Interestingly enough: 18% (n=26) of the Ro52+patients and 8% (n=13) of the Ro52+Ro60+ patients presented lung involvement, while none was detected in the Ro60+ group. Ro52+ patients showed more involvement of the lung than Ro60+ patients (p=0.003). Furthermore Ro52+ and Ro60+ groups also showed differences in the frequency of presence of sicca syndrome (p=0.024) and Raynaud phenomenon (p=0.016).
No differences were founded in the frequency of involvement of heart, renal, cutaneous, and hematological systems or in cancer.
Conclusions Antibodies against Ro60 are associated to SLE and SS while Ro52 are present in a heterogeneous group of diseases.
Our data suggest that Ro52 is a marker of systemic involvement. Ro52 patients have more involvement of the lung, sicca syndrome and Raynaud phenomena.
Disclosure of Interest None Declared