Clinical significance of anti-Ro and Anti-La antibodies: The role of isolated anti-La

Objectives The aim of the present study was to describe demographic, clinical, and immunological characteristics of SLE patients with anti-La/SSB antibodies positive versus anti-La/SSB negative patients. Methods Retrospective cross-sectional study, including all patients with SLE (≥4 ACR-1997 criteria) recruited in RELESSER registry. Sociodemographic, clinical, serological and comorbidities variables were collected. Anti-Ro-/La + patients were compared with the rest of the patients. Results In a study involving 4219 systemic lupus erythematosus (SLE) patients, 44/3893 (1.1%) were found to be positive for isolated anti-La/SSB antibodies. The mean age was 33.77 years, with a majority being female (88.6%) and Caucasian (90.5%). The most frequent comorbidities were smoking (48.8%), dyslipidemia (47.7%), and arterial hypertension (31.8%). Photosensitivity and mucosal ulcers were more common in anti-Ro+/La + patients compared to anti-Ro+/La- and anti-Ro-/La- patients. Anti-Ro+/La + patients had a lower frequency of lupus nephritis compared to anti-Ro+/La- patients. A multivariable regression model, considering various confounding factors, was applied to compare anti-La/SSB positive patients with negative ones. Isolated anti-La/SSB positive patients showed a lower occurrence of lupus nephritis and a higher frequency of cardiac manifestations. Conclusions The study suggests that patients with isolated anti-La/SSB antibodies may have a unique clinical profile, with a potential protective effect against lupus nephritis but an increased likelihood of cardiac manifestations.