Autoantibody Profile of Egyptian Juvenile Systemic Lupus Erythematosus Patients and Its Association with Clinical Characteristics and Disease Activity

Abstract

Objective: This study was conducted to estimate the frequency of anti-nuclear antibodies (ANAs), anti-dsDNA, and anti-extractable nuclear antigen (ENA) antibodies in juvenile systemic lupus erythematosus (JSLE) patients and their association with different clinical manifestations and disease activity.

Patients and methods: A cross-sectional study that includes 100 JSLE patients from Ain Shams University Hospital was conducted. All subjects underwent history taking, clinical examination, assessment of disease activity based on the SLE disease activity index (SLEDAI), laboratory investigations, and tests for autoantibodies, namely ANA, anti-dsDNA, and anti-ENA antibodies, including anti-Ro (SSA), anti-La (SSB), anti-Smith (Sm), and anti-U1-ribonucleoprotein (U1-RNP).

Results: The most common clinical features were polyarthralgia (71%), haematological manifestations (65%), malar rash (54%), and nephritis (51%), respectively. All patients had positive ANA (100%), while anti-dsDNA frequency was 83%. The most common anti-ENA antibodies were anti-RNP (41%), anti-Sm (31%), anti-SSA (27%), and anti-SSB (20%), respectively. Anti-RNP had a clinical association with oral ulcer, Raynaud' phenomena, haematological, neuropsychiatric and thromboembolic manifestations. Meanwhile, anti-Sm had a significant association with serositis, mucocutaneous, constitutional, and neuropsychiatric manifestations. Anti-SSA was associated with mucocutaneous, musculoskeletal, Raynaud' phenomena, renal, haematological and cardiac manifestations, while anti-SSB was significantly associated with malar rash, serositis, thromboembolic, musculoskeletal, and neuropsychiatric manifestations. Concerning SLEADI score, anti-dsDNA antibody was significantly associated with moderate disease activity score (p=0.032) while anti-SSA significantly associated with high disease activity (p=0.045). Both anti-SSB and anti-Sm were significantly associated with both moderate and high disease activities, meanwhile anti-U1-RNP was associated with moderate disease activity (p=0.014).

Conclusion: Anti-dsDNA and anti-ENAs antibodies were frequently found in JSLE patients (83%, 63%), respectively. They were significantly associated with variable clinical manifestations and could be used as predictors for assessment of disease activity.

Keywords: anti-ENA; clinical manifestations; disease activity score; juvenile systemic lupus erythematosus.