Prevalence and clinical significance of antiribosomal P antibody and S100 beta protein in childhood-onset systemic lupus erythematosus

Author(s)

Henrique Aldar

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Ciências Médicas
• Defense date: 2011-12-12

Examining board members

Simone Appenzeller; Jozélio Freire de Carvalho; Ibsen Bellini Coimbra

• Advisor: Simone Appenzeller

Abstract

Childhood-onset systemic lupus erythematosus (cSLE) is a chronic inflammatory disease of unknown etiology and autoimmune nature, with disease onset until 16 years of age. It is difficult to assess the central nervous system involvement in cSLE. The antiribosomal P antibodies are autoantibodies directed against epitopes of ribosomal phosphoproteins from the ribonucleoprotein complex and more frequently observed in patients with up to 18 years old. The S100? protein has a low molecular weight, being composed of 91 amino acids and mainly located in the cells of the neuroglia, Schwann cells and sensory nerves in most of the brainstem. Our objectives were to determine the association between antiribosomal P antibodies and S100? protein with clinical and laboratory manifestations in cSLE; to assess the prevalence of antiribosomal P antibodies in patients with cSLE, first-degree relatives and healthy control subjects; and to evaluate S100? protein levels in cSLE patients and healthy control subjects. Consecutive cSLE patients followed in Pediatric Rheumatology at the University of Campinas between 2009/2010 were selected for this study. First-degree relatives were also included in this work. The control group was matched for age, gender and demographic background. Clinical, laboratory, disease activity [SLE Disease Activity Index (SLEDAI)], cumulative damage [Systemic Lupus International Collaborating Clinics /American College of Rheumatology Damage Index (SDI)] and medication in use were assessed. Fifty cSLE patients, (mean age of 16.82 ± 3.46 years), 35 relatives (mean age of 38.73 ± 3.89 years) and 20 healthy controls (mean age 18.3 ± 4.97 years) were selected. Thirteen (26%) cSLE patients presented the antiribosomal P antibodies, no first-degree relative (p<0.01) or control (p<0.01) presented antiribosomal P antibodies. Antiribosomal P antibodies were associated to anxiety in this cohort of cSLE patients (p<0.02). Patients with cognitive impairment (median = 38.08) had significantly higher levels of S100? compared to patients without cognitive impairment (median = 16.12, p = 0.001) and controls (median = 23.62, p <0.05 ).No other clinical, laboratory, and treatment were associated with the antiribosomal P antibodies or S100? protein in cSLE. These data shows that the antiribosomal P antibodies are often observed in cSLE patients and that it was associated with the presence of anxiety in this group of patients. The presence of cognitive impairment was associated with elevated levels of S100?, suggesting neuronal damage in these patients (AU)

• FAPESP's process: 09/13046-3 - Analysis of the prevalence of anti-P, anti-NR2 antibodies and the neuronal marker S100 beta in sistemic lupus erythematosus.
• Grantee: Henrique Aldar
• Support type: Scholarships in Brazil - Master