Concentration of antibodies to extractable nuclear antigens and disease activity in systemic lupus erythematosus

Abstract

A hallmark of systemic lupus erythematosus (SLE) is the production of autoantibodies directed against intracellular antigens. Antibodies to double stranded DNA (dsDNA) are most closely associated with the clinical manifestations of the condition and appear to have a direct role in pathogenesis. On the contrary, the relationship between disease activity in SLE and anti-extractable nuclear antigen (ENA) antibodies has not been well demonstrated. Despite this, commercial assays for the quantification of anti-ENA antibodies are now widely available, although their usefulness in clinical practice is not known. The aim of this study was to investigate whether there is an association between disease activity in SLE and concentrations of individual anti-ENA antibodies. A prospective 2-year study of 45 patients with SLE, known to be positive for at least one anti-ENA antibody, was performed. Disease activity was assessed using the SLE Disease Activity Index (SLEDAI). Anti-ENA antibodies were quantified using a commercial antibody detection system. A total of 45 patients were studied over a 2-year period (median number of assessments 5, range 2-9). Of them 29 patients were positive for Ro, 8 for La, 9 for Sm and 27 for RNP antibodies. In the population as a whole, there was a weak relationship between peak SLEDAI score and anti-Sm concentration (r = 0.57, NS), but no relation with the other anti-ENA antibodies. In a small number of patients, there appeared to be either a positive (Ro, Sm) or negative (La, Sm, RNP) association between ENA antibody concentration and disease activity over time; however, this was not apparent for the majority of individuals. These results show that in SLE, clinically significant changes in disease activity do not correlate well with concentrations of anti-ENA antibodies, either within the population as a whole or on an individual basis. Repeated quantitative measurement of anti-ENA antibodies does not therefore appear to provide useful additional information in assessing disease activity in SLE. The widespread application of commercial quantitative assays to routine clinical practice is not recommended.

Evaluation of ENA-6 Profile by ELISA Immunoassay in Patients with Systemic Lupus Erythematodes

“…Obtained results are not in the accordance with the reports from other authors [37–39]. Possible explanations for our results might be due to small study sample.…”

Autoantibody profile and clinical patterns in 619 Italian patients with cutaneous lupus erythematosus

“…Previous epidemiologic studies have shown that patients with LE have an increased risk of comorbidity. [14][15][16][17][18][19][20][21] In our study, we found an increased risk of Sj€ ogren syndrome, as well as endocrine and respiratory diseases in SLE patients, regardless the CLE subtypes. An association among cardiovascular and gastrointestinal diseases and age was shown; accordingly, patients with vs. those without such diseases were older.…”

Are autoantibodies the targets of B-cell-directed therapy?

“…24 In contrast to the fluctuating expression of anti-DNA antibodies in patients with SLE, anti-RBP antibody levels are much less variable over time, and can be remarkably stable in patients whose anti-DNA reactivity levels rise and fall dramatically (Figure 1). 25 These divergent responses suggest that distinct pathways of B cell activation or differen tiation underlie anti-DNA antibody and anti-RBP antibody levels. In this regard, it is interesting to note that anti-Ro and anti-La autoantibodies can be detected before the expression of anti-DNA activity and the onset of clinical manifestations in individuals who will develop SLE, again suggesting differences in the biology of these responses.…”