Anti-DFS70 antibodies in systemic lupus erythematosus: Prevalence in a large Chinese cohort and an unexpected association with anti-dsDNA antibodies by a long-term follow-up

Abstract

ObjectiveMonospecific autoantibodies to dense fine speckles 70 (DFS70) antigen are purported to aid in excluding systemic autoimmune rheumatic diseases (SARD) such as systemic lupus erythematosus (SLE). However, the non-isolated anti-DFS70 still has a certain prevalence in SLE patients, and the clinical significance remains unclear. We aimed to investigate the prevalence, clinical relevance, and value of long-term monitoring of anti-DFS70 antibodies in SLE patients.MethodsAnti-DFS70 antibodies were measured by enzyme-linked immunosorbent assay (ELISA) in 851 SLE patients, 211 healthy individuals, and 194 patients with other SARD (except SLE). Demographic, serological, and clinical associations of anti-DFS70 antibodies were analyzed by a stepwise multivariable logistic regression model. The correlation of anti-DFS70 with anti-dsDNA, anti-C1q, and SLE Disease Activity Index 2000 (SLEDAI-2K) was analyzed. Sixty-one SLE patients with follow-up time ranging from 2 to 57 months were measured anti-DFS70 antibodies using both ELISA and line immunoassay. The dynamic variations of anti-DFS70 antibodies were evaluated with anti-dsDNA, anti-C1q, and SLEDAI-2K during the follow-up.ResultsThe prevalence of anti-DFS70 was significantly higher in SLE (20.7% (176/851)) than in healthy individuals (9.5% (20/211), p = 0.0002) and other SARD (10.8% (21/194), p = 0.002). Multivariable analysis revealed that anti-DFS70-positive SLE patients were associated with younger age (odds ratio (OR) = 0.982; 95% confidence interval (CI) = 0.969, 0.995), higher frequencies of anti-dsDNA (OR 1.598; 95% CI 1.107, 2.306) and anti-PCNA (OR 6.101; 95% CI 2.534, 14.688), and higher levels of serum IgG (OR 1.097; 95% CI 1.067, 1.129) and were more likely to be accompanied by mucosal ulcers (OR 5.921; 95% CI 1.652, 21.215). The O.D. value of anti-DFS70 positively correlated with levels of anti-dsDNA (r = 0.183, p < 0.0001) and anti-C1q (r = 0.181, p < 0.0001), respectively, but not with SLEDAI-2K (p = 0.920). During the follow-up, 49 (42 negative and 7 positive) patients remained stable with anti-DFS70 levels. The other 12 patients experienced significant changes in anti-DFS70, and 83.3% (10/12) of them showed similar trends between anti-DFS70 and anti-dsDNA by evaluation of dynamic variations.ConclusionAnti-DFS70 antibodies seem to be prevalent in Chinese SLE patients. The positive association of anti-DFS70 with anti-dsDNA and consistent dynamic variation between anti-DFS70 and anti-dsDNA during the follow-up suggested a potential relationship between anti-DFS70 and anti-dsDNA in patients with SLE.

Dense fine speckled nuclear immunofluorescence: A mildly reassuring antinuclear antibody pattern meriting consideration

“…Those laboratory parameters are considered to be the indicators of the active phase of SLE. These results suggest also a positive association between the presence of anti‐DFS70 and anti‐dsDNA 19 …”

“…14,16 The high level of these antibodies in a healthy population suggests that, if they are present in SLE patients, they can have a protective function and promote an enhanced response to SLE treatment. 17,18 Dai et al 19 evinced that the presence of anti-DFS70 autoantibodies in SLE patients is positively correlated with younger age, higher anti-dsDNA level, reduced C3 and C4 concentration, an elevated erythrocyte sedimentation rate (ESR), mucosal ulcers and leukopenia. Those laboratory parameters are considered to be the indicators of the active phase of SLE.…”

“…These results suggest also a positive association between the presence of anti-DFS70 and anti-dsDNA. 19 Different types of ANAs are associated with particular clinical manifestations of lupus. The level of anti-dsDNA antibodies changes with progression and correlates with the severity of lupus nephropathy.…”

Anti-DFS70 antibodies are more prevalent in UCTD and Asian SLE patients

“…Our previous studies on Chinese SLE cohort reported higher anti-DFS70 prevalence [11,21] compared with European [12,13] and American studies [6]. A Japanese study also showed that the prevalence of anti-DFS70 antibodies was generally higher in Japanese SARD patients than in patients in Europe and USA [14].…”

The significance of dense fine speckled pattern in antinuclear antibody‐associated rheumatic disease and coexisting autoantibodies: A propensity score‐matched cohort study

“…Recent studies have cast doubt on the performance of anti‐DFS70 antibodies for excluding AARD 16,18–22 . The prevalence of anti‐DFS70 antibodies in AARD varies in different studies 16,23–25 . A meta‐analysis found that in patients with positive ANA test results, the pooled specificity of using anti‐DFS70 antibodies to exclude AARD was 98%, but the pooled sensitivity was only 18% 26 .…”