Higher anti-heparan sulphate reactivity during systemic lupus erythematosus (SLE) disease exacerbations with renal manifestations; a long term prospective analysis.

Cross-reactive antibodies against heparan sulphate (HS) have been suggested to play a role in initiating renal disease in SLE. Recently, we found that HS-reactivity is mediated by anti-DNA antibodies complexed with DNA and histones. To evaluate the clinical significance of anti-HS reactivity, we studied prospectively a cohort of 72 consecutive SLE patients, of whom 22 experienced 40 exacerbations. In 20 of these exacerbations renal symptoms were present. In these 20 exacerbations significantly higher anti-DNA (median 1:160) and anti-HS (median 1:30) titres were detected compared with exacerbations without renal manifestations (median 1:60 for anti-DNA and negative for anti-HS). There were no correlations with other symptoms of SLE. Anti-HS titres showed a significant correlation with anti-DNA antibody titres (rs = 0.57, P < 0.05). Anti-HS without anti-DNA reactivity was never detected. Some SLE patients showed a high anti-DNA titre without anti-HS reactivity, suggesting that not all anti-DNA antibodies are able to bind to histone/DNA complexes and thus to exhibit anti-HS reactivity. Our findings indicate that anti-HS reactivity is correlated with renal disease in SLE.