NO EVIDENCE FOR AN INDEPENDENT ROLE OF ANTI-HEPARAN SULFATE REACTIVITY APART FROM ANTI-DNA IN LUPUS NEPHRITIS

The presence of anti-heparan sulphate (HS) reactivity in serum is clos ely related to the occurrence of nephritis in patients with systemic l upus erythematosus (SLE). Since patients with lupus nephritis in gener al also have high titres of anti-DNA antibodies, we wanted to clarify the relationship between anti-HS and anti-DNA reactivity in serum. The refore, we studied longitudinally six patients with lupus nephritis wh o experienced 12 exacerbations of their disease, and five SLE patients without nephritis experiencing 10 periods of non-renal disease exacer bations. In addition, we tested single serum samples of another 24 pat ients obtained during a renal disease exacerbation and 22 sera of pati ents without nephritis. The sera of all patients were tested for anti- DNA (Farr assay) and anti-HS reactivity (ELISA). We confirmed that SLE patients during renal exacerbations have a significantly higher anti- HS reactivity than patients without nephritis (P < 0.003). In addition , patients with nephritis also had higher titres of anti-DNA antibodie s during renal exacerbations than during non-renal exacerbations (P < 0.01). A correlation between anti-DNA and anti-HS reactivity was obser ved (r = 0.40, P < 0.02), which in itself explains the correlation bet ween nephritis and anti-HS reactivity. Comparing sera from nephritis a nd non-nephritis patients matched for anti-DNA titre, we found no diff erence in anti-HS reactivity, and therefore must conclude that the ant i-HS reactivity is a direct reflection of anti-DNA reactivity.