Anti-histone antibodies (ELISA and immunoblot) in canine lupus erythematosus.

In the canine systemic lupus erythematosus (SLE), anti-double stranded DNA (ds-DNA) antibodies (enzyme linked immunosorbent assay (ELISA) or indirect immunofluorescence on Crithidia luciliae) are rare whereas anti-histone antibodies are often found: 61.7% with ELISA and 74% with immunoblot. In canine SLE the pattern of anti-histone antibodies on immunoblot is different from anti-histone antibodies in human SLE. Indeed, histone fractions which are most often recognized by the canine antibodies are by order of frequency H3, H4 and H2A, whereas in man this order is H1, H2B then H3. In the diagnostic criteria of canine SLE, we suggest replacing the anti-ds-DNA antibodies by the anti-histone antibodies detected by immunoblot.