[Anti-endothelial cell antibodies in systemic vasculitis: detection and correlation with disease activity].

OBJECTIVE

To investigate the prevalence of anti-endothelial cell antibodies (AECA) in systemic vasculitis and to assess the correlation between AECA and disease activity, and try to discuss the classification of AECA.

METHODS

Cyto-ELISA with EA.hy926 and HMEC-1, two immortalized cell lines, as substrates, was applied to detect AECA in 122 cases of systemic vasculitis, including 43 cases of Behcet disease, 19 cases of Takayasu arteritis, 19 cases of Wegener's granulomatosis, 11 cases of microscopic polyangiitis, 9 cases of polyarteritis nodosa, 3 cases of Churg-Strause syndrome, 2 cases of giant cell arteritis and other 16 cases of which could not be classified clearly. Patients with SLE, RA, and fever of unknown origin, and normal persons were used as control groups. Then the associations of AECA to laboratory findings and clinical disease activity (scored by BVAS) were analyzed. Furthermore, the AECA value from the two different substrate cells were analyzed for correlation and difference.

RESULTS

With either EA.hy926 or HMEC-1 as substrates, the AECA prevalence rates of systemic vasculitis (respectively 33.61% and 37.70%) were significantly higher than those of the normal and RA groups (less than 10%), and the prevalence of AECA in SLE (61.75%) was higher than that of systemic vasculitis (37.70%) when using HMEC-1 as substrates. AECA was found to correlate very well with ESR in 122 cases of systemic vasculitis and with BVAS in 40 cases of small systemic vasuculitides, including Wegener's disease, microscopic polyangiitis, Churg-Strause syndrome and so on. The pair AECA values with EA.hy926 and HMEC-1 as substrate cells were found to be correlated significantly, and the matching rate was 92.62%.

CONCLUSION

Prevalence of AECA in systemic vasculitis is high. AECA indicates the clinical disease activity. As to the assumption of classification of AECA into antibodies against microvascular and macrovascular endothelial cells, further study need to be done to prove or disprove it.