[A pilot study on the significance of leucocyte CD146 expression in vasculitis]

To investigate the correlation between CD(146) expression on peripheral leucocytes with clinical activation in patients and vasculitis.

Flow cytometry was used to detect CD(146) expression on peripheral leucocytes of 39 patients with active systemic vasculitis [13 with microscopic polyangiitis (MPA), 9 with Wegener's granulomatosis (WG), 2 with chung-strauss syndrome (CSS), 9 with takayasu arteritis (TA), 2 with polyarteritis nodosa (PAN), 4 with Behcet's disease (BD)] and 24 with SLE. 18 patients (5 MPA, 4 WG, 2 CSS, 4 SLE, 2 PAN, 1 TA) were evaluated during active and improved phase.

Expression of CD(146) on polymorphonuclears (PMN), lymphocytes (LYM) and monocytes was elevated predominantly in active vasculitis patients, especially on PMN. PMN-CD(146) positive ratio in MPA group was (20.5 +/- 25.0)%, WG (16.5 +/- 20.4)%, CSS (33.5 +/- 41.8)%, SLE (16.2 +/- 23.9)%, PAN (42.7 +/- 15.3)% and TA (6.5 +/- 4.3)%, all with significant difference (P < 0.05). BD group showed no difference with normal people (P > 0.05). LYM-CD(146) positive ratio in MPA group was (7.3 +/- 8.4)%, WG (9.6 +/- 9.1)%, CSS (16.1 +/- 20.1)%, SLE (12.2 +/- 13.5)% and TA (5.1 +/- 4.4)%, all with significant difference (P < 0.05). BD and PAN group showed no difference (P > 0.05). The expression of CD(146) on the three groups of cells correlated with each other (r was 0.66 and 0.853 respectively, P = 0.000), but they did not correlate with the course of the disease, age, ESR, C reactive protein (CRP), antineutrophil cytoplasmic antibody (ANCA), birmingham vasculitis activity score (BVAS) and SLE disease activity index (SLEDAI) (P > 0.5). 18 patients were followed up after therapy with corticosteroids and immunosuppressive drugs. PMN-CD(146) positive ratio during active phase and improved phase was (40.3 +/- 27.0)% and (9.9 +/- 18.8)% (P = 0.001) and LYM-CD(146) positive ratio was (15.7 +/- 13.6)% and (6.7 +/- 5.3)% (P = 0.021) respectively. Almost in all of them the ratio decreased from active phase to improved phase. These were first reported in the world literature.

A high expression of CD(146) on peripheral leucocytes especially PMN in patients with active vasculitis is reported here for the first time and it turns to be negative with the therapy of corticosteroid and immunosuppressive drugs. This indicates that CD(146) may be a new marker for disease activation and may be important in the pathogenesis of vasculitis. Further study in this respect in needed.