Increased tryptase and myeloperoxidase levels in blister fluids of patients with bullous pemphigoid: correlations with cytokines, adhesion molecules and anti-basement membrane zone antibodies

Tryptase and myeloperoxidase respectively represent 2 specific markers of a ctivated mast cells or neutrophils. Therefore, establishing the levels of t hese enzymes may be useful to quantify the cell involvement in the tissues or fluids of different origins and in different pathologies. The aim of thi s study was to analyse the levels of these 2 markers in both the sera and b lister fluids of patients affected with bullous pemphigoid. These levels we re then correlated to the concentrations of 19 cytokines and 2 soluble adhe sion molecules determined in the same samples and also with the log (anti-b asement membrane zone antibody) titres, evaluated in the patients' sera. Fo r these purposes, 15 patients with bullous pemphigoid (10 males and 5 femal es; median age: 84 years, range 66-87; median disease duration: 0 years, ra nge 0-3: median number of skin lesions: 17, range 14-30; median anti-baseme nt membrane zone antibody titre: 1:320, range 0.0-1:2560) and 15 normal sub jects (11 males and 4 females, median age: 81 years, range 59-86) were anal ysed by means of commercially available kits. Results showed that blister f luid myeloperoxidase and tryptase levels were increased as compared with th e respective sera (P<0.01) and several correlations were observed with cyto kines and adhesion molecules. In fact, significant correlations of blister fluid tryptase levels were observed with IL-3, IL-4, IL-5, IL-6, IL-7, IL-8 , VEGF, RANTES and sICAM-1, while myeloperoxidase was correlated with IL-1b eta IL-13 and IL-15. The blister fluid tryptase levels were also significan tly correlated with the anti-basement membrane zone antibody titres (R=0.53 , P=0.05), In conclusion, these findings are in accord with an involvement of both mast cells and neutrophils in bullous pemphigoid and their recruitm ent may be mediated by different biological modulators. Our findings seem t o indicate that the cytokine (IL-3, IFN-gamma and OSM) or adhesion molecule (sICAM-1) concentrations in blister fluid are logarithmically related to t he anti-basement membrane zone antibody titers.