COMPLEMENT-SYSTEM IN BULLOUS PEMPHIGOID .4. CHEMOTACTIC ACTIVITY IN BLISTER FLUID

By a modified Boyden technique, chemotactic activity was present in bullous pemphigoid blister fluids, but was also present in the corresponding sera. Heat inactivation (56.degree. C for 30 min) only partially reduced the chemotactic activity of the blister fluid, but almost completely inhibited the activity in pemphigoid sera. Both suction-induced and cantharidin-induced blister fluids exhibited some chemotactic activity but, in contrast to pemphigoid blister fluids, this activity was almost entirely abolished by heat inactivation. Blister fluids from some patients with other blistering skin diseases exhibited heat-labile and heat-stable chemotactic activity. The chemotactic activity remaining in heat-inactivated pemphigoid blister fluid was inhibited by N-CBZ[carbobenzyloxy]-.alpha.-glutamyl-L-tyrosine and by antiserum to C5 [the 5th complement component], but not with antiserum to C3. Complement-dependent chemotactic activity is apparently present in bullous pemphigoid blister fluids, a finding that further implicates complement activation in the pathogenesis of this disease.