[Leukotriene (LT) B4 and LTC4 in the blister fluid of bullous pemphigoid].

Leukotriene (LT) B4 and LTC4 content in the blister fluid of patients with bullous pemphigoid (BP) was determined by radioimmunoassay. In samples from BP patients, the former (3.80 +/- 1.99 ng/ml, n = 7) significantly exceeded the amount noted in second degree burn patients (0.93 +/- 0.82 ng/ml, n = 5) and that in the fluid of suction blisters produced on normal human skin (0.95 +/- 0.21 ng/ml, n = 2). The immunoreactive LTC4 (i-LTC4) content in the blister fluid of BP (3.63 +/- 1.13 ng/ml, n = 6) was not statistically significantly different from that observed in second degree burns (2.09 +/- 1.66, n = 5), but more than that in suction blisters on normal skin (0.86 +/- 0.20, n = 2). The chemotactic activity of BP blister fluid toward polymorphonuclear leukocyte (PMNL) of BP blister fluid was determined by injecting them into guinea pig skin and observing the time course of the increase in the number of infiltrated PMNL. Neutrophils and eosinophils had accumulated in the dermis at 3 hours and at 6 hours; the numbers of each had increased remarkably. Methanol-eluted samples of blister fluid used for the radio-immunoassay showed the same chemotactic activity. In addition, the dermis developed marked edematous changes. On the basis of the results presented above, LTB4 and i-LTC4 appear to be generated in skin lesions of BP, the former attracting PMNL to the dermis and the latter causing exudation of blister fluid. Both compounds directly enhance the exacerbation of BP skin lesions.