[Leukocyte aggregation activity in the serum of a patient with Sweet's syndrome]

In the blood serum of a patient with Sweet's syndrome an aggregation activity of polimorphonuclear leucocytes was found in vitro. The aggregation response occurs with a latent period of one minute after the stimulation and was slow but sustained. The aggregation was totally inhibited by the hydrocortisone (500 mg./ml.). Although the polymorphonuclears of the patient aggregate normally being stimulated with C5a (ZAS), FMLP and the degranulant PMA, they remain unchanged with the patient's serum. A particular state of "leucocytic stimulation" induced by a serum agent, different from the common chemotactic factors, perhaps an immunocomplex, is postulated.