Polymorphonuclear leukocyte chemotaxis in psoriasis: enhancement by self-activated serum

Abstract

The chemotactic activity of polymorphonuclear luekocytes (PMN) directed against serum was determined in a modified Boyden chamber assay. In a total of 176 experiments, PMN and sera from healthy controls were compared with PMN and sera from patients with psoriasis. When PMN from patients with psoriasis were confronted with psoriatic serum, greatly enhanced chemotaxis was demonstrated. Non-psoriatic PMN in the presence of psoriatic serum showed no enhancement. Psoriatic PMN in the presence of normal serum were chemotactically more active compared to non-psoriatic PMN. Heat inactivation (56.degree. C, 30 min) reduced the chemotactic activity of all sera by nearly 50%. In psoriatic sera the enhancement of chemotaxis was still present after heat treatment. The presence of a functional abnormality of chemotaxis in psoriasis is indicated. This is likely to be caused by the in situ generation of chemotactically active fragments of complement. Experiments showing increased chemotactic activity of sera exposed to migrating PMN support this concept.