Increased granulocyte adherence in psoriasis and psoriatic arthritis

Circulating polymorphonuclear leukocytes (PMN) from patients with psoriasis and psoriatic arthritis were found to be significantly more adherent to nylon fiber columns when compared with both normal and nonpsoriatic patient control groups. The increased adherence correlated positively with the extent of disease and was highest in those patients with psoriatic arthritis. Total leukocyte and PMN counts were increased in psoriasis patients and were highest in the psoriatic arthritis group. No increase in cell counts was found for mononuclear leukocytes. PMN adherence was not increased in lithium-treated patients or a nonpsoriatic patient control group although such patients did have significant granulocytosis. PMN's are frequently present in lesions of psoriasis as are activated complement components and abnormal keratinocyte cyclic nucleotide levels. These factors or others may cause a generalized activation of PMN's in psoriasis leading to migration of neutrophils into the skin lesion. The present study demonstrates a systemic effector cell alteration in psoriasis and contradicts the general concept that uncomplicated psoriasis is limited to the skin.