Vaso-occlusive crisis-associated neutrophil dysfunction in patients with sickle-cell disease.

Polymorphonuclear leukocyte (PMN) aggregation and chemotaxis were studied in 27 patients with sickle cell disease (SCD). Pain-free patients with SCD had a significantly impaired aggregation response to stimulation with n-formylmethionyl-leucyl-phenylalanine (FMLP) with or without cytochalasin B (CB), compared with normal volunteers (p less than 0.001). Patients with SCD in vaso-occlusive crisis had PMN aggregation induced by FMLP with or without CB that was significantly increased compared with the cohort of pain-free SCD patients (p less than 0.001). PMN from pain-free patients had normal chemotaxis, whereas patients in vaso-occlusive crisis had a significant impairment in PMN chemotaxis. PMN chemotaxis was inversely related to the PMN aggregation response to FMLP with CB (r = -0.75). Thus, the PMN from pain-free patients with SCD appears to have normal or decreased "stickiness" and to develop increased stickiness during vaso-occlusive crisis. The mechanisms responsible for these changes need further elucidation. Alterations in PMN function may be responsible, in part, for the increased risk of infection noted in individuals with SCD and may play a role in the development of the acute chest syndrome.