Inhibitor of in vitro neutrophil migration in sera of children with homozygous sickle cell gene during pain crisis.

There is conflicting evidence for a causal relationship between infection and haematological crisis of sickle cell disease. To find out whether changes in leucotaxis occur during pain crisis, in-vitro neutrophil migration was determined in 38 children with Hb SS during steady state and during pain crisis. Migrations of neutrophils of sickle cell patients was 29 +/ 12 microns in steady state and 27.5 +/- 10.5 microns during pain crisis. These rates were comparable to migration of neutrophils of control children with normal haemoglobin of 34 +/- 9.6 microns. However, with addition of autologous serum to the cell suspension, neutrophil migration of patients in pain crisis was significantly retarded (16 +/- 13 microns) as compared to those in steady state (26 +/- 10.2 microns) and control children (28.7 +/- 10 microns). Sera of children in pain crisis also inhibited migration of neutrophils of healthy adults with normal Hb. Pooled normal plasma reversed inhibitory action of pain crisis serum on autologous and homologous neutrophil migration; but pain crisis plasma did not. Chemotactic effect of sera of Hb SS children in steady state or pain crisis and control children on neutrophils of eight adults with normal Hb were similar and comparable to that of pooled normal serum. Thus, children with sickle cell disease develop chemotactic inhibitor(s) in their circulation during pain crisis. They may lead to defective leucotaxis and enhanced susceptibility to infection.