Inhibitor of in Vitro Neutrophil Migration in Sera of Children with Homozygous Sickle Cell Gene during Pain Crisis

Abstract

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.

Investigations of host defence in patients with sickle cell disease

“…This could result from a primary abnormality of the cell surface (Crowley et al, 1980), or from the presence of circulating inhibitors (Allan et al, 1982). Akenzua & Amiengheme (1981) have demonstrated that patients with SCD accumulated factors in their serum during crises that inhibited neutrophil chemotaxis. Rod-shaped and spherical particles are released from damaged erythrocytes into the plasma of patients with SCD (Allan et al, 1981.…”

Lymphocyte Subpopulations in Homozygous Sickle Cell Anaemia

“…Several abnormalities of the body's defence mechanisms have been incrimi nated as possible causes for this tendency, but no con clusive results citing specific immunological defects associated with or resulting from the disease have been reported. The reported abnormalities include: defective alternate pathway of complement activation [13] ; impaired neutrophil activity [2]; increased sus ceptibility to salmonella infections by haemolysis [14] ; deficiency of pneumococcal serum opsonizing activity in sickle cell disease [19]; functional hyposplenism [16] and impaired cell-mediated immunity [11], Immunoglobulin levels have been reported as normal, high or low [3,4,6,8). Immunological para meters, such as variance in lymphocyte subpopula tions, have in many different states of disease been as sociated with the inability to mount an adequate im munologic response [18].…”