Leucocyte counts in children with sickle cell anaemia usefulness of stable state values during infections.

The total white blood cell count and total and differential neutrophil counts were compared in two hundred steady state sickle cell anaemia children and sixty age and sex matched AA genotype controls to establish steady state cell counts. Steady state patients were found to have significantly higher mean total white blood cell counts (T-WBC--12.4 +/- 3.0 x 10(9/1)), mean total polymorphonuclear neutrophil counts (T-PMN--4.2 +/- 1.2 x 10(9/1)), mean total segmented (T-S--2.7 +/- 0.9 x 10(9/1)), and mean total non-segmented neutrophil counts (T-NS--1.5 +/- 0.5 x 10(9/1)), when compared with their M genotype controls; T-WBC (5.2 +/- 1.9 x 10(9/1)) (P < 0.001), T-PMN (2.2 +/- 8.0 x 10(9/1)) (P < 0.001), T-S (2.2 +/- 0.9 x 10(9/1)) (P < 0.01), and T-NS (0.02 +/- 0.04 x 10(9/1)) (P < 0.001). Contrary to an expected neutrophilia, steady state patients had a low percentage polymorphonuclear neutrophil count (34%) which did not change significantly with increasing age (P > 0.05). The raised counts in steady state patients suggest that previously established criteria for the diagnosis of bacterial infections cannot be applied to sickle cell patients, and thus new criteria must be generated.