Decreased numbers of chemotactic factor receptors in chronic neutropenia with defective chemotaxis: Spontaneous recovery from the neutrophil abnormalities during early childhood

Childhood chronic neutropenia with decreased numbers of chemotactic factor receptors as well as defective chemotaxis was first demonstrated in an 8‐month‐old girl. Chemotactic factor receptors on neutrophils were assayed using tritiated N‐formyl‐methionyl‐leucyl‐phenylalanine (3H‐FMLP). The patient's neutrophils had decreased numbers of the receptors: numbers of the receptors were 20,000 (< 3 SD) as compared with those of control cells of 52,000 ± 6,000 (mean ± SD) (n = 10). The neutropenia disappeared spontaneously by 28 months of age parallel with the improvement of chemotaxis and increase in numbers of chemotactic factor receptors. These results demonstrate a transient decrease of neutrophil chemotactic factor receptors as one of the pathophysiological bases of a transient defect of neutrophil chemotaxis in this disorder.