ON THE HETEROGENEITY OF “BENIGN” NEUTROPENIA OF CHILDHOOD

Abstract

Chronic benign granulocytopenia of childhood (CBGC) is generally accepted as a homogeneous, self limited entity of variable duration, characterized by absolute peripheral blood polymorpho-nuclear leukocyte (PMN) counts <1500/mm3, relative depletion of band and mature granulocytes in bone marrow and absent to mild infections. Our previous observations that some patients within this group have distinct functional aberration of PMNS -- e.g. “Lazy Leukocyte Syndrome” prompted the current study. Eleven children with CBGC were studied. Each had absolute PMN counts <1000/mm3 with 6 <500/mm3. Four functional PMN assays were performed: chemotaxis (Boyden chamber); capillary tube migration; phagocytosis (Baker's yeast ingestion), and; membrane deformability (cell elastimetry technique). The data showed marked heterogeneity in functional PMN profiles. One child had decreased capillary tube migration, one was deficient in all functions tested, six showed various combinations of functional abnormalities and only three children had normal PMN activities in each assay. We conclude: 1) CBGC is not a distinct clinical entity; 2) the spectrum of abnormal PMN functional profiles observed strongly suggests that abnormalities of a number of individual steps of normal PMN function may produce a common clinical phenotype; 3) of the assays employed, membrane deformability was most consistently abnormal; 4) the clinical course of these patients, when followed long term, may not always be benign.