Title: NEUTROPHIL CELLULAR CHEMOTAXIS IN CHILDREN WITH DOWN'S SYNDROME
Abstract: Neutrophil (PMN) cellular chemotaxis was investigated in 8 children with Down's syndrome, their mothers and 13 adult controls. The new method used assessed separately the number of PMN's adhering to the Millipore filter of a Boyden chamber (“filter chemotaxis”, FC) and the number of PMN's migrating into its lower compartment (“compartment chemotaxis”, CC). “Total chemotaxis” (TC) was derived by adding FC and CC. Values are reported as percentage of the initial PMN number introduced into the chambers (X ± SEM): TC, which assesses best the chemotactic behavior of PMN's, was normal in all subjects, except a single patient who showed complete absence of cellular chemotaxis. Patients had significantly lower FC values than the control groups. Rather than indicating poor chemotaxis, this finding probably reflects decreased PMN adhesiveness to the Millipore filter. Abnormal PMN adhesiveness may contribute to the poor host defense against infections in Down's syndrome.