Monocyte alpha-naphtyl esterase deficiency in chronic granulomatous disease

Monocytes from five unrelated children (four boys and a girl) with chronic granulomatous disease were studied for their ability to reduce nitroblue tetrazolium dye after stimulation with zymosan, and for their alpha-naphtyl butyrate esterase activity. As expected, monocytes ingested zymosan particles but failed to reduce nitroblue tetrazolium dye. However, monocytes from two boys out of the five patients were alpha-naphtyl butyrate esterase-negative, whereas both their neutrophils and monocytes were positive for granular naphtol AS-D esterase activity.