ULTRASTRUCTURE OF FIBRILLAR GRANULES IN HUMAN NEUTROPHILS

Fibrillar granules (FGs) represent neutrophilic primary granules conta ining clustered filaments. We investigated neutrophils in the bone mar row obtained from 17 patients with chronic myeloproliferative disorder s (CMPD) by electron microscopy. FG-positive neutrophils were seen in 15 of the 17 CMPDs with varying frequencies. The diameter of FG-filame nts was 7-8 nm, showing that they corresponded to neither intermediate filaments nor actin filaments. (C) 1994 Wlley-Liss, Inc.