Changes in neutrophil granule protein and cytoplasmic fibrils in human acute myeloid leukemias

Abstract

Granule protein deficiencies in morphologically mature neutrophil cells of peripheral blood from human patients with acute myeloid leukemia was demonstrated using post-embedding immunocytochemistry. Abnormal immunoreactivity of granule proteins was detected in seven of nine patients. Decreased immunoreactivity patterns were found more for the primary granule markers elastase and myeloperoxidase than for the secondary granule marker lactoferrin. Leukemias with a predominant myeloid component, in contrast to those with a predominant monocytoid component, had more neutrophil cells showing immunodeficiencies for one or more granule markers. The proportion of neutrophil cells showing immunodeficiencies varied greatly for each granule marker; more variation was obtained for elastase, lactoferrin and myeloperoxidase than for lysozyme, possibly because lysozyme is a marker for both granule types. In addition, no correlation could be found between any of the immunoreactivity deficiencies for the neutrophil granule glycoproteins elastase, lactoferrin, lysozyme and myeloperoxidase and the abundance of a particular set of ultrastructural features in the circulating leukemic cells from any of the nine patients. Nonetheless, most of the immature myeloid cells from peripheral blood of leukemic patients showing neutrophil protein immunoreactivity abnormalities in one or more granule markers often and randomly displayed one or more unusual ultrastructural features. The clinical and pathological significance of neutrophil granule protein deficiencies and the abundance of fibrillar structures in malignant myeloid cells presently is uncertain.