Phagocytosis in myeloproliferative disorders.

The phagocytic function was investigated by means of four tests (capillary tube random migration, phagocytosis of yeast particles, quantitative nitroblue tetrazolium dye reduction and whole-blood bactericidal activity for Staphylococcus aureus) in 57 patients who had myeloproliferative disorders: 24 had chronic granulocytic leukemia, 22 had polycythemia vera, six had myelofibrosis, and five had essential thrombocythemia. This study confirms the previously reported functional anomalies of phagocytosis in all the myeloproliferative disorders and shows that, despite these anomalies, the increased number of phagocytes allows an efficient whole-blood bactericidal activity, essential for the nonspecific host defence mechanisms.