Idiopathic thrombocytopenic purpura with defective oxidative metabolism of neutrophils
Ohno, Y.; Kanoh, T.; Uchino, H.
Nihon Ketsueki Gakkai Zasshi Journal of Japan Haematological Society 47(6): 1257-1264
1984
ISSN/ISBN: 0001-5806 PMID: 6097079 Document Number: 228964
A 19-yr-old male with idiopathic thrombocytopenic purpura had no signs of infection, but superoxide production of his granulocytes stimulated with either particulate or soluble stimuli was reduced to abut 0-20% of normal; H2O2 production was reduced to 10-40% of normal. Activation signal of superoxide-forming enzyme reflected by depolarization of the membrane potential was normally generated in response to stimulants. NADPH-dependent superoxide production by subcellular particles from the patient's stimulated neutrophils showed markedly reduced maximal velocity (30.6% of normal) and moderately reduced apparent Km. A decrease in the amount of activated NADPH oxidase which responds to an activation signal or the presence of an unknown non-competitive inhibitor for the enzyme is suggested as a cause of the defective oxidative burst.