Platelet peroxidase deficiency in a case of myelodysplastic syndrome with myelofibrosis.

Abstract

SUMMARY Morphological and functional abnormalities of the megakaryocytic series have been well described in myelodysplastic syndromes. Platelet peroxidase has always been demonstrated in abnormal megakaryocytes and early megakaryoblasts in such syndromes. We have studied a case of myelodysplastic syndrome with marked morphological abnormalities of megakaryocytes in which ultrastructural studies showed the coexistence of platelet peroxidase positive and platelet peroxidase negative megakaryocytes. This enzymatic deficiency was confirmed by the ultrastructural study of circulating platelets. This case appears to be the first report of a partial platelet peroxidase deficiency. It adds to the enzymatic abnormalities in myelodysplastic syndrome already described for the red cells and the granulocytic cells.

Biology of myelodysplastic syndromes

“…Abnormalities in the expression of certain myeloid and/or monocyte antigens have also been reported [108-1101. Platelets may exhibit functional [lll] and cytochemical abnormality [112]. Coppelstone et al [125] postulate that in MDS there are unstable progenitors liable to clonal proliferation along a variety of pathways, given appropriate stimuli.…”