title: Leukaemoid reaction with megakaryocytic features in newborns with Down's syndrome.
abstract: A leukaemoid reaction was observed in 3 newborns with Down's syndrome. Thrombocytopenia was present in 2, requiring platelets transfusions in 1, and red cell transfusions were necessary in 2 patients. Blast cells characterization by specific monoclonal antibodies showed a prevalence of megakaryoblasts in all 3 cases. This feature was confirmed in 2 of them by the demonstration of platelet peroxidase (PPO) activity under transmission electron microscopy (TEM). A spontaneous remission of the leukaemoid picture was observed after 2-3 months. However, in 1 case a relapse of the myeloproliferative disorder with the same features of the blast cell population was diagnosed after 16 months. Chemotherapy with low-dose Ara-C, started because of a relevant clinical involvement, induced a complete remission.
authors.affiliation: Laboratorio di Ricerche Cliniche, Istituti Clinici di Perfezionamento, Milano, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Cantù-Rajnoldi
authors.forename: G
authors.initials: G
authors.lastname: Cattoretti
authors.forename: M L
authors.initials: ML
authors.lastname: Caccamo
authors.forename: A
authors.initials: A
authors.lastname: Biasini
authors.forename: L
authors.initials: L
authors.lastname: Bagnato
authors.forename: R
authors.initials: R
authors.lastname: Schirò
authors.forename: N
authors.initials: N
authors.lastname: Polli
mesh_terms: D000911:Antibodies, Monoclonal; D001853:Bone Marrow / Q000032:analysis / Q000473:pathology; D002471:Cell Transformation, Neoplastic / Q000032:analysis / Q000473:pathology / Q000648:ultrastructure; D004314:Down Syndrome / Q000097:blood* / Q000378:metabolism / Q000473:pathology; D005260:Female; D006651:Histocytochemistry; D006801:Humans; D007231:Infant, Newborn; D007955:Leukemoid Reaction / Q000097:blood* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008533:Megakaryocytes / Q000032:analysis / Q000473:pathology* / Q000648:ultrastructure
chemical_list: D000911:Antibodies, Monoclonal