title: Mechanisms of thrombocytopenia in patients with lymphoproliferative diseases.
abstract: Different factors are involved in the development of thrombocytopenia in patients with lymphoproliferative disorders. Significant correlation was detected between the number of megakaryocytes in bone marrow and platelet count (r = 0.485, p = 0.002, n = 37) and significant difference between the number of megakaryocyte in patients with normal platelet count (> 200,000/microliters) and patients with marked thrombocytopenia (platelet count < 100,000/microliters). All patients in the latter group (n = 15) had a relatively low number of megakaryocytes. Low but significant reverse correlation was found between the level of platelet-associated IgG (PA-IgG) and platelet count (r = -0.249, p = 0.024, n = 82) and significant difference between the mean levels of PA-IgG in the groups of patients with platelet count > 200,000/microliters and < 100,000/microliters. PA-IgG were increased in 46% of patients in the total group and in 65% of patients with platelet count < 100,000/microliters. The correlation between platelet count and PA-IgG was about 2 times higher in splenectomized (r = -0.549, p = 0.005, n = 24) than nonsplenectomized patients. All splenectomized patients with platelet count < 100,000/microliters (n = 8) had a significant increase in PA-IgG. Serum antibodies were detected in only 7% of tested patients. This group was characterized by severe thrombocytopenia (in 6 of 10 patients--platelet count < 50,000/microliters) and a high incidence of haemorrhages (in 5 of 10 patients). Thus the depression of platelet production was suggested to be the basic cause of thrombocytopenia in lymphoproliferative disorders. Involvement of immune mechanisms was revealed in a large number of patients and correlated with a deeper and more complicated thrombocytopenia.
authors.affiliation: Department of Haematology, Cardiology Research Center, Moscow, Russia.
authors.forename: A I
authors.initials: AI
authors.lastname: Kuznetsov
authors.forename: A L
authors.initials: AL
authors.lastname: Ivanov
authors.forename: L I
authors.initials: LI
authors.lastname: Idelson
authors.forename: A V
authors.initials: AV
authors.lastname: Mazurov
mesh_terms: D000906:Antibodies / Q000032:analysis; D001792:Blood Platelets / Q000276:immunology / Q000378:metabolism; D001853:Bone Marrow / Q000473:pathology; D002452:Cell Count; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism; D007943:Leukemia, Hairy Cell / Q000150:complications* / Q000276:immunology / Q000473:pathology; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000150:complications* / Q000276:immunology / Q000473:pathology; D008533:Megakaryocytes / Q000473:pathology; D010976:Platelet Count; D013921:Thrombocytopenia / Q000097:blood / Q000209:etiology*
chemical_list: D000906:Antibodies; D007074:Immunoglobulin G