Mechanisms of thrombocytopenia in patients with lymphoproliferative diseases.
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.
Kuznetsov
A I
AI
Department of Haematology, Cardiology Research Center, Moscow, Russia.
Ivanov
A L
AL
Idelson
L I
LI
Mazurov
A V
AV
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*
D000906:Antibodies; D007074:Immunoglobulin G