chiniofon and Thrombocytopenia

Thrombocytopenia is a common occurrence (20%) in sick neonates, but the causes have not been well studied. In this report we demonstrate that thrombocytopenia in the neonate is characterized by increased platelet destruction as shown by shortened homologous 111In-oxine-labeled platelet life spans. Thirty-one prospectively studied thrombocytopenic neonates were investigated by measuring the 111In-labeled platelet life span, platelet-associated IgG (PAIgG), and coagulation screening tests. In every infant, the thrombocytopenia was shown to have a destructive component since the mean platelet life span was significantly shortened to 65 +/- 6 (mean +/- SEM) hours with a range of one to 128 hours compared with adult values (212 +/- 8; range, 140 to 260; gamma function analysis). The platelet survival was directly related to the lowest platelet count and inversely related to both the highest mean platelet volume and duration of the thrombocytopenia. In 22 infants the percent recovery of the radiolabeled platelets was less than 50%, which suggested that increased sequestration also contributed to the thrombocytopenia. Infants with laboratory evidence of disseminated intravascular coagulation (n = 8) or immune platelet destruction evidenced by elevated levels of PAIgG (n = 13) had even shorter platelet survivals and a more severe thrombocytopenia compared with the ten infants in whom an underlying cause for the thrombocytopenia was not apparent. Full-body scintigraphic images obtained in 11 infants showed an increased uptake in the spleen and liver, with a spleen-to-liver ratio of 3:1. This study indicates that thrombocytopenia in sick neonates is primarily destructive, with a subgroup having evidence of increased platelet sequestration.

Topics: Blood Platelets; Cell Survival; Humans; Hydroxyquinolines; Indium; Infant; Infant, Newborn; Oxyquinoline; Platelet Count; Radioisotopes; Thrombocytopenia

The kinetics and distribution in vivo of autologous 111-In-labelled platelets were studied in 20 patients with chronic hepatic disease. The patients, 16 of whom were thrombocytopenic, exhibited a shortened platelet mean life time, a reduced platelet recovery and a normal platelet turnover, the latter 2 of which were positively correlated to the platelet count. Platelet in vivo recovery was negatively correlated to the spleen volume. In accordance with this, scintigraphic studies revealed that the spleen was the major organ of platelet sequestration and destruction, the role of the liver being almost negligible. Signs of platelet destruction in the bone marrow were also found. Our results indicate that splenic platelet pooling and accelerated platelet destruction, accompanied by inability of the bone marrow to compensate for the thrombocytopenia are the main causes of the thrombocytopenia accompanying chronic hepatic disease.

Topics: Adult; Aged; Blood Platelets; Bone Marrow; Cell Survival; Chronic Disease; Female; Humans; Hydroxyquinolines; Indium; Kinetics; Liver; Liver Diseases; Male; Middle Aged; Organometallic Compounds; Oxyquinoline; Platelet Count; Radioisotopes; Radionuclide Imaging; Spleen; Thrombocytopenia

Optimal labelling conditions of human platelets with 111In-oxine were determined in vitro. Based on this optimized technique, platelet mean life span (MLS) and platelet sequestration site were comparatively evaluated in 79 patients with two labels, 51Cr (n = 26) and 111In (n = 53). Patients were subgrouped according to clinical criteria as autoimmune thrombocytopenic purpura (AITP) (group 1; n = 49), hypersplenism (2; n = 12), impaired thrombopoiesis (3; n = 3), unclassified thrombocytopenia (4; n = 6), and nonthrombocytopenic patients (5; n = 9). In patients with AITP and hypersplenism the mean values for the MLS determined either with 51Cr or with 111In were lowered but the difference was not statistically significant, neither for group 1 (18.6 h vs 17.3 h; P greater than 0.2) nor for group 2 (94.7 vs 122.3 h; P greater than 0.2). The correlation between MLS and platelet counts in patients with AITP was significant for both labels (P less than 0.001). The 15 min recovery tended to be higher with 111In in all groups, but the difference was significant (P less than 0.05) only for group 1. The sequestration sites were similar with both labels. We conclude that, contrary to previous reports, platelet survival studies yield similar results with both the 51Cr and 111In methods. Due to its distinct advantages 111In is the label of choice for investigation of platelet kinetics.

Topics: Blood Platelets; Cell Survival; Chromium Radioisotopes; Hematopoiesis; Humans; Hydroxyquinolines; Hypersplenism; Indium; Organometallic Compounds; Oxyquinoline; Purpura, Thrombotic Thrombocytopenic; Radioisotopes; Radionuclide Imaging; Thrombocytopenia

A 4-year-old boy presented with consumptive coagulopathy suspected to be due to Kasabach-Merritt syndrome. Localization of homologous indium-111 platelets in the region of the right sacral ala confirmed that this was the site of disease and facilitated radiation treatment, which proved to be curative.

Topics: Blood Platelets; Child, Preschool; Hemangioma; Humans; Hydroxyquinolines; Indium; Male; Organometallic Compounds; Oxyquinoline; Radionuclide Imaging; Spinal Neoplasms; Syndrome; Thrombocytopenia

We have used homologous platelet labelling with 111In oxine in the diagnosis of thrombocytopenia occurring in a patient who had received two renal transplants. The technique enabled us to prove that platelet destruction was occurring in the right-sided, non-functioning transplant. In the presence of moderately impaired bone marrow function, this destructive process was sufficient to cause thrombocytopenia. Transplant nephrectomy relieved the thrombocytopenia.

Topics: Blood Platelets; Cell Survival; Female; Graft Rejection; Humans; Hydroxyquinolines; Indium; Kidney Transplantation; Middle Aged; Organometallic Compounds; Oxyquinoline; Platelet Count; Radioisotopes; Radionuclide Imaging; Thrombocytopenia

Topics: Blood Platelets; Cell Survival; Female; Humans; Hydroxyquinolines; Indium; Leukemia, Lymphoid; Male; Oxyquinoline; Radioisotopes; Thrombocytopenia