Clinical significance of optimal red cell mass and plasma volume estimation methods

BACKGROUND: The aim of this study was to present and compare the results of proposed methods for optimal red cell mass and plasma volume (RCM&PV) estimation, and their influence on the interpretation of obtained results. MATERIAL AND METHODS: In 120/280 patients with polycythaemia rubra vera, subjected to RCM&PV determination with autologous erythrocytes in vitro labelled with 51Cr-sodium chromate, optimal volumes were determined using: 1. traditional ml/kg of: - the real body weight method (ml/kg RBW); - the optimal body weight method (ml/kg OBW). 2. the body weight, height, and sex based method (Retzlaff's tables), 3. the method recommended by the International Council for Standardization in Haematology (ICSH), based on body surface area. RESULTS: Different interpretation of the same results of 120 RCM&PV measurements was registered in 48/120 patients (40%). The greatest disagreement existed between ml/kg RBW and ml/kg OBW methods (in 39/120 subjects, 32.5%). In underweight patients the ml/kg RBW method, and in overweight patients the ml/kg OBW method, offered better agreement with ICSH&Retzlaff's methods. The ml/kg RBW method disagreed with ICSH&Retzlaff's methods and ml/kg OBW in 25% and 19.2% of patients respectively. ICSH and Retzlaff's methods disagreed in 10/120 patients (8.3%). The ICSH method yielded significantly lower optimal volumes than Retzlaff's. CONCLUSION: Three methods for optimal RCM&PV estimation lead to different interpretations of the same results of RCM&PV measurements with 51Cr-erythrocytes in 40% of patients. Two ml/kg body weight methods show greater disagreement in comparison with ICSH and Retzlaff's methods, which differ significantly. The ICSH method yields lower optimal values compared to Retzlaff's

Protein S and pregnancy: Report of a case

Protein S is a cofactor of protein S which lowers the activat- ed factors VIII and V. Pregnancy reduces the level of protein S to 40-50% of normal levels but it is not clear whether the lowered protein S levels increase the risk of developing thrombo-embolism during pregnancy. This is a report of a 39-year old woman, multipart whose pregnancy terminated as IUGR and who had previously two stillbirths. After the third pregnancy loss of functional protein S level was 20%. Two months after delivery protein S activity was 60%. As it was suspected that low protein S level was a risk factor of complications in pregnancy anticoagulant therapy was used. Thereafter pregnancy and delivery at 38.5 weeks of gestation were successful and the baby weighted 3400 gr at birth. The aim of this report is to emphasize the important role of follow-up of the level of protein S in pregnancy in order to avoid the risk of thrombo-embolism in pregnancy. Anticoagulant therapy is very successful in such a pregnancy and may ensure safe birth

Mesenteric and splenic venous thrombosis in a female patient with essential thrombocytosis and the resistance to activated protein C

Splenic venous thrombosis is a rare disease in which an underlying hypercoagulable state can often be found. A 27-years old female patient with recurrent mesenteric venous and splenic thrombosis as a severe complication of an association of resistance to activated protein C and essential thrombocythemia is presented in this report. Establishing the diagnosis of essential thrombocytosis was particularly difficult because this was the case of the so called "silent" myeloproliferative disorder. The number of thrombocytes was almost normal before the splenectomy performed because of the splenic venous thrombosis. Thus, spontaneous growth of erythroid and megakaryocyte colonies in vitro and the clinical course of the disease were the clues for establishing the diagnosis, because the number of thrombocytes reached the values over 1500×109/l after only 1.5 years of the follow-up. The case of this patient was interesting particularly from the surgical point of view because of the management strategy