Stability of activated partial thromboplastin time (APTT) test under different storage conditions.

We designed this study to assess the effect of storage time and temperature on the activated partial thromboplastin time (APTT) test and plasma activity of factor VIII (FVIII). A total of 71 subjects, comprising 34 healthy controls and 37 patients receiving unfractionated heparin were enrolled. After centrifugation of collected specimens aliquots of plasma were stored at room temperature (20-22 degrees C), refrigerated at 2-6 degrees C and frozen at - 40 degrees C. Determination of APTT and plasma activity of FVIII were performed immediately after sampling (zero time) and after 6, 12 and 24 h. We found no significant difference in APTT after 6 h at room temperature and 4 degrees C compared to zero time values (P>0.05) in control group, while APTT was significantly changed at other storage conditions. With regard APTT test in patients on heparin therapy and samples for FVIII activity in healthy subjects; there was a statistically significant change in their results after 6, 12 and 24 h at room temperature, 4 and - 40 degrees C compared to zero time value(P < 0.05). Our data demonstrate that the APTT test can be done within 6 h when stored at room temperature and 4 degrees C without change in the result in healthy subjects. APTT test in patients on heparin therapy and samples for FVIII test in healthy subjects must be done immediately and without delay to avoid reduction in their activities.

Unbalanced bone turnover in children with beta-thalassemia.

The life expectancy of patients with thalassemia has greatly improved over the last decade as a result of regular transfusions and increased compliance with iron chelation therapy, however, this improvement is often accompanied by a series of serious complications including osteopenia and osteoporosis. The pathogenesis of these skeletal disorders is multifactorial which may be due to hormonal deficiency, compromised nutritional status, bone marrow expansion due to erythroid hyperplasia, increased iron stores or desferrioxamine toxicity. The non invasive assessment of bone turnover has markedly improved with the development of specific and sensitive markers of bone formation. The aim of this work is to assess the value of bone formation markers in patients with beta-thalassemia. To achieve this goal, 36 patients with thalassemia were recruited in this study. There were 20 males (56.6%) and 16 females (44.4%) and their ages ranged from 3 to 18 years. A control group of 20 apparently healthy subjects of matched age and sex was used. The patients were selected from the outpatient clinic and inpatients of the Hematology/Oncology Unit of Mansoura University Children's Hospital (MUCH). The selected subjects were subjected to thorough history taking, clinical examination, radiological evaluation and laboratory investigations in the form of: complete blood count, serum iron, serum ferritin, total iron binding capacity, serum calcium, serum phosphorus and estimation of bone formation markers as alkaline phosphatase and osteocalcin. The results were as follows: serum calcium level was within normal range and showed no statistical significance (p = 0.176) when compared to the control group, while serum phosphorus level was significantly higher in thalassemic patients than the controls (p = 0.002); this may reflect hypoparathyroidism. Analysis of the level of bone formation markers showed serum alkaline phosphatase levels slightly higher in patients than controls but not significant (p = 0.055), and this elevation can be referred to associated liver disease in these patients. On the other hand, osteocalcin level was significantly lower in patients than controls (p = 0.011), and this may be due to osteoblast poisoning by iron overload. In conclusion, thalassemic patients have unbalanced bone turnover between the bone formation and resorption markers and this is evidenced by non significant changes or decreased levels of bone formation markers, while bone resorption is an active process.