Separation of haemoglobin HbE and HbA by the fully automated, high-pressure liquid chromatography Tosoh HLC-723 G7 analyzer.

High-pressure liquid chromatography instruments specifically devised for separating haemoglobin (Hb) fractions have been increasingly employed by the hospital laboratories over the recent years since they allow easy and fast screening for several Hb variants. Although such instruments may be proposed as sensitive, specific and reliable alternatives to the classic electrophoretic techniques, a major drawback of this screening strategy is the almost identical retention time of several Hb variants. In particular, at least 18 Hb variants have been reported in the same retention window as HbA(2), including HbE, the second most common beta-chain variant in humans after sickle cell trait. Recently, we evaluated the performance characteristics of an improved buffer formulation originally conceived for Hb variants separation procedures on the fully automated high-pressure liquid chromatography instrument Tosoh G7. At variance with other fully automated high-pressure liquid chromatography analyzers, the elution pattern on the G7 in subjects heterozygous for HbE is characterized by the presence of four suggestive peaks (HbF, HbA, HbA(2) and HbE), confirming the effective separation of HbE from HbA(2). Because of its potential value in the diagnosis of the thalassaemia syndromes, the effective separation of HbA(2) from HbE can provide clinical laboratories with a valuable information for the diagnostic reasoning.

Iron management in hemodialysis patients: optimizing outcomes in Vicenza, Italy.

The management of anemia in uremic patients undergoing hemodialysis requires the appropriate combination of erythropoietin treatment, iron supplementation, and on occasion androgen therapy. Identifying and correcting functional iron deficiency is crucial to optimizing erythropoietin efficiency. Recently, however, the trend to administer maintenance iron with resultant high serum ferritin and high transferrin saturation has led to an increase in reports of iron overload. Oral iron supplementation is inexpensive and safe, but poor patient compliance and reduced intestinal absorption may limit its efficacy. Intravenous iron, on the other hand, is effective, and its safety is related to the iron salt used. Currently available data suggest that iron saccharate may be the safest iron salt available for intravenous administration, although iron gluconate is safer than the dextran forms of intravenous iron. It should be kept in mind, however, that all forms of intravenous iron may have the potential of inducing iron overload. At this time, the levels of ferritin that define iron overload are not clearly established. The side effects of iron overload are well recognized (infections, malignancies, vascular diseases); however, no guidelines exist for safe practice. There are many markers of iron deficiency, with serum ferritin and hypochromic red cell percentage currently the best markers available in clinical practice.

Systemic leukocyte filtration during cardiopulmonary bypass.

Cardiopulmonary bypass (CPB) induces a whole body inflammatory response leading to postoperative lung dysfunction. Activated leukocytes may play a role in the pathogenesis of pulmonary dysfunction. We evaluated postoperative lung function after the use of leukocyte-depleting filters incorporated in the extracorporeal circuit during CPB. From November 1997 to March 2000, 40 patients underwent isolated coronary artery bypass grafting. Patients were randomly allocated to the leukocyte-depletion group (group F, 20 patients) or to the control group (group C, 20 patients). There was no significant difference between the two groups with respect to age, sex, weight, height, body surface area, haemoglobin and haematocrit levels, preoperative left ventricular ejection fraction, cooling temperature, aortic crossclamping and CBP duration. Blood samples were drawn preoperatively, at aortic declamping, 60 min after CPB, after arriving at the intensive care unit (ICU) and 24 h after the operation. We analysed blood cell count, elastase, interleukin-8 (IL-8) and tumour necrosis factor (TNF-alpha) levels and continuous monitoring of arterial blood gases in the intensive care unit (ICU). The analysis of total circulating white blood cells (WBCs) showed a significant reduction of WBCs in both groups soon after aortic declamping [from the right atrium: 6.4 x 10(9)/l +/- 1.4 x 10(9)/l in group F vs 10.3 +/- 1.8 x 10(9)/l in group C (p<0.05); from the left atrium: 5.8 +/- 1.3 x 10(9)/l in group F vs 8.4 +/- 1.9 x 10(9)/l in group C (p<0.05)] and after 60 min of CPB [7.1 +/- 2.2 x 10(9)/l in group F vs 10.4 +/- 1.8 x 10(9)/l in group C (p<0.05)]. The analysis of circulating neutrophils showed similar findings in both groups. Elastase levels increased during CPB in both groups with a peak at the end of CPB without significant difference between the two groups (group C: 260 +/- 148 microg/l vs group F: 371 +/- 68 microg/l). The decrease of plasmatic elestase levels was observed, for both groups, in the 24 h after CPB. There was no difference in intubation time between the two groups (16.4 h for group C vs 11.2 h for group F). Pulmonary function tested by pulmonary respiratory index [RI = partial pressure of oxygen/fraction of inspired oxygen (PaO2/FiO2 x 100)] did not show significant difference between the two groups, either arriving in the ICU (group C RI 265 vs group F RI 322), or after 3 h (group RI 304 vs group F RI 305) or after 6 h (group C RI 292 vs group F RI 319). Leukocyte-depleting filters reduce with blood cells count during CPB, but, in this study, WBC depletion did not significantly improve clinical conditions or laboratory finding.