A new index to discriminate between iron deficiency anemia and thalassemia trait

ABSTRACT BACKGROUND: The most common microcytic and hypochromic anemias are iron deficiency anemia and thalassemia trait. Several indices to discriminate iron deficiency anemia from thalassemia trait have been proposed as simple diagnostic tools. However, some of the best discriminative indices use parameters in the formulas that are only measured in modern counters and are not always available in small laboratories. The development of an index with good diagnostic accuracy based only on parameters derived from the blood cell count obtained using simple counters would be useful in the clinical routine. Thus, the aim of this study was to develop and validate a discriminative index to differentiate iron deficiency anemia from thalassemia trait. METHODS: To develop and to validate the new formula, blood count data from 106 (thalassemia trait: 23 and iron deficiency: 83) and 185 patients (thalassemia trait: 30 and iron deficiency: 155) were used, respectively. Iron deficiency, ß-thalassemia trait and a-thalassemia trait were confirmed by gold standard tests (low serum ferritin for iron deficiency anemia, HbA2 > 3.5% for ß-thalassemia trait and using molecular biology for the a-thalassemia trait). RESULTS: The sensitivity, specificity, efficiency, Youden's Index, area under receiver operating characteristic curve and Kappa coefficient of the new formula, called the Matos & Carvalho Index were 99.3%, 76.7%, 95.7%, 76.0, 0.95 and 0.83, respectively. CONCLUSION: The performance of this index was excellent with the advantage of being solely dependent on the mean corpuscular hemoglobin concentration and red blood cell count obtained from simple automatic counters and thus may be of great value in underdeveloped and developing countries

Monocytes and plasma tissue factor levels in normal individuals and patients with deep venous thrombosis of the lower limbs: potential diagnostic tools?

INTRODUCTION: Tissue factor (TF) is the main physiological initiator of blood coagulation; it is membrane-bound on monocytes (mTF) and free in plasma (pTF). Abnormal expression of TF by monocytes has been implicated in various diseases. We therefore quantified monocytes expressing TF and pTF levels in patients with lower-limb deep venous thrombosis (DVT).MATERIALS AND METHODS: DVT was confirmed by Duplex Scan. Blood mTF levels under resting condition (baseline), after incubation without (unstimulated) and with (stimulated) lipopolysaccharide (LPS), and total mTF levels were determined by flow cytometry using two analytical methods (Histogram and Quadrant-Statistics). Plasma TF levels were measured using an enzyme-linked immunoabsorbent assay (ELISA). Results were compared with age-matched controls.RESULTS: Histogram analysis in patients with DVT showed significantly elevated mTF levels for baseline, unstimulated and total mTF over controls. For Quadrant-Statistics, DVT patients also showed significantly raised baseline, unstimulated, stimulated and total mTF. Similarly, pTF levels were significantly raised in subjects with DVT compared to controls. Baseline mTF levels correlated with pTF levels by Histogram and Quadrant-Statistics analysis. Using the relative operating characteristic (ROC) curve, baseline mTF and pTF assays displayed sensitivity and specificity in detecting DVT. Quadrant-Statistics baseline mTF and pTF gave the best discrimination.CONCLUSIONS: The TF assays used in this study showed acceptable sensitivity and specificity and are cost-effective and practical. Therefore, they should be considered in patients with, or at risk of, DVT