Urrechaga Eloísa, Hoffmann Johannes J M L
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Clin Chem Lab Med. 2017 Aug 28;55(10):1582-1591. doi: 10.1515/cclm-2016-0856.
Many discriminant formulas have been reported for distinguishing thalassemia trait from iron deficiency in patients with microcytic anemia. Independent verification of several discriminant formulas is deficient or even lacking. Therefore, we have retrospectively investigated discriminant formulas in a large, well-characterized patient population.
The investigational population consisted of 2664 patients with microcytic anemia: 1259 had iron deficiency, 1196 'pure' thalassemia trait (877 β- and 319 α-thalassemia), 150 had thalassemia trait with concomitant iron deficiency or anemia of chronic disease, and 36 had other diseases. We investigated 25 discriminant formulas that only use hematologic parameters available on all analyzers; formulas with more advanced parameters were disregarded. The diagnostic performance was investigated using ROC analysis.
The three best performing formulas were the Jayabose (RDW index), Janel (11T), and Green and King formulas. The differences between them were not statistically significant (p>0.333), but each of them had significantly higher area under the ROC curve than any other formula. The Jayabose and Green and King formulas had the highest sensitivities: 0.917 both. The highest specificity, 0.925, was found for the Janel formula, which is a composite score of 11 other formulas. All investigated formulas performed significantly better in distinguishing β- than α-thalassemia from iron deficiency.
In our patient population, the Jayabose RDW index, the Green and King formula and the Janel 11T score are superior to all other formulas examined for distinguishing between thalassemia trait and iron deficiency anemia. We confirmed that all formulas perform much better in β- than in α-thalassemia carriers and also that they incorrectly classify approximately 30% of thalassemia carriers with concomitant other anemia as not having thalassemia. The diagnostic performance of even the best formulas is not high enough for making a final thalassemia diagnosis, but in countries with limited resources, they can be helpful in identifying those patients who need further examinations for genetic anemia.
已有许多鉴别诊断公式用于区分小细胞性贫血患者的地中海贫血特征与缺铁性贫血。对几种鉴别诊断公式的独立验证不足甚至缺乏。因此，我们对一大群特征明确的患者进行了回顾性研究鉴别诊断公式。
研究人群包括2664例小细胞性贫血患者：1259例缺铁性贫血，1196例“单纯”地中海贫血特征（877例β地中海贫血和319例α地中海贫血），150例地中海贫血特征合并缺铁或慢性病贫血，36例患有其他疾病。我们研究了25个仅使用所有分析仪都能获得的血液学参数的鉴别诊断公式；忽略了使用更高级参数的公式。使用ROC分析研究诊断性能。
表现最佳的三个公式是Jayabose（RDW指数）、Janel（11T）以及Green和King公式。它们之间的差异无统计学意义（p>0.333），但它们各自的ROC曲线下面积均显著高于任何其他公式。Jayabose公式以及Green和King公式的灵敏度最高，均为0.917。Janel公式的特异性最高，为0.925，它是其他11个公式的综合得分。所有研究公式在区分β地中海贫血与缺铁性贫血方面比区分α地中海贫血与缺铁性贫血表现明显更好。
在我们的患者群体中，Jayabose RDW指数、Green和King公式以及Janel 11T评分在区分地中海贫血特征与缺铁性贫血方面优于所有其他研究公式。我们证实，所有公式在β地中海贫血携带者中的表现比在α地中海贫血携带者中要好得多，并且它们还将约30%合并其他贫血的地中海贫血携带者错误分类为无地中海贫血。即使是最佳公式的诊断性能也不足以做出最终的地中海贫血诊断，但在资源有限的国家，它们有助于识别那些需要进一步进行遗传性贫血检查的患者。
