Ritchie B, McNeil Y, Brewster D R
Northern Territory Clinical School, Casuarina, Australia.
Trop Med Int Health. 2004 Jan;9(1):96-105. doi: 10.1046/j.1365-3156.2003.01158.x.
Aboriginal children in tropical Australia have a high prevalence of both iron deficiency and acute infections, making it difficult to differentiate their relative contributions to anaemia. The aims of this study were to compare soluble transferrin receptor with ferritin in iron deficiency anaemia (IDA), and to examine how best to distinguish the effect of iron deficiency from infection on anaemia.
We conducted a prospective study of 228 admissions to Royal Darwin Hospital in children from 6 to 60 months of age. Transferrin receptor concentrations were measured by a particle-enhanced immunoturbidimetric assay and ferritin by a microparticle enzyme immunoassay.
On multiple regression, the best explanatory variables for haemoglobin differences (r2=33.7%, P<0.001) were mean corpuscular volume (MCV), red cell distribution width (RDW) and C-reactive protein (CRP); whereas transferrin receptor and ferritin were not significant (P>0.4). Using > or =2 abnormal indices (MCV, RDW, blood film)+haemoglobin <110 g/l as the reference standard for IDA, transferrin receptor produced a higher area under the curve on receiver operating characteristic curve analysis than ferritin (0.79 vs. 0.64, P<0.001) or the transferrin receptor-ferritin index (0.77). On logistic regression, the effect of acute infection (CRP) on haemoglobin was significant (P<0.001) at cut-offs of 105 and 110 g/l, but not at 100 g/l when only iron deficiency indicators (MCV, RDW, blood film) were significant.
Transferrin receptor does not significantly improve the diagnosis of anaemia (iron deficiency vs. infection) over full blood count and CRP, but in settings with a high burden of infectious diseases and iron deficiency, it is a more reliable adjunctive measure of iron status than ferritin.
澳大利亚热带地区的原住民儿童缺铁和急性感染的患病率都很高，因此很难区分它们对贫血的相对影响。本研究的目的是比较缺铁性贫血（IDA）中可溶性转铁蛋白受体与铁蛋白，并研究如何最好地区分缺铁和感染对贫血的影响。
我们对皇家达尔文医院收治的228名6至60个月大的儿童进行了一项前瞻性研究。采用颗粒增强免疫比浊法测定转铁蛋白受体浓度，采用微粒子酶免疫法测定铁蛋白。
多元回归分析显示，对血红蛋白差异（r2 = 33.7%，P < 0.001）的最佳解释变量是平均红细胞体积（MCV）、红细胞分布宽度（RDW）和C反应蛋白（CRP）；而转铁蛋白受体和铁蛋白无显著意义（P > 0.4）。以≥2个异常指标（MCV、RDW、血涂片）+血红蛋白<110 g/l作为IDA的参考标准，在接受者操作特征曲线分析中，转铁蛋白受体的曲线下面积高于铁蛋白（0.79对0.64，P < 0.001）或转铁蛋白受体-铁蛋白指数（0.77）。逻辑回归分析显示，急性感染（CRP）对血红蛋白的影响在截断值为105和110 g/l时具有显著性（P < 0.001），但在截断值为100 g/l时无显著性，此时只有缺铁指标（MCV、RDW、血涂片）具有显著性。
与全血细胞计数和CRP相比，转铁蛋白受体对贫血（缺铁与感染）的诊断并无显著改善，但在传染病和缺铁负担较高的情况下，它是比铁蛋白更可靠的铁状态辅助指标。
