Tenenbein M, Yatscoff R W
Department of Pediatrics, University of Manitoba, Winnipeg, Canada.
Am J Dis Child. 1991 Apr;145(4):437-9. doi: 10.1001/archpedi.1991.02160040095015.
Traditionally, a serum iron concentration in excess of the total iron-binding capacity (TIBC) is considered as an indication for deferoxamine therapy in acute iron poisoning. We observed a reversible elevation of the TIBC in patients with iron poisoning that coincided with their acute hyperferremia and have hypothesized that this is a laboratory aberration. We tested this hypothesis in vitro and found that the addition of iron to test serum samples produced a related increase in the TIBC, and alteration of the assay by providing additional adsorbent prevented this occurrence. We also evaluated the reproducibility of the TIBC as performed by 500 laboratories on 10 different reference samples. The mean coefficient of variation was 16%, which was unsatisfactory. We concluded that the TIBC should not be used in the decision for the initiation of deferoxamine therapy in acute iron poisoning. Furthermore, high TIBC values that are occasionally seen in patients with iron poisoning should not be considered as providing a protective effect.
传统上，血清铁浓度超过总铁结合力（TIBC）被视为急性铁中毒时去铁胺治疗的指征。我们观察到铁中毒患者的TIBC出现可逆性升高，这与他们的急性高铁血症同时发生，并且推测这是一种实验室偏差。我们在体外验证了这一假设，发现向测试血清样本中添加铁会使TIBC相应增加，而通过提供额外的吸附剂改变检测方法可防止这种情况发生。我们还评估了500个实验室对10种不同参考样本进行TIBC检测的可重复性。平均变异系数为16%，这并不理想。我们得出结论，在决定是否对急性铁中毒患者开始去铁胺治疗时，不应使用TIBC。此外，铁中毒患者偶尔出现的高TIBC值不应被视为具有保护作用。
