A Test of Iron Malabsorption in Patients with IDA

描述（由申请人提供）：缺铁性贫血（IDA）是成年人和老年人的主要问题。在男性和绝经后女性中，IDA目前被认为是由胃肠道（GI）失血引起的。尽管进行了彻底的胃肠道检查，但仍有相当多的患者发现粪便隐血（FOB）呈阴性，30%的患者未出现与慢性失血相符的病变，提示铁（Fe）吸收不良起重要作用。然而，目前既没有一种合适的测试来测量铁的吸收，也没有在目前的GI检查方案中发挥作用。我们建议修改目前的FOB测试方案，允许在无创测试中同时评估FOB和铁的吸收。这种改良包括在睡前摄入一种明胶胶囊，其中含有少量的铁，标记为非放射性（稳定）同位素（Fe），最近开发的不可吸收标记物DyCl3和食用着色剂FD&C Blue No. 1。然后对一小部分肉眼可见的粪便样本进行血液（目前的做法）和Fe*/Dy比率的实验室分析；后者提供了铁吸收不良存在的准确信息。在第一阶段，我们将通过确定健康的绝经前缺铁妇女在不涉及胃肠道的情况下铁吸收的预期高值来测试该方法的可行性。在ii期，我们将评估存在铁吸收不良的IDA患者（如乳糜泻、幽门螺杆菌胃炎或难以补充铁的IDA患者等）和适当“对照”（无吸收不良的IDA患者）的铁吸收不良范围。在第一阶段，我们将制造一个“测试套件”，获得FDA的批准，并与GI社区合作，利用私人资金开发用于评估IDA患者铁吸收不良的测量应用。

DESCRIPTION (provided by applicant): Iron deficiency anemia (IDA) is a major problem among adults and elderly. In men and postmenopausal women, IDA is currently thought to result from gastrointestinal (GI) blood loss. Despite thorough GI tract evaluation, a significant number of patients are found to be negative for fecal occult blood (FOB) and >30% do not have lesions consistent with chronic blood loss, suggesting that iron (Fe) malabsorption plays an important role. Currently, however, there is neither a suitable test to measure Fe absorption nor a role in the present scheme of GI examination for its evaluation. We propose to modify the current protocol for FOB testing to permit concurrent evaluation of both FOB and Fe absorption in a noninvasive test. The modification involves ingesting a gelatin capsule at bedtime that contains small quantities of Fe labeled with a non-radioactive (stable) isotope (Fe ), the recently developed nonabsorbable marker DyCl3, and the food colorant (visual stool marker) FD&C Blue No. 1.This is followed by laboratory analysis of a small sample of the visually marked stool for blood (the current practice) and the ratio Fe*/Dy; the latter provides accurate information on presence of iron malabsorption. During Phase-I, we will test the feasibility of this method by establishing the expectedly high value of iron absorption in healthy pre-menopausal women who are iron deficient without involvement of the GI tract. During Phase-II, we will evaluate the range of iron malabsorption that exists in IDA patients with suspected malabsorption (e.g celiac disease, H. pylori gastritis, or IDA patients refractory to iron supplementation, etc.) and in appropriate "controls" (IDA patients without malabsorption). During Phase-Ill, we will manufacture a "Test Kit', obtain FDA approval and work with the GI community to develop applications for measurement of iron malabsorption in the evaluation of IDA patients using private funds.