Soluble transferrin receptor and soluble transferrin receptor/log ferritin index in diagnosis of iron deficiency anemia in pediatric inflammatory bowel disease

Background

There is no single reliable marker of iron homeostasis in inflammatory bowel disease.

Decreased erythropoietin responsiveness to iron deficiency anemia in the elderly

The prevalence of anemia in the elderly raises the question of an inappropriate secretion of erythropoietin in response to increased demands. Therefore, the serum erythropoietin concentration of elderly patients (74–95 years) with iron deficiency anemia was measured and compared to that of iron deficiency anemic adults (25–60 years). A lowered erythropoietin secretion in response to anemia was observed in elderly patients in comparison with adults. However, the serum erythropoietin of the anemic elderly was inversely correlated with hemoglobin levels as shown for the anemic adults. The progressive reduction of the renal function observed with aging could explain the decreased capacity of erythropoietin secretion in elderly patients.     

补充铁剂对上海老年人缺铁性贫血的改善效果

目的观察铁剂纠正老年人缺铁性贫血的效果,为开展老年入缺铁性贫血防治工作提供参考依据。方法招募缺铁性贫血的老年人62例（男性16例,女性46例）,年龄60-79岁,每日口服一包铁营养包（主要成分为焦磷酸铁和富马酸亚铁,含元素铁8mg）,连续服用6个月,分别于干预前、第3个月、第6个月进行贫血相关指标,血清铁蛋白及C反应蛋白测定观察补铁效果,同时进行膳食调查。结果经过6个月干预,老年人血红蛋白水平由112．5g／L上升至114．4g／L,血红蛋白达标率（32．3％）、红细胞计数、平均红细胞浓度、血清铁蛋白达标率（83．9％）基线调查水平差异有统计学意义（P〈0．01）。试验期间老年人能量及有关营养素摄取量差异无统计学意义。结论连续6个月每日补充8mg铁能有效改善老年人缺铁性贫血。     

Diagnosis of iron deficiency: evaluation of the "soluble transferrin receptor/transferrin" ratio

OBJECTIVE: This study was aimed at determining the diagnostic value of conventional laboratory tests regarding the iron status and serum transferrin receptor in hospitalized patients. METHODS: Patients who had to undergo bone marrow aspirate examination were included in this 8-month prospective study. Iron deficiency was defined as the absence of stainable iron on bone marrow examination. Patients with stainable iron were included in the control group. The higher value of diagnostic efficacy determined the cut-off value for each parameter of the iron status. RESULTS: Twenty-one patients (17 females, four males) (mean age: 52 years) with iron deficiency and 33 control subjects (20 females, 13 males) (mean age: 60 years) were included in the study. The ratio serum transferrin receptor/serum ferritin had the best diagnostic efficiency (78%) with a sensitivity of 81% and a specificity of 97%. Serum ferritin alone with a cut-off value of 60 micrograms/L had the same specificity (97%) but a lower sensitivity (76%). The diagnostic value of all other analyzed tests was below 66% (transferrin alone, mean corpuscular volume, transferrin saturation, iron, serum transferrin receptor alone, red cell distribution width). CONCLUSION: Among in-patients, ferritin remains the first intention test to diagnose iron deficiency, but the cut-off value should be increased (60 micrograms/L in this study). The ratio "serum transferrin receptor to serum ferritin" provides the highest specificity with a higher cost and should be used only in doubtful cases.     

The usefulness of serum transferrin receptor for discriminating iron deficiency without anemia in children

We determined serum transferrin receptor (sTfR), serum erythropoietin and hematologic and biochemical iron parameters in 251 healthy children. The levels of sTfR were significantly higher in children with storage iron deficiency but had a poor sensivity for recognizing iron deficiency without anemia. When ferritin values cannot accurately demonstrate the iron deficiency in children, the sTfR/ferritin ratio or sTfR-log ferritin is recommended to discriminate iron deficiency in the absence of anemia.     

High serum transferrin receptor level in anemia of chronic disorders indicates coexistent iron deficiency

Blood transferrin receptor (TR) level is largely determined by the quantum of erythropoiesis and by intracellular iron content of the cells of the erythroid lineage. Hence, a high serum TR level has been found to be useful in distinguishing iron deficiency anemia (IDA) from anemia of chronic disorders (ACD). In order to examine its potential role in the diagnosis of concomitant iron deficiency in ACD, we determined serum TR levels in 130 cases of ACD, in 25 cases of IDA, and in 40 normal adults. As expected, all patients of IDA had significantly higher serum TR levels compared to the normal subjects (4.2-19.2 microg/dL vs. 1.3-3.0 microg/dL) (P < 0.002). In 11/25 cases of IDA, the total iron-binding capacity (TIBC) was in the normal range although bone marrow iron store was absent and serum TR levels were high, thereby highlighting the superiority of TR level in the diagnosis of iron deficiency compared to TIBC. Although 54% (70/130) patients of ACD had normal or low serum TR levels (0.9-3.0 microg/dL) as expected, in 46% (60/130) of ACD patients, serum TR levels were high (3.2-11.0 microg/dL). Mean corpuscular volume, red cell distribution width, and transferrin saturation were significantly lower (P < 0.001) in the latter group of patients compared to the former, and these parameters resembled those in IDA patients. Also, serum iron was lower and TIBC was higher in this group of ACD patients compared to those with normal or low serum TR. All these features point to an "IDA-like" profile of ACD patients with high TR and support the possibility of co-existent iron deficiency in this subgroup of ACD patients. In light of these observations it would be prudent to treat ACD patients with high serum TR levels with iron replacement therapy.     

Effect of green tea on iron absorption in elderly patients with iron deficiency anemia

The effect of green tea on iron absorption from tablets containing sodium ferrous citrate was investigated in four elderly patients with iron deficiency anemia and in eleven normal elderly subjects. In both groups, the serum iron level reached a maximum value from 2 to 4 hours after taking iron tablets and returned to the baseline value after 24 hours. No inhibitory effect of green tea on iron absorption was recognized.     

Diagnosis and management of iron deficiency anemia in patients with IBD

Anemia is the most prevalent extraintestinal complication of IBD. It can affect quality of life and ability to work, and can also increase the hospitalization rate in patients with IBD. Although the causes of anemia in IBD are multifactorial, iron deficiency anemia (IDA) is the most common. Assessment of the iron status of patients who have a condition associated with inflammation, such as IBD, by using common biochemical values is insufficient. However, new indices of iron metabolism (for instance ferritin:transferrin receptor ratio, reticulocyte hemoglobin content or percentage of hypochromic red blood cells) may help to improve the assessment of iron status in patients with IBD. The treatment of IDA traditionally involves oral iron supplementation. However, because of extensive gastrointestinal adverse effects, and data showing that the use of oral iron in IBD may be associated with disease exacerbation, current guidelines suggest that iron supplementation in IBD should be administered intravenously. This Review provides an overview of iron homeostasis in health before discussing diagnostic and therapeutic strategies for IDA in patients with IBD.     

Single values of serum transferrin receptor and transferrin receptor ferritin index can be used to detect true and functional iron deficiency in rheumatoid arthritis patients with anemia

OBJECTIVE: To elucidate the use of serum transferrin receptor (sTfR) to distinguish between iron-deficiency anemia (IDA) and anemia of chronic disease (ACD), and to establish an improved scheme to identify functional iron deficiency (FID) in rheumatoid arthritis (RA) patients with anemia. METHODS: We studied 30 anemic RA patients whose iron status was confirmed by bone marrow examination and determination of the sTfR level, serum ferritin level, and sTfR-log ferritin index (TfR-F Index). All patients with diminished or exhausted iron stores (n = 18) received oral iron supplementation. RESULTS: Baseline values of sTfR and the TfR-F Index predicted the response correctly in all patients who received supplementation treatment and were normal in 10 of 11 patients with normal initial iron stores (ACD). CONCLUSION: The results of this study elucidate the roles of sTfR and the TfR-F Index in the differential diagnosis between IDA and ACD and provide direct evidence that these parameters are useful in detecting FID, irrespective of the concurrent iron storage status.