Serum transferrin receptors in rheumatoid arthritis.

Zoli, Angelo; Altomonte, L; Mirone, L.; Magarò, M.; Ricerca, Bianca Maria; Storti, Sergio; Cândido, Alexandre Luna; Bizzi, Mariana F

doi:10.1136/ard.53.10.699

Cited by 21 publications

(17 citation statements)

References 12 publications

(1 reference statement)

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“…They might have had IDA and ACD at the same time, although this should be confirmed by iron supplementation, as described above. It was necessary to resolve whether s-TfR level reflects erythropoiesis or inflammation in RA [25][26][27][28][29][30]. The results of the present study showed that s-TfR level was correlated with indicators of anaemia but not of inflammation, consistent with the results of previous studies [27,28].…”

Section: Discussionsupporting

confidence: 94%

“…There have been some reports that s-TfR levels are correlated with serum cytokine levels increased at the active stage of joint inflammation in RA patients [25], or that s-TfR level is related to iron status in adult and juvenile RA patients [26][27][28][29][30]. We also found that s-TfR levels were correlated with markers of anaemia but not of inflammation, as shown in Table 1, consistent with the results of previous studies.…”

Section: Discussionsupporting

confidence: 93%

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Serum Transferrin Receptor Levels in Patients with Rheumatoid Arthritis are Correlated with Indicators for Anaemia

Chijiwa¹,

Nishiya²,

Hashimoto³

2001

Clin Rheumatol

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To measure serum soluble transferrin receptor (s-TfR) levels in patients with rheumatoid arthritis (RA), sera were obtained from 50 Japanese RA patients and 20 healthy subjects. Both s-TfR and serum erythropoietin (EPO) levels were measured by enzyme-linked immunosorbent assay (ELISA). Routine laboratory tests were also performed, including peripheral blood analysis and determination of erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF), serum iron levels, total iron-binding capacity (TIBC) and serum ferritin levels. The s-TfR levels in the 50 RA patients (mean +/- SD, 1,801 +/- 512 ng/ml) were significantly higher than those in the 20 control subjects (1,316 +/- 345 ng/ml). There were no differences in the values of s-TfR between men and women in either group, or between RA patients over and under 50 years old. Serum EPO levels in 47 RA patients were as low as 14.0 +/- 10.1 mlU/ml (mean +/- SD), ranging from 3.9 to 58.7 mIU/ml (normal range 2.8-17.2 mlU/ml), unrelated to low haemoglobin concentration. The s-TfR levels in RA patients showed negative correlations with red blood cell count, serum iron level and haemoglobin concentration, and positive correlations with ESR and serum EPO levels. However, there were no correlations between s-TfR level and markers of inflammation such as CRP, platelet count or RF titre. In conclusion, s-TfR level in RA patients could be a marker of erythropoiesis rather than of joint inflammation.

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Section: Discussionsupporting

confidence: 94%

Section: Discussionsupporting

confidence: 93%

Serum Transferrin Receptor Levels in Patients with Rheumatoid Arthritis are Correlated with Indicators for Anaemia

Chijiwa¹,

Nishiya²,

Hashimoto³

2001

Clin Rheumatol

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“…Contrarily to serum ferritin, sTfR may thus prove to be a diagnostic test of iron deficiency in patients with inflammation. However, in some studies, sTfR levels could not distinguish accurately among patients with rheumatoid arthritis [92,93], inflammatory bowel disease [94] or other inflammatory disorders [95], those with or without iron deficiency. In addition, several studies have observed higher sTfR levels in iron-replete rheumatoid arthritis patients compared to normal subjects, even if they remain lower than in iron deficiency anemia [92,96 -98].…”

Section: Soluble Tfr and Inflammationmentioning

confidence: 99%

Soluble transferrin receptor for the evaluation of erythropoiesis and iron status

Béguin

2003

Clinica Chimica Acta

384

305

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Iron transport in the plasma is carried out by transferrin, which donates iron to cells through its interaction with a specific membrane receptor, the transferrin receptor (TfR). A soluble form of the TfR (sTfR) has been identified in animal and human serum. Soluble TfR is a truncated monomer of tissue receptor, lacking its first 100 amino acids, which circulates in the form of a complex of transferrin and its receptor. The erythroblasts rather than reticulocytes are the main source of serum sTfR. Serum sTfR levels average 5.0 F 1.0 mg/l in normal subjects but the various commercial assays give disparate values because of the lack of an international standard. The most important determinant of sTfR levels appears to be marrow erythropoietic activity which can cause variations up to 8 times below and up to 20 times above average normal values. Soluble TfR levels are decreased in situations characterized by diminished erythropoietic activity, and are increased when erythropoiesis is stimulated by hemolysis or ineffective erythropoiesis. Measurements of sTfR are very helpful to investigate the pathophysiology of anemia, quantitatively evaluating the absolute rate of erythropoiesis and the adequacy of marrow proliferative capacity for any given degree of anemia, and to monitor the erythropoietic response to various forms of therapy, in particular allowing to predict response early when changes in hemoglobin are not yet apparent. Iron status also influences sTfR levels, which are considerably elevated in iron deficiency anemia but remain normal in the anemia of inflammation, and thus may be of considerable help in the differential diagnosis of microcytic anemia. This is particularly useful to identify concomitant iron deficiency in a patient with inflammation because ferritin values are then generally normal. Elevated sTfR levels are also the characteristic feature of functional iron deficiency, a situation defined by tissue iron deficiency despite adequate iron stores. The sTfR/ferritin ratio can thus describe iron availability over a wide range of iron stores. With the exception of chronic lymphocytic leukemia (CLL) and high-grade non-Hodgkin's lymphoma and possibly hepatocellular carcinoma, sTfR levels are not increased in patients with malignancies. We conclude that soluble TfR represents a valuable quantitative assay of marrow erythropoietic activity as well as a marker of tissue iron deficiency. D

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“…will a patient respond to iron therapy, either oral or parenteral? It is possible that the level of in£ammation is important, as Zoli et al 34 found a correlation between sTfR concentration and both erythrocyte sedimentation rate (ESR) and interleukin 1b concentrations in patients with active rheumatoid disease.…”

Section: Iron De Ciencymentioning

confidence: 99%

“…For example, in patients with rheumatoid arthritis, Nielsen et al 33 and Zoli et al 34 found no signi¢cant di¡erence in levels between patients without bone marrow storage iron and those with iron, and Kurer et al 35 found that the measurement of sTfR did not improve the sensitivity and speci¢city for diagnosis of iron de¢ciency compared with the assay of sFn. In contrast, Suominen et al 36 found that single values of sTfR predicted both true iron de¢ciency (absence of storage iron) and functional iron de¢ciency (iron-de¢cient erythropoiesis with adequate iron stores).…”

Section: Iron De Ciencymentioning

confidence: 99%

Serum transferrin receptor assays and their application

Worwood

2002

Ann Clin Biochem

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Most cells acquire iron from plasma transferrin and it is the transferrin receptor that is responsible for the internalization of transferrin-bound iron and its subsequent intracellular release. Plasma concentrations of the receptor re ect cellular receptor numbers and may be determined by enzyme immunoassay on automated analysers. Although determination of receptor concentrations may provide little additional value to existing measures of iron status, particular circumstances may dictate the use of these assays. This review summarizes transferrin receptor physiology and biochemistry, the limitations of the methodology that is currently available and the clinical application of assays (a) in monitoring changes in the rate of erythropoiesis, (b) as an indicator of developing iron de ciency and (c) in identifying iron de ciency in patients with anaemia of chronic disease.

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Serum transferrin receptors in rheumatoid arthritis.

Abstract: Conclusion-sTfR appear to be elevated and related to the degree of anaemia and to the inflammatory process in RA. Reduced sTfR levels in patients with RA compared with patients with irondeficiency anaemia may indicate a reduced erythropoietic activity in RA.

Cited by 21 publications

References 12 publications

Serum Transferrin Receptor Levels in Patients with Rheumatoid Arthritis are Correlated with Indicators for Anaemia

Serum Transferrin Receptor Levels in Patients with Rheumatoid Arthritis are Correlated with Indicators for Anaemia

Soluble transferrin receptor for the evaluation of erythropoiesis and iron status

Serum transferrin receptor assays and their application

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