Transferrin: Difference between revisions
imported>Howard C. Berkowitz (New page: {{subpages}} '''Transferrin''' is a beta-globulin that binds with iron to produce ferritin, which can be transported in blood.) |
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'''Transferrin''' is a beta-globulin that binds with iron to produce [[ferritin]], which can be transported in blood. | '''Transferrin''' is a beta-globulin that binds with iron to produce [[ferritin]], which can be transported in blood. | ||
In addition to ferritin level, test that have been used are serum [[iron]] level, and serum [[transferrin]] level. While serum iron varies greatly intra-individually also in response to iron intake, the other two parameters mentioned change in an [[acute phase reaction]] (ferritin rises and transferrin false) and thus cannot reliably detect iron deficiency in the presence of inflammation. They also do not measure if the iron is actually available for hematopoiesis. Modern tests that circumvent this problem include [[soluble transferrin receptor]] (sTfr), [[transferrin saturation]] (TfS or TSAT), the hemoglobin content of [[reticulocyte]]s or the percentage of hypochromic cells <ref>{{cite journal | author = Thomas C, Thomas L | title = Biochemical Markers and Hematologic Indices in the Diagnosis of Functional Iron Deficiency | journal = Clin Chem | volume = 48 | issue = 7 | pages = 1066-76 | year = 2002 | id = PMID 12089176}}</ref>. Most of these can today be readily determined on automated laboratory analysis systems. | |||
{| class="wikitable" | |||
|+ [[Likelihood ratio]]s for common tests<ref name="pmid1487761">{{cite journal |author=Guyatt GH, Oxman AD, Ali M, Willan A, McIlroy W, Patterson C |title=Laboratory diagnosis of iron-deficiency anemia: an overview |journal=J Gen Intern Med |volume=7 |issue=2 |pages=145–53 |year=1992 |pmid=1487761 |doi= |url= |issn=}}</ref> | |||
|- | |||
! Test | |||
! Cutoff value | |||
! [[Likelihood ratio]] | |||
|- | |||
| Transferrin saturation | |||
| align="center" | ≥ 50% | |||
| align="center" | 0.15 | |||
|- | |||
| Transferrin saturation | |||
| align="center" | ≤ 5% | |||
| align="center" | 10.46 | |||
|- | |||
| colspan="3"| A [[likelihood ratio]] > 10 helps establish a diagnosis while a ratio < 0.1 helps exclude a diagnosis.<ref name="pmid12213147">{{cite journal |author=McGee S |title=Simplifying likelihood ratios |journal=J Gen Intern Med |volume=17 |issue=8 |pages=646–9 |year=2002 |month=August |pmid=12213147 |doi= |url= |issn=}}</ref> | |||
|} | |||
==References== | |||
{{reflist|2}} | |||
Revision as of 15:56, 9 December 2009
Transferrin is a beta-globulin that binds with iron to produce ferritin, which can be transported in blood.
In addition to ferritin level, test that have been used are serum iron level, and serum transferrin level. While serum iron varies greatly intra-individually also in response to iron intake, the other two parameters mentioned change in an acute phase reaction (ferritin rises and transferrin false) and thus cannot reliably detect iron deficiency in the presence of inflammation. They also do not measure if the iron is actually available for hematopoiesis. Modern tests that circumvent this problem include soluble transferrin receptor (sTfr), transferrin saturation (TfS or TSAT), the hemoglobin content of reticulocytes or the percentage of hypochromic cells [1]. Most of these can today be readily determined on automated laboratory analysis systems.
| Test | Cutoff value | Likelihood ratio |
|---|---|---|
| Transferrin saturation | ≥ 50% | 0.15 |
| Transferrin saturation | ≤ 5% | 10.46 |
| A likelihood ratio > 10 helps establish a diagnosis while a ratio < 0.1 helps exclude a diagnosis.[3] | ||
References
- ↑ Thomas C, Thomas L (2002). "Biochemical Markers and Hematologic Indices in the Diagnosis of Functional Iron Deficiency". Clin Chem 48 (7): 1066-76. PMID 12089176.
- ↑ Guyatt GH, Oxman AD, Ali M, Willan A, McIlroy W, Patterson C (1992). "Laboratory diagnosis of iron-deficiency anemia: an overview". J Gen Intern Med 7 (2): 145–53. PMID 1487761. [e]
- ↑ McGee S (August 2002). "Simplifying likelihood ratios". J Gen Intern Med 17 (8): 646–9. PMID 12213147. [e]