Makindo Medical Notes.com

Related Subjects: |Alpha Thalassaemia |Anaemia of Chronic Disease |Acute Myeloblastic Leukaemia (AML)

In midst of attack
Hepcidin holds iron back
Price of war effort
Red cells right size, numbers lack
Quell the fire, marrow snaps back
@DrCindyCooper

About

• Seen in a wide-range of disorders with chronic inflammation.
• Reduced Hb for age/sex despite normal haematinics
• Usually an underlying systemic process affecting haemopoiesis

Aetiology

• Diversion of iron traffic and Diminished erythropoiesis with a blunted response to erythropoietin
• Erythrophagocytosis and bone marrow invasion by tumour cells and pathogens
• Increased hepcidin activity causes subsequent decreased iron absorption, iron release from macrophages and so Low RBC production
• Production of hepcidin is increased by inflammatory cytokines, particularly interleukin (IL) 6, as well as in conditions of iron overload,1 whereas levels reduce in iron deficiency
• Hepcidin acts by binding to ferroportin and blocking iron export from macrophages and hepatocytes.
• At the same time, iron absorption by duodenal enterocytes is downregulated. The combined effect is to produce a state of ‘functional iron deficiency

Causes

• Rheumatological diseases - RA, SLE, PMR, Vasculitis, Sarcoidosis
• Infections - TB, Osteomyelitis, HIV/AIDS, Viral, Bacterial, Protozoal, Fungal
• Inflammatory Bowel disease - Crohn's disease, Ulcerative colitis
• Chronic renal failure
• Solid tumour s, Haematological malignancy
• Cardiac - Endocarditis, Chronic heart failure

Investigations

• FBC : Low Hb - usually normocytic but may be microcytic and low reticulocytes
• Low or normal serum Iron, high or normal ferritin
• Low serum iron-binding capacity and Increased iron stores
• Increased zinc protoporphyrin IX and Increased cytokine levels
• CRP and ERS often elevated
• Serum transferrin receptor assay: the number of transferrin receptors on red cells rises in iron deficiency but remains normal in secondary anaemia. This test is replacing bone marrow aspirate in diagnosis of iron deficiency in patients such as this.

Management

• Treat underlying cause. It is important to exclude other causes of anaemia, especially iron deficiency.
• Treatment of the underlying cause may improve anaemia, but other treatment options include erythropoietin and parenteral iron; serum ferritin is a poor predictor of response to intravenous iron
• Transfuse if Hb less than 8-9g/dl or compromised

References

• Review article
• Anaemia of chronic disease 2013