anemia of chronic disease Flashcards

1
Q

define

A

Characterised by anaemia and evidence of immune system activation.

Anaemia chiefly due to decreased RBC production; may be aggravated by shortened RBC survival.

Commonly found in acute and chronic infections, autoimmune disorders, after major trauma and surgery, and in critical illness.

~~~~~~~~~~

This may be confused with iron deficiency anaemia.

However, unlike in iron deficiency anaemia,

  • the total iron binding capacity is reduced and the
  • serum ferritin is normal or increased.

nb:

TIBC is an indirect measure of the amount of iron that transferrin will bind.

Serum ferritin is an indirect yet quantitative and non-invasive measure of iron stores.

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2
Q
A
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3
Q

causes

A

Causes include:

  • chronic inflammation:
    • tuberculosis
    • systemic lupus erythematosus
    • malignancy
    • rheumatoid arthritis
  • endocrine disorders:
    • hypothyroidism
    • hypopituitarism
    • Addison’s disease
  • other causes:
    • liver disease
    • chronic renal failure
    • malnutrition
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4
Q

hx + exam

A

presence of risk factors

Key risk factors include autoimmune disorders, malignancy, acute or chronic infection, and critical illness, major trauma, or major surgery with delayed recovery.

systemic symptoms of underlying condition

Symptoms such as fever, night sweats, anorexia, weight loss, weakness, myalgias, or arthralgias should prompt a search for an underlying condition.

absent hx of bleeding

It is important to determine if symptoms of bleeding are present (e.g., melaena, haematochezia, menorrhagia, metrorrhagia), as bleeding is not expected in ACD and should prompt a different workup.

physical finding suggesting infection

This might include stiff neck; tenderness of joints, shoulder girdle, abdomen, or bones; decreased breath sounds or sticky rales.

Any non-trivial infection may cause ACD.

physical finding suggesting neoplasm

Including the presence of a mass, adenopathy, hepatomegaly, splenomegaly.

Any active neoplasm may cause ACD.

physical finding suggesting autoimmune disorder

absent hx of high alcohol intake

Although a positive history may be present in people with ACD, it may prompt consideration of an alternative cause for the anaemia.

absent hx of exposure to chemicals and radiation

Although a positive history may be present in people with ACD, it may prompt consideration of an alternative cause for the anaemia.

absent hx of drugs known to be associated with risk of anaemia

Although a positive history may be present in people with ACD, development of anaemia shortly after commencing a new drug may warrant investigation as the drug may be the causative agent.

absent hx of poor nutrition

Although a positive history may be present in people with ACD, it may prompt consideration of poor nutrition as an alternative cause for the anaemia.

decreased exercise tolerance

It is often useful to determine what changes may have occurred in the patient’s level of activity, as patients often reduce exertion to avoid symptoms.

shortness of breath with exercise

A common symptom of moderate or severe anaemia of any cause.

fatigue

A common symptom of moderate or severe anaemia of any cause.

pallor

Conjunctival pallor and pallor of the palms, palmar creases and nail beds is a feature common to all types of anaemia.

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5
Q

strong risk factors

A

autoimmune disorders

malignancy

acute or chronic infection

critical illness, major trauma, or major surgery with delayed recovery

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6
Q

ix

A

1st investigations to order

Hb

The degree of anaemia in ACD is typically mild to moderate (8-11 g/dL)

Severe anaemia may indicate an alternative or co-existing cause (e.g., blood loss, iron deficiency anaemia, or a primary haematological disorder).

women < (12 g/dL); men (13 g/dL)

WBC and differential

Associated infection or other stimuli in ACD may cause the WBC, .

  • count may be elevated

platelet count

Platelets may be mildly to moderately increased due to the underlying infection or inflammation.

  • may be increased

MCV

Anaemia in ACD is normocytic or microcytic.

  • normal or reduced

MCHC

Anaemia in ACD is normochromic or hypochromic.

  • normal or reduced

peripheral blood smear

Spherocytes, RBC fragments, macro-ovalocytes, helmet cells, pencil-shaped forms, nucleated RBC suggest other diagnoses.

  • normal

serum ferritin

Moderately helpful in distinguishing ACD and iron deficiency (ferritin rises in the former and falls in the latter).

Less helpful when the two conditions co-exist, as not infrequently occurs.

  • increased

serum iron

Less useful than the transferrin saturation.

  • reduced

TIBC

  • normal or reduced

transferrin saturation

  • reduced

absolute reticulocyte count

Indicative of underproduction by the marrow (typical in ACD).

  • low for the degree of anaemia

serum creatinine

May be useful for ruling out anaemia associated with renal insufficiency, although ACD may complicate anaemia that is primarily due to renal disease.

  • variable

LDH

Useful for ruling out haemolysis or another bone marrow disorder (elevated LDH).

  • normal generally, though may at times be increased by the condition causing ACD

~~~~~~~~~~~~~

CRP

Helps to confirm presence of inflammation, and therefore ACD, if cause of anaemia is uncertain.

elevated

ESR

Helps confirm presence of inflammation, and therefore ACD, if cause of anaemia uncertain.

  • elevated

serum B12

Useful for ruling out B12 deficiency.

  • normal

serum folate

Useful for ruling out folate deficiency.

  • normal

TFTs

Useful as a test to exclude hypo- or hyperthyroidism that can lead to anaemia.

  • normal

LFTs

Useful for ruling out liver disease as a cause of the anaemia.

  • normal

indirect and direct bilirubin

Useful for ruling out haemolysis as the cause of the anaemia.

  • normal

erythropoietin

  • typically lower than expected for degree of anaemia

quantitative haemoglobin A2 analysis

May be used to exclude beta-thalassemia trait (microcytosis, significant poikilocytosis, MCHC relatively normal).

  • normal

bone marrow biopsy

Usually performed if there is suspicion of a primary haematological disorder (e.g., myelodysplasia or a haematological malignancy).

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7
Q

mx

A
  • Treat underlying cause.
  • Erythropoietin - this is especially effective in the treatment of anaemia of chronic renal failure.
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