ANEMIA OF CHRONICH DISEASE

By amirhossein heydarian

DEFENITION The terms anemia of chronic disease or chronic disorders refer to mild to

moderately severe anemias ([Hb] 7-12 g/dl) associated with chronic

infections and inflammatory disorders and some malignancies.

The newer name for this anemia is anemia of inflammation(AI)

AI is characterized by:

Inadequate erythrocyte production

Low serum iron

Low binding capacity (i.e low transferrin)

The erythrocytes usually are normocytic and normochromic

but can be mildly hypochromic and microcytic.

EPIDEMIOLOGY

The high prevalence of infectious diseases worldwide and the

high prevalence of inflammatory and malignant disorders in the

industrialized countries suggest that AI is the second or third most

common form of anemia after iron-deficiency anemia (IDA) and

thalasemia .

ETIOLOGY

Infections (acute and chronic)

Viral infections, including HIV infection

Bacterial including tuberculosis, osteomyelitis and sepsis

Parasitic including malaria

Fungal

Cancer

Hematologic including multiple myeloma and lymphoma

Solid tumor including carcinoma

ETIOLOGY

Autoimmune

Rheumatoid arthritis and other rheumatologic disorders

Systemic lupus erythematosus

and connective-tissue diseases

Vasculitis

Sarcoidosis

Inflammatory bowel disease

systemic inflammatory response syndrome

ETIOLOGY

Chronic rejection after solid-organ transplantation

Chronic kidney disease and inflammation

PATHOGENESIS

Red cell destruction

Inadequate erythropoietin secretion and resistance to erythropoietin

Erythropoiesis as a result of iron unavailability

Interleukin -6 ,Hepcidin ,and Hypoferremia

Serum iron concentrations are dependent on iron released from

Macrophages and Hepatocytes

Inhibition of Intestinal absorption of iron

CLINICAL FEATURES

The clinical manifestations of AI usually are obscured by the signs

and symptoms of the underlying disease.

Moderate anemia (Hg<10) can exacerbate the symptoms of the

preexisting ischemic heart disease or respiratory disease.

The erythrocytes in AI are normocytic and normochromic but

, with increasing severity and duration , can become

hypochromic and eventually microcytic.

The absolute reticulocyte count is normal or slightly elevated.

Hypoferremia and decreased serum transferrin

Interleukin -6 ,Hepcidin ,and Hypoferremia

Normal to increased serum ferritin

Marrow iron stain

Hypoferremia and decreased serum

Transferrin

Hypoferremia , decrease in the serum iron concentration , is a defining feature of AI .

Moderately decreased:

The decreased in transferrin concentration develops more slowly than the decreas in the iron levels because of the longer half-life of transferrin (8-12 days ) compared to the half-life of iron ( approximately 90 minutes )

Increased serum ferritin

Serum ferritin concentrations , which reflects iron stores , are

increased in AI but decreased in Iron deficiency .

Marrow iron stain

Marrow aspiration or biopsy is rarely required for diagnosis of AI .

In general , the marrow morphology and stainable iron are normal ,

unless the underlying disease alters the picture .

The most important information that obtained from marrow

examination is the content of and distribution of iron.

DIFFERENTIAL DIAGNOSIS

Most patients with chronic infections , inflammatory diseases , or neoplastic disorders are anemic.

The diagnosis of AI should be made only if the anemia is mild to moderate ,the serum and iron binding capacity are low , and the serum ferritin is elevated .

Drug-induced marrow suppression or drug-induced hemolysis

Chronic blood loss

Renal impairment

Endocrine disorders

Anemia resulting from metastatic invasion of the bone marrow

Thalassemia minor

Dilution anemia

Algorithm for the Differential Diagnosis

THERAPY AND PROGNOSIS

Anemia that presents in the setting of infection , inflammation , or

malignancy requires sufficient diagnostic studies to more

threatening causes , such as occult hemorrhage ; iron , B12 , and

folate deficency ; hemolysis and drug reaction .

If the anemia can be designated as AI after such studies ,effective

treatment of the underlying disease resolves the anemia

Therapeutic Options for ACD