Autoimmune hemolytic anemia
Classification and external resources
ICD-10	D59.0-D59.1
ICD-9	283.0
MeSH	D000744

Autoimmune hemolytic anemia (AIHA) is a type of hemolytic anemia where the body's immune system attacks its own red blood cells (RBCs), leading to their destruction (hemolysis).^[1][2] Types of AIHA include Warm autoimmune hemolytic anemia, Cold agglutinin disease, and Paroxysmal cold hemoglobinuria.

Contents 1 Terminology 2 Pathophysiology 3 Classification 4 Laboratory findings 5 See also 6 References 7 External links

[edit] Terminology

Although MeSH uses the term "autoimmune hemolytic anemia",^[3] some sources prefer the term "immunohemolytic anemia" so that drug reactions can be included in this category.^[4][5]

The National Cancer Institute considers "immunohemolytic anemia", "autoimmune hemolytic anemia", and "immune complex hemolytic anemia" to all be synonyms.^[6]

[edit] Pathophysiology

Antibodies and associated complement system components become fixed onto the RBC surface. These antibodies can be detected with the direct antiglobulin test, also known as the direct Coombs test.

AIHA can also be induced by several drugs including methyldopa and fludarabine.

[edit] Classification

Haemolysis can be intravascular or extravascular.

• Intravascular haemolysis: Red blood cell lysis occurs in the circulation as a result of activation of the complement system cascade.

• Extravascular haemolysis: Red Blood Cells that are coated with antibodies are specifically recognized in the reticuloendothelial system and destroyed by macrophages.

[edit] Laboratory findings

Evidence for Haemolysis^[7]

Increased red cell breakdown:

• Elevated serum bilirubin (unconjugated)
• Excess urinary urobilinogen
• Reduced plasma haptoglobin
• Raised serum lactic dehydrogenase (LDH)

Increased red cell production:

• Reticulocytosis
• Erythroid hyperplasia of the bone marrow

Specific Investigations

• Positive direct Coombs test

[edit] See also

• Haematology
• Haemolytic anaemia

[edit] References

[edit] External links

• Case report of Autoimmune Hemolytic Anemia with typical laboratory findings. Clinical Cases and Images.

v • d • e Pathology: hematology · hematologic diseases of RBCs and megakaryocytes / MEP (D50-69,74, 280-287) Red blood cells ↑ Polycythemia Polycythemia vera ↓ Anemia Nutritional Micro-: Iron deficiency anemia (Plummer-Vinson syndrome) Macro-: Megaloblastic anemia (Pernicious anemia) Hemolytic (mostly Normo-) Hereditary enzymopathy: G6PD · glycolysis (PK, TI, HK) hemoglobinopathy: Thalassemia (alpha, beta, delta)  · Sickle-cell disease/trait · HPFH membrane: Hereditary spherocytosis (Minkowski-Chauffard syndrome) · Hereditary elliptocytosis (Ovalocytosis) · Hereditary stomatocytosis Acquired Autoimmune (WAHA, CAD, PCH) membrane (PNH) MAHA · TM (HUS) Drug-induced autoimmune · Drug-induced nonautoimmune Hemolytic disease of the newborn Aplastic (mostly Normo-) Hereditary: Fanconi anemia · Diamond-Blackfan anemia Acquired: PRCA · Sideroblastic anemia · Myelophthisic Blood tests MCV (Normocytic, Microcytic, Macrocytic) · MCHC (Normochromic, Hypochromic) Other Methemoglobinemia · Sulfhemoglobinemia · Reticulocytopenia Coagulation/ coagulopathy/ bleeding diathesis ↑ Thrombocytosis Essential thrombocytosis Hypercoagulability primary: Antithrombin III deficiency · Protein C deficiency/Activated protein C resistance/Protein S deficiency/Factor V Leiden · Hyperprothrombinemia acquired: DIC (Congenital afibrinogenemia, Purpura fulminans) · autoimmune (Antiphospholipid) ↓ Thrombocytopenia and purpura Nonthrombocytopenic purpura: Henoch-Schönlein purpura Thrombocytopenic purpura: ITP (Evans syndrome) · TM (TTP) Heparin-induced thrombocytopenia · May-Hegglin anomaly Platelet function adhesion (Bernard-Soulier syndrome) · aggregation (Glanzmann's thrombasthenia) · platelet storage pool deficiency (Hermansky-Pudlak syndrome, Gray platelet syndrome) Clotting factor Hemophilia (A/VIII, B/IX, C/XI) • Von Willebrand disease • Hypoprothrombinemia/II · XIII myeloid navs: cells/physio, disease of RBCs+megakaryocytes/monocytes+granulocytes/neoplasia, symptoms+signs/eponymous ↑ means increased, ↓ means decreased

v • d • e Immune disorders: hypersensitivity and autoimmune diseases Type I/allergy/atopy (IgE) Foreign Atopic dermatitis · Allergic urticaria · Hay fever · Allergic asthma · Anaphylaxis · Food allergy (Milk, Egg, Peanut, Tree nut, Seafood, Soy, Wheat), Penicillin allergy Autoimmune none Type II/ADCC (IgM, IgG) Foreign Pernicious anemia · Hemolytic disease of the newborn Autoimmune Cytotoxic Autoimmune hemolytic anemia · Idiopathic thrombocytopenic purpura  · Bullous pemphigoid  · Pemphigus vulgaris · Rheumatic fever · Goodpasture's syndrome "Type 5"/receptor Graves' disease · Myasthenia gravis Type III (Immune complex) Foreign Henoch-Schönlein purpura · Hypersensitivity vasculitis · Reactive arthritis · Rheumatoid arthritis · Farmer's lung · Post-streptococcal glomerulonephritis · Serum sickness · Arthus reaction Autoimmune Systemic lupus erythematosus · Subacute bacterial endocarditis Type IV/cell-mediated (T-cells) Foreign Contact dermatitis · Mantoux test Autoimmune Diabetes mellitus type 1 · Hashimoto's thyroiditis · Guillain–Barré syndrome  · Multiple sclerosis  · Coeliac disease · Giant cell arteritis GVHD Transfusion-associated graft versus host disease Unknown/ multiple Foreign Hypersensitivity pneumonitis (Allergic bronchopulmonary aspergillosis) · Transplant rejection · Latex allergy (I+IV) Autoimmune Sjögren's syndrome · Autoimmune hepatitis · Autoimmune polyendocrine syndrome (APS1, APS2) · Autoimmune adrenalitis lymphocyte navs: cells/physio, immunodeficiency/immunoproliferative immunoglobulin/neoplasia, proc

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