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direct antiglobulin test (DAT, direct Coomb's test)

Indications: - evaluation of hemolytic anemia - warm autoimmune hemolytic anemia Principle: - agglutination of erythrocytes by specific antihuman antibodies indicating that the erythrocytes are coated with human immunoglobulins or complement (C3d). Clinical significance: Coomb's positive anemia 1) pharmaceutical agents 2) malignancies a) chronic lymphocytic leukemia b) non-Hodgkin's lymphoma c) ovarian carcinoma 3) idiopathic a) positive DAT in 8-15% of hospitalized patients b) no cause found in 95% of these patients 4) anti-IgG & anti-C3d a) antibodies to glycoprotein antigens b) systemic lupus erythematosus 5) anti-IgG only a) antibodies to Rh proteins b) drug-induced hemolysis 1] alpha-methyldopa 2] penicillin 6) anti-C3d only a) cold-agglutinin syndrome (Donath-Landsteiner Ab) b) most drug-related antibodies c) IgM antibodies d) IgG antibodies of low affinity e) activation of complement by immune complexes

Related

gel microtube test hemolytic anemia

Specific

direct antiglobulin test IgG-specific

General

anti-human globulin test (Coomb's test)

References

  1. Clinical Diagnosis & Management by Laboratory Methods, 19th edition, J.B. Henry (ed), W.B. Saunders Co., Philadelphia, PA. 1996, pg 777-780
  2. Mayo Internal Medicine Board Review, 1998-99, Prakash UBS (ed) Lippincott-Raven, Philadelphia, 1998, pg 414
  3. Medical Knowledge Self Assessment Program (MKSAP) 11, American College of Physicians, Philadelphia 1998
  4. Harrison's Principles of Internal Medicine, 14th ed. Fauci et al (eds), McGraw-Hill Inc. NY, 1998, pg 665
  5. Direct Coombs Laboratory Test Directory ARUP: 13003
  6. Direct Coombs Laboratory Test Directory ARUP: 13005
  7. Direct Coombs Laboratory Test Directory ARUP: 13008

Component-of

anemia panel hemolysis panel