内科学溶血(英文).ppt

Microagglutinates in a patient with cold agglutinin hemolytic anemia Drug induced immune hemolysis A variety of drugs produce positive Coombs’ tests – sometimes with overt hemolytic anemia Over 100 drugs have been implicated Antimicrobials account for 40% The most frequently associated with hemolysis are cefotetan, ceftriaxone and piperacillin. Hemolysis stops with removal of the drug Classification of Hemolytic Anemia Extracellular defects Fragmentation syndromes Autoimmune hemolytic anemia Hypersplenism Infections Hypersplenism An enlarged spleen with functional hyperactivity is called hypersplenism There is often neutropenia and/or thrombocytopenia The marrow is normal or hypercellular Splenectomy or reduction in spleen size relieves the cytopenia(s). Classification of Hemolytic Anemia Extracellular defects Fragmentation syndromes Autoimmune hemolytic anemia Hypersplenism Infections Red Cell infected with malaria parasite Differential Diagnosis Of Chronic Hemolytic AnemiaHelpful Hints Is the anemia associated with an acute illness or a complicating disease? A strong relationship suggests a bacterial, parasitic, or possibly viral infection, an acquired autoimmune process, or a defect in the RBC metabolic machinery Does a drug seen to be responsible? Suspect immune hemolysis or metabolic disease Does the anemia appear to be hereditary? A life long anemia or Family History makes this likely What is the patient’s race? Hemoglobinopathies and enzyme deficiencies are genetic disorders that follow clear racial and geographic lines. Based on the answers to these questions, choose the appropriate tests to confirm or exclude your suspicion. Thank you G 6 PD deficiency Most common inherited RBC enzyme deficiency Affects over 400 million people world wide. Highest gene frequencies found in tropical and subtropical countries where the deficiency offers protection against falciparum malaria Is an example of balanced polymorphism Discovered in 1956 I