IMMUNE HEMOLYSIS
Definition : red cell life span is shortened because abnormalities in the components of the immune system are specifically directed against the patients own erythrocytes. 1.Auto-immune hemolytic anaemia. 2.Transfusion related hemolysis. 3.Drug-related immune hemolysis.AUTO- IMMUNE HEMOLYTIC ANAEMIA
The auto antibodies can be activated by either heat or cold. Warm reactive auto immune hemolysis (37oC) Causes : 1- idiopathic 2- secondary : I. Drugs (Methyldopa) II. Connective tissue disease (SLE) III. Lymphoproliferative (CLL, HD, NHL)CLINICAL MANIFESTATION
Onset rapid lead to anaemia, tiredness, fatigue. Elderly pts. with atherosclerosis lead to chest pain. Splenomegaly and Jaundice, may be absent in acute phase. Abdominal pain and fever may also occur.Diagnosis
spherocytosis, reticulocytosis, increase LDH, decrease serum haptoglolbin, increase indirect bilirubin positive direct coomb’s test; Patient’s CELLS are tested for surface Ab’sAround 10% of all warm autoimmunehaemolytic anaemias are Coombs test-negative.Treatment
1.Removal of the underlying cause 2.Corticosteroid : 1mg/kg prednisone (3-4 weeks / check-Hb. & retics.)70-80% response,then slow tapering over about 10 weeks. 3.Splenectomy : In case of steroid failure, or decrease Hb following cessation / reduction of steroid. 4. Immunosuppressive therapy with azathioprine or cyclophosphamide. 5.The anti-CD20 (B cell) monoclonal antibody, rituximab. 6. Blood transfusion?.*Cold-reactive auto immune hemolysis
Auto Antibodies usually are IgM. Occasionally IgG. Low temp make the antigen(Ag) more prominent on the membrane lead to antibodies reaction. Warm temp hiding the Ag below the membrane below the lipid component lead to prevention of Ag-Antibodies(Ag-Ab.) reaction . This can be chronic when the antibody is monoclonal, or acute or transient when the antibody is polyclonal
CAUSES
1.Idiopathic 2.Secondary: *Infection(mycoplasma pneumonia, infectious mononucleosis) *Lymphoma Chronic cold agglutinin disease; It causes a low-grade intravascular haemolysis with cold, painful and often blue fingers, toes, ears or nose (so-called acrocyanosis).1.positive direct coomb's test2.IgM Ab’s present in high titer.Treatment : Directed at the cause 1.infection : transient, self limited 2.supportive treatment (transfusion , avoid cold temp). 3.Lymphoma : specific therapy. 4.Idiopathic :common(No response to steroid, splenectomy) I-alkalating agent, II-Rituximab(mabthera) III-plasmapheresis. Diagnosis