Autoimmune hemolytic anemia is caused by antibodies that bind to and prematurely destroy red blood cells. It is classified into warm and cold types based on antibody characteristics and mechanisms of hemolysis. Workup involves a Coombs test to detect antibodies coating red blood cells via direct or indirect agglutination. Treatment depends on type but may include steroids, splenectomy, cold protection, or rituximab.

1. AUTO IMMUNE HEMOLYTIC
ANEMIA
Dr.T.Arivazhagan
Department of Pathology

2. Definition
• It is a type of hemolytic anemia caused by antibodies
that bind to red cells , leading to their premature
destructions.

4. Classification
Warm antibody Cold agglutinin type Cold hemolysin type
IgG – 37 c IgM - < 37 c IgG - < 37 c
Primary
Secondary
auto immune
disorders
Drugs
lymphoid neoplasms
Acute
mycoplasmal infections
IMN
Chronic
idiopathic
Lymphoid neoplasms
Rare forms
Occurs in children's
following viral infections

5. Warm Cold Paroxysmal cold
Opsonaisation Complement mediated Complement mediated
Extra vascular Extravascular Intravascular
Spherocytes Agglutination Agglutination
Antiglobulin test +ve for IgG +ve C3d +ve C3d
Steroids
Splenectomy
Protection from cold
Rituximab
Rituximab

10. Investigations
Coombs test
•Direct ( Pt Rbc + Antibody) = Agglutination
•Indirect ( Pt antibody + Antigen) = Agglutination