Autoimmune Hemolytic Anemia

What is Primary Idiopathic autoimmunity?

Autoimmunity that arises spontaneously with no known cause

What is autoimmunity secondary to disease?

Autoimmunity that is triggered by an underlying disease

What are the two drug related autoimmunities?

Drug-dependent and drug-independent auto-antibodies

What is drug-dependent auto-antibody?

The presence of the drug causes antibodies to bind and lyse the cells

What is drug-independent auto-antibody?

Antibodies are able to bind and lyse red blood cells even with the absence of the drug

What is Cold Hemagglutinin Disease?

Cold antibody AIHA that is IgM class

What is primary reason for CHD?

Lymphoproliferative disorder where B cells are producing pathogenic IgM

What is secondary reason for CHD?

Can develop from malignancy, infection, or other autoimmune disorders

What does Mycoplasma pneumonia infection cause?

Anti-I causing CHD but goes away once infection is over

What does Epstein-Barr virus infecton cause?

Anti-i implicated in CHD

What is the mechanism for CHD?

IgM will bind complement at cold temperatures causing IVH, then at high temps IgM will dissociate leaving C3d to be cleared by the liver causing EVH

What are the symptoms of CHD?

Anemia and fatigue

What are the laboratory results for CHD?

Increased retic, LDH, unconjugated bilirubin, decreased haptoglobin

What are the DAT results of CHD?

IgG negative and C3d positive

How can CHD be treated?

Rituximab to reduce autoantibody production (binds to Cd20 on B cells marking them for destruction, life-style changes, plasma exchange

What is the Cold Auto adsorption Method?

Removes cold autoantibodies that mask clinically significant antibodies

What is the principle of Cold auto adsorption method?

We prewarm samples to get ab into plasma. Then we remove plasma and wash patient rbc. Add the plasma back with patient rbcs and the antibody should adsorb back RBC leaving no autoantibody in plasma

What should the QC for Cold auto adsorption be?

Autocontrol should be negative

What is Paroxysmal Cold Hemoglobinuria?

Production of biphasic polyclonal IgG auto antibody that is anti-P

What is the mechanism for PCH?

Anti-P adsorbs onto P antigen at low temperatures and fixes complement to C2. Once body temperature increases to 37C, it dissociates but complement proceeds to MAC IVH

What are the symptoms of PCH?

Anemia, fatigue, intravascular hemolysis

What are the laboratory results of PCH?

Increased retic count, elevated LDG and unconjugated bilirubin, decreased haptoglobin

What are the DAT results for PCH?

IgG neg because it proceeds to complement quickly

What is the treatment for PCH?

Eculizumab drug will bind to C2 (anti-complement) or lifestyle changes

What is Warm Autoimmune hemolytic anemia?

IgG antibody that binds at 37C and usually in Rh group

What are symptoms of WAIHA?

Anemia, fatigue, dyspnea, splenomegaly, discolored urine

What are the lab findings of WAIHA?

Increased retic, elevated LDH and unconjugated bilirubin, decreased haptoglobin

What are the DAT results for WAIHA?

IgG pos and C3d negative

How can WAIHA be treated?

Corticosteroids to decrease antibody production and macrophage function, iron/folate/b12 for mild cases

What is WARM autoadsorption?

Method to remove warm autoantibodies and antigen type cells

What is the principle of WARM autoadsorption?

Plasma containing allo and auto antibodies is removed. Treat cells with WARM and wash to get rid of excess bound IgG. Mix plasma back in to allow auto-antibody to adsorb on during incubation. Allo ab is left in plasma to ID

What are the four Drug related hemolytic anemias?

Drug induced, drug adsorption, Immune complex, and membrane modification

What is Drug induced hemolytic anemia?

Aldomet (L-methyl-dopa) causes production of warm IgG antibody which binds to rbc antigens causing hemolysis

What is drug Immune complex hemolytic anema?

Quinidine causes IgG antibody production against the drug so it binds. The complex binds to C3b and C3b binds to red cells

What is drug membrane modification hemolytic anemia?

Cephalosporin changes red cell membrane making it sticky so proteins and antibodies can bind

What is drug adsorption hemolytic anemia?

Usually from penicillin where an IgG antibody is made. Penicillin binds to rbc membrane and the anti-IgG binds to penicillin

What are DAT results of drug induced hemolytic anemia?

IgG and C3d positive

What are the DAT results of immune complex hemolytic anemia?

IgG negative and C3d positive

What are the DAT results of membrane modification?

IgG and C3d positive

What are the DAT results of adsorption hemolytic anemia?

IgG positive and C3d negative