AIHA and DIHA

compensated

-immune based hemolysis

-RBC destruction

-inc retics, bili, LDH

-dec haptoglobin

-normal H/H

-pos DAT

-splenomegaly

anemia

develops when the rate of RBC destruction due to immune based hemolysis exceeds rate of production

-inc retics, bili, LDH

-dec haptoglobin

-dec H/H

-pos DAT

-splenomegaly

autoimmune hemolytic anemia (AIHA)

-cold agglutinin disease

-warm

-paroxysmal cold hemoglobinuria

-drug induced

-mixed type (warm and cold)

cold agglutinin disease (CAD)

-optimal in vitro temp 0-4 C

-usually IgM

-DAT pos

-activates complement

-presents in vitro with agglutination, sometimes hemolysis

-Ag I, IH, Pr

-clinically mild

-therapy: avoid cold

-secondary disease assoc w M. pneumo (anti I) and IM (anti i)

0-4

optimal in vitro temp for CAD agglutination

IgM

CAD Ab is usually IgG/IgM

pos

DAT pos/neg with CAD

C3

C3/IgG is activated in CAD

I, IH, Pr

Ag assoc with CAD

warm autoimmune hemolytic anemia (WAIHA)

-in vitro rxn 37 C

-usually IgG

-pos DAT

-can activate C3

-need AHG to see in vitro agglutination

-Ag Rh

-usually permanent and severe

-secondary to leukemia, lymphoma, lupus

-corticosteroids +/= splenecotmy

-not good to transfuse (lysis will continue)

37

optimal WAIHA rxn temp

Rh

WAIHA Ag

IgG

WAIHA usually IgM/IgG

pos

pos/neg DAT with WAIHA

WAIHA

need AHG to visualize WAIHA/CAD agglutination

adsorption

how to remove auto Ab masking allo Ab in testing

paroxysmal cold hemoglobinuria (PCH)

-sensitize in vitro 0-4 C, hemolysis at 37 C

-usually IgG

-biphasic hemolysin

-P Ag

-normally idiopathic

-transient anti-P Ab made after viral illness in children

-RBC tfxn beneficial when needed (P neg)

P

Ag in PCH

37

hemolysis due to PCH Ab binding seen at this temp

0-4

temp for in vitro sensitization of Ab in PCH

IgG

PCH is normally IgG/IgM

drug induced immune hemolytic anemia (DIHA)

-drug hx important

-may see hemolysis in vitro

-unexpected results in routine testing

-variable DAT

-hemolysis resolves when stop using drug

drug adsorption 

-Ab against drug or metabolites

-pos DAT

-IgG+, sometimes C3

-pt serum and eluate nonreactive with reagent and random donor cells

-reactive with drug-coated cells

pos, pos, var, neg

poly DAT, IgG, C3, eluate reactivity in drug adsorption mechanism

immune complex

-adsorption of drug-Ab complex onto RBC memb

-drugs combine w plasma prot → IgM to immunogen → forms complex → binds to red cell surface → activates complement

-pos DAT

-C3+, IgG=

-eluate nonreactive

-severe intravasc hemolysis, renal failure

-quinine, piperacillin

pos, neg, pos, neg

poly DAT, IgG, C3, eluate in immune complex mechanism

quinine, piperacillin

drugs involved in immune complex mech

membrane modif

-drugs modify RBC memb

-cephalosporins

-modified RBC memb → bind plasma prot nonimmunologically → sensitize and hemolysis

-pos DAT

-IgG+, C3+

-eluate nonreactive

cephalosporins

drug associated with membrane modif hemolysis

pos, pos, pos, neg

poly DAT, IgG, C3, eluate in membrane modif

autoAb formation

-auto directed against intrinsic RBC Ag

-reactive eluate

-methyldopa

-DAT pos

-IgG+, C3=

pos, pos, neg, pos

poly DAT, IgG, C3, eluate for autoAb formation

methyldopa

drug associated with autoAb formation

mixed type

-rare AIHA

-serology of warm and cold Ab

-IgM and IgG demonstrated

-severe hemolysis

-eluate reacts with all cells

-treat: corticosteroid

-pos DAT, IgG, C3

DAT

testing determines IgG or C3

IAT

-testing can occur at 4 C/RT for CAD

-can enzyme treat

3 mo

time frame for testing for Ab formation post tfxn

DTT

-used to treat plasma with IgM interference

-destroys IgM

-must give Kell neg blood to pts taking meds for MM

no

yes/no

cold autos mask clinically significant allo Ab

prewarm, cold adsorption, DTT

how to treat plasma with cold auto for allo testing

adsorption

-how to get rid of warm-reactive autos for allo studies

-ZZAP, autologous, allogenic