Immune Hemolytic Anemia Flashcards
disease state in which antibodies attach to red cells in circulation and those red cells either lyse in circulation or are removed from circulation, resulting in anemia
immune hemolytic anemia
types of immune hemolytic anemia
- allo-immune
- drug-induced
- autoimmune
HDFN and HTR are what type of immune hemolytic anemia?
allo-immune
drug-induced hemolytic anemia is what type hypersensitivity?
II and III
autoimmune hemolytic anemia is what type hypersensitivity?
II
~80% of all AIHA are what type?
warm autoimmune
what antibody class is implicated in WAIHA?
IgG
in WAIHA, is the DAT or IAT stronger?
DAT
do WAIHA cases bind complement?
sometimes (75%)
optimum reactivity temperature of WAIHA
37C
what percentage of WAIHA are primary (idiopathic)?
30%
why are all crossmatches incompatible at AHG in WAIHA?
antibody spill-over when all patient red cell antigen sites are full
elution results in WAIHA
panreactive
what can be used to reduce autoantibody production?
corticosteroids
what does rituximab act on in regard to WAIHA?
CD20 on B cells
antibody class implicated in cold agglutinin syndrome
IgM
optimum reaction temperature for cold agglutinin syndrome
room temp and below
cold agglutinin syndrome is associated with ___vascular immune destruction
extra
paroxysmal cold hemoglobinuria is associated with what disease state in adults
syphilis
paroxysmal cold hemoglobinuria is associated with what disease state in children?
viral infections
antibody class implicated in paroxysmal cold hemoglobinuria
IgG
what antigen is antibody directed against in paroxysmal cold hemoglobinuria?
P carbohydrate antigen
Donath-Landsteiner is confirmatory test for what?
paroxysmal cold hemoglobinuria
biphasic hemolysin is associated with what disease state?
paroxysmal cold hemoglobinuria
paroxysmal cold hemoglobinuria presents with ___vascular immune destruction
intra
disease states associated with cold agglutinins
Mycoplasma pneumonia Epstein Barr CLL mono carcinomas
diagnostic test for paroxysmal nocturnal hemoglobinuria
sucrose hemolysis
most common cold agglutinin
auto-anti-I
auto-anti-I antibody class
IgM
autoantibody associated with Mycoplasma pneumoniae
auto-anti-I
autoantibody associated with infectious mono
auto-anti-i
what blood types is auto-anti-H seen in?
A and AB
anti-H strongly agglutinates what cells
group O
cold agglutinin that agglutinates both cord cells and adult cells and patient autocontrol
nonspecific cold agglutinin
disease states associated with mixed autoimmune hemolytic anemia
lymphoproliferative disorders
lupus
HIV
most common current drug associated with drug induced hemolytic anemia
cephalosporins
DAT in drug-induced hemolytic anemia
positive
IAT in drug-induced hemolytic anemia
negative
drug induced hemolytic anemia mechanism:
positive IgG DAT
negative C3
negative elution
drug adsorption
drug-induced hemolytic anemia mechanism:
positive IgG DAT
positive C3
negative elution
membrane modification
drug-induced hemolytic anemia mechanism:
negative IgG DAT
positive C3
negative elution
immune complex
drug-induced hemolytic anemia mechanism:
positive IgG DAT
negative C3
positive elution
autoantibody
DIHA mechanism in which drug binds tightly to red cell membrane proteins and patient makes IgG antibody to the drug
drug adsorption
most common drug associated with drug adsorption mechanism of DIHA
penicillin-G
when can the eluate be positive in drug adsorption mechanism of DIHA?
if red cells are pretreated with the drug
drugs associated with drug adsorption mechanism of DIHA
penicillin-G, cephalosporin, erythromycin, methicillin, carbromal, nafcillin, cefazolin, tetracycline, cefamandole
drug adsorption mechanism DIHA patients develop hematologic complications?
usually no
DIHA mechanism in which presence of the drug causes modification of RBC membranes and this modification causes proteins to adsorb onto red cells
membrane modification
antibody class associated with membrane modification DIHA
IgG, IgM, IgA, C3, C4, albumin, fibrinogen
is membrane modification DIHA associated with red cell destruction?
no
drugs associated with membrane modification DIHA
keflin cephalothin cisplatin diglycoaldehyde suramin
drug most commonly associated with membrane modification DIHA
Keflin
DIHA mechanism in which drug-antibody complex is bound loosely and transiently to the red cell membrane
immune complex
antibody class associated with immune complex DIHA
IgM
drugs associated with immune complex DIHA
quinine, quinidine, sulfonamides, phenacetin, acetaminophin
DIHA mechanism that activates complement cascade
immune complex
DIHA mechanism in which drug does not attach to red cells but presence of drug stimulates production of antibody with IgG specificity
autoantibody
autoantibody mechanism DIHA antibody class
IgG
most common drug associated with autoantibody DIHA
methydopa/Aldomet
technique used to remove bound antibody from red cells
elution
applications of elution
positive DAT
purification or concentration of antibodies
preparation of antibody-free red cells for phenotyping
technique used to separate two or more antibodies or remove autoantibodies from a sample so that it may be evaluated for presence of alloantibodies
adsorption
products of elution
stroma-rbc membrane fragments
eluate-liquid portion containing antibody
primary means for determining whether immune-mediated destruction of red cells is contributing to patient’s anemia
DAT
what does a positive DAT confirm?
presence of red cells coated in vivo with antibodies or complement
elution technique in which acid lyses red cells
acid elution
elution technique that results in negative DAT to allow for phenotyping
glycine-HCl/EDTA
elution technique used for ABO and IgM antibodies that has poor recovery of IgG antibodies
heat/Landsteiner-Miller
elution technique that doesn’t destroy red cells
heat/Landsteiner-Miller
elution technique used for ABO HDFN
Lui Freeze-Thaw
why should adsorption procedures not be performed on samples from patients that have been transfused in the last 3 months?
potential exists for adsorption of significant alloantibodies onto transfused donor cells
removal of warm-reactive autoantibody from patient serum using patient’s cells to allow detection of possible alloantibody
adsorption
adsorption technique that contains enzymes and therefore destroys some antigen sites and cannot be used for phenotyping
W.A.R.M
adsorption technique that is mixture of proteolytic enzyme and sulfhydryl reagent that destroys enzyme sensitive antigen sites and Kell antigens
ZZAP
adsorption technique that does not contain enzymes and dissociates antibody from red cells with little or no damage to antigens allowing for phenotyping
chloroquine diphosphate
3 red cell phenotypes used in allo-adsorption technique
group O R1R1, R2R2, rr, one Jka- and one Jkb-
removal of cold reactive autoantibody from patient serum onto patient’s own cells to allow for detection of alloantibody and reverse grouping
cold auto-adsorption
why are patient cells enzyme treated in cold-autoadsorption technique?
enzyme treated autologous cells have increased ability to bind cold autoantibody for removal from serum
adsorption technique that utilizes rabbit stroma with cross-reactivity to adsorb out auto anti-I, H, and IH
RESt (rabbit erythrocyte stroma)
adsorption technique that doesn’t use patient cells and can be performed for a patient that has been recently tranfused
RESt
can adsorbed serum from RESt technique be used for ABO typing?
no, anti-B is also adsorbed
technique that eliminates interfering reactivity of cold autoagglutinins that react in AHG phase of testing
pre-warming
why would serum be treated to inactivate IgM?
abolishes agglutinating and complement-binding activities
treatments to inactivate IgM
AET, DTT, 2-ME
