DAT/WAA/AIHA

Question 1

What is an important factor to keep in mind for serological workups of WAA and AIHA

Answer 1

the reaction strength. Typically the Strength is going to be higher in a WAA or AIHA than with an HTR

Question 2

Causes of WAIHA

Answer 2

Idiopathic, lymphoma SLE, AIDS, Carcinoma

Question 3

Most commom warm auto specificities

Answer 3

Rh type, most common e- specificity

Question 4

Autologous adsorption

Answer 4

Cannot do if patient has been recently transfused. Must prepare red cells but ZZAP, Ficin, Papain, 2-ME or DTT. Pull antibodies off the surface of the red cell so that more antibodies can be adsorbed out of the system

Question 5

W.A.R.M.

Answer 5

Warm antibody removal media- this is a trademark brand

Question 6

Stroma

Answer 6

White fluffy membranes

Question 7

Autoadsorption considerations

Answer 7

Has patient been transfused? How much blood do you have, how sick is the patient, may not be able to perform enough adsorptions without high quantity of red cells

Question 8

Allogenic adsorptions 3 red cell choices

Answer 8

1. R1R1; Jka- 2. R2R2 Jkb- S- 3. rr K- s-

Question 9

DDA

Answer 9

drug dependent antibody

Question 10

WAIHA vs. DDA

Answer 10

WAIHA eluate strongly positive, persists in serum. DDA Eluate is negative or weak and disappears from serum within days if drug is discontinued

Question 11

Management of WAIHA

Answer 11

steroids, rituximab, immunosuppressive drugs (cytoxan) IVIG, plasmapheresis, cyclosporin

Question 12

Acute Cold- Hemagllutinin Disease

Answer 12

lyphoproliferative disorders, Mycoplasma pneumonia infection, infectious mono

Question 13

Chronic Cold hemagglutinin disease

Answer 13

More severe symptoms elderly during cold weather, hemolysis mild-medium

Question 14

Serology of Cold-hemagglutinin disease

Answer 14

Serology DAT show complement only increased Ttiter >1000. antibody binds at 30 degree, intravascular hemolysis

Question 15

Autoanti-i disease association

Answer 15

infectious mono

Question 16

Autoanti-I disease association

Answer 16

Mycoplasma pneumonia

Question 17

Cold Agglutinin Disease clinical manifestations

Answer 17

Mild Chronic anemia, occasional juandice, usually self limiting if associated with mono or mycoplasma pneumoniae

Question 18

Management of CAD

Answer 18

Avoid the cold, other treatments are of little help

Question 19

Drug induced immune hemolytic anemia

Answer 19

DAT usually fairly strong reacts with both IgG and complement C3. most eluate are negative , many are positive with Peg or Ficin at IAT

Question 20

drug adsorption DIIHA (hapten dependant) Type 1

Answer 20

penicillin/penicillin derivative and cephalosporins. Drug bind covalently to membrane proteins and stimulate hapten-dependent antibodies. Antibody reacts with normal rbs pretreated with drug

Question 21

Immune complex DIIHA (Type 3, drug dependent antibody)

Answer 21

Quinidine, quinine, NSAIDS, through an unknown mechanism drug induces antibodies that bind to RBC only when drug is present in soluble form , antibody reacts with rbcs when soluble drug is present. Complex of drug, rbc and antibody all three come in contact

Question 22

drug induced auto-antibody Type II

Answer 22

alpha methydopa (helpful in pregnancy), procainamide, through an unknown mechanism drug induces autoantibodies specific for RBC membrane proteins. Antibody reacts with normal RBCs in the absence of the drug

Question 23

Nonimmunologic protein adsorption NIPA membrane modification

Answer 23

cephalosporins, tazobactum, clavunate, drug coats RBCs and causes them to get “sticky” DAT weakly positive, this is rarely associated with DIIHA

Question 24

For the test: Things to Remember!!

Answer 24

1. Always look for medication history in a question- don’t assume it’s the answer 2. look at strength of reactivity of the DAT 3. Correlate DAT reactivity with patients clinical info 4.

Question 25

Drugs related to drug adsorption/hapten

Answer 25

penicillin, penicillin derivatives, cephalosporins

Question 26

Drugs related to immune complex DIIHA

Answer 26

quinidine, quinine, NSAIDS

Question 27

Drugs related to drug induced autoantibody

Answer 27

Alpha methyldopa (b.p. in pregnant women) procainamide

Question 28

Drugs related to Nonimmunologic protein adsorption membrane modificatin (NIPA)

Answer 28

cephalosporins, not typically presented as DIIHA

Question 29

PCH DAT results

Answer 29

C3d will be positive and IgG will be negative- even though caused by a biphasic IgG, it causes complement and then dissociates and warmer temperatures leaving complement bound

Question 30

Important drug related questions in light of positive DAT

Answer 30

is patient on any drugs, are they on Anti-lymphocyte or anti-thymocyte globulin

Question 31

CAS

Answer 31

cold agglutinin syndrome- cold reactive IgM auto agglutinin binds to RBCs in peripheral circulation. IgM binds complement as RBCs return to warmer parts of circuclation. Complement remains bound by IgM dissociates

Question 32

Drug related positive DAT results

Answer 32

Non-antibody-mediated binding of immunoglobulin to RBCs in patients with hypergammaglobulinemia- associated with positive DAT results. High dose IV gamma globuilin, ALG, ATG and hypergammaglobulinemia

Question 33

why doesn't the DAT require an incubation phase like the IAT

Answer 33

because the antibody-antigen interaction took place in vivo (at 37 degrees)

Question 34

What level of IgG and C3d can a DAT detect?

Answer 34

100-500 IgG molecules per RBC and 400-1100 molecules of C3d per RBC

Question 35

what level of IgG can an IAT detect

Answer 35

must be between 100-200 IgG or C3 moleucles on cell to obtain a positive reaction