Question | Answer |
The Kell blood group has which 2 major antigens? (24 exist in total) | K(or K1) and k (or K2/cellano) |
Which of the 2 Kell antigens is more immunogenic? | K or K1 |
The K and k antigens are __. | antithetical |
Two other important sets of antigens in the Kell group are ? | Kp and Js |
Kpa and Kpb are Kell antigens, but one is of higher frequency (99%). Which one? | Kpb |
Jsa and Jsb are Kell antigens, but which one is higher frequency (80%-100%)? | Jsb |
The disulfid-bonded regions on the glycoproteins of Kell antigens make them sensitive to __ reagents. | sulfhydryl reagents |
Someone who is Kell null (K0K0) can develop anti-Ku, which is on RBCs that have __ antigens. | Kell |
Another set of Kell antigens are KEL11 and KEL17. Which is the low-incidence allele? | KEL17 |
Antibodies to Kell are of which type? | IgG |
Kell antibodies are RBC stimulated, so they can develop as a result of __ or __. | pregnancy or transfusion |
Kell antibodies agglutinate best in which test? | IAT (indirect antiglobulin test) |
Do Kell antibodies bind complement? | not usually |
Kell antibodies are associated with what 2 conditions? | HTRs (hemolytic transfusion reactions) and HDFNs (hemolytic disease of the newborn) |
Kell antibodies have no effect when treated with ? | enzymes |
Which Kell antibody is the most common? | anti-K (K1) |
Kx antigens are not genetically similar to Kell antigens. But how are they related? | phenotypically |
Anyone lacking Kx antigens may demonstrate RBC abnormalities called ? | McLeod phenotype |
McLeod phenotype (or McLeod syndrome) is often seen in ? | males (inherited on the X chromosome) |
What abnormalities increase in cases of McLeod syndrome? | Acanthrocytes and reticulocytes |
What RBC qualities are decreased by McLeod syndrome? | 1. Water permeability 2. RBC survival |
Name 3 symptoms of McLeod syndrome. | 1. RBC abnormalities 2. Muscle/neurological defects 3. Raised creatine kinase |
McLeod syndrome is associated with __ __ disease. | chronic granulomatous disease |
People with chronic granulomatous disease (due to McLeod Syndrome) have impaired phagocytes that can __ but cannot __ invaders. | can engulf but cannot kill invaders |
Like the Kell blood group system, the antigens for the Duffy blood group system are well developed at __. | birth |
Can Duffy antigens be destroyed by enzymes? | Yes |
What are the 2 codominant antigens/alleles for Duffy? | Fya and Fyb |
The Duffy (Fya and Fyb) antigens are important for __ purposes. | transfusion |
Anti-Fya and anti-Fyb antibodies are of which antibody class? | IgG |
Do Duffy antibodies bind complement? | No |
Do Duffy antibodies react with enzyme-treated RBCs? | No |
Like many other blood group antibodies, production of Duffy antibodies (anti-Fya and anti-Fyb) can be stimulated by a __ or __. | transfusion or pregnancy |
Most members of which group of Americans have Fya or Fyb? | African Americans |
What kind of parasites will not invade cells that are negative for Fya or Fyb? | Malarial parasites (Plasmodium) |
Fya or Fyb act as receptors for the malarial __ to attach to the RBC. | merozoite |
The Fya/b phenotype is often found in people from west of central __. | Africa |
What are the 3 antigens in the Kidd blood group system? | Jka, Jkb, Jk3 |
Jk3 is present whenever what is present? | Jka and Jkb |
People who are null for the Kill (Jk*) phenotype are usually from where? | Far East or Pacific Islands (rare) |
People who are Kidd null may produce antibodies for ? | Jk3 |
Kidd null RBCs are resistant to ? | 2M urea |
Anti-Jka and anti-Jkb are of which antibody class? | IgG |
Can Kidd antibodies bind complement? | Yes! (Most IgG abs can't bind complement or only bind it very poorly) |
Kidd antibodies can cause __ and __. | HTRs (hemolytic transfusion reaction) HDFN (hemolytic disease of the newborn) |
Kidd antibodies usually appear with other __ when detected. | antibodies |
Jka has a weak reaction in testing called ? | evanescence |
What blood group antigens are weakly expressed on cord blood cells? | Lutheran |
Lutheran antigens are (high or low?) incidence antigens. | high |
There are 19 Lutheran antigens, but the primary ones are called ? | Lua and Lub |
Are Lutheran antigens effected by enzymes? | no |
Anti-Lua is of what class of antibody? | IgM and IgG |
Anti-Lua reacts best at ? | room temp or refrigerator temps |
Anti-Lua and anti-Lub often have a __ pattern when seen in vitro. | mixed-field |
Is anti-Lua considered clinically significant? | no |
Anti-Lub is rare because so many people have the __. | antigen |
What class of antibody is Lub? | IgG |
Anti-Lub reacts best at which phase? | AHG |
Is anti-Lub clinically significant? | yes |
Lewis B antigens can be found in plasma and in __. | secretions |
Lewis antigens adsorb onto the __ __. | RBC membrane |
Are Lewis antigens present at birth? | no |
Lewis antigens can sometimes carry over from the IS phase into what phase? | AHG |
Lea and Leb are not __. | alleles |
The Lewis blood group system needs all three of which genes to be present? | Hh, Se, Le |
Will le, h, and se genes produce Lewis antigens? | no |
Lewis antibodies belong to which class? | IgM |
Are Lewis antibodies clinically significant? | no |
Agglutination can occur with Lewis antibodies during which phases? | All of them; Is, 37C, AHG |
Enzymes can __ anti-Leb reactivity. | enhance |
Can anti-Lea bind complement? | Yes - it's IgM |
What can confirm the presence or eliminate reactions caused by the Lewis antibody? | Neutralization |
The I blood group system: adults have the __ antigen while infants have the __ antigen. | adults have I, infants have i |
I antibodies (are or are not?) clinically significant? | are NOT |
Anti-I is of which class of antibody? | IgM |
How do you avoid reactions with anti-I in vitro? | prewarming 37C (they are cold reacting) |
Anti-I is stronger reacting with which the RBCs of which blood group type? | O (many H sites) and A2 |
Autoanti-I is associated with what diseases? | 1. Mycoplasma pneumoniae 2. cold hemagglutinin |
Anti-i is associated with what diseases? | Infectious mononucleosis, lymphoproliferative disease, and (sometimes) cold hemagglutinin disease |
P1 phenotypes have P1 antigens and what other antigen? | P |
The P antigen is part of the __ blood group system. | Globoside (they are also part of their own, the P blood group system) |
Can P2 patients have the P1 antibody? | yes |
What class of antibody does P1 belong to? | IgM |
Anti-P1 can be neutralized by __ __. | P1 substance |
Autoanti-P is belongs to which class of antibody? | IgG (Donath-Landsteiner antibody) |
Donath-Landesteiner antibody binds with P1 or P2 cells at low __. | temperatures (in vitro) |
Autoanti-P may appear in children after __ __. | viral infection |
Antigens similar to P/Globoside antigens can be found in nature and used to neutralize the effect of anti-P. Name 3 of them. (This was mentioned in class, but is not in our outline.) | Pigeon eggs, bird droppings, hydatid cyst fluid |
Homozygous inheritance enhances agglutination in people who are ? (Applies to MNS blood group system.) | M+N- or M-N+ |
Besides M and N, what other types are part of the MNS blood group system? | S,s,U |
M antibodies belong to what class of antibody? | IgM AND IgG |
MNS antibodies are rarely encountered in __. | HDFN |
Variable reactions of anti-M depend on __ __. | reagent pH |
Anti-N belongs to which class of antibodies? | IgM |
N-like antibodies can form in __ patients. | dialysis |
Dialysis patients with N-like antibodies formed from formaldehyde-sterilized dialysis instruments need what kind of blood in cases requiring a blood transfusion? | N-negative |
Anti-U can be found in patients who are ? | S and s negative (also, if they are U negative) |
The test used to detect antibodies is called an __ __. | antibody screen |
Antibody screens are used in cases involving what 4 things? | 1. transfusions 2. pregnancy 3. patients who've had transfusion reactions 4. blood and plasma donors |
An antibody screen uses a patient's __ against reagent RBCs to detect antibodies. | plasma (plasma is preferred, but serum can also be used) |
Antibody screens are used when a patient is found to have __ antibodies. | unexpected |
Unexpected antibodies develop as a result of RBC stimulation. This means what 2 things can stimulate their production? | Transfusion reactions and HDFN |
Can unexpected antibodies be both IgG and IgM? | yes |
Antibody screens use a patient's plasma against reagent __ to detect antibodies. | RBCs |
IgG antibodies react best at __C. | 37C |
IgG antibodies react best during which phase? | AHG/IAT/Coombs (they all mean the same thing) |
Clinically significant antibodies (usually IgG) are associated with __ and __. | HTRs (hemolytic transfusion reactions) and HDFN (hemolytic disease of the newborn) |
When performing an antibody screen, the patient's plasma or serum is incubated with __ __. | screening cells |
After incubating the patient's plasma with screening cells, an IAT is performed using __ reagent. | AHG |
Incubation during an antibody screen refers to which phase? | 37C |
Antibody screens use a patient's plasma or serum against reagent RBCs to detect __. | antibodies |
IgG antibodies usually won't be detected during which phase? | IS (immediate spin) |
Screening cells are single or pooled donor cells of which type? | O |
Group O cells are used so what 2 things will not react? | anti-A and anti-B |
Screening cells come in sets of how many vials each? | 2 or 3 |
How many antigens are required to be tested when running an antibody screen? | 18 (remember that all the types will be listed, so don't bother memorizing them as a list) |
Screening cells come with a sheet of paper that lists the antigens present in each vial of screening cells. The paper is called an __. | antigram |
What do you use to test a patient's serum with his own RBCs? | an autocontrol |
When running an autocontrol, the autocontrol is incubated with the __ __ or __ __. | antibody screen or antibody panel |
If the autocontrol is positive, the lab tech may run a__ to detect in vivo coating. | DAT |
When a DAT is used to check an autocontrol, the DAT consists of what? | Patient cells plus AHG |
The AC and the DAT, when combined, can help determine if the antibodies are directed against which of 2 things? | 1. patient's cells (autoantibodies), or 2. transfused cells (alloantibodies) |
Substances that are used to enhance an antigen-antibody reaction for identification purposes are known as ? | potentiators |
Name 5 potentiators. | 1. Saline 2. LISS 3. BSA 4. PEG 5. Proteolytic enzymes |
Saline is a potentiator, but it only helps if the sample is ? | incubated for a long time |
LISS stands for low-ionic-strength solution. What LISS is used in our class? | N-Hance and Immuno-Add |
BSA stands for bovine serum albumin. Why isn't this potentiator used more often? | It takes a long time. |
What antibody class is most enhanced by PEG (polyethylene glycol)? | Rh |
Proteolytic enzymes are potentiators that can do what to antigens? | destroy some of them |
LISS best enhances what kind of antibodies? | cold autoantibodies |
Some weak __ antibodies may be missed when using LISS as a potentiator? | anti-K |
When using LISS, the reagent and plasma or serum must be used in __ amounts. | equal |
LISS is sensitive, cheap, and allow for a __ incubation time. | shorter |
BSA effects the second stage of agglutination and does not enhance ? | warm autoantibodies |
BSA needs a long incubation period (30 mins) and is not very sensitive for most antibodies except ? | Rh |
PEG enhances __ __. | warm autoantibodies |
PEG usually works best when which version of it is used? | monospecific/anti-IgG AHG (not anti-IgG, -C3d AHG) |
PEG may require extra __ and cannot provide readings at __ C. | extra washing, no readings at 37C |
Ficin/papain potentiators eliminate the reactivity of which 6 antigens? | Fya, Fyb, M, N. S and s are variable. |
Ficin/papain potentiators enhance which antibodies? | Rh, JK, LE, P1 |
Ficin enhances what autoantibodies? | cold and warm |
Ficin should not be used __. | alone (use other methods along with it) |
Weak anti-K may be missed by gel technology due to __-suspended red cells. | LISS |
Both gel technology and solid phase technology void __ __ antibodies and can be automated. | cold reactive |
In blood banking, it is always important to check the patient's __. | history |
Mixed RBC populations from a previous transfusion can remain for up to how long? | 3 months |
What else is important to learn besides patient history? | race, age, diagnosis, other diseases |
An __ __ is just an extended version of an antibody screen. | antibody panel |
Each panel cell is __ typed. | antigen |
The antigram lists the __ of each panel. | phenotypes |
A negative autocontrol indicates __. | alloantibodies |
A positive autocontrol AND a DAT indicate what kind of antibodies? | autoantibodies or alloantibodies from a recent transfusion |
A positive autocontrol and a negative DAT indicate what? | a false positive |
Which antibodies react at room temp and during the IS phase? | anti-Lea, anti-Leb, anti-M, anti-N, anti-I, anti-P1 |
Reactions at different phases may indicate involvement by what class of antibodies? | both IgM and IgG |
Reaction strength is related to __. | dosage |
Reactions with varying strengths indicate what? | multiple antibodies |
The rule of 3 says you should have what when recording a panel? | 3 pos and 3 negs |
When interpreting a panel, cells that are heterozygous should NOT be crossed out because the antibody may be too __ to react. | weak |
What happens if the rule of 3 does not work? | additional panel cells should be used |
If the patient has been transfused, what should be done before phenotyping? | RBC separation techniques |
Dithiothreitol is often used to denature __ antigens. | Kell |
Proteolytic enzymes can destroy __ and __ antigens. | Duffy and MNS |
Proteolytic enzymes will enhance __, __, and __ antigens. | Rh, Kidd, Lewis |
You should suspect an alloantibody to a high-fequency antigen (98% of population) is most panel cells are __. | positive |
HTLAs stand for ? | high-titer, low-avidity antibodies |
HTLAs are antibodies to high frequency antigens that react __. | weakly |
HTLAs react at what phase? | AHG |
Do HTLAs cause tranfusions reactions or HDFN? | no |
What do you need to test an HTLA that is reacting weakly? | a higher titer or concentration of antibodies |
You should suspect antibodies to low fequency antigens when the screen is __ and the crossmatching is __. | screen is negative, crossmatching is positive |
You can enhance weak IgG antibodies by repeating the procedure with a different __. | enhancement (try something you haven't tried yet if it isn't working) |
You can enhance IgG antibody reactions by increasing the __ to __ ratio. | serum to reagent/cell |
You can __ the sample longer to enhance weak IgG antibody reactions. | incubate |
If the panel cells aren't revealing the presence of the weak IgG antibodies, you can try using __ __ from a new panel. | different cells |
If you need to enhance weak IgG antibodies, you can check the antigen __. | dosage |
Another way of enhancing weak IgG antibodies is to __ the patient if he has not been recently transfused. | phenotype |
Cold alloantibodies are IgM and react during the __ phase; they sometimes also react during the __ phase. | they react during the IS crossmatching phase, and sometimes at the 37C phase |
Are cold alloantibodies clinically significant? | no |
Which cold alloantibodies have variable reactions? | anti-P1, anti-M, anti-N |
To enhance cold alloantibody reactions, you should incubate them below __ temp. | room |
How do you avoid cold alloantibody reactions so other, clinically significant reactions can be detected? | neutralization of alloantibodies |
If the AHG phase is positive, should you use check cells? | No - check cells are also positive |
__ techniques are usually performed to remove autoantibodies. | Adsorption |
Cold autoantibodies may occur in patients with a history of what 3 things? | 1. mild anemia 2. Mycoplasma pneumoniae 3. infectious mononucleosis |
Most cold autoantibodies are of what 3 groups? | anti-I, anti-H, anti-IH |
How can you ID anti-I, anti-H, or anti-IH autoantibodies? | cold panel |
Cord cells are negative for __ antigens but positive for __ antigens. | negative for I, positive for i |
I is present in all __ cells. | adult |
If all antigens are positive during the immediate spin (IS) phase, then __ autoantibodies could be to blame. | cold autoantibodies |
One way to avoid cold autoantibody reactions is to skip which of phase? | IS - go straight to 37C and keep the sample warm |
One way to avoid cold autoantibody reactions is to use what instead of LISS? | 22% bovine serum |
One way to avoid cold autoantibody reactions is to prewarm all tubes to ? | 37C |
When prewarming tubes, what should you avoid? | washing with warm saline |
If all else fails when trying to avoid cold autoantibody reactions, what should you do? | use adsorption techniques |
One adsorption technique is called RESt (rabbit erythrocyte stroma). It removes __ antibodies. | IgM/cold |
One problem with RESt is that may also adsorb __ and other IgM antibodies, which can lead to hemolysis. | anti-B |
One adsorption technique is called cold autoadsorption. Patient RBCs are used to remove cold autoantibodies to determine if __ antibodies are present. | allotransfused |
One adsorption technique is called warm autoadsorption. It works like cold autoadsorption techniques, but removes __ autoantibodies. | warm (instead of cold) |
Cold autoadsorption and warm autoadsorption should not be used if the patient has been recently __. | transfused |
Another adsorption technique is called differential adsorption. It uses known phenotyped RBCs to separate __. | specificities (like warm autoantibodies from alloantibodies or alloantibodies with several specificities) |
Differential (allogeneic) adsorption may also adsorb __ __ allantibodies. | high frequency |
Can you use cold autoadsorption with a sample from a patient who received a blood transfusion just 4 months ago? | Yes - less than 3 months would be no |
Which is more common: cold or warm autoantibodies? | warm |
Warm autoimmune hemolytic anemia may be idiopathic or the result of what 2 things? | 1. disease 2. drug |
Like the autocontrol, most panel cells will be __ when warm autoantibodies are present. | positive |
Using __ __ decreases the reactivitiy of warm autoantibodies. | 22% albumin |
What autoimmune condition can cause warm autoantibodies? | Lupus |
Can you transfuse a patient if unidentified, warm autoantibodies are present? | no - they react at body temp, so they will react in vivo if the wrong blood type is given |
Most warm autoantibodies are directed to the __ system. | Rh system, especially toward the e antigen |
Patients with warm autoantibodies will have __ and the __ antigen. | anti-e and the e antigen |
Warm autoantibodies will have a positive __. | DAT |
How can you increase donated RBC survival time in patients with warm autoantibodies? | e-negative (because patient will anti-e) |
__ can cause formation of warm autoantibodies. | Medication |
Drug induced autoantibodies will stop reacting when the RBCs affected by the drug have left the patient. This will take how long? | 2-3 months after last drug dose |
Name some commonly taken drugs that can cause warm autoantibodies to develop if the drug is taken for a long time. | 1. Methyldopa 2. Cephalosporin 3. Penicillin 4. nonsteroidal antiinflammatory drugs |
To ID antibodies when the DAT is positive, the IgG must be detached using the __ technique. | elution |
An eluate is used in an __ __ to identify an antibody. | antibody panel |
Is the elution technique always effective in all cases? | no |
Which eluate lowers the pH of the sample to remove the antibody? | Glycine acid |
Another elution technique involves heating to __C. | 56C |
An adsorption technique for removing attached antibodies involves dithiothreitol (DTT). Sometimes, DTT is combined with enzymes. This is called ? | ZZAP |
Treating cells with __ __ will disassociate the IgG from the RBCs without harming the antigens. | chloroquine diphosphate |