BB Exam 4 Practicum Flashcards
What is complete antibody? What type of antibody is usually responsible for it?
Can bind to corresponding antigen and directly agglutinate RBCs suspended in saline. IgM’s are usually suspected.
Describe incomplete antibody. What type of antibody is usually responsible for it?
Nonagglutinating because their monomer structure is too small to directly agglutinate. They need sensitized RBCs to agglutinate. IgG is usually suspected.
What is associated with anti- big i?
Cold agglutinin syndrome or cold hemagglutinin disease (CHD)
The bacteria associated with this antibody is M. pneumoniae
Patients can present with peripheral vascular occlusion (acrocyanosis) or hemolytic anemia
What is associated with anti - little i?
Infectious mononucleosis
Epstein barr virus
CMV
Lymphoproliferative disorders
Big i and little i antigens are involved in what kind of condition or diseases?
Cold agglutinins
Acquired hemolytic anemia
chronc dyserythropoietic anemia type II
Hereditary erythroblastic multinuclearity (HEMPAS)
Congenital cataracts (commonly in asians)
What is associated with anti - P?
PCH
Syphilis (Treponema pallidum)
Parasitic infection (Anti- P1) - Echinococcus granulosus
Facioliasis aka bovine liver fluke disease - Anti-P1
Habitual early abortion
Duffy null or Fy(a=b=) is associated with
Resistance to P. knowlesi and P. vivax (malaria)
Anti- Kell is associated with
McLeod Syndrome (anti-K, anti-k) - CGD
vulnerable to bacterial infection
Fetal anemia
Kell antibodies are associated with…
Immediate / delayed HTR
HDFN
Streptococcus faecium (not sure why)
What are circumstances a person might exhibit unexpected antibodies?
Transfusion
Transplantation
Pregnancy
What is an antibody screen?
Its a method to detect clinically significant antibodies ( and insignificant) in both blood donor and recipient as part of pretransfusion compatibility testing
Describe the RBC reagent used in antibody screen.
Mandated by the FDA, type O RBCs express
Type O RBCs that have the most common and significant antigens. Group O is used to avoid agglutination from Anti-A and Anti-B antibodies. This will allow other antibodies to bind. Each different O type RBCs used usually have R1R1, R2R2, or/and rr.
What is a cell panel?
A method used for antibody ID. Its a collection of 11 to 20 group O RBCs with various antigen expressed. Diverse antigen expressions are used to help rule out antibodies. They include homozygous expression of Rh, Duffy, Kidd, and MNSs antigens.
Profile sheet can indicate presence of rare cells (low prevalence antigens).
How would an antibody screen react in the presence of multiple antibodies?
The multiple antibodies would present as multiple strengths of agglutination in the same phase or different phases.
Certain antibodies can be enhanced or destroyed by enzymes
What kind of antibodies would react in RT phase?
Usually IgM
What kind of antibodies would react in 4C phase?
IgM or Cryoagglutinins
What antibodies would react at 37C or AHG phase?
IgG would react
What enzymes are found in papaya?
Papain
What enzymes are found in pineapple?
Bromelin
What enzymes are found in figs?
Ficin
What enzymes are found in a pig’s stomach?
Trypsin
What is zeta potential?
How does albumin enhance agglutinaiton?
Increases dielectric constant leading to a reduced zeta potential
What blood groups show dosage?
Kidd, Duffy, Rh, and MNSs
What blood groups are complement dependent?
Kidd, Lewis, and Big i
What blood groups are enhanced by enzymes?
Rh, Kidd, Lewis, Big i, and P1
What blood groups are destroyed by enzymes?
Duffy and MNSs
What blood groups are hemolytic?
Lewis
Anti-Vel ( low frequency)
P1
Kidd
ABO
What blood groups react best in RT with saline?
Lewis
Big I and little i
P1
M
ABH
N
Anti-Lua
What blood groups react
What does chloroquine do in antibody studies?
Strips IgG from DAT+ RBCs and removes Bg (HLA antigens) antigens from RBCs
DTT, dithiothreitol in antibody studies?
denatures RBC antigens of mutliple groups including Kell, Lutheran, Dombrock, Yt, and LW. It can also remove IgM antibody activity from serum.
ZZAP in antibody studies
Combination of DTT and proteolytic enzymes. Removes IgM antigens on RBCs
What kind of antibodies react best at 4C?
Anti - I
Anti - i
Anti - M
Anti - N
Anti - P1
What kind of antibodies react best during LISS / Albumin, or AHG phase?
Rh group antibodies
Anti - S
Anti - s
What kind of antibodies best react during AHG phase only?
Rh
Kell
Ss
Duffy
Kidd
Anti-Lub
What antibodies are crossmatch compatible?
Anti-Lea
Anti-Leb
Anti-P1
Anti-M
Anti - N
What blood groups are destroyed by sulfhydryl compounds?
Lutheran
Kell
Dombrock
Cartwright
LW
What antibody can be undetectable, clinically significant, and may required multiple techniques to identify conclusively?
Kidd, Jka & Jkb
What antibodies can be neutralized?
Lewis, Big I, P, and Sda
What antibody prefers an acidic environment?
Anti-M
Why do weak reactions sometimes occur between RBCs and their corresponding antibodies?
Occurs b/c of dosage effect4. Its a phenomenon whereby an antibody reacts more strongly with an RBC carrying a double dose (homozygous) than with a RBC carrying a single dose (heterozygous) of an antigen.
When are elutions of value?
When an antibody or complement is bound to the surface of the RBC. Eluate may be tested against an RBC panel to identify antibody. It is usually done after a positive DAT.
What is a total elution?
A method of elution that releases antibodies and RBC antigen. The RBC is destroyed in the process. Useful in antibody identification
What is a partial elution?
Antibody is released from the RBC without destroying it. The pH method uses glycine acid solution (pH 3) to release antibody into acidic supernatant. After harvesting supernatant the supernatant low pH is neutralized with buffer.
What is adsorption?
Used to remove antibody from serum by adding target antigen and allowing the antibody to bind to the antigen during incubation. It is useful in removing autoantibody that may be masking an alloantibody. There can only be a maximum number of 4 adsorptions.
When are adsorptions of value?
Used to…
Detect autoimmune disorders
Separate multiple antibodies
Remove autoantibody
Confirm antigen existence on RBC
Confirm antibody specificity
Detect weakly expressed antigens
Detect weakly reactive antibodies
What is auto-adsorption and when is it used?
Auto-adsorption removes autoantibodies from plasma, leaving behind alloantibodies. The procedure uses patient’s cells + patient’s serum. The technique is used in patients that have no been transfused and to eliminate suspicion of an autoimmune disorder.
