Unformatted text preview: MLS 480 Clinical Immunohematology II Problem Solving (Exam 4) Study Guide Objectives
: At the conclusion of this unit, the student will be able to: 1. Analyze and solve serologic problems related to blood group systems and antibody ID using enzymes, LISS, Albumin, PEG, ZZAP, 2ME, AET, REST poly vs. mono specific AHG, chloroquine, and adsorption. 2. Compare and contrast rouleaux and polyagglutination 3. Summarize enhancement/elimination and significance of cold agglutinins 4. Discuss the procedure and purposes of commonly used elution methods 5. Compare and contrast the significance of the phase of antibody reactivity 6. Describe the purpose of an absorption 7. Analyze and solve problems related to warm/cold auto antibodies 8. Analyze paternity exclusions 9. Interpret ABO discrepancies and their resolutions 10. Compare and contrast tube methodology to gel methodology and solid phase 11. List antibodies that can be neutralized by human serum 12. Examine druginduced immune hemolytic anemia 13. Discuss microbrial and nonmicrobial forms of polyagglutination 14. Examine which antibodies can be neutralized by using human serum Problem Solving (Exam 4) Study Guide 1.
Discuss Rouleaux and its effect on immunohematology procedures: Saline replacement Strong agglutination Seen at RT and 37C. Can be seen ONLY at Check cell phase 2.
When a cold reacting antibody is found in a patient's serum is it clinically significant if there is no reaction at the 37degree phase, just the IS phase: No. 3.
When is an elution performed: To remove an antibody on a POS DAT, for further ID. What is a Lui Freeze used for:
Elution of an antibody 4.
What enzymes are used in blood bank and why might you use them: Ficin, papain, trypsin, bromilin To enhance or diminish antigen reactivity with its antibody help when there is multiple or masking antibodies. 5.
What steps should be taken to resolve discrepancies in ABO typing: 1. Repeat
2. Determine what blood type (Forward type) 3. Determine reverse type
4. Examine antibody screen 5. Determine where the discrepancy is taking place
6. Confirm discrepancy rationale 6.
How do you distinguish between rouleaux and true agglutination: Rouleaux stacked coin appearance, is seen whereever the serum is used, will not affect AHG testing (washing) Agglutination will not disperse when saline is added 7.
How would you crossmatch a patient with severe rouleaux: Add 13 drops saline to crossmatch tube 8.
What is absorption? When is it used: Removing an unwanted antibody from serum. Can be used with cold/warm autoantibody is masking a different alloantibody MLS 480 Clinical Immunohematology II
Revision 2012 RPaur Problem Solving Study Guide Page 1 of 8 10. 13. 9.
List two methods of eluting: Digitonin acid elution
Lui freeze method
Heat elution How can you enhance the reactivity of a cold antibody, decrease the activity of a cold antibody, absorb antiM, IH and H out of the way? Enhance reactivity cool to RT or 4C Decrease reactivity continually keep blood at 37C to decrease binding of IgM antibodies to antigen Absorb use REST (Rabbit Erythrocyte Stroma) to attach to HI and H antibodies and remove them from serum 11.
All crossmatched units and the antibody screening test are positive at immediate spin and weaker O
and very weak at AHG. How would you proceed: Antibody panel because of reactivity at 37C; enhanced at 4C Use monospecific AHG antiIgG or antiCd3 alone 12.
How can you find the specificity of the autoantibody: Elution then ID and antigen typing Immune complex by certain drugs Antibodies to penicillin or cephalothin What reactions would be found in the auto control, antibody screen, and crossmatch, if a patient has AntiI? What steps should be taken to identify the antibody: what blood should be used for the patient: Auto Control Antibody Screen Crossmatch O
C NEG NEG NEG IS POS POS POS AHG(IgG) NEG NEG NEG Use adult O RBCs and A RBCs, and O cord RBCs. 1 14.
What is usually the specificity of warm autoantibodies: Most frequent are within the Rh group (but could be any antibody) 15.What blood would you use for transfusion in a patient with warm AIHA: Type specific without the antigen matching the antibody 16.
Define autoantibody: Antibody to selfantigen 17. Determine the phenotype and by what exclusion the father would be eliminated as being the child’s parent. Reactions with Antiserum A B M N C D E c e Phenotypes Mother Child Father Mother Child Father = + = + = = = = + = = + + = = + + = + + + = + + = + + + = = = + + + + = = = + + + = + + + + + + + + + + = + O MN dce/dce A NN DCe/dce B NN DCE/dce A MM DCE/ce O MN DcE/dce B NN dce/dce Who excluded by what systems Baby is an A Father is homo. e whereas baby is homo. E 18.
What is ZZAP and what is it used for: Thiol reagent plus a proteolytic enzyme (Dithiothreital and papain) Causes IgG antibodies to fall off the surface of sensitized RBCs Alters (some) surface antigens 19.
What are DDT and 2mecraptoethanol? What are they used for: Sulfhydryl compounds break the disulfide bonds on the IgM J chains and leave the IgG intact Aids in discovery of antibodies remove or break up masking antibodies Hidden IgG antibodies under cold reacting autoantibodies MLS 480 Clinical Immunohematology II
Revision 2012 RPaur Problem Solving Study Guide Page 2 of 8 20.
When should you use Polyethylene Glycol: To enhance agglutination usually as a potentiator in antibody screen or antibody ID 21.
What is REST? When is it used: Rabbit Erythrocyte Stroma Technique Attempts to remove antiIH, I, H from reacting to discover masked reactions (IgG underneath) What antibodies are absorbed from the serum using REST
? Anti I, H, B, P 22.
What information do you hope to gain if you use albumin as the potentiator: Rh antibodies may show reactivity at 37C phase and other antibodies may not in multiple IDs. CASE STUDIES: Given the following case studies, interpret the results of the ABO typing. If a discrepancy exists, suggest what the possible cause is and what might be done to solve the problem. 23. Case Study A:
A fiftysix year old man was admitted with a diagnosis of bleeding ulcers. He had received 3 units of blood four years earlier during another bleeding episode. At this admission, an order was received for four units of blood to be crossmatched. The following results were obtained: AntiA 2+ AntiB = AntiA,B 2+ A1 Cells 2+ B Cells 2+ Is there adiscrepancy:
No__ If there is a discrepancy, what should be the most likely cause? Unexpected alloantibody reacting at IS phase A with antiA or possible cold reacting other antibody 2 What further procedures, if any, might prove helpful in dealing with this patient? Antibody screen and testing pt. serum with A
, A and B cells 1
Pt. antigen typing
Patient's ABO type: A
(Depending on investigation whether A or A
Case Study B
An eightyseven year old man was admitted for prostate surgery. Two units of blood were ordered to be crossmatched. The ABO typing results are as follows: AntiA 4+ AntiB 4+ A1 Cells = B Cells = Is there a discrepancy:
X If there is a discrepancy, what should be the most likely cause? No What further procedures, if any, might prove helpful in dealing with this patient? No
Patient's ABO type:
AB 25. Case Study C:
A twomonthold infant was to be typed for a paternity suit. The following results were obtained: AntiA 3+ AntiB = AntiA,B 3+ A1 Cells = B Cells = Is there a discrepancy:
No__ If there is a discrepancy, what should be the most likely cause? Patient age MLS 480 Clinical Immunohematology II
Revision 2012 RPaur Problem Solving Study Guide Page 3 of 8 What further procedures, if any, might prove helpful in dealing with this patient? None
Patient's ABO type:
A Case Study D:
A fortynine year old woman was admitted for a hysterectomy and two units of blood were ordered prior to surgery. Medical history indicated she has had three pregnancies, received a transfusion after one delivery, and was diagnosed as having multiple myeloma four months earlier. 26. AntiA 1+ AntiB 4+ AntiA,B 4+ A1 Cells 3+ B Cells 1+ Is there a discrepancy:
No__ If there is a discrepancy, what should be the most likely cause? Extra antigen, antibody OR multiple myeloma What further procedures, if any, might prove helpful in dealing with this patient? Wash RBCs before typing Add 13 drops saline to reverse type (rouleaux) Antibody screen with 13 drops saline
Patient's ABO type:
Must resolve 27.
Case Study E: A seventytwo year old man required hospitalization for treatment of pneumonia. Several days later, G.I. bleeding developed and four units of blood were ordered. AntiA 4+ AntiB 4+ AntiA,B 4+ A1 Cells 1+ B Cells 1+ Is there a discrepancy:
No__ If there is a discrepancy, what should be the most likely cause? Problem with reverse type What further procedures, if any, might prove helpful in dealing with this patient? Auto control/DAT
Mycoplasma infection (pneumonia)
Antibody screen (cold antibody)
Patient's ABO type:
AB (most likely) 28.
Enzymes inactivate which antigens. M, N, Duffy, Ss 29.
Case Study F:
A thirtysix year old man was admitted after an auto accident. Suffering from internal bleeding, three units of blood were ordered immediately. The medical history indicated he had been hospitalized four years earlier with bleeding ulcers. At that time he received four units of blood. Records indicate that at that time, his antibody screen was negative. Ant ibody Scr
e een Pt. Cells Anti A Pt Ser Rh I II Anti B Anti A,B a b D Rh IS o
G Check cells IS o
G Check cells = = = 3+ 3+ = = = = 2+ = = = 2+ IS o
G Check cells = = = 2+ Auto Cross MLS 480 Clinical Immunohematology II
Revision 2012 RPaur Problem Solving Study Guide Page 4 of 8 match Unit 1 IS o
C = A
G = Unit 2 IS = = Check cells 2+ o
k cells 1+ Unit 3 IS = = 37
G = Check cells 2+ Patient's ABO and Rh: O NEG What is the apparent problem?
Unexpected antibody What is the next step? ID panel, antigen typing 30.
Case Study G:
A fiftysix year old man was admitted for treatment of an unexplained anemia. History revealed no earlier transfusions. He has been receiving treatment for high blood pressure for the last six months. A twounit crossmatch was requested. Pt. Cells Anti A Pt = 2+ Anti B S
R er h a b D
h Anti A,B 2+ 2
+ = 3
+ = An
en I II Auto I
S = 37
G = 3
+ Check cells o
S = = A
+ Check cells o
S = = A
G Check cells 3
match Unit 1 IS Unit 2 o
C = AHG = 2+ Check cells = o
C IS AHG = DAT Check cells 1+ 3+ Patient's ABO and Rh:
B POS What is the apparent problem? Autoantibody Warm autoimmune hemolytic anemia What action should be taken to make a safe transfusion possible? Elution of antibody from Pt. RBCs and investigate with antibody panel Case Study H: A sixtythree year old woman was admitted for diagnostic workup. She complained of chronic fatigue. The physician noted that hematology results indicated a severe anemia. To correct the anemia, three units of blood were ordered. The woman had never received blood but had five children. 31. Pt. Cells Pt Serum Rh I II Auto MLS 480 Clinical Immunohematology II
Revision 2012 RPaur Antibo
dy Screen Problem Solving Study Guide Page 5 of 8 Anti A Anti B 3+ 3+ Cros
ch Unit 1 IS = = a b 2+ 2+ o
C AHG = D 2+ Rh I
S = = o
C = A
G Check cells = o
C IS 2+ = A
G = = Check cells 2+ o
S = A
G = = Unit 2 Unit 3 Check cells 2+ o
C IS = AHG = = Check cells 2+ o
C IS = = AHG = AntiB = A1 Cells 3+ B Cells 3+ Rh = 2+ Rh control = Patient's type: A NEG DISCREPANCY First choice of donor: If no ID can be made, O NEG 33.
Demonstrate how the following discrepancies may appear: a.
with A1 2
AntiA 2+ AntiB = A1 Cells 2+ B Cells 2+ Rh 2+ Rh control = B Cells 3+ Rh = Rh control = B Cells = Rh 2+ Rh control = B Cells = Rh = Rh control = b.
AntiA 3+ A neg with unexpected antibody AntiB = A1 Cells 3+ c.
AntiA 2+ Type AB pos with acquired B AntiB 3+ A1 Cells = d.
AntiA = 0 neg patient missing antibody AntiB = A1 Cells = 34. Discuss microbial forms of polyagglutination T, Tk and Acquired B: T when the antigen is exposed to neuraminidase producing bacteria, the glycophorin B is altered and the antigen is exposed. RBCs will agglutinate all adult sera. Have NEG autocontrol. Tk enzymes produced by bacteria cleave a portion of the paraglaboside structure exposing GluNAc. RBCs will agglutinate all adult sera naturally occuring antiTk. Acquired B enzymes produced by bacteria have a B like determinant placed on the surface of RBCs react weakly with antiB. MLS 480 Clinical Immunohematology II
Revision 2012 RPaur Problem Solving Study Guide 2+ Check cells Patient's ABO and Rh: ABO Rh problem What is the apparent problem? Polyagglutinable What action should be taken to make a safe transfusion possible? Cord blood serum testing patient RBCs tested against cord blood sera and several normal AB adult sera. If agglutination occurs with the adult sera polyagglutination. Some polyagglutination receptors are destroyed by enzymes. 32. Case Study I:
A fiftysix year old man was admitted suffering from severe rectal bleeding due to a gastrointestinal ulcer. An emergency request for four units of blood was made. The patient's ABO and Rh were determined. AntiA 3+ Check cells Page 6 of 8 35.
Discuss nonmicrobial associated polyagglutination: Tn and Cad. Tn mutation in hematopoetic tissue that is not universally occuring on all cell precursors polyagglutination. Reacts with group A determinant. Cad Inherited autosomal dominant condition that produces antigen on the surface of RBCs. AntiSd(a) is a naturally occuring autoantibody in adults and reacts with the Cad antigen. RARE. 36. What is the purpose of chloroquine? Break the IgG antibodies off so that antigen typing can be done on a DAT POS 37.
Name a disadvantage of both gel and solid phase technology that may be detected in tube testing? Inability to detect complement coated cells 38.
How can you identify rouleaux vs polyagglutination? Rouleaux disperses with saline 39.
What could be done to enhance the reaction of an antiM and why does it work? Use LISS lowers pH 40.
Which antibodies can be neutralized using human serum? Lewis, Chido, Rogers 41. Which techniques destroy the rbc and antigen and free up the antibody for testing? Elution acid, heat, Lui 42.
If you needed to free up antigen on rbc’s that are covered with IgG (+DAT) what could you do? Add chloroguine 43.
If you had a strongly reacting nonpathogenic antiI that was reacting in all phases, what could you do to see if there were any hidden IgG’s? Warm the sample
Use REST to absorb all antiI 44.
If a patient has an antiI, what would be the expected reaction with cord cells? NEG 45.
Looking at the reaction illustrated in the screen below, which reagent would be the best to see if there is an IgG antibody underneath this auto IgM? I II III IS 3 37 3 AHG 3 NA IS 3 37 3 AHG 3 NA IS 3 37 3 AHG 3 NA Auto
rol IS 3 37 3 AHG 3 NA 2 ME will break up the IgM antibodies and allow IgG to react 46. Define first order or direct exclusion in paternity testing. Child has antigen that the neither the mother nor father has OR the father has two different antigens in the same system that the child does have. 47. Define second order or indirect exclusion in paternity testing. Child has a homo antigen and the father has a different homo antigen. 48. If the alleged father is ss(both little) and the mother is ss(both little) and the child is Ss(big S little s), what type of exclusion would this be? Second order/Indirect 49. If the alleged father is MM, the mother is MM and the child is MN, what type of exclusion would this be? First order/Direct MLS 480 Clinical Immunohematology II
Revision 2012 RPaur Problem Solving Study Guide Page 7 of 8 MLS 480 Clinical Immunohematology II
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