MMSC Exam 1 Questions With Complete Solutions |
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/.expected ABO typing results - Answer-✅forward and reverse typing results match
/.unexpected ABO typing results - Answer-✅-forward and reverse typing results do not
match (extra reactions, missing reactions)
-current typing does not match historical records
/.pre-analytical errors (ABO discrepancy) - Answer-✅errors occurring before patient
sample is tested that lead to ABO discrepancy
-incorrect identification of patient
-incorrect labeling of specimen (labeling needs to occur at the patient bedside)
-patient's samples mixed up
/.analytical errors (ABO discrepancy) - Answer-✅errors that occur during testing that
lead to ABO discrepancy
-technical errors
-clerical errors: mixing up tubes, writing down results incorrectly
-cell suspension too heavy: beyond 2-5% there is post zone effect
-failure to add reagent of patient serum
-failure to follow instructions or standard operating procedures: e.g. letting incubation go
too long
-failure to note hemolysis: always a positive reaction
-uncalibrated centrifuge
-contaminated reagents
-under/ over centrifugation
-improper resuspension of cell button: miss weak reactions
-confusing patient samples
/.post-analytical errors (ABO discrepancy) - Answer-✅things that were done in the
hospital that lead to ABO discrepancies
-dilution of antibodies: administering plasma products causes patient's own plasma and
antibodies to become diluted and react weakly in reverse type
-exchange transfusion/ RBC transfusion: introducing RBCs that are not the same ABO
type as the patient cause forward typing to show 2 cell populations
, -plasma expanders: administering albumin or crystalloids causes issues with ABO
typing
-bone marrow/ stem cell transplant: patient's ABO type might not fully convert and lead
to ABO typing discrepancies
/.determining cause of ABO discrepancies - Answer-✅-suspect weaker reactions: look
at 1+ reactions, or missing reactions as the first sign of an issue
-review patient's history: ongoing diagnoses, past treatments, or infections can help to
clue in what is going wrong
-suspect the serum: discrepancy issues are commonly due to weak reacting, or cold
reacting antibodies
/.group I ABO discrepancies - Answer-✅Unexpected reactions occur in the reverse type
due to weakly reacting or missing antibodies
-*most common type of ABO discrepancy*
-forward typing is normal
-resolutions: RT or 4C incubation to enhance IgM ABO antibodies, increasing cell to
serum ratio (4 drops of patient serum instead of 2 to get more antibody in the mix), look
at patient history
/.group I ABO discrepancies causes - Answer-✅-inability/ decreased ability to produce
antibodies: newborns up to 6 months, elderly, leukemia or lymphoma with
agammaglobulinemia, immunosuppressive therapies, congenital
hypogammaglobulinemia/ agammaglobulinemia, bone marrow transplant recipients
-diluted antibodies: massive transfusion of plasma products dilutes patient's antibodies
-ABO subgroups (if antibodies are present)
/.group II ABO discrepancies - Answer-✅unexpected reactions in the forward typing
due to weakly expressed or missing antigens
-reverse type is normal
-resolution: RT or 4 C incubation and enzyme enhancement to strengthen reactions of
antiseras with patient RBCs, look at patient history
/.group II ABO discrepancies causes - Answer-✅-2 cell populations: RBC transfusion/
exchange transfusions and chimerism (due to bone marrow or stem cell transplant) lead
to mixed field agglutination with antiseras
-polyagglutinable RBCs: react with all antiseras
-weakly expressed A or B antigen: old age or disease (hodkin's lymphoma, leukemia)
-ABO subgroups: react weakly with antiseras
-excess blood group soluble substance (BGSS): due to carcinoma of stomach or
pancreas, can neutralize reagent antiseras and appear completely negative (wash cells)
-fetal maternal bleeds
/.auto control and screening cells - Answer-✅if you run your ABO typing at room
temperature or 4 C to enhance the reactions, you will also have to run
_________________ and _____________________ at the same temperature
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/.expected ABO typing results - Answer-✅forward and reverse typing results match
/.unexpected ABO typing results - Answer-✅-forward and reverse typing results do not
match (extra reactions, missing reactions)
-current typing does not match historical records
/.pre-analytical errors (ABO discrepancy) - Answer-✅errors occurring before patient
sample is tested that lead to ABO discrepancy
-incorrect identification of patient
-incorrect labeling of specimen (labeling needs to occur at the patient bedside)
-patient's samples mixed up
/.analytical errors (ABO discrepancy) - Answer-✅errors that occur during testing that
lead to ABO discrepancy
-technical errors
-clerical errors: mixing up tubes, writing down results incorrectly
-cell suspension too heavy: beyond 2-5% there is post zone effect
-failure to add reagent of patient serum
-failure to follow instructions or standard operating procedures: e.g. letting incubation go
too long
-failure to note hemolysis: always a positive reaction
-uncalibrated centrifuge
-contaminated reagents
-under/ over centrifugation
-improper resuspension of cell button: miss weak reactions
-confusing patient samples
/.post-analytical errors (ABO discrepancy) - Answer-✅things that were done in the
hospital that lead to ABO discrepancies
-dilution of antibodies: administering plasma products causes patient's own plasma and
antibodies to become diluted and react weakly in reverse type
-exchange transfusion/ RBC transfusion: introducing RBCs that are not the same ABO
type as the patient cause forward typing to show 2 cell populations
, -plasma expanders: administering albumin or crystalloids causes issues with ABO
typing
-bone marrow/ stem cell transplant: patient's ABO type might not fully convert and lead
to ABO typing discrepancies
/.determining cause of ABO discrepancies - Answer-✅-suspect weaker reactions: look
at 1+ reactions, or missing reactions as the first sign of an issue
-review patient's history: ongoing diagnoses, past treatments, or infections can help to
clue in what is going wrong
-suspect the serum: discrepancy issues are commonly due to weak reacting, or cold
reacting antibodies
/.group I ABO discrepancies - Answer-✅Unexpected reactions occur in the reverse type
due to weakly reacting or missing antibodies
-*most common type of ABO discrepancy*
-forward typing is normal
-resolutions: RT or 4C incubation to enhance IgM ABO antibodies, increasing cell to
serum ratio (4 drops of patient serum instead of 2 to get more antibody in the mix), look
at patient history
/.group I ABO discrepancies causes - Answer-✅-inability/ decreased ability to produce
antibodies: newborns up to 6 months, elderly, leukemia or lymphoma with
agammaglobulinemia, immunosuppressive therapies, congenital
hypogammaglobulinemia/ agammaglobulinemia, bone marrow transplant recipients
-diluted antibodies: massive transfusion of plasma products dilutes patient's antibodies
-ABO subgroups (if antibodies are present)
/.group II ABO discrepancies - Answer-✅unexpected reactions in the forward typing
due to weakly expressed or missing antigens
-reverse type is normal
-resolution: RT or 4 C incubation and enzyme enhancement to strengthen reactions of
antiseras with patient RBCs, look at patient history
/.group II ABO discrepancies causes - Answer-✅-2 cell populations: RBC transfusion/
exchange transfusions and chimerism (due to bone marrow or stem cell transplant) lead
to mixed field agglutination with antiseras
-polyagglutinable RBCs: react with all antiseras
-weakly expressed A or B antigen: old age or disease (hodkin's lymphoma, leukemia)
-ABO subgroups: react weakly with antiseras
-excess blood group soluble substance (BGSS): due to carcinoma of stomach or
pancreas, can neutralize reagent antiseras and appear completely negative (wash cells)
-fetal maternal bleeds
/.auto control and screening cells - Answer-✅if you run your ABO typing at room
temperature or 4 C to enhance the reactions, you will also have to run
_________________ and _____________________ at the same temperature
