SCIE 2040 Assignment 1 PDF

# SCIE 2040 - Assignment 1 This assignment is intended to reinforce the concepts of transfusion medicine genetics and ABO discrepancies. /50 marks ## Instructions * Refer to lecture notes, textbook as well as laboratory manual to complete this assignment. * Do NOT change the wording of the questi...

# SCIE 2040 - Assignment 1 This assignment is intended to reinforce the concepts of transfusion medicine genetics and ABO discrepancies. /50 marks ## Instructions * Refer to lecture notes, textbook as well as laboratory manual to complete this assignment. * Do NOT change the wording of the questions, or the order of the questions. * Answers may be provided in bullet points, but must be accurate, and clear. * Explanation requires the use of multiple sentences. You may choose to write your answers in a different legible color. * This is an independent assignment, to be completed in your own words. Use of Artificial Intelligence of any kind is prohibited. * Submission: Assignment MUST be submitted as a WORD or PDF file in the correct assignment folder, by the due date indicated on eConestoga. Late assignments will NOT be accepted. * Grading: Each question is out of marks indicated, for a total of 50 marks. For full marks, all parts of the question must be answered clearly and correctly. A 10% deduction may be incurred for failure to follow instructions. **Student name:** Henok Demsas ## 1. Red Blood Cell Phenotype Matching Match the saliva results with the appropriate red blood cell phenotype (place letter in RBC Phenotype column) (1 mark per match). | Saliva | Saliva | Saliva | Saliva | Saliva | RBC Phenotype | |---|---|---|---|---|---| | Anti-A | Anti-B | Anti-H | Anti-Lea | Anti-Leb | | | Indicator Cell: A2 cells | Indicator Cell: B cells | Indicator Cell: O cells | Indicator Cell: Le(a+) cells | Indicator Cell: Le(b+) cells | | | Result 1: 0 | Result 1: + | Result 1: 0 | Result 1: 0 | Result 1: 0 | **C** | | Result 2: 0 | Result 2: 0 | Result 2: 0 | Result 2: 0 | Result 2: 0 | **D** | | Result 3: + | Result 3: + | Result 3: + | Result 3: + | Result 3: + | **A** | | Result 4: + | Result 4: + | Result 4: 0 | Result 4: 0 | Result 4: 0 | **B** | | Result 5: + | Result 5: + | Result 5: + | Result 5: 0 | Result 5: + | **E** | * a) O Le (a-b-) * b) AB Le (a-b+) * c) A Le (a-b+) * d) O Le (a-b+) * e) B Le (a+b-) ## Lewis Family Study Answer the following questions using the pedigree. Show all your work (i.e Punnett squares) (2 marks per question) **Note:** All inherit Le <br> A pedigree diagram is shown. It depicts a family tree with individuals numbered 1 through 6. * Individual 1: SeSe, Le(a+b-), ABO phenotype: **AO or AB**. * Individual 2: Sese, Le(a+b), ABO phenotype: **O**. * Individual 3: Sese, ABO phenotype: **A**. * Individual 4: Sese or SeSe, ABO phenotype: **BO**. * Individual 5: SeSe, ABO phenotype: **B**. * Individual 6: Sese, ABO phenotype: **O**. ### 2. ABO phenotype of #1 * **$I^A$$I^B$** It can be either **$I^A$$I^O$** or **$I^A$$I^B$**. ### 3. Secretor genotype of #3 * Secretor genotype of #3 is **Sese**. ### 4. Lewis phenotype of #3 * **Depending on Le genotype if it is dominant or recessive** * **Secretor Le (a+b+) or Le (a-b-)** ### 5. Most probable ABO genotype of #4 * #4 is **BO** genotype ### 6. Substances in saliva of #5 * **B, H and Le a and Le b or none** ### 7. Lewis phenotype of #4 * Depending on if Le genotype is dominant or recessive. * **Secretor Le (a+b+) or Le (a-b+)** ### 8. ABO genotype of #3 * #3 is **AO** genotype ### 9. Substance in saliva of #6 * #6 is **H and Le a and Le b or none** * **Depending on if Le genotype is Dominant or Recessive.** ## 10. Common ABO Typing Discrepancies Answer questions fully and include all steps in probable cause and resolution | Anti-A | Anti-B | Anti-A,B | A1 | B | |---|---|---|---|---|---| | 0 | 0 | 0 | 0 | 0 | **Probable ABO Group (1 mark):** O TYPE **Type of discrepancy (1 mark):** Missing or weak reaction on reverse group. As it is most common but also I would expect strong reactions in the forward reaction. **Probable Causes (2 marks):** A lack of reaction could suggest that the reagents used may be contaminated or expired, it could be because patient may have recently undergone therapeutic plasma exchange which may have diluted ABO antibodies to a nondetectable level, it could also be technical error or sample misidentification. **Resolution (2 marks):** First, verify the reagents used in the testing. A lack of reaction could indicate that the reagents are contaminated or expired, then repeat the test so I can rule out any technical error then incubate the samples at room temperature for 15 – 30 minutes if that didn't resolve the issue then try 4 degree centigrade for 15-30 minutes. consider patient history because if they have undergone plasma exchange that could explain the no reaction of antibody in the plasma, depending on the age we can also see if the patient is younger than 4 months or elderly which would have a decreased antibody present. <br> ## 11. Common ABO Typing Discrepancies Answer questions fully and include all steps in probable cause and resolution | Anti-A | Anti-B | Anti-A,B | A1 | B | |---|---|---|---|---|---| | 4+ | 0 | 4+ | 1+ | 4+ | **Probable ABO Group (1 mark):** A TYPE **Type of discrepancy (1 mark):** A subgroups **Probable Causes (2 marks):** Presence of A subgroups like A2 with anti-A1 **Resolution (2 marks):** Use Dolichos biflorus lectin to distinguish between possible A2 and A1 subgroups, lectin will react with A1 cells only, therefore if there is no reaction with A2 we will know for sure we are dealing with A2 subgroup. <br> ## 12. Common ABO Typing Discrepancies Answer questions fully and include all steps in probable cause and resolution | Anti-A | Anti-B | Anti-A,B | A1 | B | |---|---|---|---|---|---| | 4+ | mf | 0 | 0 | 0 | **NOTE:** Transfused within the last 3 months **Probable ABO Group (1 mark):** A TYPE **Type of discrepancy (1 mark):** Mixed field agglutination **Probable Causes (1 mark):** Recent blood transfusion with a different blood group **Resolution (2 marks):** Review the patient history to know what type he/she was transfused with and repeat test to make sure you get the same results and that it is not a technical error. ## 13. Common ABO Typing Discrepancies Answer questions fully and include all steps in probable cause and resolution | Anti-A | Anti-B | Anti-A,B | A1 | B | Auto Control | |---|---|---|---|---|---| | 4+ | 4+ | 4+ | 2+ | 2+ | 2+ | **NOTE:** Antibody screen results below | IS | 37°C | AHG | CC | |---|---|---|---| | 2+ | 0 | 0 | 2+ | **Probable ABO Group (1 mark):** AB type due to strong reaction with Anti A, Anti B, Anti A,B **Type of discrepancy (1 mark):** Weak and unexpected reaction in the reverse typing **Probable Causes (2 marks):** Possible A2 subgroup with A1 antigen, cold reactive antibodies **Resolution (2 marks):** For cold reactive antibodies incubate at 37° C for 15-30 minutes and then centrifuge for 15 seconds, strong ABO antibodies should still react, but interfering reactions should be inhibited. The fact that control cells also gave weak reaction shows me it is cold reactive antibodies. For suspected A2 subgroup, Use Dolichos biflorus lectin and if there is a reaction it is A1 subgroup but if it doesn't then it is A2 subgroup with A1 antigen developed. ## 14. Common ABO Typing Discrepancies Answer questions fully and include all steps in probable cause and resolution | Anti-A | Anti-B | Anti-A,B | A1 | B | |---|---|---|---|---|---| | 4+ | 2+ | 4+ | 0+ | 4+ | **Probable ABO Group (1 mark):** A TYPE 4+ reaction with Anti A suggests A antigen presence **Type of discrepancy (1 mark):** Forward type discrepancy, weak ABO antigen reaction with anti B **Probable Causes (2 marks):** Blood Chimerism, subgroups of A causing weak reactivity with Anti B. **Resolution (2 marks):** Modifying the test procedure by extending room temperature or 4°C incubation for 15-30 minutes and then spin for 15 seconds and check for agglutination. Enzyme treating the patient's cells as ABO antigens are enhanced by enzymes. It could be technical error and will need to repeat the test by following the procedure carefully.