Antiglobulin Information and Courses from MediaLab, Inc.
These are the MediaLab courses that cover Antiglobulin and links to relevant pages within the course.
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| Immune Antibodies Immune antibodies occur in the serum of individuals who become sensitized to foreign antigens through pregnancy or transfusion. IgM predominates in the primary response, IgG in the secondary response. Most react at 37°C and are considered clinically significant. Examples include antibodies in the Kell, Rh, Duffy, and Kidd systems. Immune antibodies can be classified as alloantibodies or autoantibodies.Alloantibodies Produced by exposure to foreign red cell antigens which are non-self antigens but are of the same species. They react only with allogenic cells. Exposure occurs through pregnancy or transfusion. Examples include anti-K and anti-E. Autoantibodies Produced in an autoimmune process and directed against one's own red cell antigens. React with patient's own cells and all cells tested. Can possibly mask the presence of other significant antibodies. It is very important to make sure that no underlying significant antibodies are present if an autoantibody is suspected. A positive direct antiglobulin test (DAT) or auto control could indicate the presence of an autoantibody. Examples include cold auto (P or I) or warm auto (Rh specificity). | View Page |
| Which of the following antibodies will most likely not be detected on immediate spin? | View Page |
| Which of the following antibodies is detected primarily in the antiglobulin phase of the crossmatch: | View Page |
| Which of the following best describes the direct antiglobulin test principle: | View Page |
| When AHG or Coombs serum is used to demonstrate that red cells are antibody coated in vivo, the procedure is termed: | View Page |
| Essential components of compatibility testing include all of the following except : | View Page |
| The use of the direct antiglobulin test is indicated in all the following except: | View Page |
| False negative results may occur with both the direct and indirect antiglobulin tests as a result of all of the following except: | View Page |
| What is Coombs sera comprised of: | View Page |
| Which of the following might cause a false positive indirect antiglobulin test: | View Page |
| To detect the presence of blocking antibodies fixed on the red cells of a newborn infant: | View Page |
| IgG coated red cells are added to negative antiglobulin tests to detect which of the following sources of error: | View Page |
| A false-negative reaction while performing the DAT technique may be the result of: | View Page |
| Evaluating inconsistencies Once an antibody has been identified and other clinically significant antibodies have been excluded, the case must be looked at as a whole to confirm the logical consistency of all results and data.This process includes assessing any inconsistencies.For example:1. Is the patient negative for the corresponding antigen? Yes: The patient is Jk(a-).2. Is the antibody specificity consistent with the typical phase(s) of reactivity for the antibody? Yes: Kidd antibodies are IgG and react in the antiglobulin phase. | View Page |
| Antibody identification checklist To improve the quality of conclusions when identifying antibodies, a checklist is a simple quality control tool to increase transfusion safety. If a specific antibody pattern cannot be identified with acceptable confidence, or if significant serologic or non-serologic data are inconsistent and cannot be rationalized, further testing will be required.Before concluding that the investigation is complete, unless not applicable, mentally reply to each question in the checklist. If any answer is no, has it been resolved? Antibody Identification Checklist Yes/No/NA 1. For a single antibody, does the reaction pattern fit only one antibody specificity? 2. Is antibody specificity consistent with the results of the initial antibody screen? 3. Are reaction phases consistent with antibody specificity? 4. If multiple antibodies are present, can all reactions be explained by the antibody combination? 5. If the autocontrol is negative, are patient red cells negative for the corresponding antigen(s)? 6. Have additional possible antibodies been excluded by selected red cells? 7. Can all variable reaction strengths be explained? 8. If tested, are antigen-negative donor cells compatible by antiglobulin crossmatch? 9. If there are data that do not fit antibody specificity or if there are results that are improbable, are they explainable? 10. Have all results and conclusions been systematically evaluated for consistency? | View Page |
| ABO, Rh and antibody screen These ABO, Rh, and antibody screen results were obtained by the TS using the blood specimen that was collected prior to starting the emergency transfusion with O Rh-negative RBCs. ABO and Rh typing ABO Forward Group ABO Reverse Group Rh anti-A anti-B A1 cells B cells anti-D 0 0 4+ 4+ 3+ Antibody screen Cells Gel IAT* Screen Cell I 3+ Screen Cell II 2+ Screen Cell III 2+ * IAT = indirect antiglobulin test | View Page |
| Crossmatch Results These are the results of the crossmatch that was being performed in the transfusion service laboratory while the patient was receiving the two units of O Rh-negative RBCs. Cells Gel IAT* Donor I** 2+ Donor 2** 2+ Donor 3 3+ Donor 4 3+ Donor 5 2+ Donor 6 3+ * IAT = indirect antiglobulin test ** O Rh-negative RBC (Donors 3 - 6 are O Rh-positive) | View Page |
| Pretransfusion Direct Antiglobulin Test Result The laboratory obtained post-transfusion blood specimens in order to perform a serological investigation. Pretransfusion and post-transfusion DATs were performed. Patient cells DAT CC Pretransfusion 0 2+ DAT = direct antiglobulin test with polyspecific antiglobulin serumCC = IgG sensitized RBC | View Page |
| Which of the following statements about mixed-field agglutination (MFA) are true? Select all that are correct. | View Page |
| In this case, which red blood cells (RBCs) do you think are agglutinating in the DAT and why? | View Page |
| Which of the following statements about antigen phenotyping are true? (Select all that apply) | View Page |