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Anti-jka Information and Courses from MediaLab, Inc.

These are the MediaLab courses that cover Anti-jka and links to relevant pages within the course.

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Blood Banking Question Bank - Review Mode (no CE)
Match the following antibodies to their appropriate immunities:View Page
Based on the phenotype of the RBC screening cells, and patient results given below, which of the following antibodies cannot be ruled out:View Page
Based on the phenotype of the RBC screening cells, and patient results given below, which of the following antibodies cannot be ruled out:View Page
Which of the following antibodies will most likely not be detected on immediate spin?View Page

Hemolytic Disease of the Fetus and Newborn
HDFN Due to Other Antibodies

After anti-D, the antibodies that are most often associated with HDFN include: anti-K anti-c anti-E anti-Fya (rarely) anti-Jka (rarely) anti-M,-N,-S,-s,-U (all rarely)Of these antibodies, anti-K, anti-c, and anti-E are more common causes. Anti-K typically causes more severe HDFN (hydrops and neonatal death) than the others. Anti-c has also been known to cause severe HDFN.Antibodies to low frequency antigens have also been known to cause HDFN, albeit rarely. Examples include anti-Mia, -Dia, -Wra and anti-Rd. In such cases the maternal antibody screen is usually negative and the only unexpected test is a positive DAT on the newborn. In theory any IgG antibodies directed against antigens that are well developed on fetal red cells can cause HDFN. The complete list of antibodies documented to cause HDFN is long and will not be covered in this survey course.

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Rh negative female with anti-D at delivery: A case study
Using the guidelines in the antibody exclusion protocol, all unexcluded antibodies (anti-C, E, K, Fyb, Jka, M, s, Leb) have been excluded by the mini-panel and the Ror control cell confirms reactivity of anti-D.View Page
Why might screen cell #2 be reacting stronger than screen cell #1?View Page
Antigram to explain prior question

The antigram below explains possible reasons for cell #2 reacting stronger: The patient may have anti-D and another antibody whose corresponding antigen is on cell # 2 (e.g., anti-E or anti-K). The patient has an antibody other than anti-D (e.g., anti-Jka) and cell #2 has a double dose of the antigen but cell #1 has only single dose. Screen Cell Rh Rhesus Kell Duffy Kidd MNSs P Lewis Lu Results Cell C D E c e Cw K k Kpa Fya Fyb Jka Jkb M N S s P1 Lea Leb Lua Gel IAT 1 R1R1 + + 0 0 + 0 0 + 0 + + + + 0 + 0 + + + 0 0 2+ 1 2 R2R2 0 + + + 0 0 + + 0 0 + + 0 + + + + + 0 + 0 3+ 2 3 rr 0 0 0 + + 0 0 + 0 + 0 0 + + 0 + 0 +S 0 + 0 0 3 Auto 0 Auto

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The Disappearing Antibody: A Case Study
Reflecting on Probability of the Solution

Similar to evaluating inconsistencies, one of the post-analytic tools for confirming that the serological data fit the solution is to consider the "big picture." For example:Is there a likely red cell stimulus (prior transfusion or pregnancy) for IgG antibodies such as anti-Jka? Can different reaction strengths with panel cells be explained by the identified antibody (e.g., dosage) or by the presence of more than one antibody? Is the antibody unusual for a patient of a particular race? For example, anti-Dib is more likely to occur in Native Americans than in Caucasians.

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As discussed earlier, one of the post-analytic tools for confirming that the serologic data fit the solution is to consider the big picture, as presented below. Think of how you would reply to each question in this case and then click each question to see sample responses.View Page
The p value in this case

This CaseWith the panel done 2 weeks post-transfusion, 5 panel cells that were Jk(a+) reacted and 5 that were Jk(a-) did not. This yields a p value of 0.004, which is less than the standard of 0.05, and therefore is more than acceptable statistically. In other words, an antibody other than anti-Jka would be expected to produce these panel results only 4 times in 1000 (which is pretty unlikely).Th true p value is much lower because many more cells were tested than in the panel alone.Concluding that the antibody is anti-Jka is further strengthened because the patient's red cells type as Jk(a-).Learning points: The most important things to know about statistical tools such as p values are that they: Relate to the probability of getting the observed results if the null hypothesis were true (the panel results were due to another antibody)Do not substitute for technical and clinical judgment.

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When performing an antibody investigation, which of the following would indicate an inconsistency that needs to be further investigated? (Select all that apply)View Page
The patient's red cell eluate initially was unidentifiable, reacting weakly with only two panel cells that did not fit a pattern. Once anti-Jka was identified, a check of the eluate panel results showed that both reactive cells were Jk(a+b-), circled in red in the image on the right, but two other JkaJka panel cells did not react, circled in blue in the image.Consider the question below, then click on the answer.View Page
Case Study Summary

This case study presents a scenario in which a patient had an unexpected antibody that disappeared after he was transfused with unmatched group O Rh negative Red Blood Cells. The patient developed a positive direct antiglobulin test (DAT) with mixed field agglutination (MFA). An antibody identification using the post-transfusion red cell eluate was inconclusive, making the antibody unidentifiable. Fortunately, the patient improved and further transfusion was not required. Ultimately, the patient's antibody was identified as anti-Jka, with a second antibody to a low frequency antigen (Radin) also unexpectedly present.The case illustrates the risks involved in using unmatched blood.

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Using the guidelines in the Antibody Exclusion Protocol, which antibodies are possible (have not been excluded) using this panel? Select all that apply.NOTE: A PDF of the panel is provided on this page and can be printed to assist in working through the antibody exclusion process.Antibody identification resultsCellRhRhesusKellDuffyKiddMNSsPLewisLuResultsCellCDEceCwKkKpaFyaFybJkaJkbMNSsP1LeaLebLuaGel IAT*1rr000++00+0+0+00++++S+001+12rr000++00+0+0++0++++S+00w+23rr000++00+0++0+0++0+0+0034r"r00+++00+0++0+0+0+++00045R2R20+++00+00+++++0+0+0+0w+56R2R20+++00++0+++++0+0+0+0w+67R1R1++00+00+00+0++0+0+S0++078R1R1++00+00+00++0+00+++001+89RZR1+++-+0++0+00++00+++000910r'r+00++00+0+00++0+0+S0+001011Auto011View Page
Variations in Antibody Strength

The antibody in the pretransfusion specimen (prior to the patient being transfused with unmatched group O Rh-negative RBC) reacted 2+ and 3+ with antibody screen and donor cells.If Jk(a+), the transfused donor red blood cells would have stimulated increased antibody production and the patient's plasma would be expected to react even more strongly with Jk(a+) red cells than in the pretransfusion specimen.However, the expected increase in antibody strength did not happen. Because Jk(a+) donor cells "mopped up" (adsorbed) the patient's anti-Jka initially, the anti-Jka decreased in strength. Later, once donor red blood cells are no longer present to adsorb the antibody, the anti-Jka would be expected to become stronger.Currently, (2-weeks post-transfusion) the patient's plasma is only reacting 1+ with Jk(a+b-) red blood cells and w+ with Jk(a+b+) red blood cells.This effect is called dosage. Learning pointsWhen a secondary immune response occurs, antibody first decreases before it increases. The expected increase in antibody strength will vary depending on the amount of excess antibody available in the patient's plasma at the time of testing versus the amount that had adsorbed to donor red cells and been removed by extravascular hemolysis.~

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When the patient's plasma was non-reactive with panel cells, and very weak and unidentifiable in the post-transfusion RBC eluate, no attempt was made to try to enhance the weak antibodies.We now know that the patient has anti-Jka and that it disappeared rapidly from the patient's plasma after transfusion with group O Rh-negative Red Blood Cells. Consider the question below, then click on the question to receive the answer.View Page
Which of the following antibodies in this scenario could explain all reactions by itself?Antibody identification results CellRhRhesusKellDuffyKiddMNSsPLewisLuResultsCell CDEceCwKkKpaFyaFybJkaJkbMNSsP1LeaLebLuaGel IAT* 1rr000++00+0+0+00++++S+001+1 2rr000++00+0+0++0++++S+00w+2 3rr000++00+0++0+0++0+0+003 4r"r00+++00+0++0+0+0+++0004 5R2R20+++00+00+++++0+0+0+0w+5 6R2R20+++00++0+++++0+0+0+0w+6 7R1R1++00+00+00+0++0+0+S0++07 8R1R1++00+00+00++0+00+++001+8 9RZR1+++-+0++0+00++00+++0009 10r'r+00++00+0+00++0+0+S0+0010 11Auto011View Page

Transfusion Reactions

The symptom most commonly associated with a delayed hemolytic transfusion reaction (DHTR) is unexplained decrease in hemoglobin and hematocrit. Patients may also present with fever and jaundice. Hemolysis occurs slowly and is primarily extravascular. Unlike an acute hemolytic transfusion reaction (AHTR), hemoglobinuria, acute renal failure, and disseminated intravascular coagulation (DIC) are not generally seen. On some occasions, patient's may not present with any symptoms. Serologic findings include a positive direct antiglobulin test (DAT) and/or a positive antibody screen in post-transfusion testing. In many cases, the physician will send a request for an additional transfusion because of the decreased hemoglobin levels, and not suspect a DHTR. The positive antibody screen will trigger an investigation including antibody identification. The DAT may have a mixed field appearance because of the antibody-sensitized transfused red cells and the non-sensitized patient red cells. Segments from the donor unit can be tested for the offending antigen once the antibody has been identified.Antibodies that are most often reported as the cause of DHTR are anti-Jka and anti- Jkb. Other antibodies that are also commonly implicated in a DHTR include Kell, Rh, and Duffy system antibodies.The patient's physician should be notified so that additional clinical and laboratory evidence can be evaluated.

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