ckcheng

Not quit understand what are you confusing? Are you studying in an SBB school, or preparing it by yourself? CK Cheng, MSc, SBB(ASCP), CQA(ASQ) Aug 1, 2009

I agree with Malcolm's advice. In addition, in order to avoid further alloimmunize the patient, you may consider XM the patient with extended phenotype-matched blood for Rhese, Duffy, Kidd, Kk, and Ss. Other additional antigens depend on race. By the way, how often do you repeat the adsorption procedures? A week, Ten days, or per admission? CK Cheng, MSc, SBB(ASCP), CQA(ASQ) Hong Kong July 22, 2009

SOP stands for Standard Operation Procedures which is an approved set of written procedures that delineated in detail the procedures, policies, and processes perfromed in a blood center or hospital blood bank. Usually SOP is written by blood bank supervisor and validated by blood bank pathologist or director. All med tech working in blood bank should read, and understand the SOP, trained , and passed the proficiency test before doing test. Here is an example of Tube Test for Rh Typing SOP Principle: Brief description of Rh and testing method. You may find info in most test books, or packing insert. Reagents: What reagent you are using? Polyclonal, monoclonal, or blend. What is the control? Size of tube, centrifuge, pipette, ...... Procedures: Step by step decribe how you perform the test. Interpretation: What make you determine it is positiive, negative, and test is invalid. Notes: Are there any particulars things you want your staff pay attention? If there is, you may write it down here. References: Where are the information come from? Please cite it here. Who prepared the SOP, and who validate the SOP. And when. When you need to re-review it. Every single test you peform in the laboratory should have an SOP. Good sources are: (1) Methods section in Technical Manual, AABB (2) Methods in Immunohematology by John Judd, AABB (3) Immunohematology Methods by American Red Cross Hope that helps. CK Cheng, MSc, SBB(ASCP), CQA(ASQ) Hong Kong July 11, 2009

Hi Malcolm, what is AbantuB? What is the reaction pattern? Thanks. Chun-kwok Hong Kong July 9, 2009

When T&S is ordered by physician, we do (1) ABO grouping and Rh typing. (2) Antibody screen for alloantibodies that are madatory to screen, for example E, e, D, C, c, Jka, Jkb, Fya, Fyb, K, k, MNSs, P1, Lea, and Leb. Others depend on your population like Mia / MUR in Asia. (3) Review and compare the results with patient past history, if any. (4) Check if patient has clinically significant alloabs detected in the past. (5) Any untow or NFHTR. (6) Check if patient needs any specific blood products, etc. I agree with Rashmi and Malcolm that you should consult your blood bank director or blood bank pathologist what guidelines you should follow, Do you have SOP in your laboratory?! Every med tech in your laboratory should follow the same guidelines and do the same thing. CK Cheng, MSc, SBB(ASCP), CQA(ASQ) Hong Kong July 9, 2009

Red cells shoud be kept between 1 - 6C in a monitored refrigerator during storage. During transportation, red cells are allowed to kept between 1 - 10C. Over 30 mins without refigerate, temperature rises over 10C. CK Cheng, MSc, SBB(ASCP), CQA(ASQ) July 8, 2009

Perform DAT on pre-transfusion sample is not necessary. Do when you perform antibody workup or transfusion reaction investigation. Also, DAT can be use to exclude or include a hemolysis is due to immune complex (antigen-antibody reaction). CK Cheng, MSc, SBB(ASCP), CQA(ASQ) Hong Kong July 8, 2009

If patient red cells give 4+ reactions against anti-A and anti-B, but negative againt anti-A1 using tube test, I favor Galvania it is an A2B. CK Cheng, MSc, SBB(ASCP), CQA(ASQ) July 8, 2009

Hi Mobea, can you send me a copy of the Platelet Transfusion in Children SOP also? My email is: chengchunkwok@yahoo.com Thanks. CK Cheng, MSc, SBB(ASCP), CQA(ASQ) Hong Kong May 22, 2009

In addition to all the wonderful information provided above in guiding one to do antibody workup, I would like to add a little info in the usefulness of incorporate an autocontrol. If autocontrol is positive, perform DAT. If DAT is negative - probably positive reactions are due to the testing medium. Choose another testing method. If DAT is positive - may be autoantibody(ies) +/- alloantibody(ies). If autocontrol is negative, perform DAT is not necessary. Most likely it is an alloantibody(ies). Or antibody against a high incidence antigen if all panel cells are reactive. But do not forget to ask for patient history cuz they are very useful information when doing antibody workup. CK Cheng, MSc, SBB(ASCP), CQA(ASQ) Hong Kong May 9, 2009

I agree with profbaud, Technical Manual is not a good book for beginner. Beside Modern Blood Banking by D Harmening, Immunohematology: Principles and Practice by Eva Quinley is also a very good book for blood bankers. CK Cheng, MSc, SBB(ASCP), CQA(ASQ) Hong Kong May 9, 2009

Hi Rashmi, the problem still remains un-resolved. The test was performed using tube test. The purpose of incorporate a negative control (6% albumin) is to test for auto-agglutination. Auto-anti-I was so potent that auto-agglutination observed even AHG reagents were not added, so the positive in AHG reagents became meaningless. Negative in negative control sure can be achieved after reeeepeeeeat washing with warm saline, but does it meaningful?? After a second thought, I tend to invalid the test because negative control remains positive after 3X washing. What do you think? CK Cheng, MSc, SBB(ASCP), CQA(ASQ) Hong Kong May 8, 2009

Thanks for the fantastic links provided by Pluto. I am also very interested in, and want to learn more in how to do the evaluation in blood banking automation, fridges, anti-sera/typing sera, etc. CK Cheng, MSc, SBB(ASCP), CQA(ASQ) Hong Kong May 7, 2009

We do not repeat antibody screen if it was positive in the past, but negative now. Just crossmatch antigen-negative blood if it is a clinical significant antibody. Repeat antibody workup when, (in case screening still positive), (1) reaction pattern does not match the current one, and/or (2) incompatible with antigen-negative blood. CK Cheng, MSc, SBB(ASCP), CQA(ASQ) Hong Kong May 7, 2009

I agree with Malcolm Needs. I just came across an example of anti-M which reacted with homozygous M-pos cells and gave a 2+ reaction with gel, but negative with heterozygous cells. Problem also seen in reverse grouping. I prewarmed plasma and screen cells separately at 37C for 5 minutes before mixing, then washed with pre-warmed saline 3X after 45 mins incubation. The screening was negative. I issued blood with EXM. One question I wanna raise is that when the patient is going to have an open heart surgery, and the cold reactive anti-M does potent enough to interfere at room temp, should we add a comment to alert the transfusionist to pre-warm the donor blood before transfusion cuz the M frequency in Whites is around 80%?! CK Cheng, MSc, SBB(ASCP), CQA(ASQ) Hong Kong May 6, 2009

Yes, I agree with John Staley, go and get patient medical history cuz they are very helpful in antibody workup and transfusion reaction workup. You may consider to add a column of [Patient History], and require all refer-in cases to fill so you do not have to ask every time. CK Cheng, MSc, SBB(ASCP), CQA(ASQ) Hong Kong May 1, 2009

Antibody workup needs patient medical and transfusion history. I suggest you request them from the patient's transfusion center or physician. Otherwise report the result negative directly, or add comment depends on the practice of your institute. 4 weeks ago weak pos, now becomes neg most likely due to titer dropped. Others like cells selection, method use, and most important is sample properly stored , not deteriate, during transportation. CK Cheng, MSc, SBB(ASCP), CQA(ASQ) Hong Kong Apr 30, 2009

I do not think you should repeat the sample if historical was positive, but now becomes negative cuz probably the titer already dropped to a level that the method you are using is not sensitive enough to pick it up. Also, it wastes time and money. If it is a clinical significant alloantibody, there should be a method in you institute to alert you, and you should give the patient antigen negative blood for that antibody forever. Hope that helps. CK Cheng, MSc, SBB(ASCP), CQA(ASQ) Hong Kong Apr 23, 2009

Chaper 9 Component Preparation of the Textbook of Blood Banking and Transfusion Medicine, 2nd edition by Sally V Rudmann might help you cuz it is very easy to read and understand. Hope that helps. CK Cheng, MSc, SBB(ASCP), CQA(ASQ) Hong Kong Apr 9, 2009

Urinalysis is an ancillary testing for hemolytic transfusion reactions. Use it to identify hemoglobinuria. May be useful if serum is not obtainable or if an acute hemolytic reaction is suspected but the serum hemolgobin is negative. Not useful in extravascular hemolyiss. Hemoglobinuria must be differentiated from hematuria. For details, please read AABB Guidlines for the Laboratory Evaluation of Transfusion Reactions. Hope that helps. CK Cheng, MSc, SBB(ASCP), CQA(ASQ) Hong Kong Mar 25, 2009

The purpose of the Rh control is to detect auto-agglutination. For low-protein reagents, you may use 6% albumin or autologous plasma. Other than that, please read the packing insert of the reagent you are using. Hope that helps. CK Cheng, MSc, SBB(ASCP), CQA(ASQ) Hong Kong Mar 19, 2009

We purchase 30% bovine abumin from DiaMed and dilute it 1:4 with PBS. Not a difficult job. No QC is required. If you do wanna buy 6% bovine albumin, please check with Novoclone. CK Cheng, MSc, SBB(ASCP), CQA(ASQ) Hong Kong Mar 19, 2009

We purchase 30% bovine

AABB Technical Manual, ARC Immunohematology Methods, Methods in Immunohematology by John Judd are fantastic resources. Hope that helps. CK Cheng, MSc, SBB(ASCP), CQA(ASQ) Hong Kong Mar 19, 2009

I agree with David cuz we do not know the purpose and what data the physician wants at that moment. One thing I wanna add is make sure the sample is not collected from the transfusion site. Otherwise most of the blood you draw will be the donor blood. Preferably the other arm, otherwise, lower than, and do not close to, the transfusion site or artery, but dangerous!! Hope that helps. CK Cheng, MSc, SBB(ASCP), CQA(ASQ) Hong Kong Mar 19, 2009