ckcheng

Janet is right that when autocontrol is negative, but panel cells are all reactive makes you suspect there is an antibody against a very high incidence antigen which the patient lacks. Probably you have to send it to a reference laboratory for investigation. But, do not forget there is a type of AIHA which is DAT negative. CK Cheng, MSc, SBB(ASCP), CQA(ASQ) Oct 11, 2008

I agree with John's comments. Make sure the physician knows and also keep a record permanent in your institute/blood bank. It should also be able to be retrieved whenever the patient visit your institute/blood bank again and alert you to select antigen-negative blood. Hope that helps. CK Cheng, MSc, SBB(ASCP), CQA(ASQ) Oct 11, 2008

Perform autocontrol when you run a panel during antibody workup. If it is positive, perform DAT. If autocontrol is positive, DAT is negative, probably the positive autocontrol is due to the testing media, repeat with another technique or no enhancement media. If autocontrol is positive, DAT is also positive, exclude TR, or DHTR before you draw any conclusion it is due to autoantibodies. Look for mix-field reaction pattern if patient has recent transfusion. If autocontrol is negative, perform DAT is not necessary. Hope that helps in autoantibodies vs DAT. CK Cheng, MSc, SBB(ASCP), CQA(ASQ) Oct 11, 2008

Before you draw any conclusion it is an auto-D, please check (1) Patient may received anti-D for the treatment of ITP which subsequently shows hemolysis. Check medical record, and call the physician to ask for further info before you draw any conclusion. (2) Also, it may patient is a D variant, which produce anti-D to the subunit(s) he missed after transfusion. Check transfusion history record. DAT should show mix-field reaction in this case. (3) LW antibodies may react just like anti-D. That is strong with D pos cells, but neg (may be weakly pos) with D neg cels, howevere, it is NOT common. Hope it helps. CK Cheng, MSc, SBB(ASCP), CQA(ASQ) HONG KONG Aug 28, 2008

D positive patient with anti-D most likely (1) D variant form anti-D against the subunit the patient missing thru pregnant or transfusion. Check the reagent you are using, patient DAT, and I recommend you send it to the reference lab if you have no idea what it is. (2) D positive ITP patient treat with anti-D. Check medical record, talk with the doctor, and perform DAT. (3) IVIG or plasma products transfused contains small amount of anti-D. D positive patient with anti-D like antibody could be anti-LW just like what Yanxia said. It reacts strong with D positive cells and weak with D negative cell. Extreme hard to find LW negative cell for transfusion. Hope it helps. CK Cheng, MSc, SBB(ASCP), CQA(ASQ) HONG KONG

There are lots of materials and ways you can choose to prepare for the SBB(ASCP) exam depends on how good your blood bank knowledge is, how much time do you have, and what is your budget. (1) go to an SBB school. it takes you one to two years (online or on site) and I believe this is the best if time and budget is not a problem. (2) study, understand, and memorize the latest editon of Technical Manual and AABB Standard from the first page to the last page. Of course not all the questions from SBB exam you can find it from the books - like calculations, management, ...... (3) Gulf Coast Regional Blood Center in Houston does offer SBB Last Chance Review every year if you do not have time to join an SBB program which last for 1 to 2 years. (4) Gulf Coast Regional Blood Center also give talk in AABB Meeting called Specialist in Blood Banking Technology/Technologist in Blood Banking (SBB/BB) Exam Review: Where Do I Begin? A good review to tell you where to start the preparation. Last one thing. Prepare well before you take the exam. CK Cheng, MSc, SBB(ASCP), CQA(ASQ) HONG KONG

Since weak D test unable to distinguish between quantitative weak D and partial D, it is not required to perform weak D test routinely in transfusion hospital. Perform weak D test in (1) donor blood to conform true D negative, and (2) baby of D negative mother. Cuz mother of weak D phenotype baby is candidate for RhIG and should evaluate for excessive FMH. D negative mother (perform weak D is not required) should receive RhoGam injection at week 28. Also, Standards for BB & Transfusion Services and Guidelines for Prenatal and Perinatal Immunohematology published by AABB are good references. CK Cheng, MSc, SBB(ASCP), CQA(ASQ) HONG KONG Aug 6, 2008

Anti-K does not show dosage and k is a high incidence antigen. It is very difficult for one to select K+k- cell to exclude anti-K. Especially if your practice is to choose only panel cells that are not expired. One heterzygous cell can be used to exclude anti-K. CK Cheng, MSc, SBB(ASCP), CQA(ASQ) HONG KONG July 23, 2008

Warm at 37C disperses cold anitbodies. Saline replacement resolves rouleaux problem. Want to know why platelet-poor plasma is required for gel test? Any document support it? Thanks. CK Cheng, MSc, SBB(ASCP), CQA(ASQ) July 9, 2008

G antigen presents on cells which has C or D or both. Cells that have been found are C-D-G+ or D+G-, but not C+G-. Rare cells rG or r”G also express weak G antigen. Hope that helps. CK Cheng, MSc, SBB(ASCP), CQA(ASQ) HONG KONG

Hi Donellda, want to know if you still have a copy of the MABB SBB lecture notes. The Assoication does not offer the SBB lecture these few years cuz from the response, there were no enough students. Can you give me a copy of the notes? CK Cheng, MSc, SBB(ASCP) HONG KONG

I agree SBB(ASCP) exam is a difficult test. Do not give up. Gulf Coast Regional Blood Center in Houston does offer SBB Last Chance Review every year if you do not have time to join a one year program. They also give talk in AABB Meeting called Specialist in Blood Banking Technology/Technologist in Blood Banking (SBB/BB) Exam Review: Where Do I Begin? Also, read lastest edition of Technical Manual and Standards from the first page to the last page. Memorize it. Prepare well before you take the exam. CK Cheng, MSc, SBB(ASCP) HONG KONG