Month: Mar 2021

COVID-19 Donor Qualification

drzeyd

Principle:

This is the latest update on donor qualifications during the COVID-19 pandemic and addresses issues about COVID-19 vaccination, COVID convalescent plasma use and donation, return of donors into the donor pool after COVID-19 vaccination.  All of this information is subject to change as new regulations are released.

Policy:

  1. All donors must be in good health and meet all donor eligibility criteria at the time of the donation.
  2. Individuals diagnosed with COVID-19 or who are suspected of having COVID-19, and who had symptomatic disease, must refrain from donating blood for at least 14 days after complete resolution of symptoms.
  3. Individuals who had a positive diagnostic test for SARS-CoV-2 (e.g., a nasopharyngeal swab), but never developed symptoms, must refrain from donating at least 14 days after the date of the positive test result.
  4. Individuals who are tested and found positive for SARS-CoV-2 antibodies, but who did not have prior diagnostic testing and never developed symptoms, can donate without a waiting period and without performing a diagnostic test (e.g., a nasopharyngeal swab).
  5. Individuals who received a non-replicating, inactivated, or mRNA-based COVID-19 vaccine can donate blood without a waiting period.
  6. Individuals who received a live-attenuated viral COVID-19 vaccine, must refrain from donating blood for 14 days after receipt of the vaccine.
  7. Individuals who are uncertain about which COVID-19 vaccine was administered must refrain from donating for 14 days if it is possible that the individual received a live-attenuated viral vaccine.
  8. Individuals who received monoclonal antibodies should be deferred for three months from the last dose.
  9. Donors who have received blood components, including COVID-19 convalescent plasma are deferred for 3 months since the last transfusion.
  10. Recovered COVID-19 patients who are eligible to donate CCP and receive an approved COVID-19 vaccine may donate if they:
    1. Had symptoms of COVID-19 and a positive test result from an approved diagnostic test
    2. Received the COVID-19 vaccine after the diagnosis of COVID-19
    3. Are within 6 months after complete resolution of COVID-19 symptoms

References:

  1. Summary:  Donation of CCP, Blood Components, and HCT/Ps Following COVID-19 Vaccines or Treatment with CCP or Monoclonals, Updated 3/2/21, AABB, Bethesda, MD, USA
  2. Updated Information for Blood Establishments Regarding COVID-19 Pandemic and Blood Donation, US FDA, 19/1/21
  3. Toolkit for COVID-19 Convalescent Plasma (CCP) Under Emergency Use Authorization Issued 02 04 21 Revision 12/2/21, AABB, Bethesda, MD, USA

Order of the Steps in Serologic Testing

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This is a teaching document I give to new staff, medical technology students, pathology and residents.  Very often I get the question, “Why can’t I just do the antiglobulin phase crossmatch first and then phenotype the RBC unit?” Or:  “Why do I have to add reagents in a particular order?”

My practice has always been to select an antigen-negative RBC unit first, then do the antiglobulin-phase AHG crossmatch.  This way I know that the unit was definitely phenotyped before release.  Likewise, the blood bank computer now only offers antigen-negative units for allocation and then crossmatching if there is a clinically significant antibody.

In a manual setting without a blood bank computer system, performing the AHG crossmatch may yield a negative result, even if the unit is antigen-positive.  With storage, some antigenic expression is weakened so it may not be detected at the time of crossmatch.  Yet, there may still be enough antigen present to cause hemolysis.  Not detected does not necessarily mean not present!!

I expect that many inexperienced staff may be tempted to forego the antigen typing if the AHG crossmatch is negative.

This is an analogous logic to the question, “Do I add the cells or the antiserum/plasma/serum first for the reaction?”  If you add the cells first, you may forget to add the patient’s plasma/serum or a typing antiserum and you might not be able to detect the omission by looking at the tube or gel.  Actually, I once recommended to one vendor that it color the typing antiserum so it was conspicuously showing on the gel.

I was taught that this is a matter of discipline to ensure that all steps are performed.

However, for every practice, there has to be flexibility.  If there is no typing reagent or if it is very expensive or in short supply, one may have no choice but to do the AHG crossmatching first.  Often there is still another option:  one can often preliminarily screen units first before using a rare reagent—examples:

  • Check if patient is group O first and antibody screen panreactive in suspected anti-H.
  • Check P1 typing first if there is a suspected anti-PP1Pk.
  • Check the antibody screen for panreactivity first for antibodies of high-incidence or prevalence antigens.

ABO Incompatible Stem Cell Transplant: What ABO type of RBCs Should I Use?

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In an ABO-incompatible stem cell transplant, both donor and recipient RBC types may be present.  Likewise, immune effector cells from both the donor and recipient may be present.

Using group O RBCs and AB plasma is an option but there are limited supplies of both.  Since we use RBCs in additive solution (SAGM), only minimal residual donor plasma is available and unlikely to be clinically significant.

Here is my approach:

  1. Use fresh specimen to perform forward and reverse type
  2. Check the reverse type:  does it show either anti-A and/or anti-?
    1. If anti-A detected, do not transfuse group A RBCs.
    2. If anti-B detected, do not transfuse group B RBCs.
    3. If both anti-A and anti-B detected, continue using only group O RBCs.

Massive Transfusion: When to Revert to the Original ABO Type

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In a massive transfusion setting, the patient’s forward and reverse type will reflect the use of group O RBCs and the patient may even fully type as group O, depending on the number of units transfused.  Group O RBCs are very precious and in short supply so we need to switch the patient back to his/her own type as soon as feasible.  RBCs in additive solution (e.g. SAGM) have only minimal residual plasma so the load of anti-A,B from the O cells is minimal.  In my organization, we did not titer ABO hemolysins in blood donors.

Here is my approach:

  1. Use fresh specimen to perform forward and reverse type
  2. Check the reverse type:  does it show either anti-A and/or anti-B from the group O massive transfusion?
    1. If anti-A detected, do not give group A RBCs.
    2. If anti-B detected, do not give group B RBCs.
    3. If both anti-A and anti-B detected, continue using only group O RBCs.

Some people would recommend performing a full AHG crossmatch using the patient’s current plasma and RBCs of the original ABO type:

  1. If compatible, return to the original ABO type.
  2. Otherwise, continue using group O RBCs.

I did NOT do the full AHG crossmatch and had no hemolytic transfusion reactions if the RBCs were compatible with the current reverse type plasma.