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Micro only reactions


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How does everyone record reactions that are only detected microscopically?

Here are the versions I have seen in my various jobs and from my various techs.  I am trying to get it more consistent.

+/=        wk+       mic+      0m+

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I have never understood this obsession with looking at reactions down a microscope in blood bank, except looking at things like a Kleihauer or when teaching, to show mixed-field reactions.

The great Peter Issitt, not a bad roll model to have, wrote, many years ago now, a passage that I attach from page 69 of his "Applied Blood Group Serology" book, 3rd edition, 1985, Montgomery Scientific Press.

That having been said, all reactions seen MUST be recorded, it is just that macroscopic reading is almost all that is ever required.

Issitt (2).jpg

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When tube testing was all we had, my moto was; "when in doubt, shake it out!"  One of the first things I did as transfusion supervisor at a new facility was convince the medical director that we needed to stop using the microscope for routine testing.  It was much harder to convince the rest of the staff.  I couldn't remove the microscopes from the department because we were doing KBs at the time and I'm pretty sure a few of the "older" staff still used them for routine testing when I wasn't looking.  Once again inertia is proven to be the most powerful force in the universe!

:coffeecup: 

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4 hours ago, Malcolm Needs said:

Or the type of microscope in which the contents of the tube are viewed while still inside the tube by placing the tube itself on the microscope stage

This is how our tubes are viewed for micro reactions.  Issitt seems to be OK with this method.

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Decades ago I worked w a tech who worked w Peter at NYBC.  I had always looked under the scope (as that was how I was trained).  I'd ask her to look at 2 or 3 or 4 cells stuck together microscopically.  Her comment was always, "If you want to call that positive go ahead, but I'd call it negative."  High anxiety to give up the scope but I did.

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I was originally trained using an "inverted microscope" - that was a thing of beauty. The light source was above, the relatively low-powered lens below. The cells stayed in the tube and the tube could be rotated to get movement and/or a suitable thickness of liquid in which to see the cells. It was great and very easy to use (even though it had a large footprint), but as others have commented, if one looked long enough, one could always find "friendly cells".

I'm not a fan of microscopic reading and I dissuade others from doing it. As I've said in the past, high level tools and techniques should only be employed by those who understand the limitations and consequences.

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When I was trained (many years ago!) we used +/- for microscopic tube reactions.

Now, I encourage MLT to only use the microscope if they are looking to verify a mixed field or rouleaux.  I suppose there could be other rare times to use a microscope - like an anti-Sda?  But generally - no microscope.  But they love the microscope...:plotting:

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27 minutes ago, AuntiS said:

like an anti-Sda?

True, but, for those unfamiliar with it,  the agglutination seen with an anti-Sda is usually mixed-field (see the attached photograph - not a fantastic photograph, but I have "tarted it up" a bit - from the original paper, Macvie SI, Morton JA, Pickles MM.  The Reactions and Inheritance of a New Blood Group Antigen, Sda.  Vox Sang 1967; 13: 485-492).

Macvie (2).jpg

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To answer the original question - we use "mi" and the computer interprets that as "positive" and we can choose our "weak positive" answer.  Works for us.  Yes ,we still read the occasional tube under the scope - still in the tube and rolling the tube.  Everything else is on the Immucor ECHO - eliminates the problem!

Weak DATs on cord bloods are sometimes found - never know how that works out for the infant.

Reading Fetal Hgb Screens requires microscopic reading - you never see the positives in the optical aids (convex mirrors).

We try to keep it to noticeable agglutination/clumping in the tube - "kissing cells" are not considered "positive".  It's a job to get the MT students to loosen up with microscopic reading, but it seems to be a good exercise for them to learn what it looks like - agglutination vs. rouleaux, etc.  We never know what will be the methods used in whatever hospital they finally wind up in, if not ours.  

And yes - everyone sees things differently.  I had one tech who must have had "microscopic" eyes.  She would take her glasses off and look at tubes and always "see" stuff that the rest of us just could not see macroscopically.  Especially on titers!

Best of luck.

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15 minutes ago, carolyn swickard said:

To answer the original question - we use "mi" and the computer interprets that as "positive" and we can choose our "weak positive" answer.  Works for us.  Yes ,we still read the occasional tube under the scope - still in the tube and rolling the tube.  Everything else is on the Immucor ECHO - eliminates the problem!

Weak DATs on cord bloods are sometimes found - never know how that works out for the infant.

Reading Fetal Hgb Screens requires microscopic reading - you never see the positives in the optical aids (convex mirrors).

We try to keep it to noticeable agglutination/clumping in the tube - "kissing cells" are not considered "positive".  It's a job to get the MT students to loosen up with microscopic reading, but it seems to be a good exercise for them to learn what it looks like - agglutination vs. rouleaux, etc.  We never know what will be the methods used in whatever hospital they finally wind up in, if not ours.  

And yes - everyone sees things differently.  I had one tech who must have had "microscopic" eyes.  She would take her glasses off and look at tubes and always "see" stuff that the rest of us just could not see macroscopically.  Especially on titers!

Best of luck.

For all I have said above, and I think I have said this before on here, when I was first working in Red Cell Reference, when the International Blood Group Reference Laboratory was in London, and the Department was run by Carolyn Giles and a very young Senior Technician by the name of Joyce Poole, I also had the problem of seeing "weak agglutination" that wasn't actually there (totally negative, in other words), and Joyce coined this as a "Malcolm Weak".  This was way back in the early 1970's.
I understand that, now and again, some 50 years on, the term is still used in the department for over enthusiastic reading of reactions!!!!!!!

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21 hours ago, Malcolm Needs said:

For all I have said above, and I think I have said this before on here, when I was first working in Red Cell Reference, when the International Blood Group Reference Laboratory was in London, and the Department was run by Carolyn Giles and a very young Senior Technician by the name of Joyce Poole, I also had the problem of seeing "weak agglutination" that wasn't actually there (totally negative, in other words), and Joyce coined this as a "Malcolm Weak".  This was way back in the early 1970's.
I understand that, now and again, some 50 years on, the term is still used in the department for over enthusiastic reading of reactions!!!!!!!

It's good to be famous and remembered!!  :rolleyes:

:coffeecup:

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On 3/5/2021 at 9:45 AM, Sonya Martinez said:

What about in gel if one tech swears they see very weak agglutination (grainy) at the bottom of the well but no one else sees it?  We have one tech I swear has magnifiers in his glasses!

When we first started using Gel, my techs would point out the shadows or 'jumpies' as they called them. 

I'd suggest 'Run the screen again using maxtime.'  If they still saw the shadows, I'd just let them run a panel (maxtime) and go crazy with the results.  After a while we all learned to ignore those reactions. 

Keep in mind, there are always a certain percent of any given cell population (especially stored reagent cells) that are just not going to make it smoothly to the very bottom solely because of steric hindrance (broken, aged, crenated, tagged for destruction, etc.).

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On 3/9/2021 at 6:23 AM, Joanne P. Scannell said:

When we first started using Gel, my techs would point out the shadows or 'jumpies' as they called them. 

I'd suggest 'Run the screen again using maxtime.'  If they still saw the shadows, I'd just let them run a panel (maxtime) and go crazy with the results.  After a while we all learned to ignore those reactions. 

Keep in mind, there are always a certain percent of any given cell population (especially stored reagent cells) that are just not going to make it smoothly to the very bottom solely because of steric hindrance (broken, aged, crenated, tagged for destruction, etc.).

Thanks Joanne P Schannell.  It is a new tech for us that also works next door at an adult hospital (we're a children's hospital) and his experience is limited.  On his last 'positive' I let him work it up and run a panel, nothing else ended up positive so we decided to result the antibody screen as negative.  I will make sure to add the part about stored red cells and steric hindrance maybe that will help him stop overcalling these very weak, probably negative, reactions.

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During the time at the Immunohematology Reference Lab I was at in the 80s-90s era we had to use microscopes to confirm negative reactivity.  What!!?  Why??   Specimens sent to us with multiple 2+ and 4+ reactions to panel cells were sent to us for investigation.  We observed 0 reactivity!  The hospital techs would get very upset with us because they were absolutely sure of what they observed and we found nothing!  As it turned out, some hospitals, using microscopes, were grading their microscopic reactivities on a 1+ to 4+ scale but just not informing us it was microscopic reactivity.   Fortunately we were able reduce these practices by providing CE during our quarterly member hospital meetings we conducted throughout the state.  We still got them occasionally but when we see the possibility of this scenerio we look for reactivity microscopically.  When we call the technologist we can then "confirm" what they are seeing but then use the time to educate and give them some assurance that the transfusion should be uneventful.

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to be fair techniques in the early 80s were not what they are today, neither for blood grouping nor for antibody screening/identification.  Methods were not standardised.  The number of drops of serum (almost always serum) to the amount of red cells could vary from 2:1 to 8:1.  The concentration of the red cells could be anything from about 2% to almost 10% - and often pooled. And pooling was one of the main reason for checking under the microscope.  Incubation time varied too - often depending on the length of your coffee break or lunch break.  LISS was in its infancy.  Washing was done by hand or with a 'Coombs washer' - 3 or 4 washes, with or without albumin.  So perhaps not surprising that people were not too confident in their visual results.  Much less knowledge then too about what was and what was not clinically significant.  (I can remember when we treated cold anti-A1 as clinically significant)

Thankfully since those dark ages things have improved massively - but sometimes some of the old habits stick - like using a microscope to read apparently negative results.  The practice lives on  (in some places) but the reasons for that practice died out long ago

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How about microscopic reactions for scoring prenatal titers?  The tech manual scoring guide has +/- as a score of 2.  Would you interpret the tech manual as meaning that +/- is microscopic positive or macro weakly positive? 

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