14 November 2024 (Thursday) - BTLP-TACT Exercise

Time for another BTLP-TACT exercise. I was given two cases:
 

85624 – a sixty-nine year old chap in A&E needing four units of blood as soon as possible

He grouped as O Rh(D) Positive with a negative antibody screen.

I selected four units of O Rh(D) Positive blood

 

12582 – a forty-three year old woman needing four units of FFP and two units of cryo for a liver transplant

She grouped as O Rh(D) Negative with antibody screen positive I cells 1 and 3. I requested antibody panels. The IAT panel was positive in cells 1, 3, 6, 9 and 10 corresponding with anti-Fy(a) but does not exclude anti Lu(a) and anti Cw. The enzyme panel was negative which (in this plane of existence) does exclude anti Lu(a) and anti Cw.

I selected four units of FFP and two units of cryo

 

I got the thumbs-up

13 November 2024 (Wednesday) - Spot the Difference

Had an interesting conversation today which made me think. What *exactly* is the difference between a myelocyte and a promyelocyte?

They can be rather tricky to tell apart…

So I’ve had a think and done some Googling…

 

• Promyelocytes are bigger.
• Promyelocytes have prominent nucleoli and Golgi apparatus.
• Myelocytes do not have nucleoli and Golgi apparatus.
• Compared to the myelocyte, much more of the promyelocyte is nucleus
• Promyelocytes have huge, dark purple, primary (azurophilic) granules both in the cytoplasm and overlying the nucleus.
• Promyelocytes do NOT have secondary (specific,to neutrophil, eosinophil or basophil) granulation – not even the beginnings of it!  If you see any of that secondary granulation (even just a little blush of it in the cytoplasm) then it’s a myelocyte. The promyelocytes of the three granulocytic lineages cannot be distinguished by routine light microscopy.

 

Here’s some references…

 

https://www.sciencedirect.com/topics/medicine-and-dentistry/promyelocyte

https://www.pathologystudent.com/how-to-tell-apart-promyelocytes-and-myelocytes/

https://imagebank.hematology.org/image/60399/promyelocyte?type=upload

12 November 2024 (Tuesday) - IBMS Update

The IBMS sent their monthly newsletter today. It was on the dull side; it usually is. I was going to write about how their focus is on people and management and science is of peripheral interest, but I say that every month don’t it?

11November 2024 (Monday) - T.T.P.

“The correct answer is plasma exchange (PE). 

The treatment of choice for patients with thrombotic thrombocytopenic purpura (TTP) is plasma exchange. 

Although fresh frozen plasma infusion might be of limited impact, it is not the definitive treatment since it does not help removing the autontibodies from circulation. 

Platelets are thought to be contraindicated in TTP because of the theoretical possibility of worsening the TTP. 

Gamma globulin is ineffective in increasing the platelet count in TTP. 

Caplacizimab is an adjunct to PE but cannot replace it.”   

Reference:  Scully M, et al. Caplacizumab Treatment for Acquired Thrombotic Thrombocytopenic Purpura. N Engl J Med. 2019;380:335-346.

 

Plasma exchange? Haven’t done one of those for years…

Thursday 7 November 2024 (Thursday) - BTLP-TACT Exercise

Whenever I sit down to write up some CPD I always feel obliged to end it with a BTLP-TACT session. And so here we go.
 
I was presented with two cases:
 

27841 – a fifty-four year old woman in outpatients with ITP requiring group & save.

She grouped as O Rh(D) Positive with a negative antibody screen.

 

99755 – a forty-four year old chap under the medics requiring group & save, FFP (4) and cryo (2) for liver transplant.

He grouped as A Rh(D) Positive with a negative antibody screen.

I selected four units of A FFP and two units of A cryo as they *are* indicated

https://emedicine.medscape.com/article/431573

https://pmc.ncbi.nlm.nih.gov/articles/PMC2967283/

 
I got the thumbs up. Which is just as well. I get wound up when I get the thumbs down. Not because I got it wrong. I get wound up because it is a wasted learning opportunity. Being told “you got it wrong for the following reasons” and having a discussion on the matter is useful. That’s how we learn.
Just being told “you stuffed it up” helps no one.

5 November 2024 (Tuesday) - Fritsma Factor Newsletter

Inhibitors, lupus, haemophilia… as ever the Fritsma Factor newsletter is an invaluable resourse.

4 November 2024 (Monday) - NEQAS 2405DM

Having looked at NEQAS 2405DM on 12 September I get the resuts today.
 
“A previously fit 34-years old female attended her GP feeling tired. Her Haemoglobin was found to be 70g/l with normal white cell count and platelets – a blood film was prepared. What is your impression?”
 
I said:

 

Red cells   Anisopoikilocytosis Fragmented cells Polychromasia Marcrocytosis Target cells Tear drop cells

White cells   Hypersegmented neutrophil Toxic granulation Vacuolated monocyte with cleft nucleus

Platelets   Unremarkable

 
“Something haemolytic, but what are those vacuoles in the white cells. And what's the hypersegmented neutrophil all about?”
 
 
The expert comments were:
 
This blood film shows a severe deficiency of vitamin B12. The features quite distinct with the expected combination of oval macrocytes and hypersegmented neutrophils. If you have not seen a case like this before however, you may be surprised by the features of red cell fragility (fragments and misshapen cells) which can sometimes be mistaken for a fragmentation syndrome or even for microcytes. Also remember that the packed marrow can lead to many typical tear-drop forms being present.  
 
Well… I spotted the salient features but I did mistake them for a fragmentation syndrome. Just as well it’s not up to me to make a diagnosis. I’ve always said it’s unfair to judge us on something we don’t actually do.
And again I’ll make the comment that it is a shame that it took two months to get the result.