How to tell a patient's sex from their neutrophils!

 

Neutrophil drumstick

Look at this neutrophil. Can you see a drumstick (or as I call it chicken leg!) protruding from the nucleus? This actually represents the inactive X chromosome and tells us therefore that this patient is female! 

Females have two X chromosomes (XX), whilst males have one X and one Y (XY).  FISH analysis has shown the active chromosomes, whether X or Y to be randomly distributed along the nuclear lobes of the neutrophil, whereas the inactive X chromosome is usually located in the end lobe of the nucleus . (Karni, Wangh and Sanchez, 2001).

Sessile nodules which are small bumps protruding from the nucleus, also represent inactive X chromosome and again are found at the terminal end of the neutrophil nucleus.

                                                                    Sessile nodules

It is possible for a  male to have these drumsticks or sessile nodules in Kleinfelters syndrome, which makes sense as here the male has an extra X chromosome (XXY). I've learnt that a female may lack drumsticks in Turner’s Syndrome (XO) as lacking an  X chromosome .

It is easy to mistake the inactive X chromosome for other nuclear projections such as ‘racket shaped’ protrusions, smaller nuclear lobes and other projections. These have  a similar appearance to the drumsticks but may be a different size and do not have the same significance. Abnormal nuclear projections can also be seen in Haematological disorders such as MDS and CMML.

This is a smaller lobe in the nucleus, not a drumstick as it's too big.

 It takes experience recognising a sessile nodule or drumstick from other nuclear projections, but i've learnt that knowing their location on the terminal lobe of the neutrophil nucleus and looking at size are  good places to start!

PIN THE CELL ON THE PLOT!

 

A fun idea I copied from a Sysmex XN course a few years ago. I asked my colleague to build the XN differential plot and place cells in the correct location using the knowledge that the more complex a white cell is (i.e. it has granules and a lobulated nucleus), the further to the right it will be, and the more DNA/RNA content it has, the higher it will be.

 I’ve found it’s a really good way to reinforce understanding of the plots and allows the correct thought process to occur when there is a potential abnormality.

 As I’ve mentioned in a previous post, MDS can be picked up as the neutrophil population extends too far left, suggesting that less complex cells are there i.e. neutrophils lacking granules or with an abnormally segmented nucleus.

Blasts can be picked up because a population with more DNA/RNA is present, higher up to the left of the plot, but have few granules so are located more to the left. Nucleated red cells however have far less DNA/RNA content and no granules, so will reside in the bottom left.

Even malaria may be seen as a very complex population over to the right, with lots of pigment.

So Scientists out there,  if you see any unusual populations  on the plot, ask yourself, what this means by truly understanding how your particular analyser builds the plot.

 

HELLP - A LIFE THREATENING COMPLICATION OF PREGNANCY

 

Another weekend shift and another emergency case.!!!

This lady recently came into the hospital at 30 weeks pregnant. The clinical details I received were ? Pre-eclampsia.

 The Full Blood Count showed that the platelet count for this lady was low at 64 x 10^⁹/l and had  significantly dropped from 266 x 10^⁹/l, two weeks previously. This situation must always be dealt with immediately. The first question is, is this a genuine result?

After ruling out a clot in the sample, or platelet clumping/ Fibrin strands, the next question is what is going on in the body to make the platelets fall like this? The Scientist must then seek the answer by looking at the white cells and red cells on the blood film, clinical details and other laboratory results.

The potential cause was revealed on the blood film, by the presence of red cell fragments in most fields. This is a serious finding in conjunction with a dropping platelet count and the question is, why are red cells being sheared in half!?

    

                                

My immediate thought was HELLP Syndrome which stands for Haemolysis, Elevated Liver Enzymes and Low Platelets. This is a severe, potentially life -threatening form of pre-eclampsia. Complications include liver haemorrhage or rupture, pulmonary odema, placental abruption, bleeding and clotting issues.

What is the cause for red cells being sheared in half ?

It seems that the main cause is a Microangiopathic Haemolytic anaemia (MAHA). The red cells are sheared off as they pass through capillaries with damaged endothelium and fibrin strands which leads to the red cells being fragmented as they pass through.

Another cause for the red cell damage can also be Disseminated Intravascular Coagulation (DIC).

Why are platelets reduced in HELLP?

The platelets are aggregating and forming clots due to endothelial damage.

Further evidence that this was HELLP Syndrome.

Protein in the urine

 A protein: creatinine ratio or >30mg/mmol suggests significant proteinuria in pregnancy (NICE, 2019). In this case the value was 341.7mg/mmol!

Elevated Liver enzymes

Nice guidelines ( NICE, 2019) suggest a rise in ALT, twice the upper limit of the normal range is of concern. The ALT in this case on presentation was 420 U/L. The normal range is <33 U/L.

What happened next?

The obstetric team and Consultant Haematologist were alerted to the blood film findings and other laboratory results. The Consultant Haematologist should be informed as red cell fragments with low platelets could also be suggestive or other life threatening microangiopathic haemolytic anaemias such as TTP and HUS, where the course of treatment would be entirely different.

The diagnosis of HELLP was indeed made in this case however  and the decision to deliver the baby prematurely, despite the lady only being 30 weeks pregnant. Delivery is the cornerstone of treatment for HELLP syndrome (Baha, 2022).

Post delivery we can see quite a quick improvement with an upward trend in the platelet count and downward trend in ALT. From a haematological point of view, if the platelet count did not improve, an alternate cause for the thrombocytopenia such as a primary Microangiopathic Haemolytic anaemia would be sort.

	Haemoglobin (g/dl)	Platelets (x 109/l)	ALT (U/L)
PRESENTATION	118	64	420
DAY 1 (post delivery)	111	114	300
DAY 2	98	178	212
DAY 3	99	239	117
DAY 4	102	337	85
DAY 8	108	558	32
DAY 15	119	354	14

Hopefuly mother and baby both had positive outcomes in this case.

 References

Baha, S., 2022. UpToDate. [online] Uptodate.com. Available at: <https://www.uptodate.com/contents/hellp-syndrome-hemolysis-elevated-liver-enzymes-and-low-platelets?search=hellp%20SYNDROME&sectionRank=3&usage_type=default&anchor=H24&source=machineLearnin> [Accessed 8 May 2022].

 Petca, A., Miron, B., Pacu, I., Dumitrașcu, M., Mehedințu, C., Șandru, F., Petca, R. and Rotar, I., 2022. HELLP Syndrome—Holistic Insight into Pathophysiology. Medicina, 58(2), p.326.

Nice.org.uk. 2022. Recommendations | Hypertension in pregnancy: diagnosis and management | Guidance | NICE. [online] Available at: <https://www.nice.org.uk/guidance/ng133/chapter/Recommendations#assessment-of-proteinuria-in-hypertensive-disorders-of-pregnancy> [Accessed 8 May 2022].