it is about a child sibling ( 2 brothers and a sister) who present severe macrothrombocytopenia with severe bleeding symptoms and an hyper expression of CD42a, CD42b, CD61 and CD41. they are treated as PTI but the treatement is not successful. the familily history of bleeding is very rich with many subjects that present the same profil and one of them died following a hemorrhagic syndrome. is there a platlet inherited disorder corresponding to this profil or should i try to search for an associated hemostasis desease such as FXIII deficiency or alpha antoplasmine deficiency?
Hi Meriem,
I do not know about the expressions of CDs as stated but have looked at this:
Article A Missense Mutation in the Alpha-Actinin 1 Gene (ACTN1) Is t...
You have probably looked here as well:
https://en.wikipedia.org/wiki/Giant_platelet_disorder
Hope that helps...
By the way, I would always want to rule out all "common" bleeding disorders like von Willebrand´s disease in such patients, just to make sure. In my oppinion, you should investigate the factor activity of FVIII, von Willebrand factor, factor IX and XIII. Do not forget to have a look at fibrinogen levels, too!
Thank you for your answer Julian,
I forgot tout tell it, investigation offre von willebrand desease ( VWF:RCO, VWF:AG, VWF:CB, FVIII:c) are normal, fibrinogen level too and FXIII is on the way. I am thinking also about an association meditteraneen macrothrombocytopenia and may ne deficiency on alpha 2 antiplasmine but WE d'ont have thé reagents.
I will tell toi about the résulte
Best regards
Meriem Yasmine
Hi, you should consider clotting factors deficiency which may be inherited in the children from their parents.
Hi Emmanuel,
PT, APTT and fibrinogen are normal that's why we excluded clotting factor deficiency.
Hi Meriem, is the hyper-expression of CD42a, CD42b, CD61 and CD41 due to the large platelet size? So in other words, the receptor density is within the normal range?
Liz.
Hi Elizabeth,
We couldn't realise quantification sites /platelet yet because of lack of reagents. What WE found is an hyper expression of MFI's with à range of 3 × the normal highest values. It is the first time WE find such values with macrothrombocytopenia. The family IS very poor and comes from very far so we are trying tout join them tout come to asses quantification. I hope my answer was clear tout you.
Best regards
Yasmine
As an easier approach, try calculating the ratio of CD42a to CD41 (for example) using MFI and compare with ratios found in healthy donors with normal platelet size, where you have used exactly the same reagents and flow cytometry protocol. This will give you a feel as to whether the density is normal and the elevated MFI is due to the larger surface area on the platelet.
Liz.
Hi Elizabeth,
I calculated ratios as you told me to do and here are the results :
for ratios of healthy people: (mean +/- 2SD)
CD42a/CD61 : 1,34+/- 0,4
CD42a/CD41: 1,11 +/- 0,6
CD42b/CD61 : 0,39 +/- 0,1
CD42b/CD41: 0,34 +/- 0,2
for the propositus:
CD42a/CD61: 0,5
CD42a/CD41 : 0,41
CD42b/CD61 : 0,24
CD42b/CD41: 0,29
Ffor his sister:
CD42a/CD61 : 0,56
CD42a/CD41: 0,38
CD42b/ CD61 : 0,39
CD42b/CD41: 0,29
As you can see there is an hypo expression of CD42a for the two. do I consider them as Bernard Soulier platelet disorder regarding this and the symptomatology ?
Best regards
Yasmine
No it is unlikely to be BSS, as CD42a and CD42b are usually (but not always) absent in BSS.
May be an MYH9-related disorder. Do your patients neutrophils have inclusion bodies on blood film?
Liz.
no inclusions in neutrophils but leukopenia 3,4 G/L and 3,35 G/L ( normal values: 4 - 10 G/L)
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