Naked Science Forum

Life Sciences => Physiology & Medicine => Topic started by: neilep on 04/11/2012 07:12:11

Title: D-Dimer ? what is it and what does it mean if test postive ?
Post by: neilep on 04/11/2012 07:12:11

I have a friend who has tested positive for D-Dimer ?

I don't have a clue what this is (im just a sheep !)

Any chance of a plain english definition and what the implications are ?


Thanks

Sheepy
xxx

Title: Re: D-Dimer ? what is it and what does it mean if test postive ?
Post by: CliffordK on 04/11/2012 07:54:48

Of course there is a Wikipedia page on D-Dimer. (http://en.wikipedia.org/wiki/D-dimer)

So, it is a product of the breakdown of blood clots.  It is indicative of a few conditions including:

• Deep Venous Thrombosis (DVT), or clots in the blood veins, typically in the legs
• Pulmonary Embolism (PE). often a blood clot that has migrated from the leg (DVT) up through the right heart, and gets stuck in the lungs
• Disseminated Intravascular Coagulation (DIC), a clotting malfunction that causes multiple mini-clots in the arterial/venous system.

Title: Re: D-Dimer ? what is it and what does it mean if test postive ?
Post by: RD on 04/11/2012 13:34:45

Apparently it’s only 50% specific for blood-clotting disease, ( i.e. only half the people with a positive result will actually have  developed blood clot(s) , the other half are false positive due to some other disease or old age ) ...

Quote

Various kits have a 93-95% sensitivity and about 50% specificity in the diagnosis of thrombotic disease.
   False positive readings can be due to various causes: liver disease, high rheumatoid factor, inflammation, malignancy, trauma, pregnancy, recent surgery as well as advanced age

https://en.wikipedia.org/wiki/D-dimer#Test_properties

Title: Re: D-Dimer ? what is it and what does it mean if test postive ?
Post by: neilep on 04/11/2012 17:59:37

Thank ewe both CliffordK and RD for your kind responses. I will pass this info on to her.

circa late 20s, female.

Title: Re: D-Dimer ? what is it and what does it mean if test postive ?
Post by: CliffordK on 04/11/2012 19:18:26

It says it can also occur with pregnancy.

According to Wikipedia, a negative result is better for excluding certain disease conditions, as a positive result may not be specific. 

I would assume there was a reason the test was conducted.

Title: Re: D-Dimer ? what is it and what does it mean if test postive ?
Post by: cheryl j on 04/11/2012 23:28:44

The value of the test is that if it's negative, it almost completely rules out a blood clot so you can cross that diagnosis off the list. But if its positive it doesnt necessarily mean there is pulmonary embolism or other clot.

Title: Re: D-Dimer ? what is it and what does it mean if test postive ?
Post by: neilep on 05/11/2012 05:34:57

Thank you again and also cheryl J.

After further inquiries she admits a history of blood clotting. You have all mentioned this. I'll consider this topic finalised now as it seems that her "treatment" is going through due process related to this.

Title: Re: D-Dimer ? what is it and what does it mean if test postive ?
Post by: RD on 05/11/2012 06:03:47

Quote from: CliffordK on 04/11/2012 07:54:48

Disseminated Intravascular Coagulation (DIC), a clotting malfunction that causes multiple mini-clots in the arterial/venous system.

Hopefully not DIC, given its backronym (https://en.wikipedia.org/wiki/Backronym) ...

Quote

... DIC is generally associated with an adverse outcome by most clinicians, and its acronym has been synonymous with "Death Is Coming."   

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC259170/