Antibodies affect to INR result - Hughes Syndrome -...

Hughes Syndrome - APS Support

9,524 members9,631 posts

Antibodies affect to INR result


I am curious can APS antibodies make INR go higher or lower with the same dose of warfarin? Is there any information about this?

Another question. Do we APS patients need higher dose of warfarin than those who don't have these antibodies in their blood? I know that the dose is very individual and there is other things that have got impact to it, food, K-vitamine and so on. But does the changes in antibody amounts in blood have any affect to it? Since antibodies are not stable all the time.

13 Replies

Hi Leenalina,

I have since 2002 had all the four antibodies pointing to APS in high or mediumhigh titres. Taken twice a year by my doctors at the hospitallab. I have never

it Went away too soon.... sorry!

I have never thought about the numbers of the antibodies and no one has let me think it is important either. When I started warfarin perhaps they have reduced a little. About the INR levels I do not think that has any importance.

as to the level of the antibodies.

People without these antibodies do not have APS. There are some people with symptoms and without antibodies so this is a very difficult question that I now notice I have difficulties to answer.

If we talk of "ordinary people without any symtoms of APS" who have warfarin because some valve-replacement they can have a lower INR because they do not have "sticky blood". This is not the answer of your question.

It is not the dose of warfarin that is important but the INR. The warfarin-dose differ a lot. I take today only 5 mg of warfarin.If you start a new medicin you can notice that on your INR.

I have tried a little to answer your question but I do not know if you are satisfied with it.

Today Finland and Sweden have played ishockey in OS but I have not heard of the result yet.

Take care from Kerstin

Congratulations Kerstin! Sweden won! :) My husband and boys have been watching but I didn't :).

According to information sent to me from my haemotoligist this morning from the thrombosis charity is that those who have aps warfarin treatment is recommended to be indefinite and that the blood thinness level for people with aps is kept at 3-4 when they have had a stroke or arterial problem whereas patients with other thrombotic risks it tends to be kept at 2-3 mind you the thrombosis charity which I'm sure is helpful to some patients and people with concerns seems to not have all the information on other problems relating to aps so I'm still unsure myself what my inr levels should be

lloydyuk in reply to bevjane74


I hope I don't offend you by stating I think this only partially correct. My INR was stable for 18 years based on a target of 2.0-2.5 warfarin 9-10 g per day since last year my target has been 3.0-3.5 based on 13 g per day however this fluctuates wildly now this week 4.2 last week 2.1 I attend for INR test weekly whereas previously it was spontaneous being roughly every 2 months!

Thank you I appreciate the response and noted the content. I couldn't agree more regarding the dosage and individuals. I believe when you take warf for heart conditions it's usually down around 2-3mg per day and stable. Which is why doctors who don't know APS act horrified when I'm taking 15mg and Clexane as has happened recently. I'm going to ask my rheumatologist at my next appointment in a few weeks. The fact I had caps a year ago probably had a lot to do with the recent unstableness both with my INR and general health. I'm lucky to be here I guess even if I am now disabled, I always think however there is always somebody worse off.

Lure2 in reply to lloydyuk

Hi Lloydyuk,

Thank you for that. I would like to say to you: FORGET about the antibodies. I have them all in medium to high titres. I hope I do not offend you now because I know that what is important for us all on warfarin is to keep a stable INR. I wrote an answer a couple of minutes ago about this. Warfarin is for some of us our "lifeline" (being said to me yesterday by a heartdoctor).

keep well wish Kerstin in Stockholm

Ok thank you,

The important part is keeping the INR stable. The dose is unimportant. A low INR means a higher antibody level and therefore increases the risk of thrombosis. Maintaining balanced diet obviously helps. I retest after a week if the INR drops. If the result though js below your required level an increase of warfarin is required. New drugs affect your INR, or antibiotics etc rise my INR rapidly, 2.8 to 6.3 in one day recently. It is the INR that's the most imlortant though.


Yes, Aps antibodies make the INR go higher. My hematologist looks at the chromogenic factor X results to make sure my INR is within range. In the past, I had experiences that my INR is high over 10 and everybody is freaking out but when they do the chromogetic factor X, gives them a different result. It is more reliable the chromogenic factor X for people who have the phospholipid antibodies. My understanding of the dosage of warfarin is different for each person. It has nothing to do with weight, or the anitbodies, it has not do with the dosage your blood needst to be in therapeutic levels. Some people might need to take 2.5 miligrams and others 10mg of warfarin to achieve therapeutic levels.

Yes, the more antibodies you have your warfarin dosage might need to be adjusted. I started with 2.5mg and I am taking 3mg at the present time because my antibodies are higher and giving me a lot of problems.

My understanding and my wife's experience is that inflammation and perhaps the degree of antibody concentration does affect inr......the inratio company web site says flat out that APS patients should not use their home test units because of phospholipid interference with their test strips (which are also phospholipid based i believe) is adamant on this issue. What is frustrating is that there is not enough input to your website and the apsfa website from medical professionals that would have answers ....not conjectures about these issues.

You may also like...