de un_ptit_gars » Lun 20 Déc 2010 12:28
Salut Yoki,
Pour ce qui est de la PTH, il n'existe qu'un seul dosage, on ne parle pas de forme active ou non, c'est le dosage sanguin de l'hormone parathyroidienne.
Pour ce qui est de l'interprétation que fait marshall vis a vis de ces dosages séparés, voici un lien que j'avais trouvé (en anglais, désolé!) qui expliquait plutot pas mal l'aspect de la sarcoidose.
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Here is the score.
None sarcoid people. Women who are osteoporotic often supplement with vitamin D. Usually these women have the following: Low 25D, High PTH. 1,25 D is rarely tested but it is usually either low or normal. They are usually kept on D until the PTH comes down to within normal range. However, if they take too much vitamin D their 25D will rise high but their 1,25D usually remains normal. Their PTH will drop also.
With sarcoidosis too much attention is paid to 25D. Due to various enzymes, 25D will nearly always be low in people with active sarcoidosis and return to normal in remission. The 1,25D level is high in sarcoidosis (but this is often occult because doctors are trained to test 25D).
Giving vitamin D to a person with sarcoidosis will not raise 25D levels unless they are in remission. However, it will raise 1,25D levels because the CYP24 Enzyme necessary to mop up excess vitamin D in sarcoidosis is not made. The PTH in sarcoid is often low despite the low 25D level, this is because the 1,25D is high.
1,25D is the active metabolic form of vitamin D, whereas 25D is only has the potential to become active D. Until 25D has an extra hydroxyl group added onto the molecule, it has no action in the body.
Here is what happens in different scenarios with Ds and PTH.
Healthys = Normal 25D
Normal 1,25D
Normal PTH
Add supplementary D and you might get this depending on the dosage and how long it is taken.
High 25D
Normal 1,25D
Low PTH
Osteoporotics
Low 25D
Low/ Normal 1,25D
High PTH
Addition of supplementary D taken for long period without checking you will eventually get
High 25D
Normal 1,25D
Low PTH
Sarcoidosis (active)
Low 25D
High 1,25D
Low PTH
Addition of supplementary D in active sarcoid you will get
Low 25D
High 1,25D
Low PTH
I hope this helps. In all cases PTH is the arbiter.
My most recent test of these came back:
25D Low
1,25D Low
PTH normal
Therefore, 1, 25D test was probably handled incorrectly or not done properly. PTH should be high if both Ds are truly low.
I hope this helps explain things
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Et encore :
Hi Bunkie,
I am sorry to hear you are having problems. What your results mean is that the process used to measure your 25D was a two step process. First, they separated D2 out and measured that, and then they measured the D3. It doesn't mean that you have no vitamin D at all.
You say you have a history of kidney stones. This is not all that common in sarcoidosis, but your treating doctor needs to know of this history.
You don't give any units for your serum calcium level. I am an Aussie, so I guess it in mg/dL. This means that your serum calcium is bang in normal range at present. However, if the units in which your calcium is measured is in mmol/L, which I doubt it is if your are in the US, then it is rather on the high side. Please check them.
Bunkie, it is your body, and if I were you, which I am not, I would not start taking pills until you get all of your results back.
I would highly recommend that you have a 1,25 hydroxy vitamin D level done. Tell your doctor that this is often raised in active sarcoidosis because the granuloma's help to manufacture it. Your kidneys and granulomas turn 25D into 1,25D. This is why your 25D appears low. If you have a high granuloma load, more and more 25D will be turned into 1,25D by the granulomas. This is why we need the results of the other tests. If you do have active sarcoid, i.e. if your blood CRP and ACE come back raised, if you have already have kidney stones, taking vitamin D tablets could make you rather ill. You need to get the 1,25D level done. It sounds to me, with a 25D that low, that you have a very high granuloma load in your body.
You might also get a PTH level done. Ask for a PTH and 1,25D level. You really need to have these tests done to ascertain whether you are actually deficient in vitamin D. With sarcoidosis, a 25D level alone will not tell you the actual state of your vitamin D status and supplementation could be dangerous if you have a past history of kidney stones.
If you have a vitamin D deficiency your PTH will be raised and you may also have a low 1,25D.
However, if your sarcoidosis is active and you have a high granuloma load in your body, your 1,25D will be high, while the PTH will be low.
These tests are the only ones which can differentiate what the cause of the low 25D is.
If the low 25D is caused by a true deficiency, taking the tablets should help you, but your calcium level will need to be monitored frequently because of your history of kidney stones.
However, if your 25D is low because of the rapid coversion of 25D into 1,25D by the granulomas, taking more 25D will only add to the levels of 1,25D in your body, and this in turn will add to the serum and urine calcium levels if left unchecked.
1,25D and PTH govern calcium levels in your blood. When PTH is raised, it stimulates production of 1,25D mobilising calcium from bones when the body needs to replete its store in the blood. PTH and 1,25D keep this level of calcium in balance.
In sarcoidosis, the balance goes awry because the granulomas are an abnormal source of 1,25D production. Your body tries to keep this in check by suppressing the PTH level. In other words, PTH tells your body to stop producing 1,25D for itself because there already seems to be more than it can handle. Less of 25D is produced so that no more 1,25D can be made from it, so in sarcoidosis, it is not a true deficiency, it is the body's way of slowing its own production of 1,25D by downregulation of both 25D and PTH. This is why you must find out what is causing the low 25D before taking the tablets. If it is sarcoid causing the low 25D, the last thing your body needs is more of it.
However, it is entirely up to you.
Pris
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C'est un peu long désolé, mais ça eclairci pas mal je trouve!
A+
Pti gars
![[img]images/icones/icon9.gif[/img]](./images/smilies/icon9.gif "etonné")
: j'en ai demandé à mon généraliste car j'avais lu qu' elle améliorait les SEP.
![[img]images/icones/icon5.gif[/img]](./images/smilies/icon5.gif "mecontent")
