Aa
A
A
Close
Avatar universal
acth reference ranges at differing times of day
I am concerned about the validity of the acth test when handled improperly.  Ours was kept at room temp 71 degrees for 1/2 hour before ice and then it was probably spun at 50 minutes or so.

I read a study that stated that there was not a significant difference (10 percent) in the degradation of the acth by keeping it at room temp for 24 hours but that spinning was what really made the difference.

The study is titled:  Preanalytical Stability of Adrenocorticotropic Hormone Depends on Time to Centrifugation Rather than Temperature  - if you can google that and let me know what you think because everywhere else I read it says that it is very unstable under those conditions.

Then, on this website, someone quoted that study that I am mentioning.  The title of their post is "acth reference ranges at differing (or different) times of day.  After they quote that same study, and included text from it stating that room temp isn't really the problem and 24 hours at room temp will only result in a 10 percent loss of the acth and that there is no difference in the loss between high acth and normal people - the person who wrote the post goes on to say that in 6-7 minutes of room temp the acth is virtually lost.

Can anyone advise about this?  I am more confused than ever!  Thanks.
Cancel
1 Answers
Page 1 of 1
657231 tn?1453836403
I advocate that you bug the tech to spin immediately.

My ACTH is in the several thousands. If the tech drops it in the centrifuge and I know they assure me they are going to freeze it shortly after it comes out, I get high results - my highest being 3629 (6-48). I can tell by my skin that it should be going up as I am darkening but my last result was 1704 - the tech would not put in the centrifuge. I have no idea how it was handled. Obviously that is a larger drop than most labs ranges, and would cover most normal people and also most abnormal ranges and drop them into normal. All this for a lousy tech error.

I found a study where they took ACTH readings all day - and this is how they processed the ACTH:
"Volunteers were admitted to the Study Unit the evening before sampling. The next day, a catheter was placed in a forearm vein at 0800. Ambulation was permitted to the lavatory only. Vigorous exercise, daytime sleep, snacks, caffeinated beverages, and cigarette smoking were disallowed. Meals were provided at 0800, 1230, and 1730, and room lights were turned off between 2200 and 2400 depending on individual sleeping habits. Blood samples (2.0 ml) were withdrawn at 10-min intervals from 0900 for 24 h. Specimens were collected in prechilled siliconized tubes containing EDTA (ACTH) or heparin (cortisol), centrifuged at 4°C to separate plasma, and frozen at –20°C within 30 min of collection. Total blood loss was <360 ml. Volunteers were compensated for the time spent in the study. "

So between draw and freezer, it was 30 minutes.

I have had testing where they stuck the tube in the freezer - it was low... bin - low - bin - degraded and could not run the test (that had to be bad considering how high I am!!) and all sorts of variations - I just wish they would stick it in the dang centrifuge and then freeze it so my docs would have an accurate test to judge me by.
Comment
Cancel
Comment
Avatar universal
Comment
Comment
Submit Comment
Your Answer
Avatar universal
Answer
Know how to answer? Tap here to leave your answer...
Answer
Submit Answer
A
A
Recent Activity
Avatar universal
Blank
Nacht246 commented on When Your Cold Is Not...
Aug 22
363281 tn?1353103243
Blank
SassyLassie commented on About Me
Aug 21
Avatar universal
Blank
CLENCH1 commented on The Turbinates: What ...
Aug 15
Top Thyroid Answerers
Avatar universal
Blank
MI
657231 tn?1453836403
Blank
Northern, NJ
Adrenal Insufficiency Community Resources