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RUT: positive or negative?

Posted: Sat Jul 27, 2019 4:25 pm
by Sajal
I have had an endoscopy yesterday around 3 pm. My GI saw the results (RUT dry test) around 6:30 pm: It was negative at the time thus my GI confirmed eradication. However, today, I saw it at around 12 pm( almost after 21 hours from test) and it has turned positive.
I don't know what does it mean. I have read that normally it takes 3 hours to show the results. But there is something which is called an interval time which is of 24 hours.

Can RUT give a positive result after 20-21 hours from test?
What do I consider it? Positive or negative?

Re: RUT: positive or negative?

Posted: Sun Jul 28, 2019 8:18 pm
by Helico_expert
hmmm... interesting result. These dry RUT, usually turn negative after long period of time. I wonder why it turns positive after 20 hrs.

Nevertheless, I assume the endoscopy did not see anything else abnormal. So that's a good sign.

If you are doubtful of the RUT result, you can get another breath test done.

Re: RUT: positive or negative?

Posted: Mon Jul 29, 2019 11:15 pm
by Sajal
My GI and I have seen the it at around 3 hours from the test and it was negative at the time. The next I saw it was around 20 hours and it has turned positive by then, but I don't know when exactly it had turned positive.

I consulted my GI upon the same. He says normally it turns positive within twenty minutes or at maximum one to three hours. According to him, there might be very tiny load of bacteria present and thus he wants me to start ppis for now.

The last endoscopy I have had(april'2019) revealed mild gastritis and mild duodenitis and RUT was negative for h pylori. However, even the last time my GI had taken the decision after observing for 3 hours only and then thrown away the slide.

Now after three and half months after that–despite the fact that I was declared neagtive for h pylori– I have developed erosions in my duodenum(revealed by the endoscopy). Moreover my antrum inflammation persist as it is. Is it not suggesting that I still carry these bugs?( I have completed my antibiotics course 5 and half months back)

Also, my symptoms though lessened have not subsided.

I have following questions:
1) what is the maximum time for observation for dry RUT? Is it common to turn positive after three hours?
2) Should I take another course of antibiotics or just start taking ppis again?

PS- the only options to check for h pylori available here is RUT. No breath test, histology, and culture of h pylori. Stool test is not considered reliable here.

Re: RUT: positive or negative?

Posted: Tue Jul 30, 2019 8:53 am
by Helico_expert
20 min after biopsy on dry RUT make sense. three hrs to me, is a bit too long. But it will have to go back to the manufacturer manual. They must have done the experiment.

Since there is no other test available, perhaps you just need to rely on PPI for now. You can repeat the endoscopy 1 year later. There are many brands of PPI, if you find your current PPI not useful, can try switch to other PPI such as rabeprazole.

Re: RUT: positive or negative?

Posted: Tue Jul 30, 2019 12:27 pm
by chetanvenki
My RUT turned positive just before 24 hours. Within initial half an hour, it was mostly yellow (negative) and started changing color very mildly. MY GI told me it could take upto 24 hours to change color. But later my UBT was tested positive after ABX therapy.

Re: RUT: positive or negative?

Posted: Tue Jul 30, 2019 4:56 pm
by Helico_expert
i am not sure which RUT brand you used, but i would think anything over 1 hr is unreliable. Nevertheless, it's unusual that your RUT is negative and later getting a UBT positive result. I wonder how positive is your UBT positive result.

Re: RUT: positive or negative?

Posted: Wed Jul 31, 2019 9:17 am
by chetanvenki
Brand was RUT Dry Test, check below
https://www.indiamart.com/proddetail/ru ... 50448.html


this article reads result can take upto 24 hrs
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4293486/


My UBT was ammonia based method, not typical C14 type. It just shows positive or negative without much quantifying, plz check below link
https://www.news-medical.net/HELIC-Ammo ... r-from-AMA

Re: RUT: positive or negative?

Posted: Wed Jul 31, 2019 2:26 pm
by Helico_expert
Most will turn positive within 120 to 180 minutes but it is best to hold those that appear negative for 24 hours (22,23). After 24 hours the test may turn positive from the presence non-H. pylori urease containing organisms (24).
Personally, I think any RUT that takes more than 1 hr is most probably false positives.

H. pylori reacts with the urea substrate very quickly. Usually you can see the RUT results within 30 min.

However, you can get a false negative from RUT when
1. you have very little H. pylori load (usually happened after antibiotics treatment)
2. you have very low acid level (usually happen after taking PPI).

Re: RUT: positive or negative?

Posted: Wed Aug 07, 2019 3:41 am
by Sajal
Just a little updat: I have conducted a (HELIC) Ammonia breath test today and the result showed negative.

Base reading( without taking urea load) - 0 mm
Reading after taking the load - 2mm
Length difference - 2mm
Result interpretation - negative
Cutoff value - 3mm

I have three follow up tests now after completing standard triple therapy on march 4, 2019.
1) RUT in april 19 - negative (the observation of dry rut was three hours)
2) RUT in july - negative after observing for three hours ( it had turned positive when I saw it after around 20 hours from the test.
3) Helic ammonia breath test today - negative.

My symptoms have not subsided and I have too much acidity. Any suggestions?

Re: RUT: positive or negative?

Posted: Fri Aug 09, 2019 8:37 am
by Helico_expert
most importantly is that you do not have H. pylori now, and so your situation is less likely to get worse.

your symptoms most likely due to the damage done by H. pylori. The recovery is subject to individual's healing ability. Usually younger people heal faster than the elderly.

Give yourself some time to heal. you can control and acid related symptoms by taking PPI (eg. rabeprazole) or H2 blockers (ranitidine).

or you can try some probiotics or natural herbs.