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Serology test - IgA +ve but not IgG

Posted: Wed Sep 01, 2021 11:00 pm
by bhumik85
I have been having wierd gi symptoms for the last 3 months

June 1st two days of diarrhea.
This was followed by excessive burping, extreme bloating, and overnight intolerance to food I ate daily due to extreme gas and flatulence.
Another symptom i had was complete lack of hunger despite not eating. Usually in morning when I wake up, I am hungry.

Over the next month the symptoms waxed and waned belching, flatulence, bloating, anorexia, diarrhea and constipation. All the basic blood work up back negative besides H pylori IgA serology being positive. So i followed this up with a stool antigen test which came back negative, and a breath test which also came back negative.

OVer the next 2 months the symptoms have been all over the place. I have done extensive stool and blood testing that is coming back negative.

I am obviously going to pursue endoscopy. but I wanted to know from the experience people, if I should make anythng of the positive serology? or just chalk it up to prior infection or encounter.

Re: Serology test - IgA +ve but not IgG

Posted: Wed Sep 01, 2021 11:01 pm
by bhumik85
the serology test was done about 5 weeks after symptoms started.
How long does it take for igG seroconversion in acute infection? any one know?

Re: Serology test - IgA +ve but not IgG

Posted: Wed Sep 01, 2021 11:23 pm
by bhumik85
Also, I do not have any pain. ONly time I am in discomfort is when the gas and bloating builds up.

I saw a GI specialist. He said, he is seeing more and more false negative stool and breath test and they are completely garbage. This goes against what i have typically read is a very high sensitivity and specificity for ubt, and stool test.

He also stated that the organism likes to migrate to particular parts of the stomach (he pointed to the fundus), and if the biopsy is not done in that particular part it will be negative.

Re: Serology test - IgA +ve but not IgG

Posted: Thu Sep 02, 2021 9:36 am
by Helico_expert
Serology only tells if you had been exposed to H. pylori before.
Stool and breath tests are both very accurate. However, they both rely on bacterial load. The more H. pylori is in your stomach, the more accurate these two tests are.

So what can lead to low H. pylori number?
1. PPI (or any acid reducing agent)
2. antibiotics (or any herbs that may kill H. pylori, eg. bismuth)
3. naturally low acid (being very young (< 10 yr old) or becoming old (> 70))
4. damage in stomach (including inflammation, intestinal metaplasia and atrophic gastritis) which can lead to lower acid secretion. this could be due to H. pylori infection.
5. cancer

If you are young and healthy, stool and breath tests should be very accurate. Otherwise, endoscopy and histology would be the second best.