PCR TESTING

[Bill]

Dr.Marshall,
Thank-you for taking my query in advance.Do you think Pcr testing will become the gold standard of invasive H Pylori testing?It's an honor to be on your discussion board.
Bill

[barjammar]

Good question. On a biopsy, visual display of bacteria on histology is very accurate in trained hands. Culture of Heliocbacter is the gold standard for a positive case. Urease, histology and culture all negative is a good gold standard for a negative case. Careful repeated breath tests and/or faeces done 4 and 8 weeks after treatment would be another alternative to invasive testing to prove cure.
PCR is prone to false positives because highly specific validated primer sequences are not available. The literature is full of reports of H.pylori being found in wierd places - lungs, under fingernails, dental plaques. in ground water - but unless validated by a culture I don't believe most of them. So, in summary then, PCR is sensitive but not specific enough. Therefore, for the present, we must rely on a combination of several tests and be satisfied with accuracy in the vicinity of 95%.
(I have been away so the answer was very delayed).