Culture Test - Advanced Labs

there is a lot of marketing hype in the testing world

these companies of course have to sell their products - but there are some half truths and omissions in the press release that would cause me to be a little warry of its promises.

fundamentally the issue with PCR for blood for Lyme is the scarcity of lyme spirochetes in the blood of chronic patients - this is a well documented phenomenon - as its a tissue centric organism.

as an example - PCR of blood - which can typically detect even a single organism in a sample - only finds lyme in 50% of patients confirmed infected by gold standard methods (culture or tissue PCR) - ie 50% sensitivity

the key issue here is that no amount of culturing or specialised culture methods can get round the fact that there may be no spirochetes in the original sample to culture .....

there are added difficulties for people who have been on antibiotics already -
here, many previous studies have described surprising difficulty in culturing anything from their blood - this is quite well known and used by the deniers of lyme to cast doubt on the presence of ongoing infection.

what looks more likely is that the persister forms of lyme are simply much harder to culture - something which microbiology researchers have been highlighting for some decades now.

i am not sure if the reasons for this have been fully elucidated - but in other species these persister/biofilm colonies have been found to make epigenetic adaptations to their host environment - that mean they are not suited to/ or even killed by the growth mediums that are normally used for culture of their free swimming siblings

this gives some cause for caution around the companies claim that one just needs to wait till 4 weeks after the antibiotics to be able to test.

it may end up being another viable testing option to add to the tests that are available today - but i suspect it will still suffer from sensitivity issues - esp in patients who have undergone abx treatment in the past - so will like be far from the silver bullet - or gold standard the company claims.

to clarify,
i am saying having more test options is a good thing for patients in general

just that based on what we know this one is not likely to quite live up to the marketing / claims of the test lab

MargaritaLyme said...
My post was just pointing out that in spite of shortcomings, the test could still serve a purpose. It was not a rebuttal. My apologies if it was taken as such.

nope - no offence taken or apologies needed

i was just clarifying my meaning