Connect
NTMs in sputum samples: is it really reliable for therapy monitoring?
I've learned that Mycobacteria are ubiquitous and can be detected even in healthy people, that's why two positive samples as well as clinical and radiological criteria are required to establish a disease diagnosis.
But if so I wonder why sputum monitoring is used to evaluate response to treatment and to take therapeutic decisions.
I'll give you a pratical example: a patient with a confirmed diagnosis of mycobacteriosis who is undergoing therapy (big 3), starts taking monthly tests to check for negativity. The first 4 sputum results are negative. CT scan has improved but the fifth sample is positive again and doctors decide to add Amikacin.
Do you think this approach is correct?
How do you determine that the fifth sample has clinical significance? If it remains an isolate relief, couldn't it simply be transient, like what could be found in healthy people?
On the other hand I wonder if it's really so common to find mycobacteria in healty people. Many people with bronchiectasis undergo periodic sputum checks and never test positive for mycobacteria throughout their lives (most of them).
Thanks for any of your contributes.
Like
Helpful
HugInterested in more discussions like this? Go to the MAC & Bronchiectasis Support Group.
Connect
I think you might be downplaying the CT reads, the radiological clearance is as important, if not more than the biological tests
@mary80 I think you will find this recent video from NJH very helpful in answering your questions:
Early in the presentation he explains how the sputum culture, CT scan, symptoms and other factors considered together lead to the decision of whether to treat or watch. At about 20 minutes, Dr. Daley explains the rationale for adding Amikacin.
-
Like -
Helpful -
Hug
4 ReactionsThanks @sueinmn It is clear to me that two samples are needed for the initial diagnosis, but in the follow-up it is not said how many samples must test positive to declare a lack of response to the therapy. Is one enough? What I'm wondering is whether a single positive sample in the context of other negatives necessarily means you have a refractory disease or it could reflect a transient presence of the mycobacterium that has nothing to do with the initial disease... I can't find an answer to this
I'm not an expert on this, but my Pulmonologist asks for 2 samples, from 2 separate days, every time to guard against transient mycobacteria or sample contamination giving a "false positive"
In my case, after testing positive for a rare NTM, and after they did susceptibility testing, my new ID doctor asked for three more sputum samples on separate days, one first thing in the morning and the other two whenever, before starting antibiotics. Super nasty productive cough and low-grade fevers are the main symptoms. Went to the ER due to coughing madness, but they only offered Robitussin. Fun times.
-
Like -
Helpful -
Hug
3 Reactions@sueinmn and have you ever found two conflicting results?
Yes, once when I submitted 3 specimens, all 3 had M intracellulare, but only one grew M abscessus. And I never had that in any other set of specimens before or since.
This is why, absent serious symptoms and/or CT evidence of cavities and nodules, the experts say you watch and wait.
-
Like -
Helpful -
Hug
2 ReactionsSue
Interesting that some are asked to send in multiple sputum viles on two to three consecutive days (or possibly one in the morning one at night???) for testing with hopes of a more concise determination and others just the once a month tests and determination of starting the antibiotics. Mine has been sent in once a month and told to start after the third month of sending in the viles to Tyler 10/2024. Now that I think of it NJH required one before the actual visit and a minimum of two during the visit of one week. NJH said watch and wait 10/2023. Mine continue to just show MAI. each submission, from my understanding. I have not been told I have cavities or nodules.
From what you understand what are considered serious symptoms.?
As I said PFT excellent, no fever, chills, gaining weight, sleeping well, appetite good, not fatigued....and told to start anitibiotics. I have messaged Irene 8 also with some information, you may have read it.
I almost hate to message you knowing you have that extra challenge with your arm in a sling, so please know I understand timing and as well...if one is feeling up to it, to answer.
Thanks,
Barbara
I think the video that I shared above from Dr. Daley explains the treat vs watch option better than I can. Have you watched it?
Yes Sue I did the other day listen to the video and apparently didn't internalize as much as I should have with one review. Listened to it again today and I think it is sinking in. From what I heard and the lack of detailed communication between the BE specialist and I (I fail to think of the questions I need to ask her when she doesn't go into detail) and what appears to be lack of lab details on the lab results that Daily speaks of.......I do have questions that I wish I had answers to at this point from the BE specialist. Reality....a bit confused just yet and need to think and give thought to my next step(s) and as well as much thought to the big picture at this time in my life.
Barbara